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Sample records for water phases

Plastic crystal phases of simple water models

International Nuclear Information System (INIS)

Aragones, J. L.; Vega, C.

2009-01-01

We report the appearance of two plastic crystal phases of water at high pressure and temperature using computer simulations. In one of them the oxygen atoms form a body centered cubic structure (bcc) and in the other they form a face centered cubic structure (fcc). In both cases the water molecules were able to rotate almost freely. We have found that the bcc plastic crystal transformed into a fcc plastic crystal via a Martensitic phase transition when heated at constant pressure. We have performed the characterization and localization in the phase diagram of these plastic crystal phases for the SPC/E, TIP4P, and TIP4P/2005 water potential models. For TIP4P/2005 model free energy calculations were carried out for the bcc plastic crystal and fcc plastic crystal using a new method (which is a slight variation of the Einstein crystal method) proposed for these types of solid. The initial coexistence points for the SPC/E and TIP4P models were obtained using Hamiltonian Gibbs–Duhem integration. For all of these models these two plastic crystal phases appear in the high pressure and temperature region of the phase diagram. It would be of interest to study if such plastic crystal phases do indeed exist for real water. This would shed some light on the question of whether these models can describe satisfactorily the high pressure part of the phase diagram of water, and if not, where and why they fail.
Review of two-phase water hammer

International Nuclear Information System (INIS)

Beuthe, T.G.

1997-01-01

In a thermalhydraulic system like a nuclear power plant, where steam and water mix and are used to transport large amounts of energy, there is a potential to create two-phase water hammer. Large water hammer pressure transients are a threat to piping integrity and represent an important safety concern. Such events may cause unscheduled plant down time. The objective of this review is to provide a summary of the information on two-phase water hammer available in the open literature with particular emphasis on water hammer occurrences in nuclear power plants. Past reviews concentrated on studies concerned with preventing water hammer. The present review focuses on the fundamental experimental, analytical, and modelling studies. The papers discussed here were chosen from searches covering up to July 1993. (author)
Complex network analysis of phase dynamics underlying oil-water two-phase flows

Science.gov (United States)

Gao, Zhong-Ke; Zhang, Shan-Shan; Cai, Qing; Yang, Yu-Xuan; Jin, Ning-De

2016-01-01

Characterizing the complicated flow behaviors arising from high water cut and low velocity oil-water flows is an important problem of significant challenge. We design a high-speed cycle motivation conductance sensor and carry out experiments for measuring the local flow information from different oil-in-water flow patterns. We first use multivariate time-frequency analysis to probe the typical features of three flow patterns from the perspective of energy and frequency. Then we infer complex networks from multi-channel measurements in terms of phase lag index, aiming to uncovering the phase dynamics governing the transition and evolution of different oil-in-water flow patterns. In particular, we employ spectral radius and weighted clustering coefficient entropy to characterize the derived unweighted and weighted networks and the results indicate that our approach yields quantitative insights into the phase dynamics underlying the high water cut and low velocity oil-water flows. PMID:27306101
The quantum phase-transitions of water

Science.gov (United States)

Fillaux, François

2017-08-01

It is shown that hexagonal ices and steam are macroscopically quantum condensates, with continuous spacetime-translation symmetry, whereas liquid water is a quantum fluid with broken time-translation symmetry. Fusion and vaporization are quantum phase-transitions. The heat capacities, the latent heats, the phase-transition temperatures, the critical temperature, the molar volume expansion of ice relative to water, as well as neutron scattering data and dielectric measurements are explained. The phase-transition mechanisms along with the key role of quantum interferences and that of Hartley-Shannon's entropy are enlightened. The notions of chemical bond and force-field are questioned.
Stationary phases for superheated water chromatography

International Nuclear Information System (INIS)

Saha, Shikha

2002-01-01

This project focused on the comparison of conventional liquid chromatography and superheated water chromatography. It examined the differences in efficiency and retention of a range of different stationary phases. Alkyl aryl ketones and eight aromatic compounds were separated on PBD-zirconia, Xterra RP 18, Luna C 18 (2) and Oasis HLB columns using conventional LC and superheated water chromatography system. The retention indices were determined in the different eluents. On changing the organic component of the eluent from methanol to acetonitrile to superheated water considerable improvements were found in the peak shapes and column efficiencies on the PBD-zirconia and Oasis HLB columns. PS-DVB, PBD-zirconia and Xterra RP 18 columns have been used in efficiency studies. It was found that simply elevating the column temperature did not increase the efficiency of a separation in superheated water chromatography. The efficiency depended on flow rate, injection volume and also mobile phase preheating system. Although high efficiencies were not achieved with superheated water on PS-DVB and Xterra RP 18 columns, a higher efficiency was achieved on a PBD-zirconia column with superheated water than with 25-35% ACN at room temperature. The proposed theoretical increases in u opt were measured on three columns using superheated water as the mobile phase. The application of the superheated water chromatographic method to the separation of the pungent constituents of ginger by superheated water chromatography-NMR coupling system was studied. The coupling of superheated water chromatography using deuterium oxide to NMR spectroscopy for the separation of dry ginger extract was successful, although the NMR sensitivity in on-line mode coupling system was low. However, four compounds were identified in the ginger extract by stop-flow mode on superheated water chromatography-UV-NMR detection system. (author)
Phase diagram of supercooled water confined to hydrophilic nanopores

Science.gov (United States)

Limmer, David T.; Chandler, David

2012-07-01

We present a phase diagram for water confined to cylindrical silica nanopores in terms of pressure, temperature, and pore radius. The confining cylindrical wall is hydrophilic and disordered, which has a destabilizing effect on ordered water structure. The phase diagram for this class of systems is derived from general arguments, with parameters taken from experimental observations and computer simulations and with assumptions tested by computer simulation. Phase space divides into three regions: a single liquid, a crystal-like solid, and glass. For large pores, radii exceeding 1 nm, water exhibits liquid and crystal-like behaviors, with abrupt crossovers between these regimes. For small pore radii, crystal-like behavior is unstable and water remains amorphous for all non-zero temperatures. At low enough temperatures, these states are glasses. Several experimental results for supercooled water can be understood in terms of the phase diagram we present.
Effects of phase transformation of steam-water relative permeabilities

Energy Technology Data Exchange (ETDEWEB)

Verma, A.K.

1986-03-01

A combined theoretical and experimental study of steam-water relative permeabilities (RPs) was carried out. First, an experimental study of two-phase concurrent flow of steam and water was conducted and a set of RP curves was obtained. These curves were compared with semi-empirical and experimental results obtained by other investigators for two-phase, two-component flow (oil/gas; gas/water; gas/oil). It was found that while the wetting phase RPs were in good agreement, RPs for the steam phase were considerably higher than the non-wetting phase RPs in two-component systems. This enhancement of steam RP is attributed to phase transformation effects at the pore level in flow channels. The effects of phase transformation were studied theoretically. This study indicates that there are two separate mechanisms by which phase transformation affects RP curves: (1) Phase transformation is converging-diverging flow channels can cause an enhancement of steam phase RP. In a channel dominated by steam a fraction of the flowing steam condenses upstream from the constriction, depositing its latent heat of condensation. This heat is conducted through the solid grains around the pore throat, and evaporation takes place downstream from it. Therefore, for a given bulk flow quality; a smaller fraction of steam actually flows through the throat segments. This pore-level effect manifests itself as relative permeability enhancement on a macroscopic level; and (2) phase transformation along the interface of a stagnant phase and the phase flowing around it controls the irreducible phase saturation. Therefore, the irreducible phase saturation in steam-water flow will depend, among other factors, on the boundary conditions of the flow.
Two-phase air-water stratified flow measurement using ultrasonic techniques

International Nuclear Information System (INIS)

Fan, Shiwei; Yan, Tinghu; Yeung, Hoi

2014-01-01

In this paper, a time resolved ultrasound system was developed for investigating two-phase air-water stratified flow. The hardware of the system includes a pulsed wave transducer, a pulser/receiver, and a digital oscilloscope. The time domain cross correlation method is used to calculate the velocity profile along ultrasonic beam. The system is able to provide velocities with spatial resolution of around 1mm and the temporal resolution of 200μs. Experiments were carried out on single phase water flow and two-phase air-water stratified flow. For single phase water flow, the flow rates from ultrasound system were compared with those from electromagnetic flow (EM) meter, which showed good agreement. Then, the experiments were conducted on two-phase air-water stratified flow and the results were given. Compared with liquid height measurement from conductance probe, it indicated that the measured velocities were explainable
The phase diagram of water at negative pressures: virtual ices.

Science.gov (United States)

Conde, M M; Vega, C; Tribello, G A; Slater, B

2009-07-21

The phase diagram of water at negative pressures as obtained from computer simulations for two models of water, TIP4P/2005 and TIP5P is presented. Several solid structures with lower densities than ice Ih, so-called virtual ices, were considered as possible candidates to occupy the negative pressure region of the phase diagram of water. In particular the empty hydrate structures sI, sII, and sH and another, recently proposed, low-density ice structure. The relative stabilities of these structures at 0 K was determined using empirical water potentials and density functional theory calculations. By performing free energy calculations and Gibbs-Duhem integration the phase diagram of TIP4P/2005 was determined at negative pressures. The empty hydrates sII and sH appear to be the stable solid phases of water at negative pressures. The phase boundary between ice Ih and sII clathrate occurs at moderate negative pressures, while at large negative pressures sH becomes the most stable phase. This behavior is in reasonable agreement with what is observed in density functional theory calculations.
Bulk water phase and biofilm growth in drinking water at low nutrient conditions

DEFF Research Database (Denmark)

Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen; Arvin, Erik

2002-01-01

, and cell-specific leucine incorporation rate. Bacteria in the bulk water phase incubated without the presence of biofilmexhibited a bacterial growth rate of 0.30 day1. The biofilmwas radioactively labelled by the addition of 14C-benzoic acid. Subsequently, a biofilmdetachm ent rate of 0.013 day1...... the formation of a mature quasi-stationary biofilm. At retention times of 12 h, total bacterial counts increased equivalent to a net bacterial growth rate of 0.048 day1. The bulk water phase bacteria exhibited a higher activity than the biofilmbacteria in terms of culturability, cell-specific ATP content......In this study, the bacterial growth dynamics of a drinking water distribution system at low nutrient conditions was studied in order to determine bacterial growth rates by a range of methods, and to compare growth rates in the bulk water phase and the biofilm. A model distribution system was used...
Bulk water phase and biofilm growth in drinking water at low nutrient conditions.

Science.gov (United States)

Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen; Arvin, Erik; Jørgensen, Claus

2002-11-01

In this study, the bacterial growth dynamics of a drinking water distribution system at low nutrient conditions was studied in order to determine bacterial growth rates by a range of methods, and to compare growth rates in the bulk water phase and the biofilm. A model distribution system was used to quantify the effect of retention times at hydraulic conditions similar to those in drinking water distribution networks. Water and pipe wall samples were taken and examined during the experiment. The pipes had been exposed to drinking water at approximately 13 degrees C, for at least 385 days to allow the formation of a mature quasi-stationary biofilm. At retention times of 12 h, total bacterial counts increased equivalent to a net bacterial growth rate of 0.048 day(-1). The bulk water phase bacteria exhibited a higher activity than the biofilm bacteria in terms of culturability, cell-specific ATP content, and cell-specific leucine incorporation rate. Bacteria in the bulk water phase incubated without the presence of biofilm exhibited a bacterial growth rate of 0.30 day(-1). The biofilm was radioactively labelled by the addition of 14C-benzoic acid. Subsequently, a biofilm detachment rate of 0.013 day(-1) was determined by measuring the release of 14C-labelled bacteria of the biofilm. For the quasi-stationary phase biofilm, the detachment rate was equivalent to the net growth rate. The growth rates determined in this study by different independent experimental approaches were comparable and within the range of values reported in the literature.
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.
Complex network analysis in inclined oil–water two-phase flow

International Nuclear Information System (INIS)

Zhong-Ke, Gao; Ning-De, Jin

2009-01-01

Complex networks have established themselves in recent years as being particularly suitable and flexible for representing and modelling many complex natural and artificial systems. Oil–water two-phase flow is one of the most complex systems. In this paper, we use complex networks to study the inclined oil–water two-phase flow. Two different complex network construction methods are proposed to build two types of networks, i.e. the flow pattern complex network (FPCN) and fluid dynamic complex network (FDCN). Through detecting the community structure of FPCN by the community-detection algorithm based on K-means clustering, useful and interesting results are found which can be used for identifying three inclined oil–water flow patterns. To investigate the dynamic characteristics of the inclined oil–water two-phase flow, we construct 48 FDCNs under different flow conditions, and find that the power-law exponent and the network information entropy, which are sensitive to the flow pattern transition, can both characterize the nonlinear dynamics of the inclined oil–water two-phase flow. In this paper, from a new perspective, we not only introduce a complex network theory into the study of the oil–water two-phase flow but also indicate that the complex network may be a powerful tool for exploring nonlinear time series in practice. (general)
Proton dynamics and the phase diagram of dense water ice.

Science.gov (United States)

Hernandez, J-A; Caracas, R

2018-06-07

All the different phases of water ice between 2 GPa and several megabars are based on a single body-centered cubic sub-lattice of oxygen atoms. They differ only by the behavior of the hydrogen atoms. In this study, we investigate the dynamics of the H atoms at high pressures and temperatures in water ice from first-principles molecular dynamics simulations. We provide a detailed analysis of the O-H⋯O bonding dynamics over the entire stability domain of the body-centered cubic (bcc) water ices and compute transport properties and vibrational density-of-states. We report the first ab initio evidence for a plastic phase of water and we propose a coherent phase diagram for bcc water ices compatible with the two groups of melting curves and with the multiple anomalies reported in ice VII around 15 GPa.
Monitoring water phase dynamics in winter clouds

Science.gov (United States)

Campos, Edwin F.; Ware, Randolph; Joe, Paul; Hudak, David

2014-10-01

This work presents observations of water phase dynamics that demonstrate the theoretical Wegener-Bergeron-Findeisen concepts in mixed-phase winter storms. The work analyzes vertical profiles of air vapor pressure, and equilibrium vapor pressure over liquid water and ice. Based only on the magnitude ranking of these vapor pressures, we identified conditions where liquid droplets and ice particles grow or deplete simultaneously, as well as the conditions where droplets evaporate and ice particles grow by vapor diffusion. The method is applied to ground-based remote-sensing observations during two snowstorms, using two distinct microwave profiling radiometers operating in different climatic regions (North American Central High Plains and Great Lakes). The results are compared with independent microwave radiometer retrievals of vertically integrated liquid water, cloud-base estimates from a co-located ceilometer, reflectivity factor and Doppler velocity observations by nearby vertically pointing radars, and radiometer estimates of liquid water layers aloft. This work thus makes a positive contribution toward monitoring and nowcasting the evolution of supercooled droplets in winter clouds.
Nonequilibrium Phase Transitions in Supercooled Water

Science.gov (United States)

Limmer, David; Chandler, David

2012-02-01

We present results of a simulation study of water driven out of equilibrium. Using transition path sampling, we can probe stationary path distributions parameterize by order parameters that are extensive in space and time. We find that by coupling external fields to these parameters, we can drive water through a first order dynamical phase transition into amorphous ice. By varying the initial equilibrium distributions we can probe pathways for the creation of amorphous ices of low and high densities.
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.
Cold water injection into two-phase mixtures

International Nuclear Information System (INIS)

1989-07-01

This report presents the results of a review of the international literature regarding the dynamic loadings associated with the injection of cold water into two-phase mixtures. The review placed emphasis on waterhammer in nuclear power plants. Waterhammmer incidence data were reviewed for information related to thermalhydraulic conditions, underlying causes and consequential damage. Condensation induced waterhammer was found to be the most significant consequence of injecting cold water into a two-phase system. Several severe waterhammer incidents have been attributed to slug formation and steam bubble collapse under conditions of stratified steam and cold water flows. These phenomena are complex and not well understood. The current body of experimental and analytical knowledge is not large enough to establish maps of expected regimes of condensation induced waterhammer. The Electric Power Research Institute, in the United States, has undertaken a major research and development programme to develop the knowledge base for this area. The limited models and data currently available show that mechanical parameters are as important as thermodynamic conditions for the initiation of condensation induced waterhammer. Examples of bounds for avoiding two-phase waterhammer are given. These bounds are system specific and depend upon parameters such as pump capacity, pipe length and pipe orientation
Robust water fat separated dual-echo MRI by phase-sensitive reconstruction.

Science.gov (United States)

Romu, Thobias; Dahlström, Nils; Leinhard, Olof Dahlqvist; Borga, Magnus

2017-09-01

The purpose of this work was to develop and evaluate a robust water-fat separation method for T1-weighted symmetric two-point Dixon data. A method for water-fat separation by phase unwrapping of the opposite-phase images by phase-sensitive reconstruction (PSR) is introduced. PSR consists of three steps; (1), identification of clusters of tissue voxels; (2), unwrapping of the phase in each cluster by solving Poisson's equation; and (3), finding the correct sign of each unwrapped opposite-phase cluster, so that the water-fat images are assigned the correct identities. Robustness was evaluated by counting the number of water-fat swap artifacts in a total of 733 image volumes. The method was also compared to commercial software. In the water-fat separated image volumes, the PSR method failed to unwrap the phase of one cluster and misclassified 10. One swap was observed in areas affected by motion and was constricted to the affected area. Twenty swaps were observed surrounding susceptibility artifacts, none of which spread outside the artifact affected regions. The PSR method had fewer swaps when compared to commercial software. The PSR method can robustly produce water-fat separated whole-body images based on symmetric two-echo spoiled gradient echo images, under both ideal conditions and in the presence of common artifacts. Magn Reson Med 78:1208-1216, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.
Nonlinear analysis of gas-water/oil-water two-phase flow in complex networks

CERN Document Server

Gao, Zhong-Ke; Wang, Wen-Xu

2014-01-01

Understanding the dynamics of multi-phase flows has been a challenge in the fields of nonlinear dynamics and fluid mechanics. This chapter reviews our work on two-phase flow dynamics in combination with complex network theory. We systematically carried out gas-water/oil-water two-phase flow experiments for measuring the time series of flow signals which is studied in terms of the mapping from time series to complex networks. Three network mapping methods were proposed for the analysis and identification of flow patterns, i.e. Flow Pattern Complex Network (FPCN), Fluid Dynamic Complex Network (FDCN) and Fluid Structure Complex Network (FSCN). Through detecting the community structure of FPCN based on K-means clustering, distinct flow patterns can be successfully distinguished and identified. A number of FDCN’s under different flow conditions were constructed in order to reveal the dynamical characteristics of two-phase flows. The FDCNs exhibit universal power-law degree distributions. The power-law exponent ...

Energy Demodulation Algorithm for Flow Velocity Measurement of Oil-Gas-Water Three-Phase Flow

Directory of Open Access Journals (Sweden)

Yingwei Li

2014-01-01

Full Text Available Flow velocity measurement was an important research of oil-gas-water three-phase flow parameter measurements. In order to satisfy the increasing demands for flow detection technology, the paper presented a gas-liquid phase flow velocity measurement method which was based on energy demodulation algorithm combing with time delay estimation technology. First, a gas-liquid phase separation method of oil-gas-water three-phase flow based on energy demodulation algorithm and blind signal separation technology was proposed. The separation of oil-gas-water three-phase signals which were sampled by conductance sensor performed well, so the gas-phase signal and the liquid-phase signal were obtained. Second, we used the time delay estimation technology to get the delay time of gas-phase signals and liquid-phase signals, respectively, and the gas-phase velocity and the liquid-phase velocity were derived. At last, the experiment was performed at oil-gas-water three-phase flow loop, and the results indicated that the measurement errors met the need of velocity measurement. So it provided a feasible method for gas-liquid phase velocity measurement of the oil-gas-water three-phase flow.
Parameterization of phase change of water in a mesoscale model

Energy Technology Data Exchange (ETDEWEB)

Levkov, L; Eppel, D; Grassl, H

1987-01-01

A parameterization scheme of phase change of water is suggested to be used in the 3-D numerical nonhydrostatic model GESIMA. The microphysical formulation follows the so-called bulk technique. With this procedure the net production rates in the balance equations for water and potential temperature are given both for liquid and ice-phase. Convectively stable as well as convectively unstable mesoscale systems are considered. With 2 figs..
Service water system aging assessment - Phase I

International Nuclear Information System (INIS)

Jarrell, D.B.; Zimmerman, P.W.; Gore, M.L.

1988-01-01

The Service Water System (SWS) represents the final heat transfer loop between decay heat generated in the nuclear core and the safe dispersal of that heat energy in the environment. It is the objective of this investigation to demonstrate that aging phenomena can be identified and quantified such that aging degradation of system components can be detected and mitigated prior to the reduction of system availability to below an acceptable threshold. The approach used during the Phase I task was to (1) perform a literature search of government and private sector reports which relate to service water, aging related degradation, and potential methodologies for analysis; (2) assemble a data base which contains all the commercial power plants in the US, their Service Water System configuration, characteristics, and water source; (3) obtain and examine the available service water data from large generic data bases, i.e. NPRDS, LER, NPE, inspection reports, and other relevant plant reference data; (4) perform a fault tree analysis of a typical plant service water systems to examine failure propagation and understand specific input requirements of probabilistic risk analyses; (5) develop an in-depth questionnaire protocol for examining the information resource at a power plant which is not available through data base query and visit a central station power plant and solicit the required information; (6) analyze the information obtained from the in-depth plant interrogation and draw contrasts and conclusions with the data base information; (7) utilize the plant information to perform an interim assessment of service water system degradation mechanisms and focus future investigations. This paper addresses the elements of this task plan numbered 1, 3, 6, and 7. The remaining items are detailed in the phase-I report
Reversed phase liquid chromatography with UV absorbance and flame ionization detection using a water mobile phase and a cyano propyl stationary phase Analysis of alcohols and chlorinated hydrocarbons.

Science.gov (United States)

Quigley, W W; Ecker, S T; Vahey, P G; Synovec, R E

1999-10-01

The development of liquid chromatography with a commercially available cyano propyl stationary phase and a 100% water mobile phase is reported. Separations were performed at ambient temperature, simplifying instrumental requirements. Excellent separation efficiency using a water mobile phase was achieved, for example N=18 800, or 75 200 m(-1), was obtained for resorcinol, at a retention factor of k'=4.88 (retention time of 9.55 min at 1 ml min(-1) for a 25 cmx4.6 mm i.d. column, packed with 5 mum diameter particles with the cyano propyl stationary phase). A separation via reversed phase liquid chromatography (RP-LC) with a 100% water mobile phase of six phenols and related compounds was compared to a separation of the same compounds by traditional RP-LC, using octadecylsilane (ODS), i.e. C18, bound to silica and an aqueous mobile phase modified with acetonitrile. Nearly identical analysis time was achieved for the separation of six phenols and related compounds using the cyano propyl stationary phase with a 100% water mobile phase, as compared to traditional RP-LC requiring a relatively large fraction of organic solvent modifier in the mobile phase (25% acetonitrile:75% water). Additional understanding of the retention mechanism with the 100% water mobile phase was obtained by relating measured retention factors of aliphatic alcohols, phenols and related compounds, and chlorinated hydrocarbons to their octanol:water partition coefficients. The retention mechanism is found to be consistent with a RP-LC mechanism coupled with an additional retention effect due to residual hydroxyl groups on the cyano propyl stationary phase. Advantages due to a 100% water mobile phase for the chemical analysis of alcohol mixtures and chlorinated hydrocarbons are reported. By placing an absorbance detector in-series and preceding a novel drop interface to a flame ionization detector (FID), selective detection of a separated mixture of phenols and related compounds and aliphatic
Organics in water contamination analyzer, phase 1

Science.gov (United States)

1986-01-01

The requirements which would result in identifying the components of an automatic analytical system for the analysis of specific organic compounds in the space station potable water supply are defined. The gas chromatographic system for such an analysis is limited to commercially available off-the-shelf hardware and includes the sample inlet, an ionization detector, capillary columns as well as computerized compound identification. The sampling system will be a special variation of the purge and trap Tenax mode using six-port valves and a 500 microliter water sample. Capillary columns used for the separating of contaminants will be bonded phase fused silica with a silicone stationary phase. Two detectors can be used: photoionization and far ultraviolet, since they are sensitive and compatible with capillary columns. A computer system evaluation and program with the principle of compound identification based on the retention index is presented.
MOLECULARLY IMPRINTED SOLID PHASE EXTRACTION FOR TRACE ANALYSIS OF DIAZINON IN DRINKING WATER

Directory of Open Access Journals (Sweden)

M. Rahiminejad ، S. J. Shahtaheri ، M. R. Ganjali ، A. Rahimi Forushani ، F. Golbabaei

2009-04-01

Full Text Available Amongst organophosphate pesticides, the one most widely used and common environmental contaminant is diazinon; thus methods for its trace analysis in environmental samples must be developed. Use of diazinon imprinted polymers such as sorbents in solid phase extraction, is a prominent and novel application area of molecular imprinted polymers. For diazinon extraction, high performance liquid chromatography analysis was demonstrated in this study. During optimization of the molecular imprinted solid phase extraction procedure for efficient solid phase extraction of diazinon, Plackett-Burman design was conducted. Eight experimental factors with critical influence on molecular imprinted solid phase extraction performance were selected, and 12 different experimental runs based on Plackett-Burman design were carried out. The applicability of diazinon imprinted polymers as the sorbent in solid phase extraction, presented obtained good recoveries of diazinon from LC-grade water. An increase in pH caused an increase in the recovery on molecular imprinted solid phase extraction. From these results, the optimal molecular imprinted solid phase extraction procedure was as follows: solid phase extraction packing with 100 mg diazinon imprinted polymers; conditioning with 5 mL of methanol and 6 mL of LC-grade water; sample loading containing diazinon (pH=10; washing with 1 mL of LC-grade water, 1 mL LC- grade water containing 30% acetonitrile and 0.5 mL of acetonitrile, respectively; eluting with 1 mL of methanol containing 2% acetic acid. The percentage recoveries obtained by the optimized molecular imprinted solid phase extraction were more than 90% with drinking water spiked at different trace levels of diazinon. Generally speaking, the molecular imprinted solid phase extraction procedure and subsequent high performance liquid chromatography analysis can be a relatively fast and proper approach for qualitative and quantitative analysis of diazinon in
Effect of water phase transition on dynamic ruptures with thermal pressurization: Numerical simulations with changes in physical properties of water

Science.gov (United States)

Urata, Yumi; Kuge, Keiko; Kase, Yuko

2015-02-01

Phase transitions of pore water have never been considered in dynamic rupture simulations with thermal pressurization (TP), although they may control TP. From numerical simulations of dynamic rupture propagation including TP, in the absence of any water phase transition process, we predict that frictional heating and TP are likely to change liquid pore water into supercritical water for a strike-slip fault under depth-dependent stress. This phase transition causes changes of a few orders of magnitude in viscosity, compressibility, and thermal expansion among physical properties of water, thus affecting the diffusion of pore pressure. Accordingly, we perform numerical simulations of dynamic ruptures with TP, considering physical properties that vary with the pressure and temperature of pore water on a fault. To observe the effects of the phase transition, we assume uniform initial stress and no fault-normal variations in fluid density and viscosity. The results suggest that the varying physical properties decrease the total slip in cases with high stress at depth and small shear zone thickness. When fault-normal variations in fluid density and viscosity are included in the diffusion equation, they activate TP much earlier than the phase transition. As a consequence, the total slip becomes greater than that in the case with constant physical properties, eradicating the phase transition effect. Varying physical properties do not affect the rupture velocity, irrespective of the fault-normal variations. Thus, the phase transition of pore water has little effect on dynamic ruptures. Fault-normal variations in fluid density and viscosity may play a more significant role.
Partitioning of semi-soluble organic compounds between the water phase and oil droplets in produced water

Energy Technology Data Exchange (ETDEWEB)

Faksness, Liv-Guri; Grini, Per Gerhard; Daling, Per S

2004-04-01

When selecting produced water treatment technologies, one should focus on reducing the major contributors to the total environmental impact. These are dispersed oil and semi-soluble hydrocarbons, alkylated phenols, and added chemicals. Experiments with produced water have been performed offshore on the Statoil operated platforms Gullfaks C and Statfjord B. These experiments were designed to find how much of the environmentally relevant compounds were dissolved in the water phase and not associated to the dispersed oil in the produced water. Results show that the distribution between the dispersed oil and the water phase varies highly for the different components groups. For example the concentration of PAHs and the C6-C9 alkylated phenols is strongly correlated to the content of dispersed oil. Therefore, the technologies enhancing the removal of dispersed oil have a higher potential for reducing the environmental impact of the produced water than previously considered.
Partitioning of semi-soluble organic compounds between the water phase and oil droplets in produced water

International Nuclear Information System (INIS)

Faksness, Liv-Guri; Grini, Per Gerhard; Daling, Per S.

2004-01-01

When selecting produced water treatment technologies, one should focus on reducing the major contributors to the total environmental impact. These are dispersed oil and semi-soluble hydrocarbons, alkylated phenols, and added chemicals. Experiments with produced water have been performed offshore on the Statoil operated platforms Gullfaks C and Statfjord B. These experiments were designed to find how much of the environmentally relevant compounds were dissolved in the water phase and not associated to the dispersed oil in the produced water. Results show that the distribution between the dispersed oil and the water phase varies highly for the different components groups. For example the concentration of PAHs and the C6-C9 alkylated phenols is strongly correlated to the content of dispersed oil. Therefore, the technologies enhancing the removal of dispersed oil have a higher potential for reducing the environmental impact of the produced water than previously considered
Interest groups, the Lesotho Highlands Water Project Phase 1

African Journals Online (AJOL)

interest groups can bring about changes in the water policy arena. ... Lesotho Highlands Water Project Phase 1 as a case study. ... attempts to influence public policy and their representation ... ties concern the relations between state actors and non-state ..... 'bears responsibility here [LHWP], since it is the sponsor of.
Water-containing derivative phases of the Srn+1FenO3n+1 series

International Nuclear Information System (INIS)

Lehtimaeki, M.; Hirasa, A.; Matvejeff, M.; Yamauchi, H.; Karppinen, M.

2007-01-01

The n=1, 2, 3 and ∞ members of the homologous series Sr n+1 Fe n O 3n+1 of layered iron oxides are investigated for their tendency to accept additional layers of water in their crystals. The phases possess a Ruddlesden-Popper-type SrO-(SrO-FeO 2 ) n crystal structure, where the n=∞ limit is nothing but the perovskite structure. It is revealed that the n=1, 2 and 3 phases readily accommodate one or two layers of water between adjacent SrO layers, whereas the n=∞ member which lacks the SrO-SrO double-layer unit remains intact in the presence of water. The speed of the water intercalation process is found to decrease with increasing n. Among the layered water derivatives, the n=2 phase with two water molecules per formula unit, i.e. Sr 3 Fe 2 O 7 .2H 2 O, was found to be most stable. - Graphical abstract: Water-containing derivative phases obtained from the homologous series of Sr n+1 Fe n O 3n+1 Ruddlesden-Popper phases through topotactic water intercalation
Experimental study on heat capacity of paraffin/water phase change emulsion

International Nuclear Information System (INIS)

Huang, L.; Noeres, P.; Petermann, M.; Doetsch, C.

2010-01-01

A paraffin/water phase change emulsion is a multifunctional fluid in which fine paraffin droplets are dispersed in water by a surfactant. This paper presents an experimental study on the heat capacity of an emulsion containing 30 wt.% paraffin in a test rig. The results show that the heat capacity of the emulsion consists of the sensible heat capacity of water and that of the paraffin as well as the latent heat capacity of the paraffin during the phase transition solid-liquid. The emulsion is an attractive alternative to chilled water for comfort cooling applications, because it has a heat capacity of 50 kJ/kg from 5 to 11 deg. C, which is two times as high as that of water in the same temperature range.
Using the electrochemical dimension to build water/Ru(0001) phase diagram

Science.gov (United States)

Lespes, Nicolas; Filhol, Jean-Sébastien

2015-01-01

The water monolayer/Ru(0001) electrochemical phase diagram as a function of surface potential and temperature is built using a DFT approach. The monolayer structure with temperature is extracted following the zero-charge line in good agreement with experiments. Below 140 K, a mix of oppositely charged hydroxyl/water and hydride/water domains is found stable; above 140 K, water molecules desorb from the hydride phase leading to a mixture of oppositely charged surface hydride and hydroxyl/water phases; above 280 K, all the residual adsorbed water desorbs. For undissociated water, a Chain structure is found stable and desorbs above 150 K. The observed nano-sized domains are suggested to be the balance between hydroxyl/hydride repulsion that tends to create two well separated domains and opposite charging that tends to favor a domain mix. An isotopic effect is computed to reduce by a factor of 160 the kinetic rate of D2O dissociation (compared to H2O) and is linked to the reduction of the ZPE in the transition state caused by a proton transport chain. Water monolayer/Ru(0001) has a specific reactivity and its organization is highly sensitive to the surface potential suggesting that under electrochemical conditions, the potential is not only tuning directly the chemical reactivity but also indirectly through the solvent structure.
A study of water hammer phenomena in a one-component two-phase bubbly flow

International Nuclear Information System (INIS)

Fujii, Terushige; Akagawa, Koji

2000-01-01

Water hammer phenomena caused by a rapid valve closure, that is, shock phenomena in two-phase flows, are an important problem for the safety assessment of a hypothetical LOCA. This paper presents the results of experimental and analytical studies of the water hammer phenomena in a one-component tow-phase bubbly flow. In order to clarify the characteristics of water hammer phenomena, experiments for a one-component two-phase flow of Freon R-113 were conducted and a numerical simulation of pressure transients was developed. An overall picture of the water hammer phenomena in a one-component two-phase flow is presented an discussed. (author)
Multivariate recurrence network analysis for characterizing horizontal oil-water two-phase flow.

Science.gov (United States)

Gao, Zhong-Ke; Zhang, Xin-Wang; Jin, Ning-De; Marwan, Norbert; Kurths, Jürgen

2013-09-01

Characterizing complex patterns arising from horizontal oil-water two-phase flows is a contemporary and challenging problem of paramount importance. We design a new multisector conductance sensor and systematically carry out horizontal oil-water two-phase flow experiments for measuring multivariate signals of different flow patterns. We then infer multivariate recurrence networks from these experimental data and investigate local cross-network properties for each constructed network. Our results demonstrate that a cross-clustering coefficient from a multivariate recurrence network is very sensitive to transitions among different flow patterns and recovers quantitative insights into the flow behavior underlying horizontal oil-water flows. These properties render multivariate recurrence networks particularly powerful for investigating a horizontal oil-water two-phase flow system and its complex interacting components from a network perspective.
Physical and Thermodynamical Properties of Water Phases in Hardening Portland Cement Systems

DEFF Research Database (Denmark)

Hansen, T. Bæk

The present study is devoted to the description of water phases in hardening portland cement paste systems containing a significant amount of micro-filler and having a low to moderate water/powder ratio. Emphasis has been placed on the early stages of the hardening process.......The present study is devoted to the description of water phases in hardening portland cement paste systems containing a significant amount of micro-filler and having a low to moderate water/powder ratio. Emphasis has been placed on the early stages of the hardening process....
Selectivity differences of water-soluble vitamins separated on hydrophilic interaction stationary phases.

Science.gov (United States)

Yang, Yuanzhong; Boysen, Reinhard I; Hearn, Milton T W

2013-06-01

In this study, the retention behavior and selectivity differences of water-soluble vitamins were evaluated with three types of polar stationary phases (i.e. an underivatized silica phase, an amide phase, and an amino phase) operated in the hydrophilic interaction chromatographic mode with ESI mass spectrometric detection. The effects of mobile phase composition, including buffer pH and concentration, on the retention and selectivity of the vitamins were investigated. In all stationary phases, the neutral or weakly charged vitamins exhibited very weak retention under each of the pH conditions, while the acidic and more basic vitamins showed diverse retention behaviors. With the underivatized silica phase, increasing the salt concentration of the mobile phase resulted in enhanced retention of the acidic vitamins, but decreased retention of the basic vitamins. These observations thus signify the involvement of secondary mechanisms, such as electrostatic interaction in the retention of these analytes. Under optimized conditions, a baseline separation of all vitamins was achieved with excellent peak efficiency. In addition, the effects of water content in the sample on retention and peak efficiency were examined, with sample stacking effects observed when the injected sample contained a high amount of water. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Gas-phase water-mediated equilibrium between methylglyoxal and its geminal diol

Science.gov (United States)

Axson, Jessica L.; Takahashi, Kaito; De Haan, David O.; Vaida, Veronica

2010-01-01

In aqueous solution, aldehydes, and to a lesser extent ketones, hydrate to form geminal diols. We investigate the hydration of methylglyoxal (MG) in the gas phase, a process not previously considered to occur in water-restricted environments. In this study, we spectroscopically identified methylglyoxal diol (MGD) and obtained the gas-phase partial pressures of MG and MGD. These results, in conjunction with the relative humidity, were used to obtain the equilibrium constant, KP, for the water-mediated hydration of MG in the gas phase. The Gibbs free energy for this process, ΔG°, obtained as a result, suggests a larger than expected gas-phase diol concentration. This may have significant implications for understanding the role of organics in atmospheric chemistry. PMID:20142510
Equilibres de phases dans les systèmes fluides petroliers-eau Phase Equilibria in Oil-Water Systems

Directory of Open Access Journals (Sweden)

Peneloux A.

2006-11-01

Full Text Available Nous présentons quelques résultats obtenus à partir du logiciel FHYD qui permet le traitement des mélanges eau-fluides pétroliers, avec la détermination de la nature des phases (huile-gaz-eau-hydrate thermodynamiquement stables dans des conditions données de température et de pression, ainsi que de la quantité, de la composition de ces différentes phases et de leurs propriétés. Ce logiciel permet le tracé automatique des diagrammes de phases et nous présentons des exemples, depuis les systèmes binaires (eau-éthane, ternaires (eau-méthane-propane jusqu'aux fluides les plus complexes. La présence de sels (chlorure de sodium dissous est envisagée, ainsi que le calcul des conditions de dépôt du sel solide. Des exemples de problèmes pétroliers sont cités (gaz de séparateur saturé en eau, huile saturée en eau dans les conditions de gisement, huile en présence d'eau salée. Les estimations sur les quantités d'hydrate formées et leurs compositions sont comparées à des données expérimentales et aux résultats obtenus par d'autres logiciels. Le programme FHYD pourrait permettre une représentation plus réaliste de l'évolution des fluides pétroliers et des propriétés de transport de leurs différentes phases dans les modèles de simulation des conduites polyphasiques. This article presents a selection of results obtained with the FHYD program. This software allows simulation of mixtures composed of petroleum fluids and water, with determination of the nature of thermodynamically stable phases (oil-gas-water-hydrate under given conditions of temperature and pressure, along with the quantity, composition and properties of these different phases. Additionally, the program can automatically produce phase diagrams. Several examples of these have been included here, ranging from binary systems (water-ethane and ternary systems (water-methane-propane to the most complex petroleum fluids. The presence of dissolved salts
The Finite Element Analysis for a Mini-Conductance Probe in Horizontal Oil-Water Two-Phase Flow

Directory of Open Access Journals (Sweden)

Weihang Kong

2016-08-01

Full Text Available Oil-water two-phase flow is widespread in petroleum industry processes. The study of oil-water two-phase flow in horizontal pipes and the liquid holdup measurement of oil-water two-phase flow are of great importance for the optimization of the oil production process. This paper presents a novel sensor, i.e., a mini-conductance probe (MCP for measuring pure-water phase conductivity of oil-water segregated flow in horizontal pipes. The MCP solves the difficult problem of obtaining the pure-water correction for water holdup measurements by using a ring-shaped conductivity water-cut meter (RSCWCM. Firstly, using the finite element method (FEM, the spatial sensitivity field of the MCP is investigated and the optimized MCP geometry structure is determined in terms of the characteristic parameters. Then, the responses of the MCP for the oil-water segregated flow are calculated, and it is found that the MCP has better stability and sensitivity to the variation of water-layer thickness in the condition of high water holdup and low flow velocity. Finally, the static experiments for the oil-water segregated flow were carried out and a novel calibration method for pure-water phase conductivity measurements was presented. The validity of the pure-water phase conductivity measurement with segregated flow in horizontal pipes was verified by experimental results.

The Finite Element Analysis for a Mini-Conductance Probe in Horizontal Oil-Water Two-Phase Flow.

Science.gov (United States)

Kong, Weihang; Kong, Lingfu; Li, Lei; Liu, Xingbin; Xie, Ronghua; Li, Jun; Tang, Haitao

2016-08-24

Oil-water two-phase flow is widespread in petroleum industry processes. The study of oil-water two-phase flow in horizontal pipes and the liquid holdup measurement of oil-water two-phase flow are of great importance for the optimization of the oil production process. This paper presents a novel sensor, i.e., a mini-conductance probe (MCP) for measuring pure-water phase conductivity of oil-water segregated flow in horizontal pipes. The MCP solves the difficult problem of obtaining the pure-water correction for water holdup measurements by using a ring-shaped conductivity water-cut meter (RSCWCM). Firstly, using the finite element method (FEM), the spatial sensitivity field of the MCP is investigated and the optimized MCP geometry structure is determined in terms of the characteristic parameters. Then, the responses of the MCP for the oil-water segregated flow are calculated, and it is found that the MCP has better stability and sensitivity to the variation of water-layer thickness in the condition of high water holdup and low flow velocity. Finally, the static experiments for the oil-water segregated flow were carried out and a novel calibration method for pure-water phase conductivity measurements was presented. The validity of the pure-water phase conductivity measurement with segregated flow in horizontal pipes was verified by experimental results.
An Experimental Study of Two-Phase Pulse Flushing Technology in Water Distribution Systems

Directory of Open Access Journals (Sweden)

Zhaozhao Tang

2017-12-01

Full Text Available The deterioration of drinking water during distribution process is caused by many factors. The microorganisms and substances peeling off from the “growth-ring” make the secondary pollution in drinking water distribution systems. To reduce the secondary pollution, two-phase pulse flushing technology is introduced to quickly remove the “growth-ring”. In this study, experiment is undertaken for investigating the efficiency of the two-phase pulse flushing and finding the best setting combination. A case study is undertaken to compare the efficiencies between the two-phase pulse and the single-phase flushing. The best setting combination of the two-phase pulse flushing is at the frequency 4 s–6 s (air inflow time is 4 s and air cut off time is 6 s and the round air inflow nozzle is set at the bottom of the pipe. Two-phase pulse flushing technology can save 95% of water and 6 h 40 min flushing time.
Phase equilibria and critical phenomena in the cesium nitrate-water-diethylamine ternary system

International Nuclear Information System (INIS)

Il'in, K.K.; Kurskij, V.F.; Cherkasov, D.G.

2008-01-01

Phase equilibria and critical events in ternary cesium nitrate-water-diethylamine system, where border binary liquid system is characterized by aliquation with lower critical temperature of solution (LCTS), have been investigated by visual-polythermal method in the 60-150 Deg C range. Interaction of cesium nitrate in the water-diethylamine system leads to lowering of its LCTS from 146.1 to 69.3 Deg C and decrease of mutual solubility. Distribution ratios of diethylamine between water and organic phases of monotectic equilibrium are calculated at different temperatures. Diethylamine salting out from aqueous solutions by cesium nitrates becomes stronger with rising temperature. Plotted isotherms of phase confirms generalized scheme of topological transformations of ternary systems phase diagrams: salt-binary solvent with salting out
Measurement of Vertical Oil-in-water Two-phase Flow Using Dual-modality ERT-EMF System

OpenAIRE

Faraj, Yousef; Wang, Mi; Jia, Jiabin; Wang, Qiang; Xie, Cheng-gang; Oddie, Gary; Primrose , Ken; Qiu, Changhua

2015-01-01

Oil-in-water two-phase flows are often encountered in the upstream petroleum industry. The measurement of phase flow rates is of particular importance for managing oil production and water disposal and/or water reinjection. The complexity of oil-in-water flow structures creates a challenge to flow measurement. This paper proposes a new method of two-phase flow metering, which is based on the use of dual-modality system and multidimensional data fusion. The Electrical Resistance Tomography sys...
Influence of acidification of circulating water on differential distribution of dispersed phase

Directory of Open Access Journals (Sweden)

Oleksandr B. Gulyaenko

2015-06-01

Full Text Available The paper analyzes the connection between processing technologies of circulating water cooling tower and coagulation-aggregation properties of colloidal particles of the dispersed phase. In circulating water cooling tower when clarifying additional water the reduction of HCO3- and CO32- concentrations happens with corresponding pH increase. Absorption of atmospheric carbon dioxide by cooling tower circulating water offsets this increase. The estimation of the probability of adhesion to the surface of the dispersed phase, distributed in the volume of circulation water, and the heat exchange surface of the condenser for different degrees of evaporation of the coolant is made. The distribution of cooling water micro-disperse particles which are adsorbed on the heat exchange surfaces of the condenser (deposit formation and on the surface of larger particles (particle aggregation reflects the efficiency of applied water treatment technology. It is shown that acidification of additional water facilitates solution of most fine fractions and increases hardness of treated water.
Phase Behavior of a Phospholipid/Fatty Acid/Water Mixture Studied in Atomic Detail

NARCIS (Netherlands)

Knecht, Volker; Mark, Alan E.; Marrink, Siewert-Jan

2006-01-01

Molecular dynamics simulations have been used to study the phase behavior of a dipalmitoylphosphatidylcholine (DPPC)/palmitic acid (PA)/water 1:2:20 mixture in atomic detail. Starting from a random solution of DPPC and PA in water, the system adopts either a gel phase at temperatures below similar
Analysis of water hammer in two-component two-phase flows

International Nuclear Information System (INIS)

Warde, H.; Marzouk, E.; Ibrahim, S.

1989-01-01

The water hammer phenomena caused by a sudden valve closure in air-water two-phase flows must be clarified for the safety analysis of LOCA in reactors and further for the safety of boilers, chemical plants, pipe transport of fluids such as petroleum and natural gas. In the present work water hammer phenomena caused by sudden valve closure in two-component two-phase flows are investigated theoretically and experimentally. The phenomena are more complicated than in single phase-flows due to the fact of the presence of compressible component. Basic partial differential equations based on a one-dimensional homogeneous flow model are solved by the method of characteristic. The analysis is extended to include friction in a two-phase mixture depending on the local flow pattern. The profiles of the pressure transients, the propagation velocity of pressure waves and the effect of valve closure on the transient pressure are found. Different two-phase flow pattern and frictional pressure drop correlations were used including Baker, Chesholm and Beggs and Bril correlations. The effect of the flow pattern on the characteristic of wave propagation is discussed primarily to indicate the effect of void fraction on the velocity of wave propagation and on the attenuation of pressure waves. Transient pressure in the mixture were recorded at different air void fractions, rates of uniform valve closure and liquid flow velocities with the aid of pressure transducers, transient wave form recorders interfaced with an on-line pc computer. The results are compared with computation, and good agreement was obtained within experimental accuracy
Continuous hydrothermal co-liquefaction of aspen wood and glycerol with water phase recirculation

DEFF Research Database (Denmark)

Pedersen, Thomas H.; Grigoras, Ionela F.; Hoffmann, Julia

2016-01-01

heating value of 34.3 MJ/kg. The volatile fraction of the biocrude consisted mostly of compounds having number of carbon atoms in the C6–C12 range similar to gasoline. In terms of process feasibility, it was revealed that total organic carbon (TOC) and ash significantly accumulated in the water phase when...... such is recirculated for the proceeding batch. After four batches the TOC and the ash mass fraction of the water phase were 136.2 [g/L] and 12.6 [%], respectively. Water phase recirculation showed a slight increase in the biocrude quality in terms on an effective hydrogen-to-carbon ratio, but it showed no effects...
Conformational Preferences of Glycerol in the Gas Phase and in Water

Energy Technology Data Exchange (ETDEWEB)

Jeong, Keun Hong [Korea Military Academy, Seoul (Korea, Republic of); Byun, Byung Jin; Kang, Young Kee [Chungbuk National University, Cheongju (Korea, Republic of)

2012-03-15

The conformational study of glycerol has been carried out using the M06-2X/cc-pVTZ level of theory in the gas phase and the SMD M06-2X/cc-pVTZ level of theory in water in order to understand its conformational preferences and solvation effects. Most of the preferred conformers of glycerol have two C{sub 5} hydrogen bonds in the gas phase, as found by the analysis of calorimetric data. It has been known that the solvation drove the hydrogen bonds of glycerol to be weaker and its potential surface to be fatter and that glycerol exists as an ensemble of many feasible local minima in water. The calculated populations of glycerol in the gas phase and in water are consistent with the observed values, which are better than the previously calculated ones at the G2(MP2), CBS-QB3, and SM5.42 HF/6-31G(d) levels of theory
Raman scattering temperature measurements for water vapor in nonequilibrium dispersed two-phase flow

International Nuclear Information System (INIS)

Anastasia, C.M.; Neti, S.; Smith, W.R.; Chen, J.C.

1982-09-01

The objective of this investigation was to determine the feasibility of using Raman scattering as a nonintrusive technique to measure vapor temperatures in dispersed two-phase flow. The Raman system developed for this investigation is described, including alignment of optics and optimization of the photodetector for photon pulse counting. Experimentally obtained Raman spectra are presented for the following single- and two-phase samples: liquid water, atmospheric nitrogen, superheated steam, nitrogen and water droplets in a high void fraction air/water mist, and superheated water vapor in nonequilibrium dispersed flow
Fine Water Mist Fire Extinguisher for Spacecraft, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This three phase SBIR project from ADA Technologies Inc. (ADA) builds upon the experience of ADA in development of fine water mist (FWM) fire suppression technology....
Direct phase coexistence molecular dynamics study of the phase equilibria of the ternary methane-carbon dioxide-water hydrate system.

Science.gov (United States)

Michalis, Vasileios K; Tsimpanogiannis, Ioannis N; Stubos, Athanassios K; Economou, Ioannis G

2016-09-14

Molecular dynamics simulation is used to predict the phase equilibrium conditions of a ternary hydrate system. In particular, the direct phase coexistence methodology is implemented for the determination of the three-phase coexistence temperature of the methane-carbon dioxide-water hydrate system at elevated pressures. The TIP4P/ice, TraPPE-UA and OPLS-UA forcefields for water, carbon dioxide and methane respectively are used, in line with our previous studies of the phase equilibria of the corresponding binary hydrate systems. The solubility in the aqueous phase of the guest molecules of the respective binary and ternary systems is examined under hydrate-forming conditions, providing insight into the predictive capability of the methodology as well as the combination of these forcefields to accurately describe the phase behavior of the ternary system. The three-phase coexistence temperature is calculated at 400, 1000 and 2000 bar for two compositions of the methane-carbon dioxide mixture. The predicted values are compared with available calculations with satisfactory agreement. An estimation is also provided for the fraction of the guest molecules in the mixed hydrate phase under the conditions examined.
Novel Downhole Electromagnetic Flowmeter for Oil-Water Two-Phase Flow in High-Water-Cut Oil-Producing Wells.

Science.gov (United States)

Wang, Yanjun; Li, Haoyu; Liu, Xingbin; Zhang, Yuhui; Xie, Ronghua; Huang, Chunhui; Hu, Jinhai; Deng, Gang

2016-10-14

First, the measuring principle, the weight function, and the magnetic field of the novel downhole inserted electromagnetic flowmeter (EMF) are described. Second, the basic design of the EMF is described. Third, the dynamic experiments of two EMFs in oil-water two-phase flow are carried out. The experimental errors are analyzed in detail. The experimental results show that the maximum absolute value of the full-scale errors is better than 5%, the total flowrate is 5-60 m³/d, and the water-cut is higher than 60%. The maximum absolute value of the full-scale errors is better than 7%, the total flowrate is 2-60 m³/d, and the water-cut is higher than 70%. Finally, onsite experiments in high-water-cut oil-producing wells are conducted, and the possible reasons for the errors in the onsite experiments are analyzed. It is found that the EMF can provide an effective technology for measuring downhole oil-water two-phase flow.
Novel Downhole Electromagnetic Flowmeter for Oil-Water Two-Phase Flow in High-Water-Cut Oil-Producing Wells

Directory of Open Access Journals (Sweden)

Yanjun Wang

2016-10-01

Full Text Available First, the measuring principle, the weight function, and the magnetic field of the novel downhole inserted electromagnetic flowmeter (EMF are described. Second, the basic design of the EMF is described. Third, the dynamic experiments of two EMFs in oil-water two-phase flow are carried out. The experimental errors are analyzed in detail. The experimental results show that the maximum absolute value of the full-scale errors is better than 5%, the total flowrate is 5–60 m3/d, and the water-cut is higher than 60%. The maximum absolute value of the full-scale errors is better than 7%, the total flowrate is 2–60 m3/d, and the water-cut is higher than 70%. Finally, onsite experiments in high-water-cut oil-producing wells are conducted, and the possible reasons for the errors in the onsite experiments are analyzed. It is found that the EMF can provide an effective technology for measuring downhole oil-water two-phase flow.
Do zooplankton contribute to an ultraviolet clear-water phase in lakes?

NARCIS (Netherlands)

Williamson, C.E.; Lange, de H.J.; Leech, D.M.

2007-01-01

Seasonal increases in the ultraviolet (UV) transparency of the surface waters of an oligotrophic lake in Pennsylvania suggest that clear-water phase (CWP) events similar to those previously observed for visible light also exist for the potentially damaging UV wavelengths. Seasonal increases in
Subscale Water Based Phase Change Material Heat Exchanger Development

Science.gov (United States)

Sheth, Rubik; Hansen, Scott

2016-01-01

Supplemental heat rejection devices are required in many spacecraft as the radiators are not sized to meet the full heat rejection demand. One means of obtaining additional heat rejection is through the use of phase change material heat exchangers (PCM HX's). PCM HX's utilize phase change to store energy in unfavorable thermal environments (melting) and reject the energy in favorable environments (freezing). Traditionally, wax has been used as a PCM on spacecraft. However, water is an attractive alternative because it is capable of storing about 40% more energy per unit mass due to its higher latent heat of fusion. The significant problem in using water as a PCM is its expansion while freezing, leading to structural integrity concerns when housed in an enclosed heat exchanger volume. Significant investigation and development has taken place over the past five years to understand and overcome the problems associated with water PCM HX's. This paper reports on the final efforts by Johnson Space Center's Thermal Systems Branch to develop a water based PCM HX. The test article developed and reported on is a subscale version of the full-scale water-based PCM HX's constructed by Mezzo Technologies. The subscale unit was designed by applying prior research on freeze front propagation and previous full-scale water PCM HX development. Design modifications to the subscale unit included use of urethane bladder, decreased aspect ratio, perforated protection sheet, and use of additional mid-plates. Testing of the subscale unit was successful and 150 cycles were completed without fail.
Magnitude and sign correlations in conductance fluctuations of horizontal oil water two-phase flow

International Nuclear Information System (INIS)

Zhu, L; Jin, N D; Gao, Z K; Zong, Y B; Zhai, L S; Wang, Z Y

2012-01-01

In experiment we firstly define five typical horizontal oil-water flow patterns. Then we introduce an approach for analyzing signals by decomposing the original signals increment into magnitude and sign series and exploring their scaling properties. We characterize the nonlinear and linear properties of horizontal oil-water two-phase flow, which relate to magnitude and sign series respectively. We find that the joint distribution of different scaling exponents can effectively identify flow patterns, and the detrended fluctuation analysis (DFA) on magnitude and sign series can represent typical horizontal oil-water two-phase flow dynamics characteristics. The results indicate that the magnitude and sign decomposition method can be a helpful tool for characterizing complex dynamics of horizontal oil-water two-phase flow.
Non-spherical micelles in an oil-in-water cubic phase

DEFF Research Database (Denmark)

Leaver, M.; Rajagopalan, V.; Ulf, O.

2000-01-01

phase, both with and without SDS, was established by NMR self-diffusion. In addition H-2 NMR relaxation experiments have demonstrated that the micelles in the cubic phase are non-spherical, having grown and changed shape upon formation of the cubic phase from the micellar solution. Small angle...... associated with the micellar cubic phase, Pm3n and Fd3m. The micellar volumes calculated for these space groups are similar and are consistent with a change in micellar geometry from spherical to prolate.......The cubic phase formed between the microemulsion and hexagonal phases of the ternary pentaethylene glycol dodecyl ether (C12E5)-decane-water system and that doped with small amounts of sodium dodecylsulfate (SDS) have been investigated. The presence of discrete oil-swollen micelles in the cubic...
Secondary phases formed during nuclear waste glass-water interactions: Thermodynamic and derived properties

International Nuclear Information System (INIS)

McKenzie, W.F.

1992-08-01

The thermodynamic properties of secondary phases observed to form during nuclear waste glass-water interactions are of particular interest as it is with the application of these properties together with the thermodynamic properties of other solid phases, fluid phases, and aqueous species that one may predict the environmental consequences of introducing radionuclides contained in the glass into groundwater at a high-level nuclear waste repository. The validation of these predicted consequences can be obtained from laboratory experiments and field observations at natural analogue sites. The purpose of this report is to update and expand the previous compilation (McKenzie, 1991) of thermodynamic data retrieved from the literature and/or estimated for secondary phases observed to form (and candidate phases from observed chemical compositions) during nuclear waste glass-water interactions. In addition, this report includes provisionally recommended thermodynamic data of secondary phases
Pattern transitions of oil-water two-phase flow with low water content in rectangular horizontal pipes probed by terahertz spectrum.

Science.gov (United States)

Feng, Xin; Wu, Shi-Xiang; Zhao, Kun; Wang, Wei; Zhan, Hong-Lei; Jiang, Chen; Xiao, Li-Zhi; Chen, Shao-Hua

2015-11-30

The flow-pattern transition has been a challenging problem in two-phase flow system. We propose the terahertz time-domain spectroscopy (THz-TDS) to investigate the behavior underlying oil-water flow in rectangular horizontal pipes. The low water content (0.03-2.3%) in oil-water flow can be measured accurately and reliably from the relationship between THz peak amplitude and water volume fraction. In addition, we obtain the flow pattern transition boundaries in terms of flow rates. The critical flow rate Qc of the flow pattern transitions decreases from 0.32 m3 h to 0.18 m3 h when the corresponding water content increases from 0.03% to 2.3%. These properties render THz-TDS particularly powerful technology for investigating a horizontal oil-water two-phase flow system.

Phase relations and physicochemical properties of the ammonium paratungstate - polyvinyl alcohol - water system

International Nuclear Information System (INIS)

Ostroushko, A.A.; Mikhalev, D.S.

2003-01-01

Phase relations were studied in the ammonium paratungstate - polyvinyl alcohol - water system, isothermal cross section of the phase diagram was obtained at room temperature. Visual and microscopic observations, as well as instrumental methods were used for the detection of lines of the homogeneous polymer-salt solutions existence. Concentration ratios of density of solutions, their dynamic viscosity and refractive index were studied. Area of polymer based solutions, area of salt crystallization, heterogeneous fields with two or three phases were separated. As compared with the ammonium heptamolybdate - polyvinyl alcohol - water system the increase of solubility of components under day lighting and ultraviolet radiation escaped detection. The studied system is provided properties indicative of the formation of mesomorphic phase, photochemical reduction of ions of d-metals for the occurrence of this phase is not requirement [ru
Water/ionic liquid/organic three-phase interfacial synthesis of coral-like polypyrrole toward enhanced electrochemical capacitance

International Nuclear Information System (INIS)

Hou Linrui; Yuan Changzhou; Li Diankai; Yang Long; Shen Laifa; Zhang Fang; Zhang Xiaogang

2011-01-01

Highlights: → Interfacial synthesis strategies are proposed to synthesize PPy samples. → Water/ionic liquid /organic three-phase interface for preparing coral-like PPy. → Coral-like PPy with more ordered structure and better electronic conductivity. → Coral-like PPy owns higher rate performance and better electrochemical stability. - Abstract: Two interfacial synthesis strategies are proposed to synthesize polypyrrole samples for electrochemical capacitors (ECs). In contrast to water/organic two-phase route, unique water/ionic liquid (IL)/organic three-phase interface strategy is first performed to prepare coral-like polypyrrole with even better electrochemical capacitance, where 1-Ethyl-3-methylimidazolium tetrafluoroborate IL, as a 'buffering zone', is set between the water and organic phases to control the morphology and micro-structure of the polypyrrole phase during polymerization. The polypyrrole synthesized by three-phase interfacial route owns more ordered structure, less charge transfer resistance and better electronic conductivity, compared with two-phase method, and delivers larger specific capacitance, higher rate performance and better electrochemical stability at large current densities in 3 M KCl aqueous electrolyte.
Effect of water content on partial ternary phase diagram water-in-diesel microemulsion fuel

Science.gov (United States)

Mukayat, Hastinatun; Badri, Khairiah Haji; Raman, Ismail Ab.; Ramli, Suria

2014-09-01

Introduction of water in the fuel gave a significant effect to the reduction of pollutant such as NOx emission. In this work, water/diesel microemulsion fuels were prepared using compositional method by mixing water and diesel in the presence of non-ionic surfactant and co-surfactant. The effects of water composition on the partial ternary phase diagram were studied at 5%, 10%, 15% and 20% (w/w). The physical stability of the microemulsion was investigated at 45°C over a period of one month. The optimum formulae obtained were diesel/T80/1-penthanol/water 60:20:15:5 wt% (System 1), 55:20:15:10 wt% (System 2), 50:20:15:15 wt% (System 3) and 45:20:15:20 wt% (System 4). Physicochemical characterizations of optimum formulae were studied. The results showed that water content has a significant effect to the formation of microemulsion, its stability, droplet size and viscosity.
EXTRACTION CHARACTERISTICS OF THE CATION OF ALKYLDIMETHYLBENZYLAMMONIUM CHLORIDE AT THE PHASE BOUNDARY WATER-MEMBRANE SOLVENT

Directory of Open Access Journals (Sweden)

O. V. Luganska

2015-06-01

Full Text Available The extraction coefficients of the cation of alkyldimethylbenzylammonium chloride at the phase boundary water-tricresylphosphate, water-dioctylphthalate, water-dibutylphtalate have been determined by the potentiometric titration of the aqueous phase with a silver electrode. The correctness of the obtained results has been proved by the titrimetric method with visual fixation of the equivalence point using methylene blue indicator.
Aromaticity of benzene in condensed phases. A case of a benzene-water system

Science.gov (United States)

Zborowski, Krzysztof K.

2014-05-01

A theoretical Density Functional Theory study was performed for a benzene molecule in water cages. Two DFT functionals (B3LYP and BLYP) were employed. The optimized geometries of the studied clusters were used to calculate the aromaticity of benzene in a condensed phase using the aromaticity indices: HOMA, NICS, PDI, and H. The results were compared with aromaticity of a single benzene molecule in the gas phase and in the solvent environment provided by the PCM continuum model. It is argued that high aromaticity of benzene in the gas phase is retained in the water environment.
Liquid crystalline phase behavior of protein fibers in water: experiments versus theory.

Science.gov (United States)

Jung, Jin-Mi; Mezzenga, Raffaele

2010-01-05

We have developed a new method allowing the study of the thermodynamic phase behavior of mesoscopic colloidal systems consisting of amyloid protein fibers in water, obtained by heat denaturation and aggregation of beta-lactoglobulin, a dairy protein. The fibers have a cross section of about 5.2 nm and two groups of polydisperse contour lengths: (i) long fibers of 1-20 microm, showing semiflexible behavior, and (ii) short rods of 100-200 nm long, obtained by cutting the long fibers via high-pressure homogenization. At pH 2 without salt, these fibers are highly charged and stable in water. We have studied the isotropic-nematic phase transition for both systems and compared our results with the theoretical values predicted by Onsager's theory. The experimentally measured isotropic-nematic phase transition was found to occur at 0.4% and at 3% for the long and short fibers, respectively. For both systems, this phase transition occurs at concentrations more than 1 order of magnitude lower than what is expected based on Onsager's theory. Moreover, at low enough pH, no intermediate biphasic region was observed between the isotropic phase and the nematic phase. The phase diagrams of both systems (pH vs concentration) showed similar, yet complex and rich, phase behavior. We discuss the possible physical fundamentals ruling the phase diagram as well as the discrepancy we observe for the isotropic-nematic phase transition between our experimental results and the predicted theoretical results. Our work highlights that systems formed by water-amyloid protein fibers are way too complex to be understood based solely on Onsager's theories. Experimental results are revisited in terms of the Flory's theory (1956) for suspensions of rods, which allows accounting for rod-solvent hydrophobic interactions. This theoretical approach allows explaining, on a semiquantitative basis, most of the discrepancies observed between the experimental results and Onsager's predictions. The sources of
Ab initio study of gas phase and water-assisted tautomerization of ...

Indian Academy of Sciences (India)

WINTEC

Water-assisted tautomerization in maleimide and formamide showed that difference in energy barrier reduces to 2⋅83 kcal/mol from 10⋅41 kcal/mol (in gas phase) at B3LYP level, which resulted that maleimide readily undergoes tautomerization in water molecule. Keywords. Ab Initio calculations; maleimide; formamide; ...
Validation of CATHENA MOD-3.5/Rev0 for single-phase water hammer

International Nuclear Information System (INIS)

Beuthe, T.G.

2000-01-01

This paper describes work performed to validate the system thermalhydraulics code CATHENA MOD-3.5c/Rev0 for single-phase water hammer. Simulations were performed and are compared quantitatively against numerical tests and experimental results from the Seven Sisters Water Hammer Facility to demonstrate CATHENA can predict the creation and propagation of pressure waves when valves are opened and closed. Simulations were also performed to show CATHENA can model the behaviour of reflected and transmitted pressure waves at area changes, dead ends, tanks, boundary conditions, and orifices in simple and more complex piping systems. The CATHENA results are shown to calculate pressure and wave propagation speeds to within 0.2% and 0.5% respectively for numerical tests and within 3.3% and 5% for experimental results respectively. These results are used to help validate CATHENA for use in single-phase water hammer analysis. They also provide assurance that the fundamental parameters needed to successfully model more complex forms of water hammer are accounted for in the MOD-3.5c/Rev0 version of CATHENA, and represent the first step in the process to validate the code for use in modelling two-phase water hammer and condensation-induced water hammer. (author)
A Two-Phase Model for Trade Matching and Price Setting in Double Auction Water Markets

Science.gov (United States)

Xu, Tingting; Zheng, Hang; Zhao, Jianshi; Liu, Yicheng; Tang, Pingzhong; Yang, Y. C. Ethan; Wang, Zhongjing

2018-04-01

Delivery in water markets is generally operated by agencies through channel systems, which imposes physical and institutional market constraints. Many water markets allow water users to post selling and buying requests on a board. However, water users may not be able to choose efficiently when the information (including the constraints) becomes complex. This study proposes an innovative two-phase model to address this problem based on practical experience in China. The first phase seeks and determines the optimal assignment that maximizes the incremental improvement of the system's social welfare according to the bids and asks in the water market. The second phase sets appropriate prices under constraints. Applying this model to China's Xiying Irrigation District shows that it can improve social welfare more than the current "pool exchange" method can. Within the second phase, we evaluate three objective functions (minimum variance, threshold-based balance, and two-sided balance), which represent different managerial goals. The threshold-based balance function should be preferred by most users, while the two-sided balance should be preferred by players who post extreme prices.
A chromatographic determination of water in non-aqueous phases of solvent extraction systems

International Nuclear Information System (INIS)

Lyle, S.J.; Smith, D.B.

1975-01-01

The disadvantages of the Karl Fischer method for the determination of water in the non-aqueous phases of solvent extraction systems are pointed out, and a gas chromatographic method is described which is claimed to be potentially capable of overcoming these disadvantages. The method, as described, was developed to satisfy conditions relevant to measurement of the transfer rate of water from an aqueous phase into tri-n-butylphosphate in toluene, but it can be used for water determination in other solvent extraction systems. The apparatus used is described in detail. The concentration of water in water-saturated TBP was found to be 3.56 mol/litre, compared with a value of 3.55 obtained by Karl Fischer titration and previous literature values of 3.59 and 3.57. Measurements of water content in benzene solutions of long chain alkylamines were also sucessfully carried out. (U.K.)
Experimental on two sensors combination used in horizontal pipe gas-water two-phase flow

International Nuclear Information System (INIS)

Wu, Hao; Dong, Feng

2014-01-01

Gas-water two phase flow phenomenon widely exists in production and living and the measurement of it is meaningful. A new type of long-waist cone flow sensor has been designed to measure two-phase mass flow rate. Six rings structure of conductance probe is used to measure volume fraction and axial velocity. The calibration of them have been made. Two sensors have been combined in horizontal pipeline experiment to measure two-phase flow mass flow rate. Several model of gas-water two-phase flow has been discussed. The calculation errors of total mass flow rate measurement is less than 5% based on the revised homogeneous flow model
One-phase and two-phase homologous curves for coolant pumps of the pressurized light water nuclear reactors

International Nuclear Information System (INIS)

Santos, G.A. dos.

1990-01-01

The two-phase coolant pump model of pressurized light water nuclear reactors is an important point for the loss of primary coolant accident analysis. The single-phase pump characteristics are an essential feature for operational transients studies, for example, the shut-down and start-up of pump. These parameters, in terms of the homologous curves, set up the complete performance of the pump and are input for transients and accidents analysis thermal-hydraulic codes. This work propose a mathematical model able to predict the single-phase and two-phase homologous curves where it was incorporated geometric and operational pump condition. The results were compared with the experimental tests data from literature and it has showed a good agreement. (author)
Pressure transient analysis in single and two-phase water by finite difference methods

International Nuclear Information System (INIS)

Berry, G.F.; Daley, J.G.

1977-01-01

An important consideration in the design of LMFBR steam generators is the possibility of leakage from a steam generator water tube. The ensuing sodium/water reaction will be largely controlled by the amount of water available at the leak site, thus analysis methods treating this event must have the capability of accurately modeling pressure transients through all states of water occurring in a steam generator, whether single or two-phase. The equation systems of the present model consist of the conservation equations together with an equation of state for one-dimensional homogeneous flow. These equations are then solved using finite difference techniques with phase considerations and non-equilibrium effects being treated through the equation of state. The basis for water property computation is Keenan's 'fundamental equation of state' which is applicable to single-phase water at pressures less than 1000 bars and temperatures less than 1300 0 C. This provides formulations allowing computation of any water property to any desired precision. Two-phase properties are constructed from values on the saturation line. The use of formulations permits the direct calculation of any thermodynamic property (or property derivative) to great precision while requiring very little computer storage, but does involve considerable computation time. For this reason an optional calculation scheme based on the method of 'transfinite interpolation' is included to give rapid computation in selected regions with decreased precision. The conservation equations were solved using the second order Lax-Wendroff scheme which includes wall friction, allows the formation of shocks and locally supersonic flow. Computational boundary conditions were found from a method-of-characteristics solution at the reservoir and receiver ends. The local characteristics were used to interpolate data from inside the pipe to the boundary
Influence of fat crystals in the oil phase on stability of oil-in-water emulsions

NARCIS (Netherlands)

Boekel, van M.A.J.S.

1980-01-01

Coalescence at rest and during flow was studied in emulsions of paraffin oil in water with several surfactants and with crystals of solid paraffin or tristearate in the oil phase. Solid fat in the oil phase was estimated by pulsed nuclear magnetic resonance. Without crystals, oil-in-water emulsions
Produced water radionuclide hazard/risk assessment, Phase 1

Energy Technology Data Exchange (ETDEWEB)

Hamilton, L.D.; Meinhold, A.F.; Nagy, J.

1991-06-01

Petroleum production may be accompanied by the production of saline water, called produced water.'' Produced water discharged into freshwater streams, estuaries, coastal and outer continental shelf waters can contained enhanced levels of radium isotopes. This document reports on the first phase of a study to estimate the risk to human health and the environment from radium discharged in produced water. The study involved five major steps: (1) evaluate the usefulness of available produced water outfall data for developing estimates of radium environmental concentrations; (2) review the literature on the bioaccumulation of radium by aquatic organism; (3) review the literature on the effects of radiation on aquatic organisms; (4) review the information available concerning the human health risks associated with exposure to Ra-226 and Ra-228 and (5) perform a conservative, screening-level assessment of the health and environmental risks posed by Ra-226 and Ra-228 discharged in produced waters. A screening-level analysis was performed to determine whether radium discharged to coastal Louisiana in produced waters presents potential health or environmental risks requiring further study. This conservative assessment suggested that no detectable impact on populations of fish, molluscs or crustaceans from radium discharged in produced waters is likely. The analysis also suggested that there is a potential for risk were an individual to ingest a large amount of seafood harvested near a produced water discharge point over a lifetime. The number of excess cancers predicted per year under a conservative scenario is comparable to those expected to result from background concentrations of radium.
Produced water radionuclide hazard/risk assessment, Phase 1

Energy Technology Data Exchange (ETDEWEB)

Hamilton, L.D.; Meinhold, A.F.; Nagy, J.

1991-06-01

Petroleum production may be accompanied by the production of saline water, called ``produced water.`` Produced water discharged into freshwater streams, estuaries, coastal and outer continental shelf waters can contained enhanced levels of radium isotopes. This document reports on the first phase of a study to estimate the risk to human health and the environment from radium discharged in produced water. The study involved five major steps: (1) evaluate the usefulness of available produced water outfall data for developing estimates of radium environmental concentrations; (2) review the literature on the bioaccumulation of radium by aquatic organism; (3) review the literature on the effects of radiation on aquatic organisms; (4) review the information available concerning the human health risks associated with exposure to Ra-226 and Ra-228 and (5) perform a conservative, screening-level assessment of the health and environmental risks posed by Ra-226 and Ra-228 discharged in produced waters. A screening-level analysis was performed to determine whether radium discharged to coastal Louisiana in produced waters presents potential health or environmental risks requiring further study. This conservative assessment suggested that no detectable impact on populations of fish, molluscs or crustaceans from radium discharged in produced waters is likely. The analysis also suggested that there is a potential for risk were an individual to ingest a large amount of seafood harvested near a produced water discharge point over a lifetime. The number of excess cancers predicted per year under a conservative scenario is comparable to those expected to result from background concentrations of radium.
Produced water radionuclide hazard/risk assessment, Phase 1

International Nuclear Information System (INIS)

Hamilton, L.D.; Meinhold, A.F.; Nagy, J.

1991-06-01

Petroleum production may be accompanied by the production of saline water, called ''produced water.'' Produced water discharged into freshwater streams, estuaries, coastal and outer continental shelf waters can contained enhanced levels of radium isotopes. This document reports on the first phase of a study to estimate the risk to human health and the environment from radium discharged in produced water. The study involved five major steps: (1) evaluate the usefulness of available produced water outfall data for developing estimates of radium environmental concentrations; (2) review the literature on the bioaccumulation of radium by aquatic organism; (3) review the literature on the effects of radiation on aquatic organisms; (4) review the information available concerning the human health risks associated with exposure to Ra-226 and Ra-228 and (5) perform a conservative, screening-level assessment of the health and environmental risks posed by Ra-226 and Ra-228 discharged in produced waters. A screening-level analysis was performed to determine whether radium discharged to coastal Louisiana in produced waters presents potential health or environmental risks requiring further study. This conservative assessment suggested that no detectable impact on populations of fish, molluscs or crustaceans from radium discharged in produced waters is likely. The analysis also suggested that there is a potential for risk were an individual to ingest a large amount of seafood harvested near a produced water discharge point over a lifetime. The number of excess cancers predicted per year under a conservative scenario is comparable to those expected to result from background concentrations of radium
Metal-ion catalyzed polymerization in the eutectic phase in water-ice

DEFF Research Database (Denmark)

Monnard, Pierre-Alain; Szostak, Jack W.

2008-01-01

The emergence of an RNA world requires among other processes the non-enzymatic, template-directed replication of genetic polymers such as RNA or related nucleic acids, possibly catalyzed by metal ions. The absence of uridilate derivative polymerization on adenine containing templates has been...... the main issue preventing an efficient template-directed RNA polymerization. We report here the investigation of template-directed RNA polymerization in the eutectic phase in water-ice. In particular, it was found that activated Uridilate monomers in the presence of metal-ion catalysts could efficiently......-pairing opportunities. These results suggest that a template-directed RNA polymerization catalyzed by metal-ions could be carried out under eutectic phase in water-ice conditions....
Air-water two-phase flow through a pipe junction

International Nuclear Information System (INIS)

Suu, Tetsuo

1991-01-01

The distribution of the local void fraction across the section of the conduit was studied experimentally in air-water two-phase flow flowing through a pipe junction with the branching angle of 90deg and the area ratio of unity. As in the previous report, the main conduit of the junction was set up vertically and upward air-water bubbly and slug flows were arranged in the main upstream section. If the flow regime, the quality and the ratio of lateral mass flow discharge of water to total mass flow discharge of water are the same, the larger the Reynolds number is, the more violent the variety of the local void fraction distribution adjacent to the branching part in the lateral conduit is. However, the variety in the main downstream section is scarcely influenced by the Reynolds number. (author)
Impacts of forest to urban land conversion and ENSO phase on water quality of a public water supply reservoir

Science.gov (United States)

We used coupled watershed and reservoir models to evaluate the impacts of deforestation and ENSO phase on drinking water quality. Source water total organic carbon (TOC) is especially important due to the potential for production of carcinogenic disinfection byproducts (DBPs). The Environmental Flui...

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

International Nuclear Information System (INIS)

Nakamura, Hideo

1996-05-01

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

DEFF Research Database (Denmark)

Zhu, Zhe; Toor, Saqib; Rosendahl, Lasse

2014-01-01

This project focuses on the investigation of addition of aqueous phase in the production of biofuel from biomass through hydrothermal liquefaction (HTL) technology. Hydrothermal liquefaction is a wet thermal conversion process, which can convert all kinds of biomass to fuels. In this study, barley...... straw was first liquefied in fresh distilled water with the presence of K2CO3 catalyst at 300 C as the reference run. Afterwards, the aqueous phase which is obtained from liquefaction process in the previous run was recycled and used as the reaction medium from the second to the fourth run....... With the addition of recycling aqueous phase in HTL process, it is expected that the amount of the waste water and energy consumption can be reduced. The effect of water recirculation on product yield and properties was investigated in this study. The results showed that bio-oil yield was 34.85 wt% when the barley...
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.
Design and numerical simulation on an auto-cumulative flowmeter in horizontal oil-water two-phase flow.

Science.gov (United States)

Xie, Beibei; Kong, Lingfu; Kong, Deming; Kong, Weihang; Li, Lei; Liu, Xingbin; Chen, Jiliang

2017-11-01

In order to accurately measure the flow rate under the low yield horizontal well conditions, an auto-cumulative flowmeter (ACF) was proposed. Using the proposed flowmeter, the oil flow rate in horizontal oil-water two-phase segregated flow can be finely extracted. The computational fluid dynamics software Fluent was used to simulate the fluid of the ACF in oil-water two-phase flow. In order to calibrate the simulation measurement of the ACF, a novel oil flow rate measurement method was further proposed. The models of the ACF were simulated to obtain and calibrate the oil flow rate under different total flow rates and oil cuts. Using the finite-element method, the structure of the seven conductance probes in the ACF was simulated. The response values for the probes of the ACF under the conditions of oil-water segregated flow were obtained. The experiments for oil-water segregated flow under different heights of the oil accumulation in horizontal oil-water two-phase flow were carried out to calibrate the ACF. The validity of the oil flow rate measurement in horizontal oil-water two-phase flow was verified by simulation and experimental results.
Two-phase upward air water flow in a prismatic channel with rectangular base

International Nuclear Information System (INIS)

Carvalho Tofani, P. de

1984-01-01

Two-phase liquid-gas mixtures provide suitable means to simulate water-water vapor flows, which may occur in nuclear reactor cores. The mastery of physical transport phenomena is of great importance, as far as the analysis of such thermal systems is concerned. Within the framework of thermal-hydraulic programs, experiments have been carried out to investigate the two-phase upward air-water flow structure, in a rectangular test section, by using independent measuring techniques, which comprise direct viewing and photography, electrical probes and gamma-ray attenuation. In this paper, flow pattern maps and correlations for flow pattern transitions, void fraction profiles, liquid film thickness and superficial average void fraction are proposed and compared to available data. (Author) [pt
Mechanism of falling water limitation in two-phase counter flow through single hole vertical channel

International Nuclear Information System (INIS)

Sudo, Yukio; Ohnuki, Akira

1983-01-01

In the safety evaluation at the time of loss coolant accident, which is a credible accident in LWRs, recently main effort has been concentrated to the optimum evaluation calculation, and the grasp of vapor-liquid two-phase flow phenomena has become important. As one of the important phenomena, there is the limitation of falling water in two-phase counter flow through a vertical channel. This phenomenon is divided into the limitation of falling water stored in an upper plenum to a core through an upper core-supporting plate and a tie plate at the time of reflooding, and the limitation of falling emergency core-cooling water in downcomer channels at the time of reflooding in PWRs, under the presence of rising steam flow. In both cases, the evaluation of the quantity of falling water is important, because it contributes directly to core cooling. In this research, in order to clarify the mechanism of limitation of falling water in two-phase vertical counter flow, first, two-phase flow of air-water system through a single-hole vertical channel was taken up, and the effect of main parameters was experimentally studied. At the same time, the theoretical investigation was performed, and the comparison with the experimental results obtained so far was carried out. The different mechanisms for short and long channels gave the good results. (Kako, I.)
Silicone sensing phase for detection of aromatic hydrocarbons in water employing near-infrared spectroscopy.

Science.gov (United States)

Albuquerque, Jackson S; Pimentel, M Fernanda; Silva, Valdinete L; Raimundo, Ivo M; Rohwedder, Jarbas J R; Pasquini, Celio

2005-01-01

The use of silicone for detection of aromatic hydrocarbons in water using near-infrared spectroscopy is proposed. A sensing phase of poly(dimethylsiloxane) (PDMS) was prepared, and a rod of this material was adapted to a transflectance probe for measurements from 850 to 1800 nm. Deionized water samples contaminated separately with known amounts of benzene, toluene, ethylbenzene, and m-xylene were used for evaluation of the PDMS sensing phase, and measurements were made in a closed reactor with constant stirring. Equilibrium states were obtained after 90, 180, 360, and 405 min for benzene, toluene, ethylbenzene, and m-xylene, respectively. The PDMS sensing phase showed a reversible response, presenting linear response ranges up to 360, 290, 100, and 80 mg L(-1), with detection limits of 8.0, 7.0, 2.6, and 3.0 mg L(-1) for benzene, toluene, ethylbenzene, and m-xylene, respectively. Reference spectra obtained with different rods showed a relative standard deviation of 0.5%, indicating repeatability in the sensing phase preparation. A relative standard deviation of 6.7% was obtained for measurements performed with six different rods, using a 52 mg L(-1) toluene aqueous solution. The sensing phase was evaluated for identification of sources of contamination of water in simulated studies, employing Brazilian gasoline type A (without ethanol), gasoline type C (with 25% of anhydrous ethanol), and diesel fuel. Principal component analysis was able to classify the water in distinct groups, contaminated by gasoline A, gasoline C, or diesel fuel.
Phase 1 summaries of radionuclide concentration data for vegetation, river water, drinking water, and fish

International Nuclear Information System (INIS)

Denham, D.H.; Dirkes, R.L.; Hanf, R.W.; Poston, T.M.; Thiede, M.E.; Woodruff, R.K.

1993-06-01

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at the Hanford Site since 1944. As part of the HEDR Project, the Environmental Monitoring Data Task (Task 05) staff assemble, evaluate, and summarize key historical measurements of radionuclide concentrations in the environment as a result of Hanford operations. The scope of work performed during Phase I included initiating the search, recovery, and inventory of environmental reports. Summaries of the environmental monitoring data that were recovered and evaluated are presented for specific periods of interest. These periods include vegetation monitoring data (primarily sagebrush) for the years 1945 through 1947, Columbia River water and drinking water monitoring data for the years 1963 through 1966, and fish monitoring data for the years 1964 through 1966. Concern was limited to those radionuclides identified as the most likely major contributors to the dose potentially received by the public during the times of interest: phosphorous-32, copper-64, zinc-65, arsenic-76, and neptunium-239 in Columbia River fish and drinking water taken from the river, and iodine-131 in vegetation. This report documents the achievement of the Phase I objectives of the Environmental Monitoring Data Task
Carbohydrates-tailored phase tunable systems composed of ionic liquids and water

International Nuclear Information System (INIS)

Chen Yuhaun; Wang Yige; Cheng Qingyan; Liu Xiaoli; Zhang Suojiang

2009-01-01

Carbohydrates were found to have substantial effects on tailoring phase tunable of ionic liquids (ILs) and water. Phase behaviors of 1-alkyl-3-methylimidazolium derivatives [C n mim]X (n = 2 to 10, X = Cl - , Br - , BF 4 - )-carbohydrate-H 2 O were systemically investigated. For hydrophilic ILs, 1-alkyl-3-methylimidazolium tetrafluoroborate [C n mim]BF 4 (n = 3, 4), the homogeneous aqueous solution can be induced to separate two aqueous phases by addition of carbohydrate. For hydrophobic ILs, [C n mim]BF 4 (n = 5 to 10), the mutual solubility with water can be lowered by addition of carbohydrate. While 1-alkyl-3-methyl imidazolium chloride ([C n mim]Cl, n = 2 to 10) and 1-alkyl-3-methyl imidazolium bromide ([C n mim]Br, n = 2 to 10) aqueous solutions never form aqueous two-phase systems (ATPSs) with carbohydrate in the investigated temperatures ranging from (242.15 to 373.15) K. The high partitioning behavior of phenol in [C n mim]BF 4 (n = 3 to 10) (1) + carbohydrate (2) + H 2 O (3) shows that carbohydrate-tailored {IL + H 2 O} systems are feasible to be used as extraction systems, especially in biological and environmental engineering.
Ammonia-water phase diagram and its implications for icy satellites

International Nuclear Information System (INIS)

Johnson, M.L.; Nicol, M.

1986-01-01

A Holzapfel-type diamond anvil cell is used to determine the NH 3 - H 2 O phase diagram in the region from 0 to 33 mole percent NH 3 , 240 to 370 K, and 0 to 5 GPa. The following phases were identified: liquid; water ices Ih, III, V, VI, VII, and VIII; ammonia monohydrate, NH 3 .H 2 O; and ammonia dihydrate NH 3 . 2 H 2 O. Ammonia dihydrate becomes prominent at moderate pressures (less than 1 GPa), with planetologically significant implications, including the possibility of layering in Titan's magma ocean
Warm Water Bath Stimulates Phase-Shifts of the Peripheral Circadian Clocks in PER2::LUCIFERASE Mouse

Science.gov (United States)

Kuriki, Daisuke; Haraguchi, Atsushi; Shibata, Shigenobu

2014-01-01

Circadian clocks in the peripheral tissues of mice are known to be entrained by pulse stimuli such as restricted feeding, novel wheel running, and several other agents. However, there are no reports on high temperature pulse-mediated entrainment on the phase-shift of peripheral clocks in vivo. Here we show that temperature treatment of mice for two days at 41°C, instead of 37°C, for 1–2 h during the inactive period, using a temperature controlled water bath stimulated phase-advance of peripheral clocks in the kidney, liver, and submandibular gland of PER2::LUCIFERASE mice. On the other hand, treatment for 2 days at 35°C ambient room temperature for 2 h did not cause a phase-advance. Maintenance of mice at 41°C in a water bath, sustained the core body temperature at 40–41°C. However, the use of 37°C water bath or the 35°C ambient room temperature elevated the core body temperature to 38.5°C, suggesting that at least a core body temperature of 40–41°C is necessary to cause phase-advance under light-dark cycle conditions. The temperature pulse stimulation at 41°C, instead of 37°C water bath for 2 h led to the elevated expression of Per1 and Hsp70 in the peripheral tissue of mice. In summary, the present study demonstrates that transient high temperature pulse using water bath during daytime causes phase-advance in mouse peripheral clocks in vivo. The present results suggest that hot water bath may affect the phase of peripheral clocks. PMID:24933288
Biological nitrate removal from water and wastewater by solid-phase denitrification process.

Science.gov (United States)

Wang, Jianlong; Chu, Libing

2016-11-01

Nitrate pollution in receiving waters has become a serious issue worldwide. Solid-phase denitrification process is an emerging technology, which has received increasing attention in recent years. It uses biodegradable polymers as both the carbon source and biofilm carrier for denitrifying microorganisms. A vast array of natural and synthetic biopolymers, including woodchips, sawdust, straw, cotton, maize cobs, seaweed, bark, polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polybutylene succinate (PBS) and polylactic acid (PLA), have been widely used for denitrification due to their good performance, low cost and large available quantities. This paper presents an overview on the application of solid-phase denitrification in nitrate removal from drinking water, groundwater, aquaculture wastewater, the secondary effluent and wastewater with low C/N ratio. The types of solid carbon source, the influencing factors, the microbial community of biofilm attached on the biodegradable carriers, the potential adverse effect, and the cost of denitrification process are introduced and evaluated. Woodchips and polycaprolactone are the popular and competitive natural plant-like and synthetic biodegradable polymers used for denitrification, respectively. Most of the denitrifiers reported in solid-phase denitrification affiliated to the family Comamonadaceae in the class Betaproteobacteria. The members of genera Diaphorobacter, Acidovorax and Simplicispira were mostly reported. In future study, more attention should be paid to the simultaneous removal of nitrate and toxic organic contaminants such as pesticide and PPCPs by solid-phase denitrification, to the elucidation of the metabolic and regulatory relationship between decomposition of solid carbon source and denitrification, and to the post-treatment of the municipal secondary effluent. Solid-phase denitrification process is a promising technology for the removal of nitrate from water and wastewater. Copyright © 2016
Determination of phase diagrams via computer simulation: methodology and applications to water, electrolytes and proteins

International Nuclear Information System (INIS)

Vega, C; Sanz, E; Abascal, J L F; Noya, E G

2008-01-01

In this review we focus on the determination of phase diagrams by computer simulation, with particular attention to the fluid-solid and solid-solid equilibria. The methodology to compute the free energy of solid phases will be discussed. In particular, the Einstein crystal and Einstein molecule methodologies are described in a comprehensive way. It is shown that both methodologies yield the same free energies and that free energies of solid phases present noticeable finite size effects. In fact, this is the case for hard spheres in the solid phase. Finite size corrections can be introduced, although in an approximate way, to correct for the dependence of the free energy on the size of the system. The computation of free energies of solid phases can be extended to molecular fluids. The procedure to compute free energies of solid phases of water (ices) will be described in detail. The free energies of ices Ih, II, III, IV, V, VI, VII, VIII, IX, XI and XII will be presented for the SPC/E and TIP4P models of water. Initial coexistence points leading to the determination of the phase diagram of water for these two models will be provided. Other methods to estimate the melting point of a solid, such as the direct fluid-solid coexistence or simulations of the free surface of the solid, will be discussed. It will be shown that the melting points of ice Ih for several water models, obtained from free energy calculations, direct coexistence simulations and free surface simulations agree within their statistical uncertainty. Phase diagram calculations can indeed help to improve potential models of molecular fluids. For instance, for water, the potential model TIP4P/2005 can be regarded as an improved version of TIP4P. Here we will review some recent work on the phase diagram of the simplest ionic model, the restricted primitive model. Although originally devised to describe ionic liquids, the model is becoming quite popular to describe the behavior of charged colloids
Water property lookup table (sanwat) for use with the two-phase computational code shaft

International Nuclear Information System (INIS)

Sherman, M.P.; Eaton, R.R.

1980-10-01

A lookup table for water thermodynamic and transport properties (SANWAT) has been constructed for use with the two-phase computational code, SHAFT. The table, which uses density and specific internal energy as independent variables, covers the liquid, two-phase, and vapor regions. The liquid properties of water are contained in a separate subtable in order to obtain high accuracy for this nearly incompressible region that is frequently encountered in studies of the characteristics of nuclear-waste repositories
Two-phase water movement in unsaturated compacted bentonite under isothermal condition

International Nuclear Information System (INIS)

Takeuchi, Shinji

1994-01-01

Bentonite is considered as one of the most promising buffer materials of engineered barrier system (EBS) for the geological isolation of high level radioactive waste (HLW) in Japan. The EBS may be composed of vitrified waste, overpack and buffer material. In the early stage of setting and backfilling of HLW, a coupled thermal-hydro-mechanical phenomenon may occur in buffer material due to various causes, but water movement may be the most important phenomenon for the coupled process. It is necessary to verify the two-phase movement for the precise modeling of the water movement in unsaturated bentonite. In this study, in order to analyze water movement, the water retention curves and water diffusivity of compacted bentonite were obtained as the functions of water content, dry density and temperature. Also water movement behavior was examined by applying the Philip and de Vries' and Darcy's equations to the obtained water diffusivity. Water potential was measured with a thermocouple psychrometer. The equation for water diffusivity is shown. The measurement of water potential and water diffusivity and the results are reported. (K.I.)
Simulation of Two-Phase Natural Circulation Loop for Core Cather Cooling Using Air Water

International Nuclear Information System (INIS)

Revankar, S. T.; Huang, S. F.; Song, K. W.; Rhee, B. W.; Park, R. J.; Song, J. H.

2012-01-01

A closed loop natural circulation system employs thermally induced density gradients in single phase or two-phase liquid form to induce circulation of the working fluid thereby obviating the need for any mechanical moving parts such as pumps and pump controls. This increases the reliability and safety of the cooling system and reduces installation, operation and maintenance costs. That is the reason natural circulation cooling has been considered in advanced reactor core cooling and in engineered safety systems. Natural circulation cooling has been proposed to remove reactor decay heat by external vessel cooling for in-vessel core retention during sever accident scenario. Recently in APR1400 reactor core catcher design natural circulation cooling is proposed to stabilize and cool the corium ejected from the reactor vessel following core melt and breach of reactor vessel. The natural circulation flow is similar to external vessel cooling where water flows through an inclined narrow gap below hot surface and is heated to produce boiling. The two-phase natural circulation enables cooling of the corium pool collected on core catcher. Due to importance of this problem this paper focuses simulation of the two-phase natural circulation through inclined gap using air-water system. Scaling criteria for air-water loop are derived that enable simulation of the flow regimes and natural circulation flow rates in such systems using air-water system
Mechanisms and modeling development of water transport/phase change in catalyst layers of portion exchange membrane fuel cells

Energy Technology Data Exchange (ETDEWEB)

Xiao, Yexiang [Dept. of Thermal Engineering, Tsinghua University Beijing (China)], email: Yexiang.Xiao@energy.lth.se; Yuan, Jinliang; Sunden, Bengt [Dept. of Energy Sciences, Faculty of Engineering, Lund University (Sweden)], email: Jinliang.yuan@energy.lth.se, email: bengt.sunden@energy.lth.se

2011-07-01

Research on proton exchange membrane fuel cells has shown that incorporation of nanosized catalysts can effectively increase active areas and catalyst activity and make a great contribution to development in performance and catalyst utilization. Multiphase transport processes are as significant and complicated as water generation/transfer processes which occur in nano-structured catalyst layers. A review project has been launched aimed at gaining a comprehensive understanding of the mechanisms of water generation or transport phenomena. It covers catalytic reactions and water-phase change within the catalyst layers. The review proceeds in three main stages: Firstly, it characterizes and reconstructs the nano/micro-structured pores and solid-phases; secondly, it emphasises the importance of sensitive and consistent analysis of various water-phase change and transport schemes; and thirdly, it recommends development of microscopic models for multi-phase transport processes in the pores and the solid phases.
Solid phase extraction of polychlorinated biphenyls from water containing humic substances

Energy Technology Data Exchange (ETDEWEB)

Bonifazi, P.; Pierini, E.; Bruner, F. [Centro di Studio per la Chimica dell`Ambiente e le Tecnologie Strumentali Avanzate dell` Universita degli Studi di Urbino, Ist. di Scienze Chimiche (Italy)

1997-06-01

A study was carried out of the recovery by solid phase extraction of the eleven most toxic polychlorinated biphenyls from water containing humic acids. Experiments were performed using water polluted with a humic acid (sodium salt) concentration of 9-18 mg L{sup -1}. The effect of humic acids on the recoveries was noticeable, especially where the more chlorinated congeners were concerned. The effect was also evident with river water containing naturally dissolved humic acids. A method for destroying humic acids prior to extraction was applied. The recoveries after the destruction of humic acids were in the range of 90%, even in the case of river water, demonstrating the applicability of the method to real samples. (orig.)
Fifty years of solid-phase extraction in water analysis--historical development and overview.

Science.gov (United States)

Liska, I

2000-07-14

The use of an appropriate sample handling technique is a must in an analysis of organic micropollutants in water. The efforts to use a solid phase for the recovery of analytes from a water matrix prior to their detection have a long history. Since the first experimental trials using activated carbon filters that were performed 50 years ago, solid-phase extraction (SPE) has become an established sample preparation technique. The initial experimental applications of SPE resulted in widespread use of this technique in current water analysis and also to adoption of SPE into standardized analytical methods. During the decades of its evolution, chromatographers became aware of the advantages of SPE and, despite many innovations that appeared in the last decade, new SPE developments are still expected in the future. A brief overview of 50 years of the history of the use of SPE in organic trace analysis of water is given in presented paper.
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

Structure-retention and mobile phase-retention relationships for reversed-phase high-performance liquid chromatography of several hydroxythioxanthone derivatives in binary acetonitrile-water mixtures

International Nuclear Information System (INIS)

Amiri, Ali Asghar; Hemmateenejad, Bahram; Safavi, Afsaneh; Sharghi, Hashem; Beni, Ali Reza Salimi; Shamsipur, Mojtaba

2007-01-01

The reversed-phase high-performance liquid chromatographic (RP-HPLC) behavior of some newly synthesized hydroxythioxanthone derivatives using binary acetonitrile-water mixtures as mobile phase has been examined. First, the variation in the retention time of each molecule as a function of mobile phase properties was studied by Kamlet-Taft solvatochromic equations. Then, the influences of molecular structure of the hydroxythioxanthone derivatives on their retention time in various mobile phase mixtures were investigated by quantitative structure-property relationship (QSPR) analysis. Finally, a unified model containing both the molecular structure parameters and mobile phase properties was developed to describe the chromatographic behavior of the systems studied. Among the solvent properties, polarity/polarizability parameter (π * ) and hydrogen-bond basicity (β), and among the solute properties, the most positive local charge (MPC), the sum of positive charges on hydrogen atoms contributing in hydrogen bonding (SPCH) and lipophilicity index (log P) were identified as controlling factors in the RP-HPLC behavior of hydroxythioxanthone derivatives in actonitrile-water binary solvents
Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

Energy Technology Data Exchange (ETDEWEB)

Zhou, Xinquan [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Sun, Xiaodong, E-mail: sun.200@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Liu, Yang [Nuclear Engineering Program, Department of Mechanical Engineering, Virginia Tech, 635 Prices Fork Road, Blacksburg, VA 24061 (United States)

2016-12-15

This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.
Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

International Nuclear Information System (INIS)

Zhou, Xinquan; Sun, Xiaodong; Liu, Yang

2016-01-01

This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.
Multi-Phase Equilibrium and Solubilities of Aromatic Compounds and Inorganic Compounds in Sub- and Supercritical Water: A Review.

Science.gov (United States)

Liu, Qinli; Ding, Xin; Du, Bowen; Fang, Tao

2017-11-02

Supercritical water oxidation (SCWO), as a novel and efficient technology, has been applied to wastewater treatment processes. The use of phase equilibrium data to optimize process parameters can offer a theoretical guidance for designing SCWO processes and reducing the equipment and operating costs. In this work, high-pressure phase equilibrium data for aromatic compounds+water systems and inorganic compounds+water systems are given. Moreover, thermodynamic models, equations of state (EOS) and empirical and semi-empirical approaches are summarized and evaluated. This paper also lists the existing problems of multi-phase equilibria and solubility studies on aromatic compounds and inorganic compounds in sub- and supercritical water.
Diamond cubic phase of monoolein and water as an amphiphilic matrix for electrophoresis of oligonucleotides.

Science.gov (United States)

Carlsson, Nils; Winge, Ann-Sofie; Engström, Sven; Akerman, Björn

2005-10-06

We used a cubic liquid crystal formed by the nonionic monoglyceride monoolein and water as a porous matrix for the electrophoresis of oligonucleotides. The diamond cubic phase is thermodynamically stable when in contact with a water-rich phase, which we exploit to run the electrophoresis in the useful submarine mode. Oligonucleotides are separated according to size and secondary structure by migration through the space-filling aqueous nanometer pores of the regular liquid crystal, but the comparatively slow migration means the cubic phase will not be a replacement for the conventional DNA gels. However, our demonstration that the cubic phase can be used in submarine electrophoresis opens up the possibility for a new matrix for electrophoresis of amphiphilic molecules. From this perspective, the results on the oligonucleotides show that water-soluble particles of nanometer size, typical for the hydrophilic parts of membrane-bound proteins, may be a useful separation motif. A charged contamination in the commercial sample of monoolein, most likely oleic acid that arises from its hydrolysis, restricts useful buffer conditions to a pH below 5.6.
Nuclear plant service water system aging degradation assessment: Phase 1

International Nuclear Information System (INIS)

Jarrell, D.B.; Johnson, A.B. Jr.; Zimmerman, P.W.; Gore, M.L.

1989-06-01

The initial phase of an aging assessment of nuclear power plant service water systems (SWSs) was performed by the Pacific Northwest Laboratory to support the Nuclear Regulatory Commission Nuclear Plant Aging Research (NPAR) program. The SWS was selected for study because of its essential role in the mitigation of and recovery from accident scenarios involving the potential for core-melt. The objectives of the SWS task under the NPAR program are to identify and characterize the principal aging degradation mechanisms relevant to this system and assess their impact on operational readiness, and to provide a methodology for the mitigation of aging on the service water aspect of nuclear plant safety. The first two of these objectives have been met and are covered in this Phase 1 report. A review of available literature and data-base information indicated that motor operated valve torque switches (an electro-mechanical device) were the prime suspect in component service water systems failures. More extensive and detailed data obtained from cooperating utility maintenance records and personnel accounts contradicted this conclusion indicating that biologic and inorganic accumulation and corrosive attack of service water on component surfaces were, in fact, the primary degradation mechanisms. A review of the development of time dependent risk assessment (aging) models shows that, as yet, this methodology has not been developed to a degree where implementation is reliable. Improvements in the accuracy of failure data documentation and time dependent risk analysis methodology should yield significant gains in relating aging phenomena to probabilistic risk assessment. 23 refs., 8 figs., 10 tabs
Phase transitions and phase miscibility of mixed particles of ammonium sulfate, toluene-derived secondary organic material, and water.

Science.gov (United States)

Smith, Mackenzie L; You, Yuan; Kuwata, Mikinori; Bertram, Allan K; Martin, Scot T

2013-09-12

The phase states of atmospheric particles influence their roles in physicochemical processes related to air quality and climate. The phases of particles containing secondary organic materials (SOMs) are still uncertain, especially for SOMs produced from aromatic precursor gases. In this work, efflorescence and deliquescence phase transitions, as well as phase separation, in particles composed of toluene-derived SOM, ammonium sulfate, and water were studied by hygroscopic tandem differential mobility analysis (HTDMA) and optical microscopy. The SOM was produced in the Harvard Environmental Chamber by photo-oxidation of toluene at chamber relative humidities of toluene-derived SOM and aqueous ammonium sulfate, suggesting phase immiscibility between the two. Optical microscopy of particles prepared for ε = 0.12 confirmed phase separation for RH 0.5, the DRH values of ammonium sulfate in mixtures with SOM produced at toluene-derived SOM and aqueous ammonium sulfate across a limited range of organic volume fractions differentiates this SOM from previous reports for isoprene-derived SOM of full miscibility and for α-pinene-derived SOM of nearly full immiscibility with aqueous ammonium sulfate.
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.
Amide-induced phase separation of hexafluoroisopropanol-water mixtures depending on the hydrophobicity of amides.

Science.gov (United States)

Takamuku, Toshiyuki; Wada, Hiroshi; Kawatoko, Chiemi; Shimomura, Takuya; Kanzaki, Ryo; Takeuchi, Munetaka

2012-06-21

Amide-induced phase separation of hexafluoro-2-propanol (HFIP)-water mixtures has been investigated to elucidate solvation properties of the mixtures by means of small-angle neutron scattering (SANS), (1)H and (13)C NMR, and molecular dynamics (MD) simulation. The amides included N-methylformamide (NMF), N-methylacetamide (NMA), and N-methylpropionamide (NMP). The phase diagrams of amide-HFIP-water ternary systems at 298 K showed that phase separation occurs in a closed-loop area of compositions as well as an N,N-dimethylformamide (DMF) system previously reported. The phase separation area becomes wider as the hydrophobicity of amides increases in the order of NMF amides due to the hydrophobic interaction gives rise to phase separation of the mixtures. In contrast, the disruption of HFIP clusters causes the recovery of the homogeneity of the ternary systems. The present results showed that HFIP clusters are evolved with increasing amide content to the lower phase separation concentration in the same mechanism among the four amide systems. However, the disruption of HFIP clusters in the NMP and DMF systems with further increasing amide content to the upper phase separation concentration occurs in a different way from those in the NMF and NMA systems.
Two-phase coolant pump model of pressurized light water nuclear reactors

International Nuclear Information System (INIS)

Santos, G.A. dos; Freitas, R.L.

1990-01-01

The two-phase coolant pump model of pressurized light water nuclear reactors is an important point for the loss of primary coolant accident analysis. The homologous curves set up the complete performance of the pump and are input for accidents analysis thermal-hydraulic codes. This work propose a mathematical model able to predict the two-phase homologous curves where it was incorporated geometric and operational pump condition. The results were compared with the experimental tests data from literature and it has showed a good agreement. (author)
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.
Rate of Isotope Exchange Reaction Between Tritiated Water in a Gas Phase and Water on the Surface of Piping Materials

International Nuclear Information System (INIS)

Nakashio, Nobuyuki; Yamaguchi, Junya; Kobayashi, Ryusuke; Nishikawa, Masabumi

2001-01-01

The system effect of tritium arises from the interaction of tritium in the gas phase with water on the surface of piping materials. It has been reported that the system effect can be quantified by applying the serial reactor model to the piping system and that adsorption and isotope exchange reactions play the main roles in the trapping of tritium. The isotope exchange reaction that occurs when the chemical form of tritium in the gas phase is in the molecular form, i.e., HT or T 2 , has been named isotope exchange reaction 1, and that which occurs when tritium in the gas phase is in water form, i.e., HTO or T 2 O, has been named isotope exchange reaction 2.The rate of isotope exchange reaction 2 is experimentally quantified, and the rate is observed to be about one-third of the rate of adsorption. The trapping and release behavior of tritium from the piping surface due to isotope exchange reaction 2 is also discussed. It is certified that swamping of water vapor to process gas is effective to release tritium from the surface contaminated with tritium
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...
Solid State Transmitters for Water Vapor and Ozone DIAL Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The focus of this Select Phase II program is to build and deliver laser components both for airborne water vapor and ozone DIAL systems. Specifically, Fibertek...
Elemental Water Impact Test: Phase 2 36-Inch Aluminum Tank Head

Science.gov (United States)

Vassilakos, Gregory J.

2014-01-01

Spacecraft are being designed based on LS-DYNA simulations of water landing impacts. The Elemental Water Impact Test (EWIT) series was undertaken to assess the accuracy of LS-DYNA water impact simulations. EWIT Phase 2 featured a 36-inch aluminum tank head. The tank head was outfitted with one accelerometer, twelve pressure transducers, three string potentiometers, and four strain gages. The tank head was dropped from heights of 1 foot and 2 feet. The focus of this report is the correlation of analytical models against test data. As a measure of prediction accuracy, peak responses from the baseline LS-DYNA model were compared to peak responses from the tests.
Interfacial structures of confined air-water two-phase bubbly flow

International Nuclear Information System (INIS)

Kim, S.; Ishii, M.; Wu, Q.; McCreary, D.; Beus, S.G.

2000-01-01

The interfacial structure of the two-phase flows is of great importance in view of theoretical modeling and practical applications. In the present study, the focus is made on obtaining detailed local two-phase parameters in the air-water bubbly flow in a rectangular vertical duct using the double-sensor conductivity probe. The characteristic wall-peak is observed in the profiles of the interracial area concentration and the void fraction. The development of the interfacial area concentration along the axial direction of the flow is studied in view of the interfacial area transport and bubble interactions. The experimental data is compared with the drift flux model with C 0 = 1.35
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
SUPERCRITICAL WATER PARTIAL OXIDATION PHASE I - PILOT-SCALE TESTING / FEASIBILITY STUDIES FINAL REPORT

Energy Technology Data Exchange (ETDEWEB)

SPRITZER,M; HONG,G

2005-01-01

Under Cooperative Agreement No. DE-FC36-00GO10529 for the Department of Energy, General Atomics (GA) is developing Supercritical Water Partial Oxidation (SWPO) as a means of producing hydrogen from low-grade biomass and other waste feeds. The Phase I Pilot-scale Testing/Feasibility Studies have been successfully completed and the results of that effort are described in this report. The Key potential advantages of the SWPO process is the use of partial oxidation in-situ to rapidly heat the gasification medium, resulting in less char formation and improved hydrogen yield. Another major advantage is that the high-pressure, high-density aqueous environment is ideal for reaching and gasifying organics of all types. The high water content of the medium encourages formation of hydrogen and hydrogen-rich products and is especially compatible with high water content feeds such as biomass materials. The high water content of the medium is also effective for gasification of hydrogen-poor materials such as coal. A versatile pilot plant for exploring gasification in supercritical water has been established at GA's facilities in San Diego. The Phase I testing of the SWPO process with wood and ethanol mixtures demonstrated gasification efficiencies of about 90%, comparable to those found in prior laboratory-scale SCW gasification work carreid out at the University of Hawaii at Manoa (UHM) as well as other biomass gasification experience with conventional gasifiers. As in the prior work at UHM, a significant amount of the hydrogen found in the gas phase products is derived from the water/steam matrix. The studies at UHM utilized an indirectly heated gasifier with an acitvated carbon catalyst. In contrast, the GA studies utilized a directly heated gasifier without catalyst, plus a surrogate waste fuel. Attainment of comparable gasification efficiencies without catalysis is an important advancement for the GA process, and opens the way for efficient hydrogen production from low
Water Based Phase Change Material Heat Exchanger Development

Science.gov (United States)

Hansen, Scott W.; Sheth, Ribik B.; Atwell, Matt; Cheek, Ann; Agarwal, Muskan; Hong, Steven; Patel, Aashini,; Nguyen, Lisa; Posada, Luciano

2014-01-01

In a cyclical heat load environment such as low Lunar orbit, a spacecraft’s radiators are not sized to reject the full heat load requirement. Traditionally, a supplemental heat rejection device (SHReD) such as an evaporator or sublimator is used to act as a “topper” to meet the additional heat rejection demands. Utilizing a Phase Change Material (PCM) heat exchanger (HX) as a SHReD provides an attractive alternative to evaporators and sublimators as PCM HXs do not use a consumable, thereby leading to reduced launch mass and volume requirements. Studies conducted in this paper investigate utilizing water’s high latent heat of formation as a PCM, as opposed to traditional waxes, and corresponding complications surrounding freezing water in an enclosed volume. Work highlighted in this study is primarily visual and includes understanding ice formation, freeze front propagation, and the solidification process of water/ice. Various test coupons were constructed of copper to emulate the interstitial pin configuration (to aid in conduction) of the proposed water PCM HX design. Construction of a prototypic HX was also completed in which a flexible bladder material and interstitial pin configurations were tested. Additionally, a microgravity flight was conducted where three copper test articles were frozen continuously during microgravity and 2-g periods and individual water droplets were frozen during microgravity.
Second-law analysis of a two-phase self-pumping solar water heater

International Nuclear Information System (INIS)

Walker, H.A.; Davidson, J.H.

1992-01-01

In this paper entropy generated by operation of a two-phase self-pumping solar water heater under Solar Rating and Certification Corporation rating conditions is computed numerically in a methodology based on an exergy cascade. An order of magnitude analysis shows that entropy generation is dominated by heat transfer across temperature differences. Conversion of radiant solar energy incident on the collector to thermal energy within the collector accounts for 87.1 percent of total entropy generation. Thermal losses are responsible for 9.9 percent of total entropy generation, and heat transfer across the condenser accounts for 2.4 percent of the total entropy generation. Mixing in the tempering valve is responsible for 0.7 percent of the total entropy generation. Approximately one half of the entropy generated by thermal losses is attributable to the self-pumping process. The procedure to determine total entropy generation can be used in a parametric study to evaluate the performance of two-phase hot water heating systems relative to other solar water heating options

Two-phase Flow Ejector as Water Refrigerant by Using Waste Heat

International Nuclear Information System (INIS)

Yamanaka, H; Nakagawa, M

2013-01-01

Energy saving and the use of clean energy sources have recently become significant issues. It is expected that clean energy sources such as solar panels and fuel cells will be installed in many private dwellings. However, when electrical power is generated, exhaust heat is simultaneously produced. Especially for the summer season, the development of refrigeration systems that can use this waste heat is highly desirable. One approach is an ejector that can reduce the mechanical compression work required in a normal refrigeration cycle. We focus on the use of water as a refrigerant, since this can be safely implemented in private dwellings. Although the energy conversion efficiency is low, it is promising because it can use heat that would otherwise be discarded. However, a steam ejector refrigeration cycle requires a large amount of energy to change saturated water into vapour. Thus, we propose a more efficient two-phase flow ejector cycle. Experiments were carried out in which the quality of the two-phase flow from a tank was varied, and the efficiency of the ejector and nozzle was determined. The results show that a vacuum state can be achieved and suction exerted with a two-phase flow state at the ejector nozzle inlet.
Gastric stromal tumor: two-phase dynamic CT findings with water as oral contrast agents

International Nuclear Information System (INIS)

Lee, Se Hyo; Cho, June Sik; Shin, Kyung Sook; Jeong, Ki Ho; Park, Jin Yong; Yu, Ho Jun; Kim, Young Min; Jeon, Kwang Jin

2000-01-01

To evaluate two-phase dynamic CT with water as oral contrast agents in the CT diagnosis of gastric stromal tumors. We retrospectively reviewed the CT findings in 21 patients with pathologically proven gastric stromal tumors. Six were found to be benign, twelve were malignant, and there were three cases of STUMP (stromal tumor uncertain malignant potential). Two-phase dynamic CT scans with water as oral contrast agents were obtained 60-70 secs (portal phase) and 3 mins (equilibrium phase) after the start of IV contrast administration. We determined the size, growth pattern, and enhancement pattern of the tumors and overlying mucosa, the presence or absence of ulceration and necrosis, tumor extent, and lymph nod and distant metastasis. The CT and pathologic findings were correlated. All six benign tumors and three STUMP were less than 5.5 cm in size, and during the portal phase showed round endogastric masses with highly enhanced, intact overlying mucosa. Twelve malignant tumors were 4.5-15.5 cm in size (mean, 11.5 cm); an endogastric mass was seen in three cases, an exogastric mass in one, and a mixed pattern in eight. On portal phase images the tumors were not significantly enhanced, but highly enhanced feeding vessels were noted in five larger tumors (greater than 10 cm). All 12 malignant tumors showed ulceration and necrosis, and interruption of overlying mucosa was clearly seen during the portal phase. We were readily able to evaluate tumor extent during this phase, and in ten malignant tumors there was no invasion of adjacent organs. Seven malignant tumors showed air density within their necrotic portion (p less than 0.05). On equilibrium phase images, all malignant tumors showed heterogeneous enhancement due to necrosis, and poorly enhanced overlying mucosa. Dynamic CT during the portal phase with water as oral contrast agents was useful for depicting the submucosal origin of gastric stromal tumors and for evaluating the extent of malignant stromal tumors. Our
Lake Whitney Comprehensive Water Quality Assessment, Phase 1B- Physical and Biological Assessment (USDOE)

Energy Technology Data Exchange (ETDEWEB)

Doyle, Robert D; Byars, Bruce W

2009-11-24

Baylor University Center for Reservoir and Aquatic Systems Research (CRASR) has conducted a phased, comprehensive evaluation of Lake Whitney to determine its suitability for use as a regional water supply reservoir. The area along the Interstate 35 corridor between Dallas / Fort Worth Metroplex and the Waco / Temple Centroplex represents one of the fastest growth areas in the State of Texas and reliable water supplies are critical to sustainable growth. Lake Whitney is situated midway between these two metropolitan areas. Currently, the City of Whitney as well as all of Bosque and Hill counties obtain their potable water from the Trinity Sands aquifer. Additionally, parts of the adjoining McLennan and Burleson counties utilize the Trinity sands aquifer system as a supplement to their surface water supplies. Population growth coupled with increasing demands on this aquifer system in both the Metroplex and Centroplex have resulted in a rapid depletion of groundwater in these rural areas. The Lake Whitney reservoir represents both a potentially local and regional solution for an area experiencing high levels of growth. Because of the large scope of this project as well as the local, regional and national implications, we have designed a multifaceted approach that will lead to the solution of numerous issues related to the feasibility of using Lake Whitney as a water resource to the region. Phase IA (USEPA, QAPP Study Elements 1-4) of this research focused on the physical limnology of the reservoir (bathymetry and fine scale salinity determination) and develops hydrodynamic watershed and reservoir models to evaluate how salinity would be expected to change with varying hydrologic and climatic factors. To this end, we implemented a basic water quality modeling program in collaboration with the Texas Parks and Wildlife Department and the Texas Commission on Environmental Quality to add to the developing long-term database on Lake Whitney. Finally, we conducted an initial
Phase equilibria of microemulsion forming system n-decyl-(beta)-D-glucopyranoside/water/n-octane/1-butanol

DEFF Research Database (Denmark)

Kahl, Heike; Quitzsch, Konrad; Stenby, Erling Halfdan

1997-01-01

of multicomponent system is the coexistence of a highly structural liquid phase enriched with amphiphilic compounds and an excess water or an excess oil phase or both of them. The phase behaviour was studied experimentally by use of turbidity titration and HPLC measurements and theoretically by application...... of the UNIQUAC-equation and the UNIFAC-method. The UNIFAC-method is able to describe the phase behaviour in the quaternary system qualitatively, without fitting parameters. However, by applying the UNIQUAC-method, with adjustable parameters, it was only possible to model the ternary subsystems. The modelling......A systematic investigation of the phase behaviour involving microemulsions is presented with respect to experimental and calculated data for the four-component system n-decyl-(beta)-D-glucopyranoside/water/n-octane/1-butanol and its corresponding ternaries at 25°C. The main feature of this kind...
Experimental and Analytical Study of Lead-Bismuth-Water Direct Contact Boiling Two-Phase Flow

Science.gov (United States)

Novitrian; Dostal, Vaclav; Takahashi, Minoru

The characteristics of lead-bismuth(Pb-Bi)-water boiling two-phase flow were investigated experimentally and analytically using a Pb-Bi-water direct contact boiling two-phase flow loop. Pb-Bi flow rates and void fraction were measured in a vertical circular tube at conditions of system pressure 7MPa, liquid metal temperature 460°C and injected water temperature 220°C. The drift-flux model with the assumption that bubble sizes were dependent on the fluid surface tension and the density ratio of Pb-Bi to steam-water mixture was chosen and modified by the best fit to the measured void fraction. Pb-Bi flow rates were analytically estimated using balance condition between buoyancy force and pressure losses, where the buoyancy force was calculated from void fraction estimated using the modified drift-flux model. The deviation of the analytical results of the flow rates from the experimental ones was less than 10%.
Thermodynamic modelling of phase equilibrium for water + poly(Ethylene glycol + salt aqueous two-phase systems

Directory of Open Access Journals (Sweden)

R.A.G. Sé

2002-04-01

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

Science.gov (United States)

Chirkin, V. A.; Karpov, S. I.; Selemenev, V. F.

2012-12-01

The thermodynamics of the sorption of certain water-soluble vitamins on a C18 reverse phase from water-acetonitrile solutions of different compositions is studied. The thermodynamic characteristics of the investigated chromatographic systems are calculated. The dependences of standard molar enthalpy and changes in entropy when the sorbate transfers from the bulk solution to the surface layer on the concentration of the organic component in the mobile phase are analyzed. The boundaries for applying the main retention models describing the sorption of the investigated compounds are discussed.
Interfacial structures of confined air-water two-phase bubbly flow

Energy Technology Data Exchange (ETDEWEB)

Kim, S.; Ishii, M.; Wu, Q.; McCreary, D.; Beus, S.G.

2000-08-01

The interfacial structure of the two-phase flows is of great importance in view of theoretical modeling and practical applications. In the present study, the focus is made on obtaining detailed local two-phase parameters in the air-water bubbly flow in a rectangular vertical duct using the double-sensor conductivity probe. The characteristic wall-peak is observed in the profiles of the interracial area concentration and the void fraction. The development of the interfacial area concentration along the axial direction of the flow is studied in view of the interfacial area transport and bubble interactions. The experimental data is compared with the drift flux model with C{sub 0} = 1.35.
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.
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
Water Use Optimization Toolset Project: Development and Demonstration Phase Draft Report

Energy Technology Data Exchange (ETDEWEB)

Gasper, John R. [Argonne National Laboratory; Veselka, Thomas D. [Argonne National Laboratory; Mahalik, Matthew R. [Argonne National Laboratory; Hayse, John W. [Argonne National Laboratory; Saha, Samrat [Argonne National Laboratory; Wigmosta, Mark S. [PNNL; Voisin, Nathalie [PNNL; Rakowski, Cynthia [PNNL; Coleman, Andre [PNNL; Lowry, Thomas S. [SNL

2014-05-19

This report summarizes the results of the development and demonstration phase of the Water Use Optimization Toolset (WUOT) project. It identifies the objective and goals that guided the project, as well as demonstrating potential benefits that could be obtained by applying the WUOT in different geo-hydrologic systems across the United States. A major challenge facing conventional hydropower plants is to operate more efficiently while dealing with an increasingly uncertain water-constrained environment and complex electricity markets. The goal of this 3-year WUOT project, which is funded by the U.S. Department of Energy (DOE), is to improve water management, resulting in more energy, revenues, and grid services from available water, and to enhance environmental benefits from improved hydropower operations and planning while maintaining institutional water delivery requirements. The long-term goal is for the WUOT to be used by environmental analysts and deployed by hydropower schedulers and operators to assist in market, dispatch, and operational decisions.
Theoretical investigation of flow regime for boiling water two-phase flow in horizontal rectangular narrow channels

International Nuclear Information System (INIS)

Zhang Chunwei; Qiu Suizheng; Yan Mingyu; Wang Bulei; Nie Changhua

2005-01-01

The flow regime transition criteria for the boiling water two-phase flow in horizontal rectangular narrow channels (1 x 20 mm, 2 x 20 mm) were theoretically explored. The discernible flow patterns were bubble, intermittent slug, churn, annular and steam-water separation flow. By using two-fluid model, equations of conservation of momentum were established for the two-phase flow. New flow-regime criteria were obtained and agreed well with the experiment data. (authors)
[Detecting Thallium in Water Samples using Dispersive Liquid Phase Microextraction-Graphite Furnace Atomic Absorption Spectroscopy].

Science.gov (United States)

Zhu, Jing; Li, Yan; Zheng, Bo; Tang, Wei; Chen, Xiao; Zou, Xiao-li

2015-11-01

To develope a method of solvent demulsification dispersive liquid phase microextraction (SD-DLPME) based on ion association reaction coupled with graphite furnace atomic absorption spectroscopy (GFAAS) for detecting thallium in water samples. Methods Thallium ion in water samples was oxidized to Tl(III) with bromine water, which reacted with Cl- to form TlCl4-. The ionic associated compound with trioctylamine was obtained and extracted. DLPME was completed with ethanol as dispersive solvent. The separation of aqueous and organic phase was achieved by injecting into demulsification solvent without centrifugation. The extractant was collected and injected into GFAAS for analysis. With palladium colloid as matrix modifier, a two step drying and ashing temperature programming process was applied for high precision and sensitivity. The linear range was 0.05-2.0 microg/L, with a detection limit of 0.011 microg/L. The relative standard derivation (RSD) for detecting Tl in spiked water sample was 9.9%. The spiked recoveries of water samples ranged from 94.0% to 103.0%. The method is simple, sensitive and suitable for batch analysis of Tl in water samples.
Use of gas-phase ethanol to mitigate extreme UV/water oxidation of extreme UV optics

Science.gov (United States)

Klebanoff, L. E.; Malinowski, M. E.; Clift, W. M.; Steinhaus, C.; Grunow, P.

2004-03-01

A technique is described that uses a gas-phase species to mitigate the oxidation of a Mo/Si multilayer optic caused by either extreme UV (EUV) or electron-induced dissociation of adsorbed water vapor. It is found that introduction of ethanol (EtOH) into a water-rich gas-phase environment inhibits oxidation of the outermost Si layer of the Mo/Si EUV reflective coating. Auger electron spectroscopy, sputter Auger depth profiling, EUV reflectivity, and photocurrent measurements are presented that reveal the EUV/water- and electron/water-derived optic oxidation can be suppressed at the water partial pressures used in the tests (~2×10-7-2×10-5 Torr). The ethanol appears to function differently in two time regimes. At early times, ethanol decomposes on the optic surface, providing reactive carbon atoms that scavenge reactive oxygen atoms before they can oxidize the outermost Si layer. At later times, the reactive carbon atoms form a thin (~5 Å), possibly self-limited, graphitic layer that inhibits water adsorption on the optic surface. .
Artificial neural network modelling of retention of pesticides in various octadecylsiloxane-bonded reversed-phase columns and water-acetonitrile mobile phase

Energy Technology Data Exchange (ETDEWEB)

D' Archivio, Angelo Antonio, E-mail: angeloantonio.darchivio@univaq.it [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy); Maggi, Maria Anna; Mazzeo, Pietro; Ruggieri, Fabrizio [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy)

2009-07-30

Previously, retention of 26 pesticides in the reversed-phase column Gemini (Phenomenex) and water-acetonitrile mobile phase was modelled using a feed-forward artificial neural network (ANN) learned by error back-propagation, accounting for both the effect of solute structure and mobile phase composition. To this end, log K{sub ow} of solutes and four quantum chemical molecular descriptors (the dipole moment, the mean polarizability, the anisotropy of the polarizability and an hydrogen-bonding descriptor based on the atomic charges located on the acid and basic functional groups) and acetonitrile % (v/v) in the eluent (%ACN) were used as ANN inputs. The above ANN-based approach is here tested on further five similar octadecylsiloxane-bonded columns in water-acetonitrile mobile phase within the %ACN range 30-70%. A quite good predictive performance evaluated on three external solutes in the whole %ACN range is observed, prediction errors being lower than {+-}0.1 log k units or slightly higher although still within {+-}0.15 log k units. On the other hand, multilinear regression used in place of ANN provides a more diffuse and non-uniform residual distribution for all the investigated columns. ANN multiple-column retention prediction is attempted by adding to the above variables a column descriptor defined as the average retention of calibration solutes extrapolated to 100% water. This more general model is built using 16 solutes and five 5-{mu}m columns in calibration, while its predictive performance is tested on the remaining 10 compounds. Under these conditions, prediction errors are generally within {+-}0.2 log k units regardless of the kind of column. The possibility of cross-column prediction is evaluated by column leave-one-out cross-validation within the five 5-{mu}m stationary phases and on a 4-{mu}m external column. This analysis reveals that accuracy of retention prediction for unknown solutes in unknown columns is acceptable provided that the external
Artificial neural network modelling of retention of pesticides in various octadecylsiloxane-bonded reversed-phase columns and water-acetonitrile mobile phase

International Nuclear Information System (INIS)

D'Archivio, Angelo Antonio; Maggi, Maria Anna; Mazzeo, Pietro; Ruggieri, Fabrizio

2009-01-01

Previously, retention of 26 pesticides in the reversed-phase column Gemini (Phenomenex) and water-acetonitrile mobile phase was modelled using a feed-forward artificial neural network (ANN) learned by error back-propagation, accounting for both the effect of solute structure and mobile phase composition. To this end, log K ow of solutes and four quantum chemical molecular descriptors (the dipole moment, the mean polarizability, the anisotropy of the polarizability and an hydrogen-bonding descriptor based on the atomic charges located on the acid and basic functional groups) and acetonitrile % (v/v) in the eluent (%ACN) were used as ANN inputs. The above ANN-based approach is here tested on further five similar octadecylsiloxane-bonded columns in water-acetonitrile mobile phase within the %ACN range 30-70%. A quite good predictive performance evaluated on three external solutes in the whole %ACN range is observed, prediction errors being lower than ±0.1 log k units or slightly higher although still within ±0.15 log k units. On the other hand, multilinear regression used in place of ANN provides a more diffuse and non-uniform residual distribution for all the investigated columns. ANN multiple-column retention prediction is attempted by adding to the above variables a column descriptor defined as the average retention of calibration solutes extrapolated to 100% water. This more general model is built using 16 solutes and five 5-μm columns in calibration, while its predictive performance is tested on the remaining 10 compounds. Under these conditions, prediction errors are generally within ±0.2 log k units regardless of the kind of column. The possibility of cross-column prediction is evaluated by column leave-one-out cross-validation within the five 5-μm stationary phases and on a 4-μm external column. This analysis reveals that accuracy of retention prediction for unknown solutes in unknown columns is acceptable provided that the external column is not very
Solid phase extraction for the speciation and preconcentration of inorganic selenium in water samples: a review.

Science.gov (United States)

Herrero Latorre, C; Barciela García, J; García Martín, S; Peña Crecente, R M

2013-12-04

Selenium is an essential element for the normal cellular function of living organisms. However, selenium is toxic at concentrations of only three to five times higher than the essential concentration. The inorganic forms (mainly selenite and selenate) present in environmental water generally exhibit higher toxicity (up to 40 times) than organic forms. Therefore, the determination of low levels of different inorganic selenium species in water is an analytical challenge. Solid-phase extraction has been used as a separation and/or preconcentration technique prior to the determination of selenium species due to the need for accurate measurements for Se species in water at extremely low levels. The present paper provides a critical review of the published methods for inorganic selenium speciation in water samples using solid phase extraction as a preconcentration procedure. On the basis of more than 75 references, the different speciation strategies used for this task have been highlighted and classified. The solid-phase extraction sorbents and the performance and analytical characteristics of the developed methods for Se speciation are also discussed. Copyright © 2013 Elsevier B.V. All rights reserved.
Examination of water phase transitions in Loblolly pine and cell wall components by differential scanning calorimetry

Science.gov (United States)

Samuel L. Zelinka; Michael J. Lambrecht; Samuel V. Glass; Alex C. Wiedenhoeft; Daniel J. Yelle

2012-01-01

This paper examines phase transformations of water in wood and isolated wood cell wall components using differential scanning calorimetry with the purpose of better understanding "Type II water" or "freezable bound water" that has been reported for cellulose and other hydrophilic polymers. Solid loblolly pine (Pinus taeda...
Supercritical fluid chromatographic resolution of water soluble isomeric carboxyl/amine terminated peptides facilitated via mobile phase water and ion pair formation.

Science.gov (United States)

Patel, M A; Riley, F; Ashraf-Khorassani, M; Taylor, L T

2012-04-13

Both analytical scale and preparative scale packed column supercritical fluid chromatography (SFC) have found widespread applicability for chiral separations of multiple polar pharmaceutical candidates. However, SFC is rapidly becoming an achiral technique. More specifically, ion pair SFC is finding greater utility for separation of ionic analytes such as amine salts and organic sulfonates. The key to this success is, in part, the incorporation of additives such as trifluoroacetic acid and ammonium acetate into the mobile phase in association with a wide variety of both bonded silica stationary phases and high purity bare silica. Ion pairing SFC coupled with evaporative light scattering detection and mass spectrometric detection is presented here for the separation of water soluble, uncapped, isomeric peptide pairs that differ in amino acid arrangement. The separation is best achieved on either diol-bonded silica or bare silica with 1-5% (w/w) water as a significant ingredient in the mobile phase. Nitrogenous stationary phases such as 2-ethylpyridine, which had been very successful for the separation of capped peptides failed to yield the desired separation regardless of the mobile phase composition. A HILIC type retention mechanism is postulated for the separation of both isomeric uncapped peptide pairs. Copyright © 2012 Elsevier B.V. All rights reserved.
A FTIR study water in membrane of nitrocellulose prepared by phase inversion

International Nuclear Information System (INIS)

Benosmane, N.; Boutemeur, B.; Hamdi, M.

2004-01-01

Full text.Cellulose derivates were the first biopolymers used to produce synthesis membranes for technical applications, in this study the state of water in asymmetric membrane of nitrocellulose, prepared by the phase inversion process, was investigated using infrared spectroscopy (FTIR), after membrane preparation by the wet inversion process in acetone, the spectre FTIR of wet asymmetric membrane of nitrocellulose after immersion in water (after one week) is compared to the spectre of dried asymmetric membrane of nitrocellulose, the difference in spectre of dried and wet membrane indicate a weakly hydrogen-bonded to the polymer hydroxyl groups between water and hydroxyl groups in surface of membrane, the results demonstrate the amount of water species present in the surface of asymmetric membrane and heterogeneous of surface

Three-phase flow (water, oil and gas in a vertical circular cylindrical duct with leaks: A theoretical study

Directory of Open Access Journals (Sweden)

W Santos

2016-10-01

Full Text Available This article describes the fluid dynamic behavior of a three-phase flow (water-oil-natural gas in a vertical pipe with or without leakage. The studied pipe has 8 meters in length, circular cross-section with 25 cm in diameter and a leak, which hole has a circular shape with 10mm diameter located in the center of pipe. The conservation equations of mass, momentum and energy for each phase (continuous phase - oil, dispersed phases - gas and water were numerically solved using ANSYS CFX software, in which the Eulerian-Eulerian model and the RNG - turbulence model were applied. Results of the pressure, velocity, temperature and volume fraction distributions of the involved phases are present and analyzed.
Feasibility study of the water Cherenkov detector as a D-T fusion power monitor in the system using neutron activation of flowing water. First experimental phase

International Nuclear Information System (INIS)

Verzilov, Yury M.; Ochiai, Kentaro; Nishitani, Takeo

2003-09-01

The technique of monitoring D-T neutrons using water flow is based on the reaction of the 16 O(n, p) 16 N. In order to significantly improve the D-T neutron monitoring system in the ITER reactor in comparison with the system that uses a γ-ray scintillation detector, a new approach was proposed. The basic idea of this approach is to utilize the Cherenkov light, produced by energetic β-particles from 16 N in water near the first wall of the fusion reactor, and then deliver the light by the optical fiber to the remote light detector. The proof of the principle experiment is divided into two phases. The main idea of the first experimental phase is to examine Cherenkov light measurements using a remotely located water and light detector. During the second phase the water radiator will be placed next to the neutron source, then the Cherenkov light will be transferred by an optical fiber to the remotely located light detector. For the purpose of the first experimental phase, a water Cherenkov detector was installed in the shielded measurement room. A closed water loop, with circulating water, was used to transport 16 N from the D-T source to the Cherenkov detector. The experiment was carried out at FNS/JAERI, with the accelerator set to a direct current mode, the source neutron yield around 2 x 10 11 n/s, and the water flowage approximately 2 m/s. The registered Cherenkov signal was identified as the light produced by β-particles from 16 N using the time decay and the energy spectra data. According to the present study, the water Cherenkov detector is very effective for measurements of the 16 N activity, due to high counting efficiency, absence of the scintillation detector and simplicity of the method. (author)
Measurement and Modelling of Phase Equilibrium of Oil - Water - Polar Chemicals

DEFF Research Database (Denmark)

Frost, Michael Grynnerup

in the temperature range of 303-323 K at atmospheric pressure. In the second part of this work, the CPA EoS has been used for modeling hydrocarbon systemcontaining polar chemicals, such as water and gas hydrate inhibitor MEG or methanol. All the experimental data measured in this work have been investigated using...... with the measurement of newexperimental data, but through the development of new experimental equipment for the study ofmulti-phase equilibrium. In addition to measurement of well-defined systems, LLE have beenmeasured for North Sea oils with MEG and water. The work can be split up into two parts: Experimental: VLE...... systems presented, confirming the quality of theequipment. The equipment is used for measurement of VLE for several systems of interest; methane+ water, methane + methanol, methane + methanol + water and methane + MEG. Details dealing with the design, assembling and testing of new experimental equipment...
Multi-Scale Long-Range Magnitude and Sign Correlations in Vertical Upward Oil-Gas-Water Three-Phase Flow

Science.gov (United States)

Zhao, An; Jin, Ning-de; Ren, Ying-yu; Zhu, Lei; Yang, Xia

2016-01-01

In this article we apply an approach to identify the oil-gas-water three-phase flow patterns in vertical upwards 20 mm inner-diameter pipe based on the conductance fluctuating signals. We use the approach to analyse the signals with long-range correlations by decomposing the signal increment series into magnitude and sign series and extracting their scaling properties. We find that the magnitude series relates to nonlinear properties of the original time series, whereas the sign series relates to the linear properties. The research shows that the oil-gas-water three-phase flows (slug flow, churn flow, bubble flow) can be classified by a combination of scaling exponents of magnitude and sign series. This study provides a new way of characterising linear and nonlinear properties embedded in oil-gas-water three-phase flows.
Carrier phase altimetry using Zeppelin based GNSS-R observations and water gauge reference data

Science.gov (United States)

Semmling, Maximilian; Schön, Steffen; Beckheinrich, Jamila; Beyerle, Georg; Ge, Maorong; Wickert, Jens

2014-05-01

The increasing number of transmitters in global navigation satellite systems (GNSS), like GPS, Galileo, Glonass or Compass, provide observations with an increasing coverage for positioning but also for remote sensing. A space based GNSS remote sensing application is radio occultation, a limb sounding method. Globally distributed vertical profiles of temperature, water vapour and electron density are provided operationally for weather forecast and ionospheric monitoring. Another application is GNSS reflectometry (GNSS-R) that is currently developed especially for ocean remote sensing. The high reflection coefficient of water is crucial for GNSS-R. This study presents a method that uses GNSS phase observations for lake altimetry with the potential for ocean application. Phase observations are deduced from a GORS (GNSS Occultaction Reflectometry Scatterometry) receiver in Master-Slave-Configuration. The Master sampling dedicated for direct signal acquisition is connected to an up-looking antenna with right hand circular polarization (RHCP). Two Slave samplings dedicated for acquisition of the reflected signals are connected to down-looking antennas with right- and left-hand circular polarization (RHCP and LHCP). Based on in-phase and quad-phase (I, Q) sample components, an altimetric phase residual is retrieved. This residual can be related to the height of the reflecting surface. An altimetric challenge arises from the unknown ambiguity of phase residuals that introduces a height bias. The presented study uses ancillary data deduced from water gauges to mitigate the ambiguity bias. Reference tracks are formed by linear surface height interpolation between the water gauge stations. At crossover points of reflection tracks with reference tracks a phase ambiguity estimate is determined for bias mitigation. For this study airborne GNSS measurements were conducted aboard a Zeppelin NT (New Technology) airship with a geodetic receiver for navigation and a GORS receiver for
Variability of phase and amplitude fronts due to horizontal refraction in shallow water.

Science.gov (United States)

Katsnelson, Boris G; Grigorev, Valery A; Lynch, James F

2018-01-01

The variability of the interference pattern of a narrow-band sound signal in a shallow water waveguide in the horizontal plane in the presence of horizontal stratification, in particular due to linear internal waves, is studied. It is shown that lines of constant phase (a phase front) and lines of constant amplitude/envelope (an amplitude front) for each waveguide mode may have different directions in the spatial vicinity of the point of reception. The angle between them depends on the waveguide's parameters, the mode number, and the sound frequency. Theoretical estimates and data processing methodology for obtaining these angles from experimental data recorded by a horizontal line array are proposed. The behavior of the angles, which are obtained for two episodes from the Shallow Water 2006 (SW06) experiment, show agreement with the theory presented.
Phase equilibrium study of the binary systems (N-hexyl-3-methylpyridinium tosylate ionic liquid + water, or organic solvent)

International Nuclear Information System (INIS)

Domanska, Urszula; Krolikowski, Marek

2011-01-01

Highlights: → Synthesis, DSC, and measurements of phase equilibrium of N-hexyl-3-methylpyridinium tosylate. → Solvents used: water, alcohols, benzene, alkylbenzenes, and aliphatic hydrocarbons. → Correlation with UNIQUAC, Wilson and NRTL models. → Comparison with different tosylate-based ILs. - Abstract: The (solid + liquid) phase equilibrium (SLE) and (liquid + liquid) phase equilibrium (LLE) for the binary systems ionic liquid (IL) N-hexyl-3-methylpyridinium tosylate (p-toluenesulfonate), {([HM 3 Py][TOS] + water, or an alcohol (1-butanol, or 1-hexanol, or 1-octanol, or 1-decanol), or an aromatic hydrocarbon (benzene, toluene, or ethylbenzene, or propylbenzene), or an alkane (n-hexane, n-heptane, n-octane)} have been determined at ambient pressure using a dynamic method. Simple eutectic systems with complete miscibility in the liquid phase were observed for the systems involving water and alcohols. The phase equilibrium diagrams of IL and aromatic or aliphatic hydrocarbons exhibit eutectic systems with immiscibility in the liquid phase with an upper critical solution temperature as for most of the ILs. The correlation of the experimental data has been carried out using the UNIQUAC, Wilson and the non-random two liquid (NRTL) correlation equations. The results reported here have been compared with analogous phase diagrams reported by our group previously for systems containing the tosylate-based ILs.
Phase I: the pipeline-gas demonstration plant. Demonstration plant engineering and design. Volume 18. Plant Section 2700 - Waste Water Treatment

Energy Technology Data Exchange (ETDEWEB)

None

1981-05-01

Contract No. EF-77-C-01-2542 between Conoco Inc. and the US Department of Energy provides for the design, construction, and operation of a demonstration plant capable of processing bituminous caking coals into clean pipeline quality gas. The project is currently in the design phase (Phase I). This phase is scheduled to be completed in June 1981. One of the major efforts of Phase I is the process and project engineering design of the Demonstration Plant. The design has been completed and is being reported in 24 volumes. This is Volume 18 which reports the design of Plant Section 2700 - Waste Water Treatment. The objective of the Waste Water Treatment system is to collect and treat all plant liquid effluent streams. The system is designed to permit recycle and reuse of the treated waste water. Plant Section 2700 is composed of primary, secondary, and tertiary waste water treatment methods plus an evaporation system which eliminates liquid discharge from the plant. The Waste Water Treatment Section is designed to produce 130 pounds per hour of sludge that is buried in a landfill on the plant site. The evaporated water is condensed and provides a portion of the make-up water to Plant Section 2400 - Cooling Water.
The structure of a lipid-water lamellar phase containing two types of lipid monolayers

International Nuclear Information System (INIS)

Ranck, J.L.; Luzzati, V.; Zaccai, G.

1980-01-01

One lamellar phase, observed in the mitochondrial lipids-water system at low temperature (ca 253 K) and at low water content (ca 15%), contains four lipid monolayers in its unit cell, two of type α and two of type β. Previous X-ray scattering studies of this phase led to an ambiguity: the phase could contain either two homogeneous bilayers, one α and one β, or two mixed bilayers, each formed by an α and a β monolayer. A solution to this problem was sought in a neutron scattering study as a function of the D 2 O/H 2 O ratio. Because of limited resolution, straightforward analysis of the neutron scattering data leads also to ambiguous results. Using a more sophisticated analysis based upon the zeroth- and second-order moments of the Patterson peaks relevant to the exchangeable components, it is shown that the weight of the evidence is in favour of a structure containing mixed bilayers. (Auth.)
Heat transfer to air-water two-phase flow in slug/churn region

International Nuclear Information System (INIS)

Wadekar, V.V.; Tuzla, K.; Chen, J.C.

1996-01-01

Measured heat transfer data for air-water two-phase flow in the slug/churn flow region are reported. The measurements were obtained from a 1.3 m tall, 15.7 mm diameter vertical tube test-section. It is observed that the data exhibit different heat transfer characteristics to those predicted by the standard correlations for the convective component of flow boiling heat transfer. Comparison with the predictions of a slug flow model for evaporation shows a significant overprediction of the data. The reason for the overprediction is attributed to the sensible heating requirement of the gas phase. The slug flow model is therefore suitably modified for non-evaporating two-phase flow. This specially adapted model is found to give reasonably good predictions of the measured data
Individual extraction constants of some univalent cations in the two-phase water-phenyltrifluoromethyl sulfone system

International Nuclear Information System (INIS)

Makrlik, E.

2011-01-01

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M + (aq) + Cs + (org) ↔ M + (org) + Cs + (aq) taking place in the two-phase water-phenyltrifluoromethyl sulfone (abbrev. FS 13) system (M + Li + , H 3 O + , Na + , NH 4 + , Ag + , Tl + , K + , Rb + ; aq = aqueous phase, org FS 13 phase) were evaluated. Furthermore, the individual extraction constants of the M + cations in the mentioned two-phase system were calculated; they were found to increase in the series of Li + 3 O + + 4 + + + + + + . (author)
Water treatment system for utilities: Phase 1 -- Technology assessment. Interim report

International Nuclear Information System (INIS)

Janss, T.M.; Tucker, R.E.

1997-12-01

A conceptual design for a water treatment system to reduce pollutants in manhole and vault water is presented as an alternative to current water disposal practices. Runoff and groundwater seepage that collects in vaults and manholes contains, or is likely to contain, concentrations of pollutants in excess of regulatory guidelines. Pollutants commonly present in storm water runoff consist of lead, cadmium, oil, grease and asbestos. The conceptual design presents the basis for a water treatment system that will reduce pollutant concentrations to levels below regulatory thresholds. The water treatment system is relatively inexpensive, small and simple to operate. A strainer is used to remove gross particulates, which are then stored for disposal. Utilizing centrifugal force, vault and manhole water is separated into constituent fractions including fine particulates, inorganics and oils. Fine particulates are stored with gross particulates for disposal. Chemical fixation is used to stabilize inorganics. Organic substances are stored for disposal. The water treatment system uses a granular activated carbon filter as an effluent polish to adsorb the remaining pollutants from the effluent water stream. The water can be discharged to the street or storm drain and the pollutants are stored for disposal as non-hazardous waste. This system represents a method to reduce pollutant volumes, reduced disposal costs and reduce corporate environmental liability. It should be noted that the initial phase of the development process is still in progress. This report is presented to reflect work in progress and as such should be considered preliminary
Efficient quantification of water content in edible oils by headspace gas chromatography with vapour phase calibration.

Science.gov (United States)

Xie, Wei-Qi; Gong, Yi-Xian; Yu, Kong-Xian

2018-06-01

An automated and accurate headspace gas chromatographic (HS-GC) technique was investigated for rapidly quantifying water content in edible oils. In this method, multiple headspace extraction (MHE) procedures were used to analyse the integrated water content from the edible oil sample. A simple vapour phase calibration technique with an external vapour standard was used to calibrate both the water content in the gas phase and the total weight of water in edible oil sample. After that the water in edible oils can be quantified. The data showed that the relative standard deviation of the present HS-GC method in the precision test was less than 1.13%, the relative differences between the new method and a reference method (i.e. the oven-drying method) were no more than 1.62%. The present HS-GC method is automated, accurate, efficient, and can be a reliable tool for quantifying water content in edible oil related products and research. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.
Multivariate multiscale complex network analysis of vertical upward oil-water two-phase flow in a small diameter pipe.

Science.gov (United States)

Gao, Zhong-Ke; Yang, Yu-Xuan; Zhai, Lu-Sheng; Dang, Wei-Dong; Yu, Jia-Liang; Jin, Ning-De

2016-02-02

High water cut and low velocity vertical upward oil-water two-phase flow is a typical complex system with the features of multiscale, unstable and non-homogenous. We first measure local flow information by using distributed conductance sensor and then develop a multivariate multiscale complex network (MMCN) to reveal the dispersed oil-in-water local flow behavior. Specifically, we infer complex networks at different scales from multi-channel measurements for three typical vertical oil-in-water flow patterns. Then we characterize the generated multiscale complex networks in terms of network clustering measure. The results suggest that the clustering coefficient entropy from the MMCN not only allows indicating the oil-in-water flow pattern transition but also enables to probe the dynamical flow behavior governing the transitions of vertical oil-water two-phase flow.
Inlet effects on vertical-downward air–water two-phase flow

Energy Technology Data Exchange (ETDEWEB)

Qiao, Shouxu; Mena, Daniel; Kim, Seungjin, E-mail: skim@psu.edu

2017-02-15

Highlights: • Inlet effects on two-phase flow parameters in vertical-downward flow are studied. • Flow regimes in the vertical-downward two-phase flow are defined. • Vertical-downward flow regime maps for three inlet configurations are developed. • Frictional pressure loss analysis for three different inlets is performed. • Database of local two-phase flow parameters for each inlet configuration. - Abstract: This paper focuses on investigating the geometric effects of inlets on global and local two-phase flow parameters in vertical-downward air–water two-phase flow. Flow visualization, frictional pressure loss analysis, and local experiments are performed in a test facility constructed from 50.8 mm inner diameter acrylic pipes. Three types of inlets of interest are studied: (1) two-phase flow injector without a flow straightener (Type A), (2) two-phase flow injector with a flow straightener (Type B), and (3) injection through a horizontal-to-vertical-downward 90° vertical elbow (Type C). A detailed flow visualization study is performed to characterize flow regimes including bubbly, slug, churn-turbulent, and annular flow. Flow regime maps for each inlet are developed and compared to identify the effects of each inlet. Frictional pressure loss analysis shows that the Lockhart–Martinelli method is capable of correlating the frictional loss data acquired for Type B and Type C inlets with a coefficient value of C = 25, but additional data may be needed to model the Type A inlet. Local two-phase flow parameters measured by a four-sensor conductivity probe in four bubbly and near bubbly flow conditions are analyzed. It is observed that vertical-downward two-phase flow has a characteristic center-peaked void profile as opposed to a wall-peaked profile as seen in vertical-upward flow. Furthermore, it is shown that the Type A inlet results in the most pronounced center-peaked void fraction profile, due to the coring phenomenon. Type B and Type C inlets
Loss of Propiconazole and Its Four Stereoisomers from the Water Phase of Two Soil-Water Slurries as Measured by Capillary Electrophoresis

Directory of Open Access Journals (Sweden)

Rebecca D. Miller

2011-08-01

Full Text Available Propiconazole is a chiral fungicide used in agriculture for control of many fungal diseases on a variety of crops. This use provides opportunities for pollution of soil and, subsequently, groundwater. The rate of loss of propiconazole from the water phase of two different soil-water slurries spiked with the fungicide at 50 mg/L was followed under aerobic conditions over five months; the t1/2 was 45 and 51 days for the two soil slurries. To accurately assess environmental and human risk, it is necessary to analyze the separate stereoisomers of chiral pollutants, because it is known that for most such pollutants, both biotransformation and toxicity are likely to be stereoselective. Micellar electrokinetic chromatography (MEKC, the mode of capillary electrophoresis used for analysis of neutral chemicals, was used for analysis of the four propiconazole stereoisomers with time in the water phase of the slurries. MEKC resulted in baseline separation of all stereoisomers, while GC-MS using a chiral column gave only partial separation. The four stereoisomers of propiconazole were lost from the aqueous phase of the slurries at experimentally equivalent rates, i.e., there was very little, if any, stereoselectivity. No loss of propiconazole was observed from the autoclaved controls of either soil, indicating that the loss from active samples was most likely caused by aerobic biotansformation, with a possible contribution by sorption to the non-autoclaved active soils. MEKC is a powerful tool for separation of stereoisomers and can be used to study the fate and transformation kinetics of chiral pesticides in water and soil.
Experimental study of flow monitoring instruments in air-water, two-phase downflow

International Nuclear Information System (INIS)

Sheppard, J.D.; Hayes, P.H.; Wynn, M.C.

1976-01-01

The performance of a turbine meter, target flow meter (drag disk), and a gamma densitometer was studied in air-water, two-phase vertical downflow. Air and water were metered into an 0.0889-m-ID (3.5-in.) piping system; air flows ranged from 0.007 to 0.3 m 3 /sec (16 to 500 scfm) and water flows ranged from 0.0006 to 0.03 m 3 /sec (10 to 500 gpm). The study included effects of flow rate, quality, flow regime, and flow dispersion on the mean and fluctuating components of the instrument signals. Wire screen flow dispersers located at the inlet to the test section had a significant effect on the readings of the drag disk and gamma densitometer, but had little effect on the turbine. Further, when flow dispersers were used, mass flow rates determined from the three instrument readings and a two-velocity, slip flow model showed good agreement with actual mass flow rate over a three-fold range in quality; mass flows determined with the drag disk and densitometer readings assuming homogeneous flow were nearly as accurate. However, when mass flows were calculated using the turbine and densitometer or turbine and drag disk readings assuming homogeneous flow, results were scattered and relatively inaccurate compared to the actual mass flows. Turbine meter data were used with a two-velocity turbine model and continuity relationships for each phase to determine the void fraction and mean phase velocities in the test section. The void fraction was compared with single beam gamma densitometer results and fluid momentum calculated from a two-velocity model was compared with drag disk readings
A system model for assessing vehicle use-phase water consumption in urban mobility networks

International Nuclear Information System (INIS)

Yen, Jeff; Bras, Bert

2012-01-01

Water consumption is emerging as an important issue potentially influencing the composition of future urban transportation networks, especially as projected urban populations are expected to outpace water availability and as alternative fuels and vehicles are being implemented in such regions. National and State policies aimed at reducing dependence on imported fuels and energy can increase local production of fuels and energy, impacting demand on local water resources. This article details the development of a model-based assessment on water consumption and withdrawal pertaining to the use-phase of conventional and alternative transportation modes based on regional energy and fuel production. An extensive literature review details water consumption from fuel extraction, processing, and distribution as well as power plant operations. Using Model-Based Systems Engineering principles and the Systems Modeling Language, a multi-level, multi-modal framework was developed and applied to the Metro Atlanta transportation system consisting of conventional and alternative vehicles across varying conditions. According to the analysis, vehicles powered by locally produced biofuels and electricity (assuming average local grid mix for charging) consume more water than locally refined gasoline and CNG-powered vehicles. Improvements in power plant technologies, electricity generation (e.g., use of solar and wind versus hydro power) and vehicle efficiencies can reduce such water consumption significantly. Total water withdrawal for each vehicle and fuel is significantly greater than water consumption. - Highlights: ► A model was made to assess the local water consumption due to conventional and alternatively powered vehicles in a city. ► Water consumed in the local and external production of various fuels was reviewed and included. ► Basic battery electric and biofuel powered vehicles consume on average more water than conventional gasoline and Compressed Natural Gas (CNG
Investigation for vertical, two-phase steam-water flow of three turbine models

International Nuclear Information System (INIS)

Silverman, S.; Goodrich, L.D.

1977-01-01

One of the basic quantities of interest during a loss-of-coolant experiment (LOCE) is the primary system mass flow rate. Presently, there are no transducers commercially available which continuously measure this parameter. Therefore, a transducer was designed at EG and G Idaho, Inc. which combines a drag-disc and turbine into a single unit. The basis for the design was that the drag-disc would measure momentum flux (rhoV 2 ), the turbine would measure velocity and the mass flow rate could then be calculated from the two quantities by assuming a flow profile. For two-phase flow, the outputs are approximately proportional to the desired parameter, but rather large errors can be expected under those assumptions. Preliminary evaluation of the experimental two- and single-phase calibration data has resulted in uncertainty estimates of +-8% of range for the turbine and +-20% of range for the drag-disc. In an effort to reduce the errors, further investigations were made to determine what the drag-disc and turbine really measure. In the present paper, three turbine models for vertical, two-phase, steam/water flow are investigated; the Aya Model, the Rouhani Model, and a volumetric flow model. Theoretical predictions are compared with experimental data for vertical, two-phase steam/water flow. For the purposes of the mass flow calculation, velocity profiles were assumed to be flat for the free-field condition. It is appreciated that this may not be true for all cases investigated, but for an initial inspection, flat profiles were assumed
Phase behavior and phase inversion for dispersant systems

International Nuclear Information System (INIS)

Solheim, A.; Brandvik, P.J.

1991-06-01

This report describes some preliminary phase behavior studies and phase inversion temperature measurements in seawater, bunker oil and dispersant. The objectives have been to find new ways of characterizing dispersants for dispersing oil spill at sea and, perhaps, to throw new lights on the mechanism of dispersion formation (oil-in-water emulsification). The work has been focussed on the relation to phase behavior and the existence of microemulsion in equilibrium with excess oil and water phases. The dispersing process is also compared to the recommended conditions for emulsion formation. When forming an oil-in-water emulsion in an industrial process, it is recommended to choose an emulsifier which gives a phase inversion temperature (PIT) which is 20 - 60 o C higher than the actual temperature for use. The emulsification process must take place close to the PIT which is the temperature at which the emulsion change from oil-in-water emulsion to water-in-oil emulsion when the system is stirred. This condition corresponds to the temperature where the phase behavior change character. The purpose has been to find out if the composition of the dispersants corresponds to the recommendations for oil-in-water emulsification. The amount of experimental work has been limited. Two kinds of experiments have been carried out. Phase behavior studies have been done for seawater, bunker oil and four different dispersants where one had an optimal composition. The phase behavior was hard to interpret and is not recommended for standard dispersants test. The other experimental technique was PIT-measurements by conductivity measurements versus temperature. 4 figs., 1 tab., 4 refs

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"...
A test section design to simulate horizontal two-phase air-water flow

International Nuclear Information System (INIS)

Faccini, Jose Luiz H.; Cesar, Silvia B.G.; Coutinho, Jorge A.; Freitas, Sergio Carlos; Addor, Pedro N.

2002-01-01

In this work an air-water two-phase flow horizontal test section assembling at Nuclear Engineering Institute (IEN) is presented. The test section was designed to allow four-phase flow patterns to be simulated: bubble flow, stratified flow, wave flow and slug flow. These flow patterns will be identified by non-conventional ultrasonic techniques which have been developed to meet this particular application. Based on the separated flow and drift-flux models the test section design steps are shown. A description of the test section and its instrumentation and data acquisition system is also provided. (author)
The removal of fatty acids from edible oil : removal of the dispersed phase of a water-in-oil dispersion by a hydrophilic membrane

NARCIS (Netherlands)

Keurentjes, J.T.F.; Doornbusch, G.I.; Riet, van 't K.

1991-01-01

Fatty acids can be extracted from an oil phase by forming a dispersed phase of saponified fatty acids/water/isopropanol in oil. This dispersion can be separated in the two phases by two membranes of opposite polarity in series. In this study the separation of the water phase from the dispersion by a
Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

Energy Technology Data Exchange (ETDEWEB)

Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

2004-03-11

This report summarizes work of this project from October 2003 through March 2004. The major focus of the research was to further investigate BTEX removal from produced water, to quantify metal ion removal from produced water, and to evaluate a lab-scale vapor phase bioreactor (VPB) for BTEX destruction in off-gases produced during SMZ regeneration. Batch equilibrium sorption studies were conducted to evaluate the effect of semi-volatile organic compounds commonly found in produced water on the sorption of benzene, toluene, ethylbenzene, and xylene (BTEX) onto surfactant-modified zeolite (SMZ) and to examine selected metal ion sorption onto SMZ. The sorption of polar semi-volatile organic compounds and metals commonly found in produced water onto SMZ was also investigated. Batch experiments were performed in a synthetic saline solution that mimicked water from a produced water collection facility in Wyoming. Results indicated that increasing concentrations of semi-volatile organic compounds increased BTEX sorption. The sorption of phenol compounds could be described by linear isotherms, but the linear partitioning coefficients decreased with increasing pH, especially above the pKa's of the compounds. Linear correlations relating partitioning coefficients of phenol compounds with their respective solubilities and octanol-water partitioning coefficients were developed for data collected at pH 7.2. The sorption of chromate, selenate, and barium in synthetic produced water were also described by Langmuir isotherms. Experiments conducted with a lab-scale vapor phase bioreactor (VPB) packed with foam indicated that this system could achieve high BTEX removal efficiencies once the nutrient delivery system was optimized. The xylene isomers and benzene were found to require the greatest biofilter bed depth for removal. This result suggested that these VOCs would ultimately control the size of the biofilter required for the produced water application. The biofilter
Experimental investigation on the use of water-phase change material storage in conventional solar water heating systems

Energy Technology Data Exchange (ETDEWEB)

Al-Hinti, I.; Al-Ghandoor, A.; Maaly, A.; Abu Naqeera, I.; Al-Khateeb, Z.; Al-Sheikh, O. [The Hashemite University, Zarqa 13115 (Jordan)

2010-08-15

This paper presents an experimental investigation of the performance of water-phase change material (PCM) storage for use with conventional solar water heating systems. Paraffin wax contained in small cylindrical aluminum containers is used as the PCM. The containers are packed in a commercially available, cylindrical hot water storage tank on two levels. The PCM storage advantage is firstly demonstrated under controlled energy input experiments with the aid of an electrical heater on an isolated storage tank, with and without the PCM containers. It was found that the use of the suggested configuration can result in a 13-14 C advantage in the stored hot water temperature over extended periods of time. The storage performance was also investigated when connected to flat plate collectors in a closed-loop system with conventional natural circulation. Over a test period of 24 h, the stored water temperature remained at least 30 C higher than the ambient temperature. The use of short periods of forced circulation was found to have minimum effect on the performance of the system. Finally, the recovery effect and the storage performance of the PCM was analyzed under open-loop operation patterns, structured to simulate daily use patterns. (author)
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.
Continued Water-Based Phase Change Material Heat Exchanger Development

Science.gov (United States)

Hansen, Scott; Poynot, Joe

2014-01-01

In a cyclical heat load environment such as low Lunar orbit, a spacecraft's radiators are not sized to reject the full heat load requirement. Traditionally, a supplemental heat rejection device (SHReD) such as an evaporator or sublimator is used to act as a "topper" to meet the additional heat rejection demands. Utilizing a Phase Change Material (PCM) heat exchanger (HX) as a SHReD provides an attractive alternative to evaporators and sublimators as PCM HXs do not use a consumable, thereby leading to reduced launch mass and volume requirements. In continued pursuit of water PCM HX development two full-scale, Orion sized water-based PCM HX's were constructed by Mezzo Technologies. These HX's were designed by applying prior research and experimentation to the full scale design. Design options considered included bladder restraint and clamping mechanisms, bladder manufacturing, tube patterns, fill/drain methods, manifold dimensions, weight optimization, and midplate designs. Design and construction of these HX's led to successful testing of both PCM HX's.
Oxo-exchange of gas-phase uranyl, neptunyl, and plutonyl with water and methanol.

Science.gov (United States)

Lucena, Ana F; Odoh, Samuel O; Zhao, Jing; Marçalo, Joaquim; Schreckenbach, Georg; Gibson, John K

2014-02-17

A challenge in actinide chemistry is activation of the strong bonds in the actinyl ions, AnO2(+) and AnO2(2+), where An = U, Np, or Pu. Actinyl activation in oxo-exchange with water in solution is well established, but the exchange mechanisms are unknown. Gas-phase actinyl oxo-exchange is a means to probe these processes in detail for simple systems, which are amenable to computational modeling. Gas-phase exchange reactions of UO2(+), NpO2(+), PuO2(+), and UO2(2+) with water and methanol were studied by experiment and density functional theory (DFT); reported for the first time are experimental results for UO2(2+) and for methanol exchange, as well as exchange rate constants. Key findings are faster exchange of UO2(2+) versus UO2(+) and faster exchange with methanol versus water; faster exchange of UO2(+) versus PuO2(+) was quantified. Computed potential energy profiles (PEPs) are in accord with the observed kinetics, validating the utility of DFT to model these exchange processes. The seemingly enigmatic result of faster exchange for uranyl, which has the strongest oxo-bonds, may reflect reduced covalency in uranyl as compared with plutonyl.
Numerical analysis for two-dimensional compressible and two-phase flow fields of air-water in Eulerian grid framework

International Nuclear Information System (INIS)

Park, Chan Wook; Lee, Sung Su

2008-01-01

Two-phase compressible flow fields of air-water are investigated numerically in the fixed Eulerian grid framework. The phase interface is captured via volume fractions of ech phase. A way to model two phase compressible flows as a single phase one is found based on an equivalent equation of states of Tait's type for a multiphase cell. The equivalent single phase field is discretized using the Roe's approximate Riemann solver. Two approaches are tried to suppress the pressure oscillation phenomena at the phase interface, a passive advection of volume fraction and a direct pressure relaxation with the compressible form of volume fraction equation. The direct pressure equalizing method suppresses pressure oscillation successfully and generates sharp discontinuities, transmitting and reflecting acoustic waves naturally at the phase interface. In discretizing the compressible form of volume fraction equation, phase interfaces are geometrically reconstructed to minimize the numerical diffusion of volume fraction and relevant variables. The motion of a projectile in a water-filled tube which is fired by the release of highly pressurized air is simulated presuming the flow field as a two dimensional one, and several design factors affecting the projectile movement are investigated
European supercritical water cooled reactor (HPLWR Phase 2 project)

International Nuclear Information System (INIS)

Schulenberg, Thomas; Starflinger, Joerg; Marsault, Philippe; Bittermann, Dietmar; Maraczy, Czaba; Laurien, Eckart; Lycklama, Jan Aiso; Anglart, Henryk; Andreani, Michele; Ruzickova, Mariana; Heikinheimo, Liisa

2010-01-01

The High Performance Light Water Reactor (HPLWR), how the European Supercritical Water Cooled Reactor is called, is a pressure vessel type reactor operated with supercritical water at 25 MPa feedwater pressure and 500 deg C maximum core outlet temperature. It is designed and analyzed by a European consortium of 13 partners from 8 Euratom member states in the second phase of the HPLWR project. Most emphasis has been laid on a core with a thermal neutron spectrum, consisting of small, housed fuel assemblies with 40 fuel pins each and a central water box to improve the neutron moderation despite the low coolant density. Peak cladding temperatures of the fuel rods have been minimized by heating up the coolant in three steps with intermediate coolant mixing. The innovative core design with upward and downward flow through its assemblies has been studied with neutronic, thermal-hydraulic and stress analyses and has been reviewed carefully in a mid-term assessment. The containment design with its safety and residual heat removal systems is based on the latest boiling water reactor concept, but with different passive high pressure coolant injection systems to cause a forced convection through the core. The design concept of the steam cycle is indicating the envisaged efficiency increase to around 44%. Moreover, it provides the constraints to design the components of the balance of the plant. The project is accompanied by numerical studies of heat transfer of supercritical water in fuel assemblies and by material tests of candidate cladding alloys, performed by the consortium and supported by additional tests of the Joint Research Centre of the European Commission. An overview of results achieved up to now, given in this paper, is illustrating the latest scientific and technological advances. (author)
Experimental measurement of oil–water two-phase flow by data fusion of electrical tomography sensors and venturi tube

International Nuclear Information System (INIS)

Liu, Yinyan; Deng, Yuchi; Zhang, Maomao; Yu, Peining; Li, Yi

2017-01-01

Oil–water two-phase flows are commonly found in the production processes of the petroleum industry. Accurate online measurement of flow rates is crucial to ensure the safety and efficiency of oil exploration and production. A research team from Tsinghua University has developed an experimental apparatus for multiphase flow measurement based on an electrical capacitance tomography (ECT) sensor, an electrical resistance tomography (ERT) sensor, and a venturi tube. This work presents the phase fraction and flow rate measurements of oil–water two-phase flows based on the developed apparatus. Full-range phase fraction can be obtained by the combination of the ECT sensor and the ERT sensor. By data fusion of differential pressures measured by venturi tube and the phase fraction, the total flow rate and single-phase flow rate can be calculated. Dynamic experiments were conducted on the multiphase flow loop in horizontal and vertical pipelines and at various flow rates. (paper)
Experimental evaluation of ability of Relap5 and DRAKO to calculate water hammer with phase changes

International Nuclear Information System (INIS)

Marcinkiewicz, Jerzy; Adamkowski, Adam; Lewandowski, Mariusz

2007-01-01

Mechanical loadings on pipe systems caused by water hammer with phase changes make calculation of final forces difficult in nuclear power plants. The common procedure in Sweden is to calculate the water hammer loadings, according to the classical one-dimensional theory of liquid transient flow in pipeline, and then transfer the results to strength analyses of pipeline structure. This procedure assumes that there is quasi-steady response of the pipeline structure to pressure surges - no dynamic interaction between the fluid and the pipeline construction. The hydraulic loadings are calculated with 1-D so-called 'network' programs. Commonly used in Sweden are Relap5 (Mod3.2.2 and higher) and Drako. As a third party accredited inspection body INSPECTA NUCLEAR AB reviews calculations of water hammer loadings. An important question for the reviewer (and also for the users) is knowledge about their ability to calculate the dynamic loadings. While the ability of Relap5 and DRAKO to calculate water hammer without phase changes is relatively well investigated the skills of the programs when phase changes are present need some more attention. The presented work shall be seen as an attempt to illustrate ability of Relap5, and Drako programs to calculate the water hammer loadings with phase changes. A special attention was paid to using of Relap5 for calculation of water hammer pressure surges (including some aspects of influence of discretisation of space on the calculation results). The calculations are compared with experimental results. The experiments have been conducted at a test rig designed and constructed at the Szewalski Institute of Fluid-Flow Machinery of the Polish Academy of Sciences (IMP PAN) in Gdansk, Poland. The comparison of calculated and measured pressures shows some differences, only the first pressure peak, occurring before evaporation is calculated quite exactly. All next coming pressure peaks differ slightly from the measured with respect to amplitude
Amorphous ices explained in terms of nonequilibrium phase transitions in supercooled water

Science.gov (United States)

Limmer, David; Chandler, David

2013-03-01

We analyze the phase diagram of supercooled water out-of-equilibrium using concepts from space-time thermodynamics and the dynamic facilitation theory of the glass transition, together with molecular dynamics simulations. We find that when water is driven out-of-equilibrium, it can exist in multiple amorphous states. In contrast, we find that when water is at equilibrium, it can exist in only one liquid state. The amorphous non-equilibrium states are solids, distinguished from the liquid by their lack of mobility, and distinguished from each other by their different densities and local structure. This finding explains the experimentally observed polyamorphism of water as a class of nonequilibrium phenomena involving glasses of different densities. While the amorphous solids can be long lived, they are thermodynamically unstable. When allowed to relax to equilibrium, they crystallize with pathways that pass first through liquid state configurations and then to ordered ice.
Hydration, phase separation and nonlinear rheology of temperature-sensitive water-soluble polymers

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Fumihiko; Koga, Tsuyoshi [Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510 (Japan); Kaneda, Isamu [Department of Food Science, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501 (Japan); Winnik, Francoise M, E-mail: ftanaka@phys.polym.kyoto-u.ac.jp [Department of Chemistry and Faculty of Pharmacy, University of Montreal, Montreal, H3C 3J7 (Canada)

2011-07-20

The collapse of a poly(N-isopropylacrylamide) (PNIPAM) chain upon heating and the phase diagrams of aqueous PNIPAM solutions with a very flat lower critical solution temperature (LCST) phase separation line are theoretically studied on the basis of cooperative dehydration (simultaneous dissociation of bound water molecules in a group of correlated sequence), and compared with the experimental observation of temperature-induced coil-globule transition by light scattering methods. The transition becomes sharper with the cooperativity parameter {sigma} of hydration. The reentrant coil-globule-coil transition and cononsolvency in a mixed solvent of water and methanol are also studied from the viewpoint of competitive hydrogen bonds between polymer-water and polymer-methanol. The downward shift of the cloud-point curves (LCST cononsolvency) with the mol fraction of methanol due to the competition is calculated and compared with the experimental data. Aqueous solutions of hydrophobically modified PNIPAM carrying short alkyl chains at both chain ends (telechelic PNIPAM) are theoretically and experimentally studied. The LCST of these solutions is found to shift downward along the sol-gel transition curve as a result of end-chain association (association-induced phase separation), and separate from the coil-globule transition line. Associated structures in the solution, such as flower micelles, mesoglobules, and higher fractal assembly, are studied by ultra small-angle neutron scattering with theoretical modeling of the scattering function. Dynamic-mechanical modulus, nonlinear stationary viscosity, and stress build-up in start-up shear flows of the associated networks are studied on the basis of the affine and non-affine transient network theory. The molecular conditions for thickening, strain hardening, and stress overshoot are found in terms of the nonlinear amplitude A of the chain tension and the tension-dissociation coupling constant g.
Measurement of thickness of thin water film in two-phase flow by capacitance method

International Nuclear Information System (INIS)

Sun, R.K.; Kolbe, W.F.; Leskovar, B.; Turko, B.

1981-09-01

A technique has been developed for measuring water film thickness in a two-phase annular flow system by the capacitance method. An experimental model of the flow system with two types of electrodes mounted on the inner wall of a cylindrical tube has been constructed and evaluated. The apparatus and its ability to observe fluctuations and wave motions of the water film passing over the electrodes is described in some detail
Characterization of horizontal air–water two-phase flow

Energy Technology Data Exchange (ETDEWEB)

Kong, Ran; Kim, Seungjin, E-mail: skim@psu.edu

2017-02-15

Highlights: • A visualization study is performed to develop flow regime map in horizontal flow. • Database in horizontal bubbly flow is extended using a local conductivity probe. • Frictional pressure drop analysis is performed in horizontal bubbly flow. • Drift flux analysis is performed in horizontal bubbly flow. - Abstract: This paper presents experimental studies performed to characterize horizontal air–water two-phase flow in a round pipe with an inner diameter of 3.81 cm. A detailed flow visualization study is performed using a high-speed video camera in a wide range of two-phase flow conditions to verify previous flow regime maps. Two-phase flows are classified into bubbly, plug, slug, stratified, stratified-wavy, and annular flow regimes. While the transition boundaries identified in the present study compare well with the existing ones (Mandhane et al., 1974) in general, some discrepancies are observed for bubbly-to-plug/slug, and plug-to-slug transition boundaries. Based on the new transition boundaries, three additional test conditions are determined in horizontal bubbly flow to extend the database by Talley et al. (2015a). Various local two-phase flow parameters including void fraction, interfacial area concentration, bubble velocity, and bubble Sauter mean diameter are obtained. The effects of increasing gas flow rate on void fraction, bubble Sauter mean diameter, and bubble velocity are discussed. Bubbles begin to coalesce near the gas–liquid layer instead of in the highly packed region when gas flow rate increases. Using all the current experimental data, two-phase frictional pressure loss analysis is performed using the Lockhart–Martinelli method. It is found that the coefficient C = 24 yields the best agreement with the data with the minimum average difference. Moreover, drift flux analysis is performed to predict void-weighted area-averaged bubble velocity and area-averaged void fraction. Based on the current database, functional
Responses of Cloud Type Distributions to the Large-Scale Dynamical Circulation: Water Budget-Related Dynamical Phase Space and Dynamical Regimes

Science.gov (United States)

Wong, Sun; Del Genio, Anthony; Wang, Tao; Kahn, Brian; Fetzer, Eric J.; L'Ecuyer, Tristan S.

2015-01-01

Goals: Water budget-related dynamical phase space; Connect large-scale dynamical conditions to atmospheric water budget (including precipitation); Connect atmospheric water budget to cloud type distributions.
Phase separation of acetonitrile-water mixtures and minimizing of ice crystallites from there in confinement of MCM-41.

Science.gov (United States)

Kittaka, Shigeharu; Kuranishi, Miki; Ishimaru, Shinji; Umahara, Osamu

2007-03-07

The effect of confinement of an acetonitrile-water mixture, whose correlation length was comparable to the pore size of the mesopores of MCM-41 (d=2.4-3.6 nm), on the phase changes was studied. Used techniques were low temperature differential scanning calorimetry and Fourier transform infrared spectroscopy, where the phase separation, lowering of the freezing and melting temperatures, and phase transitions of the acetonitrile were detected. The latter occurred in the mesopores at temperatures similar to that of the pure liquid, while the melting temperature of the water in the mesopores<3.1 nm decreased markedly at higher acetonitrile contents, suggesting a marked lowering of ice crystallite size.
Final Report: Phase II Nevada Water Resources Data, Modeling, and Visualization (DMV) Center

Energy Technology Data Exchange (ETDEWEB)

Jackman, Thomas [Desert Research Institute; Minor, Timothy [Desert Research Institute; Pohll, Gregory [Desert Research Institute

2013-07-22

Water is unquestionably a critical resource throughout the United States. In the semi-arid west -- an area stressed by increase in human population and sprawl of the built environment -- water is the most important limiting resource. Crucially, science must understand factors that affect availability and distribution of water. To sustain growing consumptive demand, science needs to translate understanding into reliable and robust predictions of availability under weather conditions that could be average but might be extreme. These predictions are needed to support current and long-term planning. Similar to the role of weather forecast and climate prediction, water prediction over short and long temporal scales can contribute to resource strategy, governmental policy and municipal infrastructure decisions, which are arguably tied to the natural variability and unnatural change to climate. Change in seasonal and annual temperature, precipitation, snowmelt, and runoff affect the distribution of water over large temporal and spatial scales, which impact the risk of flooding and the groundwater recharge. Anthropogenic influences and impacts increase the complexity and urgency of the challenge. The goal of this project has been to develop a decision support framework of data acquisition, digital modeling, and 3D visualization. This integrated framework consists of tools for compiling, discovering and projecting our understanding of processes that control the availability and distribution of water. The framework is intended to support the analysis of the complex interactions between processes that affect water supply, from controlled availability to either scarcity or deluge. The developed framework enables DRI to promote excellence in water resource management, particularly within the Lake Tahoe basin. In principle, this framework could be replicated for other watersheds throughout the United States. Phase II of this project builds upon the research conducted during
Modeling of phase equilibrium of North Sea oils with water and MEG

DEFF Research Database (Denmark)

Frost, Michael Grynnerup; Kontogeorgis, Georgios; von Solms, Nicolas

2016-01-01

The complex phase equilibrium between reservoir fluids and associating compounds like water and glycols has become very important as the increasing global energy demand pushes the oil industry to use advanced methods to increase oil recovery, such as increasing the use of various chemicals...... to ensure a constant and safe production. The CPA equation of state has been successfully applied in the past to well defined systems and gas condensates containing associating compounds. It has also been extended to reservoir fluids in presence of water and polar chemicals using modified correlations...... for critical temperature, pressure and acentric factor.In this work, we evaluate CPA using recently developed correlations for predicting the binary interaction parameters between MEG/hydrocarbons and water/hydrocarbons, for a wide range of systems containing reservoir fluids and production chemicals...

Water adsorbate phases on ZnO and impact of vapor pressure on the equilibrium shape of nanoparticles

Science.gov (United States)

Kenmoe, Stephane; Biedermann, P. Ulrich

2018-02-01

ZnO nanoparticles are used as catalysts and have potential applications in gas-sensing and solar energy conversion. A fundamental understanding of the exposed crystal facets, their surface chemistry, and stability as a function of environmental conditions is essential for rational design and improvement of synthesis and properties. We study the stability of water adsorbate phases on the non-polar low-index (10 1 ¯ 0 ) and (11 2 ¯ 0 ) surfaces from low coverage to multilayers using ab initio thermodynamics. We show that phonon contributions and the entropies due to a 2D lattice gas at low coverage and multiple adsorbate configurations at higher coverage have an important impact on the stability range of water adsorbate phases in the (T,p) phase diagram. Based on this insight, we compute and analyze the possible growth mode of water films for pressures ranging from UHV via ambient conditions to high pressures and the impact of water adsorption on the equilibrium shape of nanoparticles in a humid environment. A 2D variant of the Wulff construction shows that the (10 1 ¯ 0 ) and (11 2 ¯ 0 ) surfaces coexist on 12-faceted prismatic ZnO nanoparticles in dry conditions, while in humid environment, the (10 1 ¯ 0 ) surface is selectively stabilized by water adsorption resulting in hexagonal prisms.
The selective partitioning of the oligomers of polyethoxylated surfactant mixtures between interface and oil and water bulk phases.

Science.gov (United States)

Graciaa, Alain; Andérez, José; Bracho, Carlos; Lachaise, Jean; Salager, Jean-Louis; Tolosa, Laura; Ysambertt, Fredy

2006-11-16

Because their affinities for the oil and water phases vary considerably with the number of ethylene oxide units in their hydrophilic group, the ethoxylated nonionic species occurring in commercial products tend to behave in a non-collective way, with the low ethoxylation oligomers partitioning mostly in the oil phase. This results in a surfactant mixture at the interface which is more hydrophilic than the one which was introduced in the system in the first place. The pseudophase model is used to study the partitioning in Winsor III type systems, and to estimate the deviation of the interfacial mixture composition from the overall one. New results indicate that the selective partitioning into the oil phase increases when the oil phase becomes aromatic, when the total surfactant concentration decreases and when the water-to-oil ratio decreases.
Design Development of SMART ECC Water Asymmetric Two-phase choking test facility

Energy Technology Data Exchange (ETDEWEB)

Cho, Young Il; Cho, Seok; Ko, Yung Joo; Shin, Yong Cheol; Kwon, Tae Soon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2011-05-15

SMART pressurized water reactor type is different from the existing integral NSSS commercial pressurized water reactor system which is equipped with the main features. In addition RCS piping is removed and the feature of the SBLOCA is a major design break accident. The TASS / SMR code is analyzed SMART SBLOCA. In order to verify analysis code, SMART analysis for verification of conservatism is promoting using data for experiments with Integral Effect Test and Separate Effect. In this paper, the design feature of the SWAT (SMART ECC Water Asymmetric Two-phase choking test facility) is described. SWAT is linearly reduced to a 1/5 ratio while the geometrical shape is conserved. In major shape of SMART ECC injection performance test, distortions which caused by gravitational effects are minimized. Because both the emergency core cooling water injection nozzle height and the break nozzle height match the RCP Suction Nozzle height in test section of the main forms. The main part of the test section is SG-side upper down-comer. The boundary conditions are saturated steam and water flow condition and drain flow rate to control the collapsed water level in the down-comer
SUPERCRITICAL WATER PARTIAL OXIDATION PHASE I - PILOT-SCALE TESTING/FEASIBILTY SUDIES FINAL REPORT

Energy Technology Data Exchange (ETDEWEB)

SPRITZER.M; HONG,G

2005-01-01

General Atomics (GA) is developing Supercritical Water Partial Oxidation (SWPO) as a means of producing hydrogen from low-grade biomass and other waste feeds. The Phase I Pilot-scale Testing/Feasibility Studies have been successfully completed and the results of that effort are described in this report. The key potential advantage of the SWPO process is the use of partial oxidation in-situ to rapidly heat the gasification medium, resulting in less char formation and improved hydrogen yield. Another major advantage is that the high-pressure, high-density aqueous environment is ideal for reacting and gasifying organics of all types. The high water content of the medium encourages formation of hydrogen and hydrogen-rich products and is especially compatible with high water content feeds such as biomass materials. The high water content of the medium is also effective for gasification of hydrogen-poor materials such as coal. A versatile pilot plant for exploring gasification in supercritical water has been established at GA's facilities in San Diego. The Phase I testing of the SWPO process with wood and ethanol mixtures demonstrated gasification efficiencies of about 90%, comparable to those found in prior laboratory-scale SCW gasification work carried out at the University of Hawaii at Manoa (UHM), as well as other biomass gasification experience with conventional gasifiers. As in the prior work at UHM, a significant amount of the hydrogen found in the gas phase products is derived from the water/steam matrix. The studies at UHM utilized an indirectly heated gasifier with an activated carbon catalyst. In contrast, the GA studies utilized a directly heated gasifier without catalyst, plus a surrogate waste fuel. Attainment of comparable gasification efficiencies without catalysis is an important advancement for the GA process, and opens the way for efficient hydrogen production from low-value, dirty feed materials. The Phase I results indicate that a practical
Characterization of a plant leaf cuticle model wax, phase behaviour of model wax–water systems

International Nuclear Information System (INIS)

Fagerström, Anton; Kocherbitov, Vitaly; Westbye, Peter; Bergström, Karin; Mamontova, Varvara; Engblom, Johan

2013-01-01

Highlights: • Four individual crystalline phases were discovered in the model wax–water system. • Eutectic melting occurred in both dry and hydrated model wax. • The total transition enthalpy is smaller for the cuticle wax than for the model wax. • Water has a large plasticizing effect on cuticle wax. • The thermotropic transitions of model wax fit in the window of extracted leaf waxes. - Abstract: We investigated the thermotropic phase behaviour of plant leaf intracuticular wax and two representatives of its main components, 1-docosanol (C 22 H 45 OH) and dotriacontane (C 32 H 66 ), in dry and hydrated state. One objective was to obtain a model wax, which can be used to estimate formulations effects on cuticle diffusivity in vitro. The two wax components were chosen based on results from Gas Chromatography coupled to Mass Spectrometry analysis of cuticular wax. The wax was extracted from Clivia Miniata Regel leaves and contained 68% primary alcohols (C 16 –C 32 ) and 16% n-alkanes (C 21 –C 33 ). Differential Scanning Calorimetry, Polarized Light Microscopy and Small- and Wide Angle X-ray Diffraction were used to characterize the cuticular extract and the phase behaviour of the C 22 H 45 OH/C 32 H 66 /H 2 O model system. Four individual crystalline phases were discovered in the model wax–water system and eutectic melting occurred in both dry and hydrated state. The thermotropic transitions of the model wax occur within the broader transition region of the extracted leaf wax
Photocatalytic overall water splitting promoted by an α-β phase junction on Ga2O3.

Science.gov (United States)

Wang, Xiang; Xu, Qian; Li, Mingrun; Shen, Shuai; Wang, Xiuli; Wang, Yaochuan; Feng, Zhaochi; Shi, Jingying; Han, Hongxian; Li, Can

2012-12-21

When Alpha met Beta: a tuneable α-β surface phase junction on Ga(2)O(3) can significantly improve photocatalytic overall water splitting into H(2) and O(2) over individual α-Ga(2)O(3) or β-Ga(2)O(3) surface phases. This enhanced photocatalytic performance is mainly attributed to the efficient charge separation and transfer across the α-β phase junction. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
A dual phased approach for bioremediation of petroleum contaminated soil and ground water

International Nuclear Information System (INIS)

Kennel, N.D.; Maher, A.; Buckallew, B.

1994-01-01

A case study will be presented to demonstrate an effective and timely method of site remediation which yields complete contaminant destruction rather than the contaminant transfer that traditional ground water extraction and treatment techniques result in. By utilizing bioremediation at this site, the client was able to completely degrade the contamination beneath the property, and in the process avoid future liability from transfer of the contamination to another party (i.e. landfill) or phase (i.e. liquid to vapor through air stripping). The provisions of a real estate transaction involving a former service station site in Central Iowa stipulated that the site be remediated prior to title transfer. Previous Environmental Investigative activities revealed significant soil and ground water contamination resulting from over 50 years of diesel and gasoline fuel storage and dispensing operations at the site. Microbial Environmental Services, Inc. (MES) utilized a dual phased bioremediation approach to meet regulatory clean-up guidelines in order for a timely property transfer to occur. To facilitate and expedite ground water remediation, contaminated soil was excavated and remediated via Advanced Biological Surface Treatment (ABST) techniques. ABST techniques are utilized by MES to treat excavated soil in closed cell to control emissions and treatment conditions. Following contaminant source removal, ground water was extracted and treated in a submerged, fixed film, flow through 1,000 gallon fixed film bioreactor at a rate of 2.5 gallons per minute
Monitoring of chloropesticide methoxychlor preconcentration from waste water using hplc - solid phase extraction (abstract)

International Nuclear Information System (INIS)

Butt, S.B.; Saqlin, M.; Riaz, M.

2011-01-01

The method involves preconcentration of methoxychlor by solid phase extraction (SPE) with 1 mL silica based C-18 and 3 mL polymer based C-18 cartridge and then quantification by high performance liquid chromatography with UV detector (HPLC-UV). Optimization of HPLC parameters was done by determining max of methoxychlor on a double beam UV/Visible spectrophotometer, flow rate of mobile phase on reversed phase columns. Lowest detection limit for methoxychlor dissolved in water and methanol was 0.2ppm and 0.1ppm respectively. For solid phase extraction recovery studies and effect of different parameters such as initial concentration of analyte 0.01 to 0.05 ppm, loading rate 1 and 2mL/min, nature of desorbing solvent (methanol, ethyl acetate and acetonitrile) were investigated. Periodic self degradation of methoxychlor, and reusing potential of both SPE materials was also explored. Lower initial concentrations and slower loading rate of methoxychlor solutions gave improved recoveries. Recoveries were in the range of 80 to 90% for new SPE cartridge and reduced to 35 to 57% for once used silica based C-18 tubes. It was around 73 % for HLB C18 on their second use, and decreased on their repeated reuse. Lastly recoveries for stimulant and real waste water samples were determined to be 77 and 60% respectively. (author)
Influence of main process variables on the treatment of waste waters using a new technology Mixer-Settler based on Phase Inversion (MSPI)

Energy Technology Data Exchange (ETDEWEB)

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

2011-04-15

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

Energy Technology Data Exchange (ETDEWEB)

Helmdach, L.; Ulrich, J. [Martin-Luther-Universitaet Halle-Wittenberg, Zentrum fuer Ingenieurwissenschaft, Verfahrenstechnik/TVT, Halle (Saale) (Germany); Feth, M.P. [Sanofi-Aventis Deutschland GmbH, Chemical and Process Development Frankfurt Chemistry, Frankfurt (Germany)

2012-09-15

It was demonstrated exemplarily for the crystallization of citric acid that the usage of an ultrasound device as well as Raman spectroscopy enables the inline measurement and the control of phase transitions. The influence of different solvent compositions (water and ethanol-water) on the crystallization of citric acid was investigated. By increasing the ethanol content the transformation point was shifted towards higher temperatures. In addition, a strong impact on the nucleation point as well as on the crystal habit was detected in ethanol-water mixtures. The results lead to the assumption that a citric acid solvate exists, which is, however, highly unstable upon isolation from mother liquor and converts fast into the known anhydrate or monohydrate forms of citric acid. The presence of such a solvate, however, could not be proven during this study. Furthermore, factors such as temperature and humidity which might influence the phase transition of the solid product were analyzed by Hotstage-Raman Spectroscopy and Water Vapor Sorption Gravimetry-Dispersive Raman Spectroscopy. Both, temperature as well as humidity show a strong influence on the behaviour of CAM. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
New lipid family that forms inverted cubic phases in equilibrium with excess water: molecular structure-aqueous phase structure relationship for lipids with 5,9,13,17-tetramethyloctadecyl and 5,9,13,17-tetramethyloctadecanoyl chains.

Science.gov (United States)

Yamashita, Jun; Shiono, Manzo; Hato, Masakatsu

2008-10-02

With a view to discovering a new family of lipids that form inverted cubic phases, the aqueous phase behavior of a series of lipids with isoprenoid-type hydrophobic chains has been examined over a temperature range from -40 to 65 degrees C by using optical microscopy, DSC (differential scanning calorimetry), and SAXS (small-angle X-ray scattering) techniques. The lipids examined are those with 5,9,13,17-tetramethyloctadecyl and 5,9,13,17-tetramethyloctadecanoyl chains linked to a series of headgroups, that is, erythritol, pentaerythritol, xylose, and glucose. All of the lipid/water systems displayed a "water + liquid crystalline phase" two-phase coexistence state when sufficiently diluted. The aqueous phase structures of the most diluted liquid crystalline phases in equilibrium with excess water depend both on the lipid molecular structure and on the temperature. Given an isoprenoid chain, the preferred phase consistently follows a phase sequence of an H II (an inverted hexagonal phase) to a Q II (an inverted bicontinuous cubic phase) to an L alpha (a lamellar phase) as A* (cross-section area of the headgroup) increases. For a given lipid/water system, the phase sequence observed as the temperature increases is L alpha to Q II to H II. The present study allowed us to find four cubic phase-forming lipid species, PEOC 18+4 [mono- O-(5,9,13,17-tetramethyloctadecyl)pentaerythritol], beta-XylOC 18+4 [1- O-(5,9,13,17-tetramethyloctadecyl)-beta- d-xylopyranoside], EROCOC 17+4 [1- O-(5,9,13,17-tetramethyloctadecanoyl)erythritol], and PEOCOC 17+4 [mono- O-(5,9,13,17-tetramethyloctadecanoyl)pentaerythritol]. The values of T K (hydrated solid-liquid crystalline phase transition temperature) of the cubic phase-forming lipids are all below 0 degrees C. Quantitative analyses of the lipid molecular structure-aqueous phase structure relationship in terms of the experimentally evaluated "surfactant parameter" allow us to rationally select an optimum combination of hydrophilic
Characterization of two-phase mixture (petroleum, salted water or gas) by gamma radiation transmission

International Nuclear Information System (INIS)

Eichlt, Jair Romeu

2003-01-01

A mathematical description was accomplished to determine the discrimination of a substance in a two-phase mixture, for one beam system, using the five energy lines (13.9, 17.8,26.35 and 59,54 keV) of the 241 Am source. The mathematical description was also accomplished to determine the discrimination of two substances in a three-phase mixture, for a double beam system.. he simulated mixtures for the one beam system were petroleum/salted water or gas. The materials considered in these simulations were: four oils types, denominated as A, B, Bell and Generic, one kind of natural gas and salted water with the following salinities: 35.5, 50, 100, 150, 200, 250 and 300 kg/m 3 of Na Cl. The simulation for the one beam system consisted of a box with acrylic walls and other situation with a box of epoxi walls reinforced with fiber of carbon. The epoxi with carbon fiber was used mainly due to the fact that this material offers little attenuation to the fotons and it resists great pressures. With the results of the simulations it was calculated tables of minimum discrimination for each possible two-phase mixture with petroleum, gas and salted water at several salinities. These discrimination tables are the theoretical forecasts for experimental measurements, since they supply the minimum mensurable percentage for each energy line, as well as the ideal energy for the measurement of each mixture, or situation. The simulated discrimination levels were tested employing experimental arrangements with conditions and materials similar to those of the simulations, for the case of box with epoxi wall reinforced with carbon fiber, at the energies of 20.8 and 59.54 keV. It was obtained good results. For example, for the mixture of salted water (35.5 kg/m 3 ) in paraffin (simulating the petroleum), it was obtained an experimental discrimination minimum of 10% of salted water for error statistics of 5% in I and I o , while the theoretical simulation foresaw the same discrimination level
Isoporous PS-b-PEO ultrafiltration membranes via self-assembly and water-induced phase separation

KAUST Repository

Karunakaran, Madhavan; Nunes, Suzana Pereira; Qiu, Xiaoyan; Yu, Haizhou; Peinemann, Klaus-Viktor

2014-01-01

A simple and efficient approach towards the fabrication of a skinned membrane with highly ordered pores in the nanometer range is presented here. We successfully combined the self-assembly of PS-b-PEO block copolymer and water induced phase
Colorimetric Solid Phase Extraction (CSPE): Using Color to Monitor Spacecraft Water Quality

Science.gov (United States)

Gazda, Daniel B.; Nolan, Daniel J.; Rutz, Jeffrey A.; Schultz, John R.; Siperko, Lorraine M.; Porter, Marc D.; Lipert, Robert J.; Flint, Stephanie M.; McCoy, J. Torin

2010-01-01

In August 2009, an experimental water quality monitoring kit based on Colorimetric Solid Phase Extraction (CSPE) technology was delivered to the International Space Station (ISS). The kit, called the Colorimetric Water Quality Monitoring Kit (CWQMK), was launched as a Station Development Test Objective (SDTO) experiment to evaluate the suitability of CSPE technology for routine use monitoring water quality on the ISS. CSPE is a sorption-spectrophotometric technique that combines colorimetric reagents, solid-phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water samples. In CSPE, a known volume of sample is metered through a membrane disk that has been impregnated with an analyte-specific colorimetric reagent and any additives required to optimize the formation of the analyte-reagent complex. As the sample flows through the membrane disk, the target analyte is selectively extracted, concentrated, and complexed. Formation of the analyte-reagent complex causes a detectable change in the color of the membrane disk that is proportional to the amount of analyte present in the sample. The analyte is then quantified by measuring the color of the membrane disk surface using a hand-held diffuse reflectance spectrophotometer (DRS). The CWQMK provides the capability to measure the ionic silver (Ag +) and molecular iodine (I2) in water samples on-orbit. These analytes were selected for the evaluation of CSPE technology because they are the biocides used in the potable water storage and distribution systems on the ISS. Biocides are added to the potable water systems on spacecraft to inhibit microbial growth. On the United States (US) segment of the ISS molecular iodine serves as the biocide, while the Russian space agency utilizes silver as a biocide in their systems. In both cases, the biocides must be maintained at a level sufficient to control bacterial growth, but low enough to avoid any negative effects on crew health. For example, the
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% Â± 7.1 recovery from water samples and 61.8% Â± 11.1 recovery from soil samples....
Availability of MCNP and MATLAB for reconstructing the water-vapor two-phase flow pattern in neutron radiography

International Nuclear Information System (INIS)

Feng Qixi; Feng Quanke; Takeshi, K.

2008-01-01

The China Advanced Research Reactor (CARR) is scheduled to be operated in the autumn of 2008. In this paper, we report preparations for installing the neutron radiography instrument (NRI) and for utilizing it efficiently. The 2-D relative neutron intensity profiles for the water-vapor two-phase flow inside the tube were obtained using the MCNP code without influence of γ-ray and electronic-noise. The MCNP simulation of the 2-D neutron intensity profile for the water-vapor two-phase flow was demonstrated. The simulated 2-D neutron intensity profiles could be used as the benchmark data base by calibrating part of the data measured by the CARR-NRI. The 3-D objective images allow us to understand the flow pattern more clearly and it is reconstructed using the MATLAB through the threshold transformation techniques. And thus it is concluded that the MCNP code and the MATLAB are very useful for constructing the benchmark data base for the investigation of the water-vapor two-phase flow using the CARR-NRI. (authors)
Effect of Alcohols on the Phase Behavior and Emulsification of a Sucrose Fatty Acid Ester/Water/Edible Oil System.

Science.gov (United States)

Matsuura, Tsutashi; Ogawa, Akihiro; Ohara, Yukari; Nishina, Shogo; Nakanishi, Maho; Gohtani, Shoichi

2018-02-01

The effect of alcohols (ethanol, 1-propanol, propylene glycol, glycerin, sucrose) on the phase behavior and emulsification of sucrose stearic acid ester (SSE)/water/edible vegetable oil (EVO) systems was investigated. Adding sucrose, propylene glycol, and glycerin narrowed the oil-separated two-phase region in the phase diagram of the SSE/water/EVO systems, whereas adding ethanol and 1-propanol expanded the oil-separated two-phase region. Changing the course of emulsification in the phase diagram showed that the size of the oil-droplet particle typically decreased in a system with a narrowed oil-separated region. The emulsification properties of the systems varied with respect to changes in the phase diagram. The microstructure of the systems was examined using small-angle X-ray scattering, and the ability to retain the oil in the lamellar structure of the SSEs was suggested as an important role in emulsification, because the mechanism of the systems was the same as that for the liquid crystal emulsification method.
Investigation of the mixture flow rates of oil-water two-phase flow using the turbine flow meter

International Nuclear Information System (INIS)

Li Donghui; Feng Feifei; Wu Yingxiang; Xu Jingyu

2009-01-01

In this work, the mixture flow rate of oil-water flows was studied using the turbine flow-meter. The research emphasis focuses on the effect of oil viscosity and input fluids flow rates on the precision of the meter. Experiments were conducted to measure the in-situ mixture flow rate in a horizontal pipe with 0.05m diameter using seven different viscosities of white oil and tap water as liquid phases. Results showed that both oil viscosity and input oil fraction exert a remarkable effect on measured results, especially when the viscosity of oil phase remained in the area of high value. In addition, for metering mixture flow rate using turbine flow-meter, the results are not sensitive to two-phase flow pattern according to the experimental data.
Radioactive and industrial waste water collection system study, Phase I

International Nuclear Information System (INIS)

1993-01-01

Phase I of the Radioactive Liquid Waste (RLW) Collection System Study has been completed, and the deliverables for this portion of the study are enclosed. The deliverables include: The Work Break-down Structure (WBS) for Phase II; The Annotated Outline for the Collection Study Report; The Process Flow Diagrams (PFD) of the RLW collection system based on current literature and knowledge; The Configuration database; The Reference Index, listing all currently held documents of the RLW collection system; The Reference Drawing Index listing all currently held, potentially applicable, drawings reviewed during the PFD development; The Regulation Identification Document for RCRA and CWA; The Regulation Database for RCRA and CWA; The Regulation Review Log, including statements justifying the non-applicability of certain regulations; Regulation Library, including the photocopied regulations with highlighted text for RCRA and CWA; The summary of RTG's waste water treatment plant design experience and associated regulations on which RTG based the design of these treatment facilities; TA-50 Influent Database; Radioactive Liquid Waste Stream Characterization Database
Biomechanical analysis of the contact phase in drop jumps performed in water and on dry land

Directory of Open Access Journals (Sweden)

Caroline Ruschel

2016-03-01

Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n1p41 Plyometric training in the aquatic environment has been used as way of reducing loads through the action of buoyancy. However, little is known about the biomechanical characteristics of plyometric exercises in water, which can assist in the prescription of training in this environment. This study aimed to analyze the vertical component of the ground reaction force and contact duration of drop jumps (DJ performed on land and at hip level water immersion. Participants were 22 male athletes (19.1 ± 3.7 years, who performed three maximum DJs in water and on dry land. Peak force and duration of braking and propulsion sub-phases of the DJ contact were analyzed with the use of two underwater force platforms, a 2-D waterproofed electrogoniometer, acquisition systems ADS2000-IP and TeleMyo 2400TG2, and a signal synchronizer. The effect of immersion was investigated through comparison tests for dependent samples (p <0.05. In water, the following results were observed: (a reduction of 41.8% (p <0.001, d = 2.24 and 23.8% (p <0.001, d = 1.50 of peak forces during braking and propulsion sub-phases respectively; and (b increase of 41.8% in the braking (p <0.001, d = 1.41 and 12.3% in the propulsion contact times (p = 0.006, d = 0.75. The aquatic environment can be an alternative when one aims to reduce the load during the DJ contact; however, the longer duration increasing of contact sub-phases in water at hip immersion may compromise the proper functioning of the stretch-shortening cycle in water.

Performance comparison between ethanol phase-change immersion and active water cooling for solar cells in high concentrating photovoltaic system

International Nuclear Information System (INIS)

Wang, Yiping; Wen, Chen; Huang, Qunwu; Kang, Xue; Chen, Miao; Wang, Huilin

2017-01-01

Highlights: • Thermal performances of ethanol phase-change immersion and active water cooling are compared. • Effects of operation parameters on ethanol phase-change immersion are studied. • Optimum filling ratio is 30% for ethanol phase-change immersion cooling system. • Exergy efficiency of ethanol phase-change immersion method increases by 57%. - Abstract: This paper presents an optimized ethanol phase-change immersion cooling method to obtain lower temperature of dense-array solar cells in high concentrating photovoltaic system. The thermal performances of this system were compared with a conventional active water cooling system with minichannels from the perspectives of start-up characteristic, temperature uniformity, thermal resistance and heat transfer coefficient. This paper also explored the influences of liquid filling ratio, absolute pressure and water flow rate on thermal performances. Dense-array LEDs were used to simulate heat power of solar cells worked under high concentration ratios. It can be observed that the optimal filling ratio was 30% in which the thermal resistance was 0.479 °C/W and the heat transfer coefficient was 9726.21 W/(m 2 ·°C). To quantify the quality of energy output of two cooling systems, exergy analysis are conducted and maximum exergy efficiencies were 17.70% and 11.27%, respectively. The experimental results represent an improvement towards thermal performances of ethanol phase-change immersion cooling system due to the reduction in contact thermal resistance. This study improves the operation control and applications for ethanol phase-change immersion cooling technology.
Microbiological Tests Performed During the Design of the International Space Station ECLSS: Part 1, Bulk Phase Water and Wastewater

Science.gov (United States)

Roman, Monsi C.; Mittelman, Marc W.

2010-01-01

This slide presentation summarizes the studies performed to assess the bulk phase microbial community during the Space Station Water Recover Tests (WRT) from 1990-1998. These tests show that it is possible to recycle water from different sources including urine, and produce water that can exceed the quality of municpally produced tap water.
Specific features of phase distribution in a draught part of the tank type boiling water cooled reactor

International Nuclear Information System (INIS)

Fedulin, V.N.; Bartolomej, G.G.; Solodkij, V.A.; Shmelev, V.E.

1984-01-01

The results of experimental investigation of the two-phase flow structure in a draught part of the VK-50 boiling water cooled reactor are presented. A qualitative physical model of steam-water mixture flow in the large diameter draught part is suggested. It is shown that for hydrodynamically unstable two-phase flows a considerable nonuniformity in steam content distribution over the draught part volume which determines the possibility of the recirculating coolant flow formation in the peripheral zone is observed. At the draught part inlet the radial distribution of steam content is determined by the complex effects of power distribution and coolant flow rate change over the core radius. The flow structure in the lower section of the draught part adjoining to the core is determined to a considerable degree by a coolant jet outflow from fuel assembly (FA) nozzels Jet height depends on the velocity of outgoing two-phase flow, working pressure and hydrodynamics of the draught part. The jet height does not exceed 0.4 m for the K-50 reactor. Due to the increased steam outflow from the central FAs and the existence of radial pressure gradient the water-steam mixture is turned from the draught part periphery to its central part, where accelerated water steam flow with an increased steam content is formed. When a certain height is achieved a graduel expansion of the water-steam flow begins leading to equalizing the steam content over the draught part cross section
An Adaptive Threshold Image Reconstruction Algorithm of Oil-Water Two-Phase Flow in Electrical Capacitance Tomography System

International Nuclear Information System (INIS)

Qin, M; Chen, D Y; Wang, L L; Yu, X Y

2006-01-01

The subject investigated in this paper is the ECT system of 8-electrode oil-water two-phase flow, and the measuring principle is analysed. In ART image-reconstruction algorithm, an adaptive threshold image reconstruction is presented to improve quality of image reconstruction and calculating accuracy of concentration, and generally the measurement error is about 1%. Such method can well solve many defects that other measurement methods may have, such as slow speed, high cost, and poor security and so on. Therefore, it offers a new method for the concentration measurement of oil-water two-phase flow
Stabilization of two-phase octanol/water flows inside poly(dimethylsiloxane) microchannels using polymer coatings

NARCIS (Netherlands)

van der Linden, H. J.; Jellema, L. C.; Holwerda, M.; Verpoorte, E.

In this paper we present our first results on the realization of stable water/octanol, two-phase flows inside poly(dimethylsiloxane) (PDMS) microchannels. Native PDMS microchannels were coated with high molecular weight polymers to change the surface properties of the microchannels and thus
Water solar distiller productivity enhancement using concentrating solar water heater and phase change material (PCM

Directory of Open Access Journals (Sweden)

Miqdam T. Chaichan

2015-03-01

Full Text Available This paper investigates usage of thermal energy storage extracted from concentrating solar heater for water distillation. Paraffin wax selected as a suitable phase change material, and it was used for storing thermal energy in two different insulated treasurers. The paraffin wax is receiving hot water from concentrating solar dish. This solar energy stored in PCM as latent heat energy. Solar energy stored in a day time with a large quantity, and some heat retrieved for later use. Water’s temperature measured in a definite interval of time. Four cases were studied: using water as storage material with and without solar tracker. Also, PCM was as thermal storage material with and without solar tracker.The system working time was increased to about 5 h with sun tracker by concentrating dish and adding PCM to the system. The system concentrating efficiency, heating efficiency, and system productivity, has increased by about 64.07%, 112.87%, and 307.54%, respectively. The system working time increased to 3 h when PCM added without sun tracker. Also, the system concentrating efficiency increased by about 50.47%, and the system heating efficiency increased by about 41.63%. Moreover, the system productivity increased by about 180%.
Loss of Propiconazole and its Four Stereoisomers from the Water Phase of Two Soil-Water Slurries as Measured by Capillary Electrophoresis

Science.gov (United States)

Propiconazole is a chiral fungicide used in agriculture for control of many fungal diseases on a variety of crops. This use provides opportunities for pollution of soil and, subsequently, groundwater. The rate of loss of propiconazole from the water phase of two different soil-wa...
Characterization of a plant leaf cuticle model wax, phase behaviour of model wax–water systems

Energy Technology Data Exchange (ETDEWEB)

Fagerström, Anton, E-mail: anton.fagerstrom@mah.se [Biomedical Science, Faculty of Health and Society, Malmö University, Malmö (Sweden); Kocherbitov, Vitaly [Biomedical Science, Faculty of Health and Society, Malmö University, Malmö (Sweden); Westbye, Peter; Bergström, Karin [Agro Applications Europe, AkzoNobel Surface Chemistry AB, Stenungsund (Sweden); Mamontova, Varvara [Ecological and Chemical Research, St. Petersburg Scientific Research Center for Ecological Safety, Russian Academy of Sciences, St. Petersburg (Russian Federation); Engblom, Johan [Biomedical Science, Faculty of Health and Society, Malmö University, Malmö (Sweden)

2013-11-10

Highlights: • Four individual crystalline phases were discovered in the model wax–water system. • Eutectic melting occurred in both dry and hydrated model wax. • The total transition enthalpy is smaller for the cuticle wax than for the model wax. • Water has a large plasticizing effect on cuticle wax. • The thermotropic transitions of model wax fit in the window of extracted leaf waxes. - Abstract: We investigated the thermotropic phase behaviour of plant leaf intracuticular wax and two representatives of its main components, 1-docosanol (C{sub 22}H{sub 45}OH) and dotriacontane (C{sub 32}H{sub 66}), in dry and hydrated state. One objective was to obtain a model wax, which can be used to estimate formulations effects on cuticle diffusivity in vitro. The two wax components were chosen based on results from Gas Chromatography coupled to Mass Spectrometry analysis of cuticular wax. The wax was extracted from Clivia Miniata Regel leaves and contained 68% primary alcohols (C{sub 16}–C{sub 32}) and 16% n-alkanes (C{sub 21}–C{sub 33}). Differential Scanning Calorimetry, Polarized Light Microscopy and Small- and Wide Angle X-ray Diffraction were used to characterize the cuticular extract and the phase behaviour of the C{sub 22}H{sub 45}OH/C{sub 32}H{sub 66}/H{sub 2}O model system. Four individual crystalline phases were discovered in the model wax–water system and eutectic melting occurred in both dry and hydrated state. The thermotropic transitions of the model wax occur within the broader transition region of the extracted leaf wax.
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
A novel drag force coefficient model for gas–water two-phase flows under different flow patterns

Energy Technology Data Exchange (ETDEWEB)

Shang, Zhi, E-mail: shangzhi@tsinghua.org.cn

2015-07-15

Graphical abstract: - Highlights: • A novel drag force coefficient model was established. • This model realized to cover different flow patterns for CFD. • Numerical simulations were performed under wide range flow regimes. • Validations were carried out through comparisons to experiments. - Abstract: A novel drag force coefficient model has been developed to study gas–water two-phase flows. In this drag force coefficient model, the terminal velocities were calculated through the revised drift flux model. The revised drift flux is different from the traditional drift flux model because the natural curve movement of the bubble was revised through considering the centrifugal force. Owing to the revisions, the revised drift flux model was to extend to 3D. Therefore it is suitable for CFD applications. In the revised drift flux model, the different flow patterns of the gas–water two-phase flows were able to be considered. This model innovatively realizes the drag force being able to cover different flow patterns of gas–water two-phase flows on bubbly flow, slug flow, churn flow, annular flow and mist flow. Through the comparisons of the numerical simulations to the experiments in vertical upward and downward pipe flows, this model was validated.
Non-Darcy interfacial dynamics of air-water two-phase flow in rough fractures under drainage conditions.

Science.gov (United States)

Chang, Chun; Ju, Yang; Xie, Heping; Zhou, Quanlin; Gao, Feng

2017-07-04

Two-phase flow interfacial dynamics in rough fractures is fundamental to understanding fluid transport in fractured media. The Haines jump of non-Darcy flow in porous media has been investigated at pore scales, but its fundamental processes in rough fractures remain unclear. In this study, the micron-scale Haines jump of the air-water interface in rough fractures was investigated under drainage conditions, with the air-water interface tracked using dyed water and an imaging system. The results indicate that the interfacial velocities represent significant Haines jumps when the meniscus passes from a narrow "throat" to a wide "body", with jump velocities as high as five times the bulk drainage velocity. Locally, each velocity jump corresponds to a fracture aperture variation; statistically, the velocity variations follow an exponential function of the aperture variations at a length scale of ~100 µm to ~100 mm. This spatial-scale-invariant correlation may indicate that the high-speed local velocities during the Haines jump would not average out spatially for a bulk system. The results may help in understanding the origin of interface instabilities and the resulting non-uniform phase distribution, as well as the micron-scale essence of the spatial and temporal instability of two-phase flow in fractured media at the macroscopic scale.
A Classroom Demonstration of Water-Induced Phase Separation of Alcohol-Gasoline Biofuel Blends

Science.gov (United States)

Mueller, Sherry A.; Anderson, James E.; Wallington, Timothy J.

2009-01-01

A significant issue associated with ethanol-gasoline blends is the phase separation that occurs with the addition of small volumes of water, producing an ethanol-deficient gasoline layer and an ethanol-rich aqueous layer. The gasoline layer may have a lower-than-desired octane rating due to the decrease in ethanol content, resulting in engine…
Elemental Water Impact Test: Phase 3 Plunge Depth of a 36-Inch Aluminum Tank Head

Science.gov (United States)

Vassilakos, Gregory J.

2014-01-01

Spacecraft are being designed based on LS-DYNA water landing simulations. The Elemental Water Impact Test (EWIT) series was undertaken to assess the accuracy of LS-DYNA water impact simulations. Phase 3 featured a composite tank head that was tested at a range of heights to verify the ability to predict structural failure of composites. To support planning for Phase 3, a test series was conducted with an aluminum tank head dropped from heights of 2, 6, 10, and 12 feet to verify that the test article would not impact the bottom of the test pool. This report focuses on the comparisons of the measured plunge depths to LS-DYNA predictions. The results for the tank head model demonstrated the following. 1. LS-DYNA provides accurate predictions for peak accelerations. 2. LS-DYNA consistently under-predicts plunge depth. An allowance of at least 20% should be added to the LS-DYNA predictions. 3. The LS-DYNA predictions for plunge depth are relatively insensitive to the fluid-structure coupling stiffness.
Investigation of temperature fluctuation phenomena in a stratified steam-water two-phase flow in a simulating pressurizer spray pipe of a pressurized water reactor

Energy Technology Data Exchange (ETDEWEB)

Miyoshi, Koji, E-mail: miyoshi.koj@inss.co.jp; Takenaka, Nobuyuki; Ishida, Taisuke; Sugimoto, Katsumi

2017-05-15

Highlights: • Thermal hydraulics phenomena were discussed in a spray pipe of pressurizer. • Temperature fluctuation was investigated in a stratified steam-water two-phase. • Remarkable liquid temperature fluctuations were observed in the liquid layer. • The observed temperature fluctuations were caused by the internal gravity wave. • The temperature fluctuations decreased with increasing dissolved oxygen. - Abstract: Temperature fluctuation phenomena in a stratified steam-water two-phase flow in a horizontal rectangular duct, which simulate a pressurizer spray pipe of a pressurized water reactor, were studied experimentally. Vertical distributions of the temperature and the liquid velocity were measured with water of various dissolved oxygen concentrations. Large liquid temperature fluctuations were observed when the water was deaerated well and dissolved oxygen concentration was around 10 ppb. The large temperature fluctuations were not observed when the oxygen concentration was higher. It was shown that the observed temperature fluctuations were caused by the internal gravity wave since the Richardson numbers were larger than 0.25 and the temperature fluctuation frequencies were around the Brunt-Väisälä frequencies in the present experimental conditions. The temperature fluctuations decreased by the non-condensable gas since the non-condensable gas suppressed the condensation and the temperature difference in the liquid layer was small.
Phase extraction equilibria in systems rare earth (3) nitrates-ammonium nitrate-water-trialkylmethylammonium nitrate

International Nuclear Information System (INIS)

Pyartman, A.K.; Kopyrin, A.A.; Puzikov, E.A.

1995-01-01

The distribution of rare earth metals (3) between aqueous and organic phases in the systems rare earth metal (3) (praseodymium-lutetium (3), yttrium (3)) nitrate-ammonium nitrate-water-trialkylmethylammonium (kerosene diluent nitrate has been studied. It is shown that in organic phase di- and trisolvates of metals (3) with tralkylmethylammonium nitrate are formed. The influence of concentration of rare earth metal (3) nitrate and ammonium nitrate on the values of extraction concentrational constants has been ascertained: they decrease with increase in the ordinal number of lanthanide (3). 11 refs., 4 figs. 1 tab
Results of the mid-term assessment of the 'High Performance Light Water Reactor Phase 2' project

International Nuclear Information System (INIS)

Starflinger, J.; Schulenberg, T.; Marsault, P.

2009-01-01

The High Performance Light Water Reactor (HPLWR) is a Light Water Reactor (LWR) operating at supercritical pressure (p>22.1 MPa). In Europe, investigations on the HPLWR have been integrated into a joint research project, called High Performance Light Water Reactor Phase 2 (HPLWR Phase 2), which is co-funded by the European Commission. Within the second year of the project, the design of the reactor core, the pressure vessel and its internals have been analysed in detail by means of advanced codes and methods. The mechanical design has been assessed and shows that stresses inside components and possible deformations keep within acceptable limits. The neutronics and the flow inside the core have been investigated. The addition of a water layer in the reflector helps to flatten the radial power profile. The moderator flow path must be changed because of possible reverse flow in the gaps between the assemblies (downward flow). First calculations of transients showed an acceptable behaviour of the cladding temperatures. Material oxidation experiments were successfully performed. The auxiliary loop of the Supercritical Water Loop has been constructed. Heat transfer has been investigated numerically analysing heat transfer deterioration (HTD) and flow around fuel pins with wire wrap spacers. (author)
Identification of the two-phase flow in the upper part of a boiling water reactor core using reactor noise analysis

International Nuclear Information System (INIS)

Miteff, L.

1983-08-01

The starting point of this work were neutron flux correlation measurements in the core of the Muehleberg boiling water reactor. During these measurements a new effect was observed i.e. that the cross power spectral density (CPSD) phases could be approximated by two straight lines of different slopes. The two linear domains of the CPSD-phases are separated along the frequency axis by a transition interval. It was supposed that such CPSD-phases could account for the propagation in the axial direction of two different thermohydraulic perturbations in the upper part of the Muehleberg BWR-core. It was also assumed that the second linear domain of these CPSD-phases could be related to a characteristic property of an annular flow regime of the steam-water two-phase flows in the bundles around the neutron detectors. The author attempts to give an explanation for the existence of a second transport phenomenon. This was achieved by in-core and out-core correlation measurements as well as by theoretical work. The out-core measurements were performed on an water-air simulation loop by use of laser beams. (Auth.)
Search for the first-order liquid-to-liquid phase transition in low-temperature confined water by neutron scattering

Science.gov (United States)

Chen, Sow-Hsin; Wang, Zhe; Kolesnikov, Alexander I.; Zhang, Yang; Liu, Kao-Hsiang

2013-02-01

It has been conjectured that a 1st order liquid-to-liquid (L-L) phase transition (LLPT) between high density liquid (HDL) and low density liquid (LDL) in supercooled water may exist, as a thermodynamic extension to the liquid phase of the 1st order transition established between the two bulk solid phases of amorphous ice, the high density amorphous ice (HDA) and the low density amorphous ice (LDA). In this paper, we first recall our previous attempts to establish the existence of the 1st order L-L phase transition through the use of two neutron scattering techniques: a constant Q elastic diffraction study of isobaric temperature scan of the D2O density, namely, the equation of state (EOS) measurements. A pronounced density hysteresis phenomenon in the temperature scan of the density above P = 1500 bar is observed which gives a plausible evidence of crossing the 1st order L-L phase transition line above this pressure; an incoherent quasi-elastic scattering measurements of temperature-dependence of the α-relaxation time of H2O at a series of pressures, namely, the study of the Fragile-to-Strong dynamic crossover (FSC) phenomenon as a function of pressure which we interpreted as the results of crossing the Widom line in the one-phase region. In this new experiment, we used incoherent inelastic neutron scattering (INS) to measure the density of states (DOS) of H atoms in H2O molecules in confined water as function of temperature and pressure, through which we may be able to follow the emergence of the LDL and HDL phases at supercooled temperature and high pressures. We here report for the first time the differences of librational and translational DOSs between the hypothetical HDL and LDL phases, which are similar to the corresponding differences between the well-established HDA and LDA ices. This is plausible evidence that the HDL and LDL phases are the thermodynamic extensions of the corresponding amorphous solid water HDA and LDA ices.
A double parameters measurement of steam-water two-phase flow with single orifice

International Nuclear Information System (INIS)

Zhong Shuoping; Tong Yunxian; Yu Meiying

1992-08-01

A double parameters measurement of steam-water two-phase flow with single orifice is described. An on-line measurement device based on micro-computer has been developed. The measured r.m.s error of steam quality is less than 6.5% and the measured relative r.m.s. error of mass flow rate is less than 9%
Phase Change Material Trade Study: A Comparison Between Wax and Water for Manned Spacecraft

Science.gov (United States)

Quinn, Gregory; Hodgson, Ed; Stephan, Ryan A,

2011-01-01

Phase change material heat sinks have been recognized as an important tool in optimizing thermal control systems for space exploration vehicles and habitats that must deal with widely varying thermal loads and environments. In order to better focus technology investment in this arena, NASA has supported a trade study with the objective of identifying where the best potential pay-off can be found among identified aqueous and paraffin wax phase change materials and phase change material heat sink design approaches. The study used a representative exploration mission with well understood parameters to support the trade. Additional sensitivity studies were performed to ensure the applicability of study results across varying systems and destinations. Results from the study indicate that replacing a wax PCM heat sink with a water ice PCM heat sink has the potential to decrease the equivalent system mass of the mission s vehicle through a combination of a smaller heat sink and a slight 5% increase in radiator size or the addition of a lightweight heat pump. An evaluation of existing and emerging PCM heat sink technologies indicates that further mass savings should be achievable through continued development of those technologies. The largest mass savings may be realized by eliminating the melting and freezing pressure of wax and water, respectively.

Heavy oil, water and air three-phase flow patterns in horizontal pipes; Padroes de escoamento trifasico de oleo pesado, agua e ar em tubulacoes horizontais

Energy Technology Data Exchange (ETDEWEB)

Trevisan, Francisco Exaltacao; Bannwart, Antonio Carlos [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil)

2004-07-01

A significant extent of the Brazilian oil reserves consists of heavy oil, and its importance and economic value have been increasing in the last years. However, these oils, besides their elevated densities (API degree lower than 20), have viscosities higher than 100 mPa.s, which make it more difficult their transportation in pipelines. A solution for this problem is the injection of water in the pipe, which causes a reduction of the friction factor and, consequently, of the energy expend for a given oil flow rate. The two-phase flow of heavy oil and water has been the object of a number of recent studies, and concepts such as the core-flow technology can be useful for heavy oil transportation. But in production operations, gas is also present, initially dissolved in the oil phase then leaving the solution to form a free gas phase if the pressure drops below the bubble point pressure, the study of three-phase flow of heavy oil, water and gas is in order. The present paper presents the experimental work developed to evaluate the effect that this third phase causes on the heavy oil-water two-phase flow pattern. Initially two-phase flow of heavy and gas-water was studied to establish the flow rate ranges that cover the main patterns already known. The superficial velocities used varied from 0,04 to 0,5 m/s for water, 0,01 to 22 m/s for gas and 0,02 to 1,2 m/s for oil. After that, three-phase flow patterns were visually determined through a 2,84 cm i.d. plexiglas tube using a high-speed camera. Nine three-phase flow patterns were identified which are presented visually and described. These flow-patterns are also presented in flow maps where the effect of the gas phase can be observed. Water was the continuous phase for all flow patterns observed, ensuring a low pressure drop along the pipe. (author)
Water interactions with condensed organic phases: a combined experimental and theoretical study of molecular-level processes

Science.gov (United States)

Johansson, Sofia M.; Kong, Xiangrui; Thomson, Erik S.; Papagiannakopoulos, Panos; Pettersson, Jan B. C.; Lovrić, Josip; Toubin, Céline

2016-04-01

Water uptake on aerosol particles modifies their chemistry and microphysics with important implications for air quality and climate. A large fraction of the atmospheric aerosol consists of organic aerosol particles or inorganic particles with condensed organic components. Here, we combine laboratory studies using the environmental molecular beam (EMB) method1 with molecular dynamics (MD) simulations to characterize water interactions with organic surfaces in detail. The over-arching aim is to characterize the mechanisms that govern water uptake, in order to guide the development of physics-based models to be used in atmospheric modelling. The EMB method enables molecular level studies of interactions between gases and volatile surfaces at near ambient pressure,1 and the technique may provide information about collision dynamics, surface and bulk accommodation, desorption and diffusion kinetics. Molecular dynamics simulations provide complementary information about the collision dynamics and initial interactions between gas molecules and the condensed phase. Here, we focus on water interactions with condensed alcohol phases that serve as highly simplified proxies for systems in the environment. Gas-surface collisions are in general found to be highly inelastic and result in efficient surface accommodation of water molecules. As a consequence, surface accommodation of water can be safely assumed to be close to unity under typical ambient conditions. Bulk accommodation is inefficient on solid alcohol and the condensed materials appear to produce hydrophobic surface structures, with limited opportunities for adsorbed water to form hydrogen bonds with surface molecules. Accommodation is significantly more efficient on the dynamic liquid alcohol surfaces. The results for n-butanol (BuOH) are particularly intriguing where substantial changes in water accommodation taking place over a 10 K interval below and above the BuOH melting point.2 The governing mechanisms for the
Entrainment and deposition studies in two-phase cross flow: comparison between air-water and steam-water in a square horizontal duct. Technical report (final)

International Nuclear Information System (INIS)

Berryman, R.J.; Ralph, J.C.; Wade, C.D.

1981-03-01

Air-water simulation studies of two phase steam water flow relevant to the upper plenum of a PWR during reflood situations have recently been undertaken at Harwell for the US Nuclear Regulatory Commission. In order to give confidence that the simulation fluids were capable of modelling the important features of the actual system, a relatively basic comparison experiment has been carried out. Water entrainment and deposition tests have been carried out on a pair of 2.5 cm diameter vertical rods mounted in a cross flow of steam or air in a 10.2 cm x 10.2 cm tunnel. The air and steam systems exhibited similar characteristics to one another. A 'critical' film flowrate was identified for the rods which, once reached, either by injection through the sinters or by entrainment from the main two phase stream, was not exceeded with further water addition. The 'critical' film flowrate decreased with increase of cross flow velocity and was lower for air than steam at the same velocity. The results from the air and steam tests were found to be reasonably well correlated on the basis of the cross flow momentum flux of the air or steam
An Experimental Design Approach for the Analysis of Liquid Phase Products in Water for Hydrogenolysis of Glycerol using Immersed Solid-Phase Micro extraction

International Nuclear Information System (INIS)

Noraini Hamzah; Rozita Osman; Noraini Hamzah; Mohd Ambar Yarmo

2013-01-01

In this study, a response surface methodology (RSM) was applied to optimize the immersed-solid-phase micro extraction (immersed-SPME) conditions for the first time using a polyacrylate (PA) coated fiber. This was to determine liquid phase compounds in water for hydrogenolysis reaction of glycerol. There are a three-factor response surface experimental design was used to evaluate the interactive effects of extraction temperature (30-70 degree Celsius), extraction time (10-30 minutes) and desorption time (2-18 minutes) on the analysis of liquid phase compounds in water for hydrogenolysis of glycerol using immersed-solid-phase micro extraction (immersed-SPME). The extraction conditions using immersed-SPME were optimized in order to achieve high enrichment of the analytes from aqueous samples. The isolated compounds from the SPME fiber were desorbed and separated on a capillary polar column of a gas chromatography-flame ionization detector (GC-FID). The extraction time and desorption time were found significant in increasing the amount of glycerol in aqueous hydrogenolysis of glycerol. Nevertheless, the effect of extraction temperature was not significant. In terms of interactions between the effects, the relation between extraction temperature and extraction time was the most significant. The optimised immersed-SPME conditions were at extraction temperature of 27 degree Celsius, extraction time of 30 minutes and 15 minutes of desorption time. Thus, the application of SPME was found to be a rapid and effective technique in the determination of glycerol and propylene glycol compounds in aqueous hydrogenolysis glycerol. (author)
Systematic comparison of crystalline and amorphous phases: Charting the landscape of water structures and transformations

International Nuclear Information System (INIS)

Pietrucci, Fabio; Martoňák, Roman

2015-01-01

Systematically resolving different crystalline phases starting from the atomic positions, a mandatory step in algorithms for the prediction of structures or for the simulation of phase transitions, can be a non-trivial task. Extending to amorphous phases and liquids which lack the discrete symmetries, the problem becomes even more difficult, involving subtle topological differences at medium range that, however, are crucial to the physico-chemical and spectroscopic properties of the corresponding materials. Typically, system-tailored order parameters are devised, like global or local symmetry indicators, ring populations, etc. We show that a recently introduced metric provides a simple and general solution to this intricate problem. In particular, we demonstrate that a map can be traced displaying distances among water phases, including crystalline as well as amorphous states and the liquid, consistently with experimental knowledge in terms of phase diagram, structural features, and preparation routes
Analysis of Mechanical Energy Transport on Free-Falling Wedge during Water-Entry Phase

Directory of Open Access Journals (Sweden)

Wen-Hua Wang

2012-01-01

Full Text Available For better discussing and understanding the physical phenomena and body-fluid interaction of water-entry problem, here mechanical-energy transport (wedge, fluid, and each other of water-entry model for free falling wedge is studied by numerical method based on free surface capturing method and Cartesian cut cell mesh. In this method, incompressible Euler equations for a variable density fluid are numerically calculated by the finite volume method. Then artificial compressibility method, dual-time stepping technique, and Roe's approximate Riemann solver are applied in the numerical scheme. Furthermore, the projection method of momentum equations and exact Riemann solution are used to calculate the fluid pressure on solid boundary. On this basis, during water-entry phase of the free-falling wedge, macroscopic energy conversion of overall body-fluid system and microscopic energy transformation in fluid field are analyzed and discussed. Finally, based on test cases, many useful conclusions about mechanical energy transport for water entry problem are made and presented.
Two types of lamellar phase in TTAB/water/pentanol system as detected by positron lifetime spectroscopy

International Nuclear Information System (INIS)

Khani, P.H.; Yadav, R.; Singh, K.C.; Jain, P.C.

2004-01-01

Positron lifetime measurements were performed in TTAB(Tetradecyl trimethyl ammonium bromide)/water/pentanol ternary systems prepared by adding varying amounts of pentanol to different mother solutions of TTAB/water system having fixed TTAB concentrations. Besides delineating various phase boundaries as obtained by other conventional techniques, positron annihilation parameters were also found to be sensitive in detecting two kinds of lamellar structures in the otherwise considered to be a single liquid crystalline D phase of the system. The existence of such lamellar structures has been demonstrated by a change in the trend of o-Ps lifetime parameter when the system passes from one type of lamellar structure to the other type. The results of such a finding are presented in this paper. (orig.)
Identification of secondary phases formed during unsaturated reaction of UO2 with EJ-13 water

International Nuclear Information System (INIS)

Bates, J.K.; Tani, B.S.; Veleckis, E.

1989-01-01

A set of experiments, wherein UO 2 has been contacted by dripping water, has been conducted over a period of 182.5 weeks. The experiments are being conducted to develop procedures to study spent fuel reaction under unsaturated conditions that are expected to exist over the lifetime of the proposed Yucca Mountain repository site. One half of the experiments have been terminated, while one half are ongoing. Analyses of solutions that have dripped from the reacted UO 2 have been performed for all experiments, while the reacted UO 2 surfaces have been examined for the terminated experiments. A pulse of uranium release from the UO 2 solid, combined with the formation of schoepite on the surface of the UO 2 , was observed between 39 and 96 weeks of reaction. Thereafter, the uranium release decreased and a second set of secondary phases was observed. The latter phases incorporated cations from the EJ-13 water and included boltwoodite, uranophane, sklodowskite, compreignacite, and schoepite. The experiments are continuing to monitor whether additional changes in solution chemistry or secondary phase formation occurs. 6 refs., 2 figs., 2 tabs
Method development for determination of herbicides and insecticides in surface waters using solid-phase extraction and high performance liquid chromatography

International Nuclear Information System (INIS)

Lebre, Daniel Temponi

2000-01-01

Determination of low concentrations of pesticides in surface and ground waters requires high sensitivity analytical techniques. Solid-Phase Extraction (SPE) has been successfully employed to pre concentrate and extract pesticides compounds from water samples. High Performance Liquid Chromatography (HPLC) coupled with UV/Vis detector was used to separate and quantify the extracted compounds. In this work, samples of surface waters with known concentrations of herbicides (atrazine, simazine and trifluralin) and insecticides (aldicarb, carbofuran and carbaryl) were extracted by using SPE off-line technique. The compounds were separated and quantified by reverse phase HPLC with UV detection at 220 ηm. The extraction efficiency was compared between two columns filled with different materials: C 18 -bonded silica phase (500 mg) and copolymer styrenedivynilbenzene resin (250 mg). The results were evaluated as the percent recovery of compounds obtained using different solvents at different concentrations. The results showed that recovery of the analytes greater than 80 % were obtained in SPE columns filled with C 18 bonded silica phase with 6 mL of acetonitrile. Once the optimum conditions were chosen for simulate water samples, the method was validated through analytical and statistical procedures and applied for surface waters. The suitability of the method was verified for the studied compounds showing good sensitivity, i. e., concentrations within the range of 0.4 to 4.0 μgL -1 of pesticides could be quantified attending the limits proposed by official regulations. (author)
A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants.

Science.gov (United States)

Heub, Sarah; Tscharner, Noe; Kehl, Florian; Dittrich, Petra S; Follonier, Stéphane; Barbe, Laurent

2016-01-01

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and enables to perform rapid, automated and simple SPE. The pre-concentrated solution is compatible with analysis by immunoassay, with a low organic solvent content. A method is described for the extraction and pre-concentration of natural hormone 17β-estradiol in 100 ml water samples. Reverse phase SPE is performed with octadecyl-silica sorbent and elution is done with 200 µl of methanol 50% v/v. Eluent is diluted by adding di-water to lower the amount of methanol. After preparing manually the SPE column, the overall procedure is performed automatically within 1 hr. At the end of the process, estradiol concentration is measured by using a commercial enzyme-linked immune-sorbent assay (ELISA). 100-fold pre-concentration is achieved and the methanol content in only 10% v/v. Full recoveries of the molecule are achieved with 1 ng/L spiked de-ionized and synthetic sea water samples.
Transient analysis of air-water two-phase flow in channels and bends

International Nuclear Information System (INIS)

Khan, H.J.; Ye, W.; Pertmer, G.A.

1992-01-01

The algorithm used in this paper is the Newton Block Gauss Seidel method, which has been applied to both simple and complex flow conditions in two-phase flow. This paper contains a description of difference techniques and an iterative solution algorithm that is used to solve the field and constitutive equations of the two-fluid model. In practice, this solution procedure has been proven to be stable and capable of generating solutions in problems where other schemes have failed. The method converges rapidly for reasonable error tolerances and is easily extended to three-dimensional geometries. Using air-water as the two-phase medium, transient flow behavior in several geometries of interest are shown. Flow through a vertical channel with flow obstruction, large U bends, and 90-deg bends are being demonstrated with variation of inlet void fraction and slip ratio. Significant changes in the velocity and void distribution profiles have been observed. Various regions of flow recirculation are obtained in the flow domain for each phase. The phasic velocity and void distributions are dominated by gravity-induced phase separation causing air to accumulate in the upper region. The influence of inlet slip ratio and interfacial momentum transfer on the transient flow profile has been demonstrated in detail
Single-phase flow and flow boiling of water in horizontal rectangular microchannels

OpenAIRE

Mirmanto

2013-01-01

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University The current study is part of a long term experimental project devoted to investigating single-phase flow pressure drop and heat transfer, flow boiling pressure drop and heat transfer, flow boiling instability and flow visualization of de-ionized water flow in microchannels. The experimental facility was first designed and constructed by S. Gedupudi (2009) and in the present study; ...
Comparison of electrical and optical characteristics in gas-phase and gas-liquid phase discharges

Energy Technology Data Exchange (ETDEWEB)

Qazi, H. I. A.; Li, He-Ping, E-mail: liheping@tsinghua.edu.cn; Zhang, Xiao-Fei; Bao, Cheng-Yu [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Nie, Qiu-Yue [School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang Province 150001 (China)

2015-12-15

This paper presents an AC-excited argon discharge generated using a gas-liquid (two-phase) hybrid plasma reactor, which mainly consists of a powered needle electrode enclosed in a conical quartz tube and grounded deionized water electrode. The discharges in the gas-phase, as well as in the two-phase, exhibit two discharge modes, i.e., the low current glow-like diffuse mode and the high current streamer-like constrict mode, with a mode transition, which exhibits a negative resistance of the discharges. The optical emission spectral analysis shows that the stronger diffusion of the water vapor into the discharge region in the two-phase discharges boosts up the generation of OH (A–X) radicals, and consequently, leads to a higher rotational temperature in the water-phase plasma plume than that of the gas-phase discharges. Both the increase of the power input and the decrease of the argon flow rate result in the increase of the rotational temperature in the plasma plume of the water-phase discharge. The stable two-phase discharges with a long plasma plume in the water-phase under a low power input and gas flow rate may show a promising prospect for the degradation of organic pollutants, e.g., printing and dyeing wastewater, in the field of environmental protection.
Characterization of the Solutol® HS15/water phase diagram and the impact of the Δ9-tetrahydrocannabinol solubilization.

Science.gov (United States)

Murgia, Sergio; Fadda, Paolo; Colafemmina, Giuseppe; Angelico, Ruggero; Corrado, Luigi; Lazzari, Paolo; Monduzzi, Maura; Palazzo, Gerardo

2013-01-15

Here, the phase behavior of the commercial non-ionic surfactant Solutol® HS15 in water was investigated. The focus was on the evolution of the system nanostructure at low water content. Particularly, it was demonstrated that spherical micelles found in dilute surfactant solutions coalesce at a surfactant volume fraction close to 0.5. As consequence, a heterogeneous pseudo-binary mixture occurs. No liquid crystalline phases were detected even at the highest HS15 concentrations in water. Alteration of the micellar morphology induced by the addition of Δ(9)-tetrahydrocannabinol to the surfactant/water binary system was also investigated. It was found that the cannabinoid molecules become entrapped within the surfactant hydrophobic tails, thus increasing the surfactant effective packing parameter and inducing a radical change of the micelle shape. At sufficiently low water content (18-35 wt.%), such alteration of the interfacial packing results in a lamellar organization of the surfactant molecules. Copyright © 2012 Elsevier Inc. All rights reserved.
Air-water two-phase flow in a four by four rod bundle with partial length rods

International Nuclear Information System (INIS)

Ohta, Motoki; Kamei, Akihiro; Mizutani, Yoshitaka; Hosokawa, Shigeo; Tomiyama, Akio

2009-01-01

Partial length rods (PLR) are used in fuel bundles of BWR to reduce pressure drops in two-phase regions and to optimize the power distribution. Since little is known about effects of PLR on two-phase flows, air-water two-phase flow around PLRs in a four by four rod bundle is visualized by using a high-speed video camera. The experimental apparatus consists of acrylic channel box and transparent rods. Air and water at atmospheric pressure and room temperature are used for the gas and liquid phases, respectively. The ranges of the gas and liquid volume fluxes, J G and J L , are 0.4 L G L , the flow pattern in the downstream of PLR transits to slug flow, and the flow patterns in the surrounding subchannels transit to bubbly flow due to the redistribution of gas flow. (2) In annular flow, the liquid film on the PLR forms a liquid column above the end cap of PLR. Droplets are generated by column breakup and deposit on liquid films on the neighboring rods. (3) The liquid film thickness on the surface of neighbor rods facing the PLR increases and it reduces that on their opposite surface in the downstream of PLR. (author)
Phase diagram of tetradecyltrimethylammonium bromide (TTAB) + water + octanol system with application of mechanical deformation

Science.gov (United States)

Yavuz, Aykut Evren; Masalci, Özgür; Kazanci, Nadide

2014-11-01

Morphological properties of tetradecyltrimethylammonium bromide (TTAB) + water + octanol system in different concentrations have been studied. In the process, isotropic phase (L1) and nematic calamitic (NC), nematic discotic (ND), hexagonal E and lamellar D anizotropic mesophases have been determined by polarizing microscopy method and partial ternary phase diagram of the system set up. Textural properties of the anisotropic mesophases of the system have been discussed and their birefringence values measured. Mechanical deformation has been applied to the mesophases. The textural properties and the birefringence values have been observed to be changed by the deformation, after and before which changes have been compared.
Three-Phase Melting Curves in the Binary System of Carbon Dioxide and Water

Science.gov (United States)

Abramson, E. H.

2017-10-01

Invariant, three-phase melting curves, of ice VI in equilibrium with solid CO2, of ice VII in equilibrium with solid CO2, and of solid CO2 in simultaneous equilibrium with a majority aqueous and a majority CO2 fluid, were explored in the binary system of carbon dioxide and water. Diamond-anvil cells were used to develop pressures of 5 GPa. Water exhibits a large melting temperature depression (73°C less than its pure melting temperature of 253°C at 5 GPa) indicative of large concentrations of CO2 in the aqueous solution. The melting point of water-saturated CO2 does not show a measureable departure from that of the pure system at temperatures lower than ∼200°C and only 10°C at 5 GPa (from 327°C).
X-ray photoelectron spectroscopy characterization of the ω phase in water quenched Ti-5553 alloy

International Nuclear Information System (INIS)

Qin, Dongyang; Lu, Yafeng; Zhang, Kong; Liu, Qian; Zhou, Lian

2012-01-01

X-ray photoelectron spectroscopy was used to investigate the ω phase in water quenched Ti-5553 alloy with a nominal composition of Ti–5Al–5V–5Mo–3Cr (wt.%), and the ω and the β phase were distinguished by deconvoluting the XPS spectra of Al2p, V2p and Cr2p core level regions. In addition, it is found that the binding energy of core level electron of alloying elements shifts comparing with that of pure metals, and the fact was interpreted by charge redistribution model. X-ray photoelectron spectroscopy technique could be used to characterize the nano-scale ω phase in β alloys. - Highlights: ► We characterize the ω phase in Ti-5553 alloy by XPS. ► Binding energy of Al2p, V2p and Cr2p electron are different in the ω and β phase. ► Structural difference leads to the binding energy gap.
Water and fat separation in real-time MRI of joint movement with phase-sensitive bSSFP.

Science.gov (United States)

Mazzoli, Valentina; Nederveen, Aart J; Oudeman, Jos; Sprengers, Andre; Nicolay, Klaas; Strijkers, Gustav J; Verdonschot, Nico

2017-07-01

To introduce a method for obtaining fat-suppressed images in real-time MRI of moving joints at 3 Tesla (T) using a bSSFP sequence with phase detection to enhance visualization of soft tissue structures during motion. The wrist and knee of nine volunteers were imaged with a real-time bSSFP sequence while performing dynamic tasks. For appropriate choice of sequence timing parameters, water and fat pixels showed an out-of-phase behavior, which was exploited to reconstruct water and fat images. Additionally, a 2-point Dixon sequence was used for dynamic imaging of the joints, and resulting water and fat images were compared with our proposed method. The joints could be visualized with good water-fat separation and signal-to-noise ratio (SNR), while maintaining a relatively high temporal resolution (5 fps in knee imaging and 10 fps in wrist imaging). The proposed method produced images of moving joints with higher SNR and higher image quality when compared with the Dixon method. Water-fat separation is feasible in real-time MRI of moving knee and wrist at 3 T. PS-bSSFP offers movies with higher SNR and higher diagnostic quality when compared with Dixon scans. Magn Reson Med 78:58-68, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.
The study on three-dimensional mathematical model of river bed erosion for water-sediment two-phase flow

Science.gov (United States)

Fang, Hongwei

1996-02-01

Based on the tensor analysis of water-sediment two-phase flow, the basic model equations for clear water flow and sediment-laden flow are deduced in the general curve coordinates for natural water variable-density turbulent flow. Furthermore, corresponding boundary conditions are also presented in connection with the composition and movement of non-uniform bed material. The theoretical results are applied to the calculation of the float open caisson in the construction period and good results are obtained.

Effect of insulin phase state in water on its radiation stability

Energy Technology Data Exchange (ETDEWEB)

Soboleva, N N; Ivanova, A I; Tal' roze, V L; Trofimov, V I; Fedotov, V P [Nauchno-Issledovatel' skij Inst. po Biologicheskim Ispytaniyam Khimicheskikh Soedinenij (USSR); AN SSSR, Moscow. Inst. Khimicheskoj Fiziki; Akademiya Meditsinskikh Nauk SSSR, Moscow. Inst. Ehksperimental' noj Ehndokrinologii i Khimii Gormonov)

1980-01-01

Radiation stability of the aqueous solution and the insulin suspension is investigated. The degree of radiation transformations is determined by means of chromatography on paper and with the method of cramp reaction in mice. ..gamma..-irradiation is carried out at room temperature, at dose rate of 0.75 M rad/h. The data obtained prove the earlier suggested hypothesis of a phase division of a biologically active compound, personally medicinal substance and water (for example, in the case of which permits to prolong the preservation of medicine in the case of irradiation.
Evidence for phase separation of ethanol-water mixtures at the hydrogen terminated nanocrystalline diamond surface.

Science.gov (United States)

Janssens, Stoffel D; Drijkoningen, Sien; Saitner, Marc; Boyen, Hans-Gerd; Wagner, Patrick; Larsson, Karin; Haenen, Ken

2012-07-28

Interactions between ethanol-water mixtures and a hydrophobic hydrogen terminated nanocrystalline diamond surface, are investigated by sessile drop contact angle measurements. The surface free energy of the hydrophobic surface, obtained with pure liquids, differs strongly from values obtained by ethanol-water mixtures. Here, a model which explains this difference is presented. The model suggests that, due to a higher affinity of ethanol for the hydrophobic surface, when compared to water, a phase separation occurs when a mixture of both liquids is in contact with the H-terminated diamond surface. These results are supported by a computational study giving insight in the affinity and related interaction at the liquid-solid interface.
Determination of Inorganic Arsenic in Natural Water by Solid Phase Extraction

International Nuclear Information System (INIS)

Nazaratul Ashifa Abdullah Salim; Amares Chatt, A.

2011-01-01

Arsenic (As) is generally known for its toxicity. The toxicity and mobility of As in the environment are dependent on the chemical forms or species in which it exists. Arsenic (III) and (V) are the most often determined species in environmental water, soil and sediment, while organic As species are common constituents of biological tissue and fluids. It is well known that inorganic As, such as arsenite (As(III)) and arsenate (As(V)) are more toxic than their organic counterparts. This study is conducted to investigate the separation of each As inorganic species using solid phase extraction (SPE) technique. The technique utilizes SPE column for selective retention of As species, followed by elution and measurement of eluted fractions by inductively coupled plasma mass spectrometry (ICP-MS) for total As. Several type of SPE columns namely strongly anion exchange (SAX), strongly cation exchange (SCX), weakly anion exchange (WAX) and weakly cation exchange (WCX) were tested using three different types of media including deionized water, succinic acid and acetic acid containing inorganic As species. The SPE technique is suitable for on-site separation and preservation of As species from water. (author)
Petroleum activity in ice covered waters - development and operation phase. Focus of eventual consequential explanation

International Nuclear Information System (INIS)

Thomassen, J.; Andresen, K.H.; Moe, K.A.

1996-06-01

This report from a seminar relates to the petroleum activities in the Barentshavet north. The focal point was to put on petroleum activities in ice covered waters covering the drilling and operation phase, to identify discharges from various technical solutions, and to classify possible research requirements when mapping the impacts of such components. In addition to this approach, the seminar also focused on other factors regarding drilling and production activities in ice covered waters. 3 refs., 13 figs., 25 tabs
Application of non-aqueous solvents to batteries. I Physicochemical properties of propionitrile/water two-phase solvent relevant to zinc-bromine batteries

Science.gov (United States)

Singh, P.; White, K.; Parker, A. J.

1983-11-01

The properties of bromine/propionitrile solution are investigated with a view to its use as an electrolyte in zinc-bromine batteries which use circulating electrolyte. The solution, which forms a two-phase system with water, has higher conductivity than the oils formed by complexation of bromine with organic salts such as N,N-methoxymethyl methylpiperidinium bromide and N,N-ethyl methylmorpholinium bromide. The activity of bromine in the aqueous phase of the bromine-propionitrile/water, two-phase system is very low; thus, coulombic efficiencies greater than 85 percent are achieved. Zinc-bromine batteries containing this solvent system show good charge/discharge characteristics.
Impacts of Forest to Urban Land Conversion and ENSO Phase on Water Quality of a Public Water Supply Reservoir

Directory of Open Access Journals (Sweden)

Emile Elias

2016-01-01

Full Text Available We used coupled watershed and reservoir models to evaluate the impacts of deforestation and l Niño Southern Oscillation (ENSO phase on drinking water quality. Source water total organic carbon (TOC is especially important due to the potential for production of carcinogenic disinfection byproducts (DBPs. The Environmental Fluid Dynamics Code (EFDC reservoir model is used to evaluate the difference between daily pre- and post- urbanization nutrients and TOC concentration. Post-disturbance (future reservoir total nitrogen (TN, total phosphorus (TP, TOC and chlorophyll-a concentrations were found to be higher than pre-urbanization (base concentrations (p < 0.05. Predicted future median TOC concentration was 1.1 mg·L−1 (41% higher than base TOC concentration at the source water intake. Simulations show that prior to urbanization, additional water treatment was necessary on 47% of the days between May and October. However, following simulated urbanization, additional drinking water treatment might be continuously necessary between May and October. One of six ENSO indices is weakly negatively correlated with the measured reservoir TOC indicating there may be higher TOC concentrations in times of lower streamflow (La Niña. There is a positive significant correlation between simulated TN and TP concentrations with ENSO suggesting higher concentrations during El Niño.
ESTIMATION OF PHASE DELAY DUE TO PRECIPITABLE WATER FOR DINSARBASED LAND DEFORMATION MONITORING

Directory of Open Access Journals (Sweden)

J. Susaki

2017-09-01

Full Text Available In this paper, we present a method for using the estimated precipitable water (PW to mitigate atmospheric phase delay in order to improve the accuracy of land-deformation assessment with differential interferometric synthetic aperture radar (DInSAR. The phase difference obtained from multi-temporal synthetic aperture radar images contains errors of several types, and the atmospheric phase delay can be an obstacle to estimating surface subsidence. In this study, we calculate PW from external meteorological data. Firstly, we interpolate the data with regard to their spatial and temporal resolutions. Then, assuming a range direction between a target pixel and the sensor, we derive the cumulative amount of differential PW at the height of the slant range vector at pixels along that direction. The atmospheric phase delay of each interferogram is acquired by taking a residual after a preliminary determination of the linear deformation velocity and digital elevation model (DEM error, and by applying high-pass temporal and low-pass spatial filters. Next, we estimate a regression model that connects the cumulative amount of PW and the atmospheric phase delay. Finally, we subtract the contribution of the atmospheric phase delay from the phase difference of the interferogram, and determine the linear deformation velocity and DEM error. The experimental results show a consistent relationship between the cumulative amount of differential PW and the atmospheric phase delay. An improvement in land-deformation accuracy is observed at a point at which the deformation is relatively large. Although further investigation is necessary, we conclude at this stage that the proposed approach has the potential to improve the accuracy of the DInSAR technique.
Concentration data for anthropogenic organic compounds in ground water, surface water, and finished water of selected community water systems in the United States, 2002-05

Science.gov (United States)

Carter, Janet M.; Delzer, Gregory C.; Kingsbury, James A.; Hopple, Jessica A.

2007-01-01

The National Water-Quality Assessment Program of the U.S. Geological Survey began implementing Source Water-Quality Assessments (SWQAs) in 2001 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems (CWSs) in the United States. As used for SWQA studies, source water is the raw (ambient) water collected at the supply well prior to water treatment (for ground water) or the raw (ambient) water collected from the river near the intake (for surface water), and finished water is the water that is treated and ready to be delivered to consumers. Finished water is collected before entering the distribution system. SWQA studies are conducted in two phases, and the objectives of SWQA studies are twofold: (1) to determine the occurrence and, for rivers, seasonal changes in concentrations of a broad list of anthropogenic organic compounds (AOCs) in aquifers and rivers that have some of the largest withdrawals for drinking-water supply (phase 1), and (2) for those AOCs found to occur most frequently in source water, characterize the extent to which these compounds are present in finished water (phase 2). These objectives were met for SWQA studies by collecting ground-water and surface-water (source) samples and analyzing these samples for 258 AOCs during phase 1. Samples from a subset of wells and surface-water sites located in areas with substantial agricultural production in the watershed were analyzed for 19 additional AOCs, for a total of 277 compounds analyzed for SWQA studies. The 277 compounds were classified according to the following 13 primary use or source groups: (1) disinfection by-products; (2) fumigant-related compounds; (3) fungicides; (4) gasoline hydrocarbons, oxygenates, and oxygenate degradates; (5) herbicides and herbicide degradates; (6) insecticides and insecticide degradates; (7) manufacturing additives; (8) organic synthesis compounds; (9) pavement- and
Two-phase flow in the upper plenum of a boiling water nuclear reactor

International Nuclear Information System (INIS)

Tinoco, Hernan

2003-01-01

The end part of the Emergency Core Spray System (ECSS) of the Boiling Water Reactors (BWRs) at Forsmark Nuclear Power Plant (NPP) is situated in the Upper Plenum. It consists of a pipe network equipped with water injection nozzles. In case of Lost-of-Coolant Accidents (LOCAs), the ECSS should maintain the core covered by water and, at the same time, rapidly cool and decompress the reactor by means of cold water injection. In similar reactors, some welds belonging to the ECSS support have, after a period of time, shown crack indications. Inspection, repair or replacement of these welds is time consuming and expensive. For this reason, it has now been decided to permanently remove the end part of the ECSS and to replace it by water injection in the Downcomer. However, this removal should not be accompanied by undesirable effects like an increase in the moisture of the steam used for operating the turbines. To investigate the effect of this removal on the steam moisture, a CFD analysis of the two-phase flow in the Upper Plenum of Unit 3, with and without ECSS, has been carried out by means of a two-phase Euler model in FLUENT 6.0. The inlet conditions are given by an analysis of the core kinetics and thermal hydraulics by mean of the POLCA-code. The outlet conditions, i. e. the steam separator pressure drops, are given by empirical correlations from the experiments carried out at the SNORRE facility. The predicted the mass flow-rates to each separator, together with empirical correlations for the moisture content of the steam leaving the separators and the steam dryer, indicate a slight decrease in the steam moisture when the ECSS is removed. Also, a minor decrease in pressure losses over the Upper Plenum is achieved with this removal. On the other hand, rounding the sharp edges of the inlet openings to the steam separators at the shroud cover may give a large reduction in pressure losses
Determination of colloidal and dissolved silver in water samples using colorimetric solid-phase extraction.

Science.gov (United States)

Hill, April A; Lipert, Robert J; Porter, Marc D

2010-03-15

The increase in bacterial resistance to antibiotics has led to resurgence in the use of silver as a biocidal agent in applications ranging from washing machine additives to the drinking water treatment system on the International Space Station (ISS). However, growing concerns about the possible toxicity of colloidal silver to bacteria, aquatic organisms and humans have led to recently issued regulations by the US EPA and FDA regarding the usage of silver. As part of an ongoing project, we have developed a rapid, simple method for determining total silver, both ionic (silver(I)) and colloidal, in 0.1-1mg/L aqueous samples, which spans the ISS potable water target of 0.3-0.5mg/L (total silver) and meets the US EPA limit of 0.1mg/L in drinking water. The method is based on colorimetric solid-phase extraction (C-SPE) and involves the extraction of silver(I) from water samples by passage through a solid-phase membrane impregnated with the colorimetric reagent DMABR (5-[4-(dimethylamino)benzylidene]rhodanine). Silver(I) exhaustively reacts with impregnated DMABR to form a colored compound, which is quantified using a handheld diffuse reflectance spectrophotometer. Total silver is determined by first passing the sample through a cartridge containing Oxone, which exhaustively oxidizes colloidal silver to dissolved silver(I). The method, which takes less than 2 min to complete and requires only approximately 1 mL of sample, has been validated through a series of tests, including a comparison with the ICP-MS analysis of a water sample from ISS that contained both silver(I) and colloidal silver. Potential earth-bound applications are also briefly discussed. Copyright (c) 2009 Elsevier B.V. All rights reserved.
Primary collector wall local temperature fluctuations in the area of water-steam phase boundary

Energy Technology Data Exchange (ETDEWEB)

Matal, O.; Klinga, J.; Simo, T. [Energovyzkum Ltd., Brno (Switzerland)

1995-12-31

A limited number of temperature sensors could be installed at the primary collector surface in the area of water - steam phase boundary. The surface temperatures as well WWER 440 steam generator process data were measured and stored for a long time and off-line evaluated. Selected results are presented in the paper. (orig.). 2 refs.
Primary collector wall local temperature fluctuations in the area of water-steam phase boundary

Energy Technology Data Exchange (ETDEWEB)

Matal, O; Klinga, J; Simo, T [Energovyzkum Ltd., Brno (Switzerland)

1996-12-31

A limited number of temperature sensors could be installed at the primary collector surface in the area of water - steam phase boundary. The surface temperatures as well WWER 440 steam generator process data were measured and stored for a long time and off-line evaluated. Selected results are presented in the paper. (orig.). 2 refs.
Evaporation phase change processes of water/methanol mixtures on superhydrophobic nanostructured surfaces

Science.gov (United States)

Chiang, Cheng-Kun; Lu, Yen-Wen

2011-07-01

Evaporation phenomena are a critical and frequently seen phase change process in many heat transfer applications. In this paper, we study the evaporation process of a sessile droplet on two topologically different surfaces, including smooth and nanostructured surfaces. The nanostructured surface has an array of high-aspect-ratio nanowires (height/diameter ~ 125) and is implemented by using a simple template-based nanofabrication method. It possesses superhydrophobicity (>140°) and low contact angle hysteresis (1.2-2.1°), allowing the liquid droplets to remain in the 'fakir' state throughout the evaporation processes. Sessile droplets of deionized (DI) water and water/methanol binary mixture test liquids with their contact angles and base diameters are monitored. The results show that the nanostructures play a critical role in the droplet dynamics during evaporation.
Evaporation phase change processes of water/methanol mixtures on superhydrophobic nanostructured surfaces

International Nuclear Information System (INIS)

Chiang, Cheng-Kun; Lu, Yen-Wen

2011-01-01

Evaporation phenomena are a critical and frequently seen phase change process in many heat transfer applications. In this paper, we study the evaporation process of a sessile droplet on two topologically different surfaces, including smooth and nanostructured surfaces. The nanostructured surface has an array of high-aspect-ratio nanowires (height/diameter ∼ 125) and is implemented by using a simple template-based nanofabrication method. It possesses superhydrophobicity (>140°) and low contact angle hysteresis (1.2–2.1°), allowing the liquid droplets to remain in the 'fakir' state throughout the evaporation processes. Sessile droplets of deionized (DI) water and water/methanol binary mixture test liquids with their contact angles and base diameters are monitored. The results show that the nanostructures play a critical role in the droplet dynamics during evaporation
Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis

Science.gov (United States)

Meyer, M.T.; Mills, M.S.; Thurman, E.M.

1993-01-01

An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 ??g/l was achieved for each compound tested. More than 10,000 surface and ground water samples have been analyzed by this method.
Phase II modification of the Water Availability Tool for Environmental Resources (WATER) for Kentucky: The sinkhole-drainage process, point-and-click basin delineation, and results of karst test-basin simulations

Science.gov (United States)

Taylor, Charles J.; Williamson, Tanja N.; Newson, Jeremy K.; Ulery, Randy L.; Nelson, Hugh L.; Cinotto, Peter J.

2012-01-01

This report describes Phase II modifications made to the Water Availability Tool for Environmental Resources (WATER), which applies the process-based TOPMODEL approach to simulate or predict stream discharge in surface basins in the Commonwealth of Kentucky. The previous (Phase I) version of WATER did not provide a means of identifying sinkhole catchments or accounting for the effects of karst (internal) drainage in a TOPMODEL-simulated basin. In the Phase II version of WATER, sinkhole catchments are automatically identified and delineated as internally drained subbasins, and a modified TOPMODEL approach (called the sinkhole drainage process, or SDP-TOPMODEL) is applied that calculates mean daily discharges for the basin based on summed area-weighted contributions from sinkhole drain-age (SD) areas and non-karstic topographically drained (TD) areas. Results obtained using the SDP-TOPMODEL approach were evaluated for 12 karst test basins located in each of the major karst terrains in Kentucky. Visual comparison of simulated hydrographs and flow-duration curves, along with statistical measures applied to the simulated discharge data (bias, correlation, root mean square error, and Nash-Sutcliffe efficiency coefficients), indicate that the SDPOPMODEL approach provides acceptably accurate estimates of discharge for most flow conditions and typically provides more accurate simulation of stream discharge in karstic basins compared to the standard TOPMODEL approach. Additional programming modifications made to the Phase II version of WATER included implementation of a point-and-click graphical user interface (GUI), which fully automates the delineation of simulation-basin boundaries and improves the speed of input-data processing. The Phase II version of WATER enables the user to select a pour point anywhere on a stream reach of interest, and the program will automatically delineate all upstream areas that contribute drainage to that point. This capability enables
Determination of phenyl-N-methylcarbamates and their hydrolysis products in water, using solid-phase extraction and reversed-phase liquid chromatography with UV and electrospray mass spectrometric detection

International Nuclear Information System (INIS)

El Atrache, L.L.; Sabbah, S.

2003-01-01

In this study, eight phenyl-N-methylcarbamates (PNMCs) were considered. Reversed-phase LC was set up for UV and mass spectrometry (MS) detection mode. Gradient elution was used, and the mobile phase was composed of acetonitrile and water. UV-vis was performed at 220 nm. The method was tested with different reversed-phase columns. Comparison between chromatographic parameters: retention time (t R ), resolution (R S ), and selectivity (α) was established. Hydrolysis kinetics of three of the PNMCs were reported. The major hydrolysis products were determined by LC-UV, and the effect of pH on hydrolysis was also studied. Also, chromatographic separation of a mixture of PNMCs and four of their hydrolysis products was carried out. The preconcentration of 12 studied solutes was realized by solid-phase extraction. C18 extraction cartridges of 1 g were used to extract solutes from a 100 mL volume of tap and surface water spiked at 10 μg/L. The recoveries were, respectively, between 68-86% and 62-83% with relative a standard deviation of less than 11%. Limits of detection (LODs) and limits of quantitation (LOQs) ranged, respectively, from 1-4 μg/L and from 4-10 μg/L. Since standard UV detection does not provide adequate selectivity for water samples, an electrospray (ES)-MS instrument equipped with a triple quadrupole mass filter was used. MS data acquisition was performed by a time-scheduled, selected-ion monitoring (SIM) program. Limits of quantitation gave values between 0.1-0.5 μg/L. (author)
The potential influence of Asian and African mineral dust on ice, mixed-phase and liquid water clouds

Directory of Open Access Journals (Sweden)

A. Wiacek

2010-09-01

Full Text Available This modelling study explores the availability of mineral dust particles as ice nuclei for interactions with ice, mixed-phase and liquid water clouds, also tracking the particles' history of cloud-processing. We performed 61 320 one-week forward trajectory calculations originating near the surface of major dust emitting regions in Africa and Asia using high-resolution meteorological analysis fields for the year 2007. Dust-bearing trajectories were assumed to be those coinciding with known dust emission seasons, without explicitly modelling dust emission and deposition processes. We found that dust emissions from Asian deserts lead to a higher potential for interactions with high ice clouds, despite being the climatologically much smaller dust emission source. This is due to Asian regions experiencing significantly more ascent than African regions, with strongest ascent in the Asian Taklimakan desert at ~25%, ~40% and 10% of trajectories ascending to 300 hPa in spring, summer and fall, respectively. The specific humidity at each trajectory's starting point was transported in a Lagrangian manner and relative humidities with respect to water and ice were calculated in 6-h steps downstream, allowing us to estimate the formation of liquid, mixed-phase and ice clouds. Downstream of the investigated dust sources, practically none of the simulated air parcels reached conditions of homogeneous ice nucleation (T≲−40 °C along trajectories that have not experienced water saturation first. By far the largest fraction of cloud forming trajectories entered conditions of mixed-phase clouds, where mineral dust will potentially exert the biggest influence. The majority of trajectories also passed through atmospheric regions supersaturated with respect to ice but subsaturated with respect to water, where so-called "warm ice clouds" (T≳−40 °C theoretically may form prior to supercooled water or mixed-phase clouds. The importance of "warm ice
Continued Water-Based Phase Change Material Heat Exchanger Development

Science.gov (United States)

Hansen, Scott W.; Sheth, Rubik B.; Poynot, Joe; Giglio, Tony; Ungar, Gene K.

2015-01-01

In a cyclical heat load environment such as low Lunar orbit, a spacecraft's radiators are not sized to meet the full heat rejection demands. Traditionally, a supplemental heat rejection device (SHReD) such as an evaporator or sublimator is used to act as a "topper" to meet the additional heat rejection demands. Utilizing a Phase Change Material (PCM) heat exchanger (HX) as a SHReD provides an attractive alternative to evaporators and sublimators as PCM HX's do not use a consumable, thereby leading to reduced launch mass and volume requirements. In continued pursuit of water PCM HX development two full-scale, Orion sized water-based PCM HX's were constructed by Mezzo Technologies. These HX's were designed by applying prior research on freeze front propagation to a full-scale design. Design options considered included bladder restraint and clamping mechanisms, bladder manufacturing, tube patterns, fill/drain methods, manifold dimensions, weight optimization, and midplate designs. Two units, Units A and B, were constructed and differed only in their midplate design. Both units failed multiple times during testing. This report highlights learning outcomes from these tests and are applied to a final sub-scale PCM HX which is slated to be tested on the ISS in early 2017.
Phase transition and water incorporation into Eu2Sn2O7 pyrochlore at high pressure

Science.gov (United States)

Zhang, F. X.; Lang, M.; Ewing, R. C.

2016-04-01

Structural changes of europium stannate pyrochlore, Eu2Sn2O7, have been investigated at high pressures with in situ Raman spectroscopy, photoluminescence (PL), and synchrotron X-ray diffraction (XRD) techniques. The XRD measurements suggest that a pressure-induced phase transition starts at 34.4 GPa. The PL spectrum from Eu3+ cations also suggests a phase transition above 36 GPa. XRD analysis shows that the unit cell of the cubic phase deviates from the equation of state at pressures above 23.8 GPa. This is due to the incorporation of water from the pressure medium in the structure at high pressures, which is confirmed by optical spectroscopy measurements.

Water/ice phase transition: The role of zirconium acetate, a compound with ice-shaping properties

Science.gov (United States)

Marcellini, Moreno; Fernandes, Francisco M.; Dedovets, Dmytro; Deville, Sylvain

2017-04-01

Few compounds feature ice-shaping properties. Zirconium acetate is one of the very few inorganic compounds reported so far to have ice-shaping properties similar to that of ice-shaping proteins, encountered in many organisms living at low temperature. When a zirconium acetate solution is frozen, oriented and perfectly hexagonal ice crystals can be formed and their growth follows the temperature gradient. To shed light on the water/ice phase transition while freezing zirconium acetate solution, we carried out differential scanning calorimetry measurements. From our results, we estimate how many water molecules do not freeze because of their interaction with Zr cations. We estimate the colligative properties of the Zr acetate on the apparent critical temperature. We further show that the phase transition is unaffected by the nature of the base which is used to adjust the pH. Our results provide thus new hints on the ice-shaping mechanism of zirconium acetate.
Phase transition of LB films of mixed diblock copolymer at the air/water interface

Science.gov (United States)

Seo, Y. S.; Kim, K. S.; Samuilov, V.; Rafailovich, M. H.; Sokolov, J.; Lammertink, Rob G. H.; Vancso, G. J.

2000-03-01

We have studied the morphology of Langmuir blodgett films at the air/water interface of mixed diblock copolymer films. Solutions of poly(styrene-b-ferrocenyldimethylsilane) and PS-b-P2VP mixed in a ratio of 20/80 in chloroform were spread at the air/water interface. The morphology of the films was studied with AFM as a function of the surface pressure and the diblock copolymer molecular weight. The results show that the two diblock copolymers can be induced to mix at the air/water interface with increasing surface pressure. A reversible transition from spherical to cylindrical morphologies is induced in the mixture which can not be observed in films formed of the two components separately. The effective surface phase diagram as a function of block copolymer composition and pressure will be presented.
Quantitative analysis of aqueous phase composition of model dentin adhesives experiencing phase separation

Science.gov (United States)

Ye, Qiang; Park, Jonggu; Parthasarathy, Ranganathan; Pamatmat, Francis; Misra, Anil; Laurence, Jennifer S.; Marangos, Orestes; Spencer, Paulette

2013-01-01

There have been reports of the sensitivity of our current dentin adhesives to excess moisture, for example, water-blisters in adhesives placed on over-wet surfaces, and phase separation with concomitant limited infiltration of the critical dimethacrylate component into the demineralized dentin matrix. To determine quantitatively the hydrophobic/hydrophilic components in the aqueous phase when exposed to over-wet environments, model adhesives were mixed with 16, 33, and 50 wt % water to yield well-separated phases. Based upon high-performance liquid chromatography coupled with photodiode array detection, it was found that the amounts of hydrophobic BisGMA and hydrophobic initiators are less than 0.1 wt % in the aqueous phase. The amount of these compounds decreased with an increase in the initial water content. The major components of the aqueous phase were hydroxyethyl methacrylate (HEMA) and water, and the HEMA content ranged from 18.3 to 14.7 wt %. Different BisGMA homologues and the relative content of these homologues in the aqueous phase have been identified; however, the amount of crosslinkable BisGMA was minimal and, thus, could not help in the formation of a crosslinked polymer network in the aqueous phase. Without the protection afforded by a strong crosslinked network, the poorly photoreactive compounds of this aqueous phase could be leached easily. These results suggest that adhesive formulations should be designed to include hydrophilic multimethacrylate monomers and water compatible initiators. PMID:22331596
Study of a three-phase flow metering process for oil-water-gas flows; Etude d`un procede de mesure des debits d`un ecoulement triphasique de type eau-huile-gaz

Energy Technology Data Exchange (ETDEWEB)

Boyer, Ch.

1996-11-01

We propose a theoretical and experimental study of a three-phase flow metering process for oil-water-gas flows. The selected process is based on a combination of a mixer, a Venturi and ultrasonic methods. To perform an experimental validation of this process an instrumented set-up for three-phase air-oil-water flows has been designed, conceived and adjusted. An original theoretical model have been built to predict three-phase dispersed flows across a contraction. Once validated with two-phase air-water, oil-water and air-oil-water flows data, this model has been used to solve the Venturi metering problems. After a critical review of the available techniques, the ultrasonic propagation velocity has been selected to determine two-phase liquid-liquid flow composition. Two original models have been developed to describe the ultrasonic propagation with the dispersed phase fraction. The comparison with experimental data in oil-water flows show the superiority of one of the two models, the scattering model. For the void fraction determination in air-water flows, the work of Bensler (1990) based on the ultrasonic attenuation measurement has been extended to take into account the multiple scattering effects. Finally these techniques have been combined to determine the different flow rates in air-water, oil-water flows. For two-phase air-water and oil-water flows the problem is solved and the flow rates are measured with a very good accuracy ({+-} 3%). The results quality obtained with three-phase oil-water-gas flows and the secure theoretical bases allowing their interpretation give us the opportunity to strongly recommend the development of an industrial prototype based on the process we studied. (author) 183 refs.
Experiment of the downcomer effective water head during a reflood phase of PWR LOCA

International Nuclear Information System (INIS)

Sudo, Yukio; Murao, Yoshio

1978-12-01

The results and analysis are described of a downcomer effective water head experiment. Downcomer effective water head is the driving force to feed an emergency coolant to the core during a reflood phase of PWR LOCA. The test rig has dimensions of the full-scale height and gap. Experimental conditions are: downcomer wall temperature = 250 0 -- 300 0 C, back pressure = 1 atm, coolant temperature = 98 0 -- 100 0 C, extraction water velocity = 0 -- 2 cm/s, and gap size = 200 mm. The effective water head histories obtained by experiment were compared with those predicted from the heat release from the downcomer walls. The heat release was calculated from the temperature histories indicated by thermocouples instrumented in and on the walls during experiment. The following were revealed: (1) The relation of heat flux and superheat (q vs ΔT sub(s)) obtained in the experiment is much different from that in pool boiling. (2) The predicted effective water head is in good agreement with the experimental one after 120 sec from the initiation of coolant injection. (3) The effect of extraction water velocity is negligible. (4) The effect of initial wall temperatures is evident. (author)
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.
An in-line clean system for the solid-phase extraction of emerging contaminants in natural waters

OpenAIRE

Sodré, Fernando F.; Locatelli, Marco Antonio F.; Jardim, Wilson F.

2010-01-01

A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L) using commercial solid-phase extraction (SPE) cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus i...
Phase behaviour and microstructure of the micro-emulsions composed of cholinium-based ionic liquid, Triton X-100 and water

International Nuclear Information System (INIS)

Pei, Yuanchao; Huang, Yanjie; Li, Lin; Wang, Jianji

2014-01-01

Highlights: • The microemulsions composed of cholinium-based ionic liquid, Triton X-100 and water have been prepared and characterised. • Ternary phase diagrams of the microemulsions have been established at T = 298.15 K. • The microemulsions exhibit IL-in-water, bicontinuous and water-in-IL microstructures. • Droplets with the size smaller than 20 nm are formed in these IL-based microemulsions. - Abstract: In this paper, micro-emulsions composed of cholinium-based ionic liquids (ILs), octylphenol ethoxylate (Triton X-100) and water were prepared. These ternary systems were found to be stable over 12 months at room temperature. Their phase behaviour was investigated by using cloud titrations, and their microstructures were characterised by means of cyclic voltammetry and electrical conductance measurements at T = 298.15 K. It was shown that the micro-emulsions exhibited IL-in-water, bi-continuous and water-in-IL microstructures. Dynamic light scattering data suggest that Triton X-100 forms micelles in water, which were swelled by the ILs added. Droplets with the size about 20 nm were formed in these IL-based micro-emulsions, and the droplet size increased with the increase of the IL concentrations. These IL-based micro-emulsions may have potential in drug delivery, chemical reactions and nanomaterial preparation as a new type of nanoreactors
Hydrate phase equilibrium and structure for (methane + ethane + tetrahydrofuran + water) system

International Nuclear Information System (INIS)

Sun Changyu; Chen Guangjin; Zhang Lingwei

2010-01-01

The separation of methane and ethane through forming hydrate is a possible choice in natural gas, oil processing, or ethylene producing. The hydrate formation conditions of five groups of (methane + ethane) binary gas mixtures in the presence of 0.06 mole fraction tetrahydrofuran (THF) in water were obtained at temperatures ranging from (277.7 to 288.2) K. In most cases, the presence of THF in water can lower the hydrate formation pressure of (methane + ethane) remarkably. However, when the composition of ethane is as high as 0.832, it is more difficult to form hydrate than without THF system. Phase equilibrium model for hydrates containing THF was developed based on a two-step hydrate formation mechanism. The structure of hydrates formed from (methane + ethane + THF + water) system was also determined by Raman spectroscopy. When THF concentration in initial aqueous solution was only 0.06 mole fraction, the coexistence of structure I hydrate dominated by ethane and structure II hydrate dominated by THF in the hydrate sample was clearly demonstrated by Raman spectroscopic data. On the contrary, only structure II hydrate existed in the hydrate sample formed from (methane + ethane + THF + water) system when THF concentration in initial aqueous solution was increased to 0.10 mole fraction. It indicated that higher THF concentration inhibited the formation of structure I hydrate dominated by ethane and therefore lowered the trapping of ethane in hydrate. It implies a very promising method to increase the separation efficiency of methane and ethane.
Modelling of the steam-water-countercurrent flow in the rewetting and flooding phase after loss-of-coolant accidents in pressurized water reactors

International Nuclear Information System (INIS)

Curca-Tivig, F.

1990-01-01

A new interphase momentum exchange model has been developed to simulate the Refill- Reflood Phase after LOCAs. Special phenomena of steam/water- countercurrent flow - like limitation or onset of downward-watee penetration - have been modelled and integrated into a flooding model. The interphase momentum exchange model interconnected with the flooding model has been implemented into the advanced system code RELAP5/MOD1. The new version of this code can now be utilized to predict the hot leg emergency-core-cooling (ECC) injection for German PWRs. The interfacial momentum transfer model developed includes the interphase frictional drag, the force due to virtual mass and the momenta due to interphase mass transfer. The modelling of the interfacial shear or drag accounts for the effects of phase and velocity profiles. The flooding model predicts countercurrent-flow limitation, onset of water penetration and partial delivery. The flooding correlation specifies the maximum down flow liquid velocity in case of countercurrent flow through flow restrictions for a given vapor velocity. (orig./HP) [de
Structure of two-phase adiabatic flow in air sparging regime in vertical cylindrical channel with water

Directory of Open Access Journals (Sweden)

V. I. Solonin

2014-01-01

Full Text Available The article presents a research of two-phase adiabatic flow in air sparging regime in vertical cylindrical channel filled with water. A purpose of the work is to obtain experimental data for further analysis of a character of the moving phases. Research activities used the optic methods PIV (Particle Image Visualization because of their noninvasiveness to obtain data without disturbing effect on the flow. A laser sheet illuminated the fluorescence particles, which were admixed in water along the channel length. A digital camera recorded their motion for a certain time interval that allowed building the velocity vector fields. As a result, gas phase velocity components typical for a steady area of the channel and their relations for various intensity of volume air rate were obtained. A character of motion both for an air bubble and for its surrounding liquid has been conducted. The most probable direction of phases moving in the channel under sparging regime is obtained by building the statistic scalar fields. The use of image processing enabled an analysis of the initial area of the air inlet into liquid. A characteristic curve of the bubbles offset from the axis for various intensity of volume gas rate and channel diameter is defined. A character of moving phases is obtained by building the statistic scalar fields. The values of vertical components of liquid velocity in the inlet part of channel are calculated. Using the obtained data of the gas phase velocities a true void fraction was calculated. It was compared with the values of void fraction, calculated according to the liquid level change in the channel. Obtained velocities were compared with those of the other researchers, and a small difference in their values was explained by experimental conditions. The article is one of the works to research the two-phase flows with no disturbing effect on them. Obtained data allow us to understand a character of moving the two-phase flows in
Quasi-three dimensional dynamic modeling of a proton exchange membrane fuel cell with consideration of two-phase water transport through a gas diffusion layer

International Nuclear Information System (INIS)

Kang, Sanggyu

2015-01-01

Water management is one of the challenging issues for low-temperature PEMFCs (proton exchange membrane fuel cells). When liquid water is formed at the GDL (gas diffusion layer), the pathway of reactant gas can be blocked, which inhibits the electrochemical reaction of PEMFC. Thus, liquid water transport through GDL is a critical factor determining the performance of a PEMFC. In present study, quasi-three dimensional dynamic modeling of PEMFC with consideration of two-phase water transport through GDL is developed. To investigate the distributions of PEMFC characteristics, including current density, species mole fraction, and membrane hydration, the PEMFC was discretized into twenty control volumes along the anode channel. To resolve the mass and energy conservation, the PEMFC is discretized into eleven and fifteen control volumes in the perpendicular direction, respectively. The dynamic variation of PEMFC characteristics of cell voltage, overvoltage of activation and ohmic, liquid water saturation through a GDL, and oxygen concentration were captured during transient behavior. - Highlights: • A quasi-three dimensional two-phase dynamic model of PEMFC is developed. • Presented model is validated by comparison with experimental data. • Two-phase model is compared with one-phase model at steady-states and transients.
Study of microbial community and biodegradation efficiency for single- and two-phase anaerobic co-digestion of brown water and food waste.

Science.gov (United States)

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

2013-11-01

The objective of this work was to study the microbial community and reactor performance for the anaerobic co-digestion of brown water and food waste in single- and two-phase continuously stirred tank reactors (CSTRs). Bacterial and archaeal communities were analyzed after 150 days of reactor operation. As compared to single-phase CSTR, methane production in two-phase CSTR was found to be 23% higher. This was likely due to greater extent of solubilization and acidification observed in the latter. These findings could be attributed to the predominance of Firmicutes and greater bacterial diversity in two-phase CSTR, and the lack of Firmicutes in single-phase CSTR. Methanosaeta was predominant in both CSTRs and this correlated to low levels of acetate in their effluent. Insights gained from this study would enhance the understanding of microorganisms involved in co-digestion of brown water and food waste as well as the complex biochemical interactions promoting digester stability and performance. Copyright © 2013 Elsevier Ltd. All rights reserved.
Analyte induced water adsorbability in gas phase biosensors: the influence of ethinylestradiol on the water binding protein capacity.

Science.gov (United States)

Snopok, Borys; Kruglenko, Ivanna

2015-05-07

An ultra-sensitive gas phase biosensor/tracer/bio-sniffer is an emerging technology platform designed to provide real-time information on air-borne analytes, or those in liquids, through classical headspace analysis. The desired bio-sniffer measures gaseous 17α- ethinylestradiol (ETED) as frequency changes on a quartz crystal microbalance (QCM), which is a result of the interactions of liquid sample components in the headspace (ETED and water) with a biorecognition layer. The latter was constructed by immobilization of polyclonal antiserum against a phenolic A-ring of estrogenic receptors through protein A. The QCM response exhibited stretched exponential kinetics of negative frequency shifts with reversible and "irreversible" components of mass uptake onto the sensor surface in static headspace conditions when exposed to water solutions of ETED over the sensor working range, from 10(-10) to 10(-17) g L(-1). It was shown that the variations in the QCM response characteristics are due to the change of the water-binding capacity of the sensing layer induced by protein transformations initiated by the binding of ETED molecules. This result is well correlated with the natural physiological function of estrogens in controlling the homeostasis of body fluids in living beings.
A Fast Algorithm to Simulate Droplet Motions in Oil/Water Two Phase Flow

KAUST Repository

Zhang, Tao

2017-06-09

To improve the research methods in petroleum industry, we develop a fast algorithm to simulate droplet motions in oil and water two phase flow, using phase field model to describe the phase distribution in the flow process. An efficient partial difference equation solver—Shift-Matrix method is applied here, to speed up the calculation coding in high-level language, i.e. Matlab and R. An analytical solution of order parameter is derived, to define the initial condition of phase distribution. The upwind scheme is applied in our algorithm, to make it energy decay stable, which results in the fast speed of calculation. To make it more clear and understandable, we provide the specific code for forming the coefficient matrix used in Shift-Matrix Method. Our algorithm is compared with other methods in different scales, including Front Tracking and VOSET method in macroscopic and LBM method using RK model in mesoscopic scale. In addition, we compare the result of droplet motion under gravity using our algorithm with the empirical formula common used in industry. The result proves the high efficiency and robustness of our algorithm and it’s then used to simulate the motions of multiple droplets under gravity and cross-direction forces, which is more practical in industry and can be extended to wider application.
Evaluation of corrosivity of the vapor-phase environments to sterilized water with chlorine; Enso kei mekkin shorisui no kisho kankyo no fushokusei

Energy Technology Data Exchange (ETDEWEB)

Nakata, Michio. [Nippon Steel Corp. Yamaguchi (Japan). Technical Development Bureau

1999-08-15

Corrosivity of vapor-phase aenvironments in indoor pool, water thank, and water purification plants was investigated. Sodium hypochlorite (NaClO) was used as a sterilizing agent in indoor pool, while chlorine gas was used in water tank and water purification plants. It was found that Cl{sup -} ion were concentrated in the dew formed in the indoor pool. H{sup +} ions as well as Cl{sup -} ions were accumulated in the dew dormed in the water tank ans water purification plants. Thus, the corrosion condition was varied with the type of sterilizing agents used. Through the investigation of water tanl, the relationship between pH and Cl{sup -} ion concentration was given as follow; pH=-1.09-2.19 log [Cl{sup -}] (mol/L). Corrosivity of vapor-phase enviroments in sterilizing water systems would be characterized by the exstence of oxidizing chemical agents such as ClO{sup -} and HClO, the shift of corrosion potenrial of the thin water film, and the accumulation of H{sup +} and/or Cl{sup -} ions in the dew. (author)
Method Development for the Analysis of Pharmaceuticals with Acethylcholinesterase Activity in Water Using HPLC-DAD and Solid Phase Extraction

Directory of Open Access Journals (Sweden)

Samuel Budi Wardhana

2014-03-01

Full Text Available An SPE followed by HPLC-DAD method with ion pair chromatography technique to analyze pharmaceuticals with acethylcholinesterase activity including pyridostigmine (PYR, galathamine (GAL, neostigmine (NEO, eserine (ESE, and donepezil (DON in water samples was developed. Acetylcholinesterase (AChE inhibitors have been used to treat less severe dementias such as Alzheimer’s disease. Chromatographic separation was achieved using reversed-phase SymmetryShield column using gradient system with mobile phase consisting of H2O/ACN (99:1, v/v as mobile phase A with 10 mM sodium 1-hexanesulfonate and 0.1% acetic acid (HAc. The HPLC/DAD method was linear between concentrations of 5 to 100 ng/μL. The IDL and IQL ranged from 0.50 to 1.25 ng/μL and 1.5 to 3.0 ng/μL, respectively. SPE was used to extract and clean up the target substances in spiked pure water, tap water, and wastewater samples. The application of extraction method of 5 target substances in wastewater sample was divided into 2 parts: Oasis WCX (6 mL, 500 mg for PYR and Oasis HLB (6 mL, 200 mg for GAL, NEO, ESE and DON. The developed SPE and HPLC/DAD method is applicable for quantification of the 5 target substances in water samples in a concentration range > 50 µg/L and assumable lower for DON (> 25 µg/L.
Recycling of water of high pressure cleaning of pipes. Phase 1. Quality demands and economical aspects

International Nuclear Information System (INIS)

Van Weers, A.W.; Zwaard, J.

1999-01-01

According to the regulation 6.1 in the current licence Surface Water Pollution Law (WVO, abbreviated in Dutch) of October 10, 1997, ECN carried out the first phase of a study on the title subject with respect to pipes applied in oil and gas exploration. In the present situation water of the so-called pipe-cleaner is transported via a seapipe after precipitation and membrane filtration. Next to the quality demands and economical aspects attention is paid to a number of environmental aspects
Changes in the zero-point energy of the protons as the source of the binding energy of water to A-phase DNA.

Science.gov (United States)

Reiter, G F; Senesi, R; Mayers, J

2010-10-01

The measured changes in the zero-point kinetic energy of the protons are entirely responsible for the binding energy of water molecules to A phase DNA at the concentration of 6 water molecules/base pair. The changes in kinetic energy can be expected to be a significant contribution to the energy balance in intracellular biological processes and the properties of nano-confined water. The shape of the momentum distribution in the dehydrated A phase is consistent with coherent delocalization of some of the protons in a double well potential, with a separation of the wells of 0.2 Å.
Changes in the Zero-Point Energy of the Protons as the Source of the Binding Energy of Water to A-Phase DNA

International Nuclear Information System (INIS)

Reiter, G. F.; Senesi, R.; Mayers, J.

2010-01-01

The measured changes in the zero-point kinetic energy of the protons are entirely responsible for the binding energy of water molecules to A phase DNA at the concentration of 6 water molecules/base pair. The changes in kinetic energy can be expected to be a significant contribution to the energy balance in intracellular biological processes and the properties of nano-confined water. The shape of the momentum distribution in the dehydrated A phase is consistent with coherent delocalization of some of the protons in a double well potential, with a separation of the wells of 0.2 Angst .

Automatic reactor for solid-phase synthesis of molecularly imprinted polymeric nanoparticles (MIP NPs) in water.

Science.gov (United States)

Poma, Alessandro; Guerreiro, Antonio; Caygill, Sarah; Moczko, Ewa; Piletsky, Sergey

We report the development of an automated chemical reactor for solid-phase synthesis of MIP NPs in water. Operational parameters are under computer control, requiring minimal operator intervention. In this study, "ready for use" MIP NPs with sub-nanomolar affinity are prepared against pepsin A, trypsin and α-amylase in only 4 hours.
Experimental Investigation of Two-Phase Oil (D130)-Water Flow in 4″ Pipe for Different Inclination Angles

Science.gov (United States)

Shaahid, S. M.; Basha, Mehaboob; Al-Hems, Luai M.

2018-03-01

Oil and water are often produced and transported together in pipelines that have various degrees of inclination from the horizontal. The flow of two immiscible liquids oil and water in pipes has been a research topic since several decades. In oil and chemical industries, knowledge of the frictional pressure loss in oil-water flows in pipes is necessary to specify the size of the pump required to pump the emulsions. An experimental investigation has been carried out for measurement of pressure drop of oil (D130)-water two-phase flows in 4 inch diameter inclined stainless steel pipe at different flow conditions. Experiments were conducted for different inclination angles including; 0°, 15°, 30° (for water cuts “WC” 0 - 100%). The flow rates at the inlet were varied from 4000 to 8000 barrels-per-day (BPD). For a given flow rate the frictional pressure drop has been found to increase (for all angles) from WC = 0 - 60%, and thereafter friction pressure drop decreases, this could be due phase inversion. For a given WC 40%, the frictional pressure drop has been found to increase with angle and flow rate. It has been noticed that inclination angle has appreciable effect on frictional pressure drop.
Determining estrogenic steroids in Taipei waters and removal in drinking water treatment using high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Chen, C.-Y. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China)]. E-mail: dbms@ntu.edu.tw; Wen, T.-Y. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Wang, G.-S. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Department of Public Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Cheng, H.-W. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Lin, Y.-H. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China); Lien, G.-W. [Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Hsu-Chou Road, Taipei (10055), Taiwan (China)

2007-06-01

River water and wastewater treatment plant (WWTP) effluents from metropolitan Taipei, Taiwan were tested for the presence of the pollutants estrone (E{sub 1}), estriol (E{sub 3}), 17{beta}-estradiol (E{sub 2}), and 17{alpha}-ethinylestradiol (EE{sub 2}) using a new methodology that involves high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry. The method was also used to investigate the removal of the analytes by conventional drinking water treatment processes. Without adjusting the pH, we extracted 1-L samples with PolarPlus C{sub 18} Speedisks under a flow rate exceeding 100 mL/min, in which six samples could be done simultaneously using an extraction station. The adsorbent was washed with 40% methanol/60% water and then eluted by 50% methanol/50% dichloromethane. The eluate was concentrated until almost dry and was reconstituted by 20 {mu}L of methanol. Quantitation was done by LC-MS/MS-negative electrospray ionization in the selected reaction monitoring mode with isotope-dilution techniques. The mobile phase was 10 mM N-methylmorpholine aqueous solution/acetonitrile with gradient elution. Mean recoveries of spiked Milli-Q water were 65-79% and precisions were within 2-20% of the tested concentrations (5.0-200 ng/L). The method was validated with spiked upstream river water; precisions were most within 10% of the tested concentrations (10-100 ng/L) with most RSDs < 10%. LODs of the environmental matrixes were 0.78-7.65 ng/L. A pre-filtration step before solid-phase extraction may significantly influence the measurement of E{sub 1} and EE{sub 2} concentrations; disk overloading by water matrix may also impact analyte recoveries along with ion suppression. In the Taipei water study, the four steroid estrogens were detected in river samples (ca. 15 ng/L for E{sub 2} and EE{sub 2} and 35-45 ng/L for E{sub 1} and E{sub 3}). Average levels of 19-26 ng/L for E{sub 1}, E{sub 2}, and EE{sub 2} were detected in most wastewater effluents
Evaluation of the thermal performance of a solar water heating thermosyphon versus a two-phase closed thermosyphon using different working fluids

Energy Technology Data Exchange (ETDEWEB)

Ordaz-Flores, A. [Posgrado en Ingenieria (Energia), Univ. Nacional Autonoma de Mexico, Temixco, Morelos (Mexico); Garcia-Valladares, O.; Gomez, V.H. [Centro de Investigacion en Energia, Univ. Nacional Autonoma de Mexico, Temixco, Morelos (Mexico)

2008-07-01

A water heating closed two-phase thermosyphon solar system was designed and built. The system consists of a flat plate solar collector coupled to a thermotank by a continuous copper tubing in which the working fluid circulates. The working fluid evaporates in the collector and condensates in the thermotank transferring its latent heat to the water through a coil heat exchanger. The tested fluids are acetone and R134a. The thermal performance of the proposed systems is compared with a conventional solar water thermosyphon under the same operating conditions. Advantages of a two-phase system include the elimination of freezing, fouling, scaling and corrosion. Geometry and construction materials are the same except for the closed circuit presented in the two-phase system. Data were collected from temperature and pressure sensors throughout the two systems. Early results suggest that R134a may provide a better performance than acetone for this kind of systems. (orig.)
Water-induced phase separation of miconazole-poly (vinylpyrrolidone-co-vinyl acetate) amorphous solid dispersions: Insights with confocal fluorescence microscopy.

Science.gov (United States)

Saboo, Sugandha; Taylor, Lynne S

2017-08-30

The aim of this study was to evaluate the utility of confocal fluorescence microscopy (CFM) to study the water-induced phase separation of miconazole-poly (vinylpyrrolidone-co-vinyl acetate) (mico-PVPVA) amorphous solid dispersions (ASDs), induced during preparation, upon storage at high relative humidity (RH) and during dissolution. Different fluorescent dyes were added to drug-polymer films and the location of the dyes was evaluated using CFM. Orthogonal techniques, in particular atomic force microscopy (AFM) coupled with nanoscale infrared spectroscopy (AFM-nanoIR), were used to provide additional analysis of the drug-polymer blends. The initial miscibility of mico-PVPVA ASDs prepared under low humidity conditions was confirmed by AFM-nanoIR. CFM enabled rapid identification of drug-rich and polymer-rich phases in phase separated films prepared under high humidity conditions. The identity of drug- and polymer-rich domains was confirmed using AFM-nanoIR imaging and localized IR spectroscopy, together with Lorentz contact resonance (LCR) measurements. The CFM technique was then utilized successfully to further investigate phase separation in mico-PVPVA films exposed to high RH storage and to visualize phase separation dynamics following film immersion in buffer. CFM is thus a promising new approach to study the phase behavior of ASDs, utilizing drug and polymer specific dyes to visualize the evolution of heterogeneity in films exposed to water. Copyright © 2017 Elsevier B.V. All rights reserved.
[Corrected Title: Solid-Phase Extraction of Polar Compounds from Water] Automated Electrostatics Environmental Chamber

Science.gov (United States)

Sauer, Richard; Rutz, Jeffrey; Schultz, John

2005-01-01

A solid-phase extraction (SPE) process has been developed for removing alcohols, carboxylic acids, aldehydes, ketones, amines, and other polar organic compounds from water. This process can be either a subprocess of a water-reclamation process or a means of extracting organic compounds from water samples for gas-chromatographic analysis. This SPE process is an attractive alternative to an Environmental Protection Administration liquid-liquid extraction process that generates some pollution and does not work in a microgravitational environment. In this SPE process, one forces a water sample through a resin bed by use of positive pressure on the upstream side and/or suction on the downstream side, thereby causing organic compounds from the water to be adsorbed onto the resin. If gas-chromatographic analysis is to be done, the resin is dried by use of a suitable gas, then the adsorbed compounds are extracted from the resin by use of a solvent. Unlike the liquid-liquid process, the SPE process works in both microgravity and Earth gravity. In comparison with the liquid-liquid process, the SPE process is more efficient, extracts a wider range of organic compounds, generates less pollution, and costs less.
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.
Automatic reactor for solid-phase synthesis of molecularly imprinted polymeric nanoparticles (MIP NPs) in water

OpenAIRE

Poma, Alessandro; Guerreiro, Antonio; Caygill, Sarah; Moczko, Ewa; Piletsky, Sergey

2014-01-01

We report the development of an automated chemical reactor for solid-phase synthesis of MIP NPs in water. Operational parameters are under computer control, requiring minimal operator intervention. In this study, “ready for use” MIP NPs with sub-nanomolar affinity are prepared against pepsin A, trypsin and α-amylase in only 4 hours.
Quantum phase transitions

International Nuclear Information System (INIS)

Sachdev, S.

1999-01-01

Phase transitions are normally associated with changes of temperature but a new type of transition - caused by quantum fluctuations near absolute zero - is possible, and can tell us more about the properties of a wide range of systems in condensed-matter physics. Nature abounds with phase transitions. The boiling and freezing of water are everyday examples of phase transitions, as are more exotic processes such as superconductivity and superfluidity. The universe itself is thought to have passed through several phase transitions as the high-temperature plasma formed by the big bang cooled to form the world as we know it today. Phase transitions are traditionally classified as first or second order. In first-order transitions the two phases co-exist at the transition temperature - e.g. ice and water at 0 deg., or water and steam at 100 deg. In second-order transitions the two phases do not co-exist. In the last decade, attention has focused on phase transitions that are qualitatively different from the examples noted above: these are quantum phase transitions and they occur only at the absolute zero of temperature. The transition takes place at the ''quantum critical'' value of some other parameter such as pressure, composition or magnetic field strength. A quantum phase transition takes place when co-operative ordering of the system disappears, but this loss of order is driven solely by the quantum fluctuations demanded by Heisenberg's uncertainty principle. The physical properties of these quantum fluctuations are quite distinct from those of the thermal fluctuations responsible for traditional, finite-temperature phase transitions. In particular, the quantum system is described by a complex-valued wavefunction, and the dynamics of its phase near the quantum critical point requires novel theories that have no analogue in the traditional framework of phase transitions. In this article the author describes the history of quantum phase transitions. (UK)
Micro-channel heat sink with slurry of water with micro-encapsulated phase change material: 3D-numerical study

International Nuclear Information System (INIS)

Sabbah, Rami; Farid, Mohammad M.; Al-Hallaj, Said

2009-01-01

This study investigates the influence of using micro-encapsulated phase change material (MEPCM) on the thermal and hydraulic performance of micro-channel heat sinks used for heat dissipation of high power electronic devices. A three-dimensional, one-phase, laminar flow model of a rectangular channel using water slurry of MEPCM with temperature dependent physical properties was developed. The results showed a significant increase in the heat transfer coefficient under certain conditions for heat flux rates of 100 W/cm 2 and 500 W/cm 2 that is mainly dependant on the channel inlet and outlet temperatures and the selected MEPCM melting temperature. Lower and more uniform temperatures across the electronic device can be achieved at less pumping power compared to using water only as the cooling fluid
Phase II Water Rental Pilot Project: Snake River Resident Fish and Wildlife Resources and Management Recommendations.

Energy Technology Data Exchange (ETDEWEB)

Stovall, Stacey H.

1994-08-01

The Idaho Water Rental Pilot Project was implemented in 1991 as part of the Non-Treaty Storage Fish and Wildlife Agreement between Bonneville Power Administration and the Columbia Basin Fish and Wildlife Authority. The goal of the project is to quantify resident fish and wildlife impacts resulting from salmon flow augmentation releases made from the upper Snake River Basin. Phase I summarized existing resource information and provided management recommendations to protect and enhance resident fish and wildlife habitat resulting from storage releases for the I improvement of an adromous fish migration. Phase II includes the following: (1) a summary of recent biological, legal, and political developments within the basin as they relate to water management issues, (2) a biological appraisal of the Snake River between American Falls Reservoir and the city of Blackfoot to examine the effects of flow fluctuation on fish and wildlife habitat, and (3) a preliminary accounting of 1993--1994 flow augmentation releases out of the upper Snake, Boise, and Payette river systems. Phase III will include the development of a model in which annual flow requests and resident fish and wildlife suitability information are interfaced with habitat time series analysis to provide an estimate of resident fish and wildlife resources.
Sustainable Water Purification, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Newly developed phase-engineered and low dimensional materials have opened the door to the design of materials structures that exhibit extremely efficient ionic...
Experimental study on two-phase flow natural circulation in a core catcher cooling channel for EU-APR1400 using air-water system

Energy Technology Data Exchange (ETDEWEB)

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

2017-05-15

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

Science.gov (United States)

G Archana; Dhodapkar, Rita; Kumar, Anupama

2016-09-01

The present study reports a precise and simple offline solid-phase extraction (SPE) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of five representative and commonly present pharmaceuticals and personal care products (PPCPs), a new class of emerging pollutants in the aquatic environment. The target list of analytes including ciprofloxacin, acetaminophen, caffeine benzophenone and irgasan were separated by a simple HPLC method. The column used was a reversed-phase C18 column, and the mobile phase was 1 % acetic acid and methanol (20:80 v/v) under isocratic conditions, at a flow rate of 1 mL min(-1). The analytes were separated and detected within 15 min using the photodiode array detector (PDA). The linearity of the calibration curves were obtained with correlation coefficients 0.98-0.99.The limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and ruggedness demonstrated the reproducibility, specificity and sensitivity of the developed method. Prior to the analysis, the SPE was performed using a C18 cartridge to preconcentrate the targeted analytes from the environmental water samples. The developed method was applied to evaluate and fingerprint PPCPs in sewage collected from a residential engineering college campus, polluted water bodies such as Nag river and Pili river and the influent and effluent samples from a sewage treatment plant (STP) situated at Nagpur city, in the peak summer season. This method is useful for estimation of pollutants present in microquantities in the surface water bodies and treated sewage as compared to nanolevel pollutants detected by mass spectrometry (MS) detectors.
Organogel-emulsions with mixtures of β-sitosterol and γ-oryzanol: influence of water activity and type of oil phase on gelling capability.

Science.gov (United States)

Sawalha, Hassan; den Adel, Ruud; Venema, Paul; Bot, Arjen; Flöter, Eckhard; van der Linden, Erik

2012-04-04

In this study, water-in-oil emulsions were prepared from water containing different salt concentrations dispersed in an oil phase containing a mixture of β-sitosterol and γ-oryzanol. In pure oil, the β-sitosterol and γ-oryzanol molecules self-assemble into tubular microstructures to produce a firm organogel. However, in the emulsion, the water molecules bind to the β-sitosterol molecules, forming monohydrate crystals that hinder the formation of the tubules and resulting in a weaker emulsion-gel. Addition of salt to the water phase decreases the water activity, thereby suppressing the formation of sitosterol monohydrate crystals even after prolonged storage times (∼1 year). When the emulsions were prepared with less polar oils, the tubular microstructure was promoted, which significantly increased the firmness of the emulsion-gel. The main conclusion of this study is that the formation of oryzanol and sitosterol tubular microstructure in the emulsion can be promoted by reducing the water activity and/or by using oils of low polarity.
Two-phase natural circulation experiments in a pressurized water loop with CANDU geometry

International Nuclear Information System (INIS)

Ardron, K.H.; Krishnan, V.S.; McGee, G.R.; Anderson, J.W.D.; Hawley, E.H.

1984-07-01

To provide information on two-phase natural circulation in a CANDU-type coolant circuit a series of tests has been performed in the RD-12 loop at the Whiteshell Nuclear Research Establishment. RD-12 is a 10-MPa pressurized-water loop containing two active boilers, two pumps, and two, or four, heated horizontal channels arranged in a symmetrical figure-of-eight configuration characteristic of the CANDU reactor primary heat-transport system. In the tests, single-phase natural circulation was established in the loop and void was introduced by controlled draining, with the surge tank (pressurizer) valved out of the system. The paper reviews the experimental results obtained and describes the evolution of natural circulation flow in particular cases as voidage is progressively increased. The stability behaviour is discussed briefly with reference to a simple stability model
Stochastic modelling of two-phase flows including phase change

International Nuclear Information System (INIS)

Hurisse, O.; Minier, J.P.

2011-01-01

Stochastic modelling has already been developed and applied for single-phase flows and incompressible two-phase flows. In this article, we propose an extension of this modelling approach to two-phase flows including phase change (e.g. for steam-water flows). Two aspects are emphasised: a stochastic model accounting for phase transition and a modelling constraint which arises from volume conservation. To illustrate the whole approach, some remarks are eventually proposed for two-fluid models. (authors)
Phase behavior and formation of o/w nano-emulsion in vegetable oil/ mixture of polyglycerol polyricinoleate and polyglycerin fatty acid ester/water systems.

Science.gov (United States)

Wakisaka, Satoshi; Nakanishi, Masami; Gohtani, Shoichi

2014-01-01

It is reported that mixing polyglycerol polyricinoleate (PGPR) and polyglycerol laurilester has a great emulsifying capacity, and consequently fine oil-in-water (o/w) emulsions can be formed. However, the role of PGPR is not clear. The objective of this research is to investigate the phase behavior of vegetable oil/mixture of PGPR and polyglycerol fatty acid ester/water systems, and to clarify the role of PGPR in making a fine emulsion. Phase diagrams were constructed to elucidate the optimal process for preparing fine emulsions. In all the systems examined in this study, the phases, including the liquid crystal phase (L(c)) and sponge phase (L(3)), spread widely in the phase diagrams. We examined droplet size of the emulsions prepared from each phase and found that o/w nano-emulsions with droplet sizes as small as 50 nm were formed by emulsifying either from a single L(3) phase or a two-phase region, L(c) + L(3). These results indicate that a sponge phase L(3) or liquid crystal phase L(c) or both is necessary to form an o/w nano-emulsion whose average droplet diameter is less than 50 nm for PGPR and polyglycerin fatty acid ester mixtures used as surfactant.
Determination of Trichloroethylene in Water by Liquid–Liquid Microextraction Assisted Solid Phase Microextraction

Directory of Open Access Journals (Sweden)

Mengliang Zhang

2015-02-01

Full Text Available A method for the determination of trichloroethylene (TCE in water using portable gas chromatography/mass spectrometry (GC/MS was developed. A novel sample preparation method, liquid–liquid microextraction assisted solid phase microextraction (LLME–SPME, is introduced. In this method, 20 µL of hexane was added to 10 mL of TCE contaminated aqueous samples to assist headspace SPME. The extraction efficiency of SPME was significantly improved with the addition of minute amounts of organic solvents (i.e., 20 µL hexane. The absolute recoveries of TCE at different concentrations were increased from 11%–17% for the samples extracted by SPME to 29%–41% for the samples extracted by LLME–SPME. The method was demonstrated to be linear from 10 to 1000 ng mL−1 for TCE in water. The improvements on extraction efficiencies were also observed for toluene and 1, 2, 4-trichlorobenzene in water by using LLME–SPME method. The LLME–SPME method was optimized by using response surface modeling (RSM.
Reflooding phase after loss of coolant of an advanced pressurized water reactor with high conversion ratio

International Nuclear Information System (INIS)

Schumann, S.

1984-01-01

The emergency core cooling behaviour of an advanced pressurized water reactor (APWR) during the reflooding phase of the LOCA with double-ended break is analysed and compared to a common pressurized water reactor (PWR). The code FLUT-BS, its models and correlations are explained in detail and have been verified by numerous PWR-reflood experiments with large parameter range. The influence of core-design on ECC-behaviour as well as the influences of initial and boundary values are examined. The results show the essential differences of ECC-behaviour between PWR and APWR. (orig.) [de

Engineering phase transformation of cobalt selenide in carbon cages and the phases’ bifunctional electrocatalytic activity for water splitting

Science.gov (United States)

Gao, Jiaojiao; Liu, Li; Qiu, Hua-Jun; Wang, Yu

2017-08-01

Using Co-based metal-organic frameworks as the precursor, we synthesized cobalt selenide (CoSe2) nanoparticles imbedded in carbon cages. By simply controlling the annealing conditions, phase transformation of CoSe2 from the orthorhombic phase to the cubic phase has been realized. Benefitting from the metallic character, the cubic phase CoSe2 shows greatly enhanced electrocatalytic activity for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The as-prepared cubic phase CoSe2 electrode possesses onset overpotentials of 43 and 200 mV, and Tafel slopes of 51 and 83 mV dec-1 for HER and OER, respectively, which are remarkably superior to that of the orthorhombic phase CoSe2 catalyst and comparable to those of commercial noble-metal catalysts. In addition, the cubic phase CoSe2 electrode also demonstrates excellent stability after long-term operations. Our work not only provides a high performance catalyst for water splitting, but also introduces a new route to the design of a highly efficient catalyst by phase transformation.
Calculation of ethanol refining by means of extractive distillation with water using simulated data on phase equilibria

Energy Technology Data Exchange (ETDEWEB)

Rosak, J; Mertl, I; Huml, M; Wichterle, I

1980-01-01

Available data on phase equilibria in binary mixtures pertaining to the system ethanol - water - impurities (7 compounds that represent the main impurities present in raw synthetic or fermentation ethanol) have been gathered for the computer calculation of a column to be used for the refining of ethanol. Missing experimental data on phase equilibria were supplied by simulation using the increment method UNIFAC which predicts phase equilibria on the basis of the chemical structure. All data about the behavior of binary mixtures were correlated by means of the NRTL method and the sets of constants thus obtained were then used in calculations of the column for the refining of ethanol. The results were compared with reality verified on industrial scale.
Determination of chlorinated polycyclic aromatic hydrocarbons in water by solid-phase extraction coupled with gas chromatography and mass spectrometry.

Science.gov (United States)

Wang, Xianli; Kang, Haiyan; Wu, Junfeng

2016-05-01

Given the potential risks of chlorinated polycyclic aromatic hydrocarbons, the analysis of their presence in water is very urgent. We have developed a novel procedure for determining chlorinated polycyclic aromatic hydrocarbons in water based on solid-phase extraction coupled with gas chromatography and mass spectrometry. The extraction parameters of solid-phase extraction were optimized in detail. Under the optimal conditions, the proposed method showed wide linear ranges (1.0-1000 ng/L) with correlation coefficients ranging from 0.9952 to 0.9998. The limits of detection and the limits of quantification were in the range of 0.015-0.591 and 0.045-1.502 ng/L, respectively. Recoveries ranged from 82.5 to 102.6% with relative standard deviations below 9.2%. The obtained method was applied successfully to the determination of chlorinated polycyclic aromatic hydrocarbons in real water samples. Most of the chlorinated polycyclic aromatic hydrocarbons were detected and 1-monochloropyrene was predominant in the studied water samples. This is the first report of chlorinated polycyclic aromatic hydrocarbons in water samples in China. The toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in the studied tap water were 9.95 ng the toxic equivalency quotient m(-3) . 9,10-Dichloroanthracene and 1-monochloropyrene accounted for the majority of the total toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in tap water. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Optimization of cloud point extraction and solid phase extraction methods for speciation of arsenic in natural water using multivariate technique.

Science.gov (United States)

Baig, Jameel A; Kazi, Tasneem G; Shah, Abdul Q; Arain, Mohammad B; Afridi, Hassan I; Kandhro, Ghulam A; Khan, Sumaira

2009-09-28

The simple and rapid pre-concentration techniques viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As(3+) and total inorganic arsenic (iAs) in surface and ground water samples. The As(3+) was formed complex with ammonium pyrrolidinedithiocarbamate (APDC) and extracted by surfactant-rich phases in the non-ionic surfactant Triton X-114, after centrifugation the surfactant-rich phase was diluted with 0.1 mol L(-1) HNO(3) in methanol. While total iAs in water samples was adsorbed on titanium dioxide (TiO(2)); after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The multivariate strategy was applied to estimate the optimum values of experimental factors for the recovery of As(3+) and total iAs by CPE and SPE. The standard addition method was used to validate the optimized methods. The obtained result showed sufficient recoveries for As(3+) and iAs (>98.0%). The concentration factor in both cases was found to be 40.
[Optimization of solid-phase extraction for enrichment of toxic organic compounds in water samples].

Science.gov (United States)

Zhang, Ming-quan; Li, Feng-min; Wu, Qian-yuan; Hu, Hong-ying

2013-05-01

A concentration method for enrichment of toxic organic compounds in water samples has been developed based on combined solid-phase extraction (SPE) to reduce impurities and improve recoveries of target compounds. This SPE method was evaluated in every stage to identify the source of impurities. Based on the analysis of Waters Oasis HLB without water samples, the eluent of SPE sorbent after dichloromethane and acetone contributed 85% of impurities during SPE process. In order to reduce the impurities from SPE sorbent, soxhlet extraction of dichloromethane followed by acetone and lastly methanol was applied to the sorbents for 24 hours and the results had proven that impurities were reduced significantly. In addition to soxhlet extraction, six types of prevalent SPE sorbents were used to absorb 40 target compounds, the lgK(ow) values of which were within the range of 1.46 and 8.1, and recovery rates were compared. It was noticed and confirmed that Waters Oasis HLB had shown the best recovery results for most of the common testing samples among all three styrenedivinylbenzene (SDB) polymer sorbents, which were 77% on average. Furthermore, Waters SepPak AC-2 provided good recovery results for pesticides among three types of activated carbon sorbents and the average recovery rates reached 74%. Therefore, Waters Oasis HLB and Waters SepPak AC-2 were combined to obtain a better recovery and the average recovery rate for the tested 40 compounds of this new SPE method was 87%.
Solid-Phase Extraction Coupled to a Paper-Based Technique for Trace Copper Detection in Drinking Water.

Science.gov (United States)

Quinn, Casey W; Cate, David M; Miller-Lionberg, Daniel D; Reilly, Thomas; Volckens, John; Henry, Charles S

2018-03-20

Metal contamination of natural and drinking water systems poses hazards to public and environmental health. Quantifying metal concentrations in water typically requires sample collection in the field followed by expensive laboratory analysis that can take days to weeks to obtain results. The objective of this work was to develop a low-cost, field-deployable method to quantify trace levels of copper in drinking water by coupling solid-phase extraction/preconcentration with a microfluidic paper-based analytical device. This method has the advantages of being hand-powered (instrument-free) and using a simple "read by eye" quantification motif (based on color distance). Tap water samples collected across Fort Collins, CO, were tested with this method and validated against ICP-MS. We demonstrate the ability to quantify the copper content of tap water within 30% of a reference technique at levels ranging from 20 to 500 000 ppb. The application of this technology, which should be sufficient as a rapid screening tool, can lead to faster, more cost-effective detection of soluble metals in water systems.
Evaluation method for two-phase flow and heat transfer in a feed-water heater

International Nuclear Information System (INIS)

Takamori, Kazuhide; Minato, Akihiko

1993-01-01

A multidimensional analysis code for two-phase flow using a two-fluid model was improved by taking into consideration the condensation heat transfer, film thickness, and film velocity, in order to develop an evaluation method for two-phase flow and heat transfer in a feed-water heater. The following results were obtained by a two-dimensional analysis of a feed-water heater for a power plant. (1) In the model, the film flowed downward in laminar flow due to gravity, with droplet entrainment and deposition. For evaluation of the film thickness, Fujii's equation was used in order to account for forced convection of steam flow. (2) Based on the former experimental data, the droplet deposition coefficient and droplet entrainment rate of liquid film were determined. When the ratio at which the liquid film directly flowed from an upper heat transfer tube to a lower heat transfer tube was 0.7, the calculated total heat transfer rate agreed with the measured value of 130 MW. (3) At the upper region of a heat transfer tube bundle where film thickness was thin, and at the outer region of a heat transfer tube bundle where steam velocity was high, the heat transfer rate was large. (author)
Isoporous PS-b-PEO ultrafiltration membranes via self-assembly and water-induced phase separation

KAUST Repository

Karunakaran, Madhavan

2014-03-01

A simple and efficient approach towards the fabrication of a skinned membrane with highly ordered pores in the nanometer range is presented here. We successfully combined the self-assembly of PS-b-PEO block copolymer and water induced phase separation for the preparation of isoporous PS-b-PEO block copolymer membranes. We produced for the first time asymmetric isoporous PS-b-PEO membranes with a 100nm thin isoporous separating layer using water at room temperature as coagulant. This was possible by careful selection of the block lengths and the solvent system. FESEM, AFM and TEM measurements were employed to characterize the nanopores of membranes. The pure water fluxes were measured and the flux of membrane was exceptionally high (around 800Lm-2h-1bar-1). Protein rejection measurements were carried out for this membrane and the membrane had a retention of about 67% of BSA and 99% of γ-globulin. © 2013 Elsevier B.V.
Solid phase extraction using molecular imprinting polymers (MISPE for the determination of estrogens in surface water by HPLC

Directory of Open Access Journals (Sweden)

Viviane do Nascimento Bianchi

2017-05-01

Full Text Available Estrogens are emerging pollutants and traditional sewage treatments unable to remove them. They are harmful to human health and to the environment. It is therefore important to evaluate the presence and concentration of estrogens in water bodies and environmental matrices. This work presents the development and application of a methodology for the determination of E1, E3, EE2 and E2 in surface waters using solid phase extraction with molecular imprinting polymers (MISPE followed by identification and quantification by HPLC-DAD. Acetonitrile and water deionized acidified with phosphoric acid pH 3 (1:1, v/v, a flow rate of 1.0 ml min-1, at 40°C and an injection volume of 5 µL. The method was validated according to the protocol ICH Q2R. Reproducibility and repeatability tests resulted in a smaller variation coefficient of 10%; the calibration curves in the concentration ranged from 1 to 20 mg L-1, with return linearity values greater than 0.99. The limits of detection and quantification were less than 1 mg L-1 and the method was satisfactory for specificity and selectivity tests using caffeine, which is often found in water bodies receiving effluent, and DES, an estrogen used in the treatment of prostate cancer. Selected samples underwent clean-up and pre-concentration treatments using solid phase extraction with commercial phase (C18 and molecularly imprinted polymers (MISPE. The analysis of MISPE extracts indicate that it is possible to obtain results with greater sensitivity and precision for analyses of complex environmental matrices, demonstrating that the developed method can be applied in complex environmental matrices.
The phase equilibria of multicomponent gas hydrate in methanol/ethylene glycol solution based formation water

International Nuclear Information System (INIS)

Xu, Shurui; Fan, Shuanshi; Yao, Haiyuan; Wang, Yanhong; Lang, Xuemei; Lv, Pingping; Fang, Songtian

2017-01-01

Highlights: • The equilibrium data in THI solution based formation water is first investigated. • The 0.55 mass fraction concentration of EG 0.55 mass fraction fills the vacancy of this area. • The testing pressure range from 4.22 MPa to 34.72 MPa was rare in published data. - Abstract: In this paper, the three-phase coexistence points are generated for multicomponent gas hydrate in methanol (MeOH) solution for (0.05, 0.10, 0.15, and 0.35) mass fraction and ethylene glycol (EG) solution for (0.05, 0.10, 0.15, 0.35, 0.40 and 0.55) mass fraction. The phase equilibrium curves of different system were obtained by an isochoric pressure-search method on high pressure apparatus. The phase equilibrium regions of multicomponent gas hydrate were measured using the same composition of natural gas distributed in the South China Sea. And the different concentration solutions were prepared based formation water. The experimental data were measured in a wide range temperature from 267.74 to 298.53 K and a wide range pressure from 4.22 MPa to 34.72 MPa. The results showed that the hydrate phase equilibrium curves shifted to the inhibition region in accordance with the increased inhibitor concentration. In addition, the equilibrium temperature would decrease about 2.7 K when the concentration of MeOH increased 0.05 mass fraction. Besides, the suppression temperature was 1.25 K with the 0.05 mass fraction increase of EG concentration in the range of 0.05 mass fraction to 0.15 mass fraction. While in high EG concentration region, the suppression temperature was 3.3 K with the same increase of EG concentration (0.05 mass fraction).
Water, Water, Everywhere.

Science.gov (United States)

Selinger, Ben

1979-01-01

Water is a major component in many consumer products. Azeotropic distillation of products such as detergents and foodstuffs to form a two-phase distillate is a simple experimental method to determine the percentage of water in the product. (Author/GA)
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.
Determination of ethylenediaminetetraacetic acid in sea water by solid-phase extraction and high-performance liquid chromatography.

Science.gov (United States)

Kemmei, Tomoko; Kodama, Shuji; Fujishima, Hironori; Yamamoto, Atsushi; Inoue, Yoshinori; Hayakawa, Kazuichi

2012-01-04

The chelating agent EDTA is widely used, and as a result is showing up widely in the aquatic environment. Here we describe a preconcentration procedure for measuring EDTA concentration in sea water samples by HPLC. The procedure consists of forming an Fe(III) complex followed by solid-phase extraction using an activated carbon cartridge. After the preconcentration, EDTA was quantified by HPLC with ultraviolet detection (260 nm). The enrichment permitted the determination of EDTA at concentrations as low as 1 nM. Good recoveries were obtained for both brackish and full-strength sea water with high repeatability (RSD<6%). The method was applied to sea water samples taken from near the mouth of the Oyabe River in Japan. Copyright © 2011 Elsevier B.V. All rights reserved.
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%.
Industrial application of green chromatography--I. Separation and analysis of niacinamide in skincare creams using pure water as the mobile phase.

Science.gov (United States)

Yang, Yu; Strickland, Zackary; Kapalavavi, Brahmam; Marple, Ronita; Gamsky, Chris

2011-03-15

In this work, chromatographic separation of niacin and niacinamide using pure water as the sole component in the mobile phase has been investigated. The separation and analysis of niacinamide have been optimized using three columns at different temperatures and various flow rates. Our results clearly demonstrate that separation and analysis of niacinamide from skincare products can be achieved using pure water as the eluent at 60°C on a Waters XTerra MS C18 column, a Waters XBridge C18 column, or at 80°C on a Hamilton PRP-1 column. The separation efficiency, quantification quality, and analysis time of this new method are at least comparable with those of the traditional HPLC methods. Compared with traditional HPLC, the major advantage of this newly developed green chromatography technique is the elimination of organic solvents required in the HPLC mobile phase. In addition, the pure water chromatography separations described in this work can be directly applied in industrial plant settings without further modification of the existing HPLC equipment. Copyright © 2011 Elsevier B.V. All rights reserved.
SIMPLE METHOD FOR ESTIMATING POLYCHLORINATED BIPHENYL CONCENTRATIONS ON SOILS AND SEDIMENTS USING SUBCRITICAL WATER EXTRACTION COUPLED WITH SOLID-PHASE MICROEXTRACTION. (R825368)

Science.gov (United States)

A rapid method for estimating polychlorinated biphenyl (PCB) concentrations in contaminated soils and sediments has been developed by coupling static subcritical water extraction with solid-phase microextraction (SPME). Soil, water, and internal standards are placed in a seale...
Corrosion detection of carbon steel in water/oil two phases environment by electrochemical noise analysis

International Nuclear Information System (INIS)

Gusmano, G.; Montesperelli, G.; De Grandis, A.

1998-01-01

The aim of this paper is to demonstrate the effectiveness of the electrochemical noise analysis to detect the onset of corrosion phenomena in a very high resistivity medium. Tests were carried out on carbon steel electrodes immersed in a water/mineral oil two phases environment with high concentration of CO 2 , different aqueous/organic phase ratio, sulphide content between 0 and 0.5 g/l and pH between 1 and 5. The evolution of corrosion phenomena were followed by collecting current and potential noise between three nominally identical electrodes. The noise data were analysed in the time and in the frequency domain. In spite of a great loss of sensitivity of the method with respect to tests performed in aqueous solution, the data indicate a good agreement between the standard deviations and the power level of power spectra density (PSD) of current and potential noise signals and corrosion rates by means of weight loss. The values of the PSD slope, indicate the form of corrosion. The effect of water/oil ratio, sulphide concentration and pH on the corrosion rate was determined. Finally two methods to increase the sensitivity of the electrochemical noise are proposed. (orig.)
Frictional pressure drop of steam-water two-phase flow in helical coils with small helix diameter of HTR-10

International Nuclear Information System (INIS)

Bi Qincheng; Chen Tingkuan; Luo Yushan; Zheng Jianxue

1996-01-01

Experiments of steam-water two-phase flow frictional pressure drop through five vertically and horizontally positioned helical coils were carried out in the high pressure steam water test loop of Xi'an Jiaotong University. Two kinds of tube with inner diameters of 10 mm and 12 mm were used to form the coils. The helix diameter was 115 mm with coil pitch 22.5 mm. The experimental conditions were: pressure p = 4-14 MPa, mass velocity G = 400-2000 kg/(m 2 ·s), and inner wall heat flux q = 0-750 kW/m 2 . Theoretical analysis with a semi-empirical correlation was made to predict the two-phase flow fictional pressure drop through these kinds of helical coils
Preconcentrate of thorium in solid phase and its direct determination by X-ray fluorescence in natural waters

International Nuclear Information System (INIS)

Carvalho, Marcelo S. de; Domingues, Maria de Lourdes F.; Mantovano, Jose Luiz; Cunha, Jose Waldemar S.D. da

2000-01-01

This paper describe a methodology to pre concentrate thorium from natural water samples by using solid phase extraction (SPE) before its direct determination by X-ray fluorescence. Polyurethane foam supporting 2- ethyl hexyl phosfonic acid was used as SPE. The extraction was maximum at 0.25 mol/L in hydrochloric acid, for 30 minutes of shaking time. At least 8 mg/L thorium could be determined what allowed us to apply this methodology successfully for determination of thorium in natural water reference samples. (author)
Study on frictional pressure drop of steam-water two phase flow in optimized four-head internal-ribbed tube

International Nuclear Information System (INIS)

Wang Weishu; Zhu Xiaojing; Bi Qincheng; Wu Gang; Yu Shuiqing

2012-01-01

The optimized internal-ribbed tube is different from the normal internal-ribbed tube on the frictional pressure drop characteristics. The frictional pressure drop characteristics of steam-water two phase flow in horizontal four-head optimized internal-ribbed were studied under adiabatic condition. According to the experimental and calculation results, the two-phase multiplier is greatly affected by the steam quality and pressure. The two-phase multiplier increases with increasing quality, and decreases with increasing pressure. In the near-critical pressure region, the two-phase multiplier is close to 1. The frictional pressure drop of two phase flow in optimized tube is less than that in the normal tube under the same work condition. The good hydrodynamic condition could be achieved when the optimized internal-ribbed tube is used in the heat transfer equipment because the self-compensating characteristics exist due to the reduction of frictional pressure drop. (authors)

Amorphous and crystalline aerosol particles interacting with water vapor: conceptual framework and experimental evidence for restructuring, phase transitions and kinetic limitations

Directory of Open Access Journals (Sweden)

T. Koop

2009-12-01

Full Text Available Interactions with water are crucial for the properties, transformation and climate effects of atmospheric aerosols. Here we present a conceptual framework for the interaction of amorphous aerosol particles with water vapor, outlining characteristic features and differences in comparison to crystalline particles. We used a hygroscopicity tandem differential mobility analyzer (H-TDMA to characterize the hydration and dehydration of crystalline ammonium sulfate, amorphous oxalic acid and amorphous levoglucosan particles (diameter ~100 nm, relative humidity 5–95% at 298 K. The experimental data and accompanying Köhler model calculations provide new insights into particle microstructure, surface adsorption, bulk absorption, phase transitions and hygroscopic growth. The results of these and related investigations lead to the following conclusions:

(1 Many organic substances, including carboxylic acids, carbohydrates and proteins, tend to form amorphous rather than crystalline phases upon drying of aqueous solution droplets. Depending on viscosity and microstructure, the amorphous phases can be classified as glasses, rubbers, gels or viscous liquids.

(2 Amorphous organic substances tend to absorb water vapor and undergo gradual deliquescence and hygroscopic growth at lower relative humidity than their crystalline counterparts.

(3 In the course of hydration and dehydration, certain organic substances can form rubber- or gel-like structures (supramolecular networks and undergo transitions between swollen and collapsed network structures.

(4 Organic gels or (semi-solid amorphous shells (glassy, rubbery, ultra-viscous with low molecular diffusivity can kinetically limit the uptake and release of water and may influence the hygroscopic growth and activation of aerosol particles as cloud condensation nuclei (CCN and ice nuclei (IN. Moreover, (semi-solid amorphous phases may influence the uptake of gaseous photo
Steam content of the two-phase flow in the Vk-50 boiling water cooled reactor draught section

International Nuclear Information System (INIS)

Fedulin, V.N.; Shmelev, V.E.; Solodkij, V.A.; Bartolomej, G.G.

1983-01-01

Results are presented of experimental investigation of the two-phase steam-water coolant flow hydrodynamics within the VK-50 reactor draught section. On the basis of the analysis of the obtained data a two-phase coolant flow model in a large diameter channel is proposed. It is shown that the steam-content distribution in the volume of the draught section has a pronounced non-equilibrium character manifested in the steam migration from the periphery to the central region. A minimum value of the steam content at the periphery is attained at the 0.7-1.0 m height; it is followed by a partial steam content levelling over the section. However the total steam content levelling over the cross section of the draught section does not take place. The steam distribution in the water layer over the draught section (overflow zone) is also nonuniform over the reactor section. The non-uniform steam distribution enchances with reduction nn pressure
Mars Regolith Water Extractor, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The Mars Regolith Water Extractor (MRWE) is a system for acquiring water from the Martian soil. In the MRWE, a stream of CO2 is heated by solar energy or waste heat...
Effect of the water content on the retention and enantioselectivity of albendazole and fenbendazole sulfoxides using amylose-based chiral stationary phases in organic-aqueous conditions.

Science.gov (United States)

Materazzo, Sabrina; Carradori, Simone; Ferretti, Rosella; Gallinella, Bruno; Secci, Daniela; Cirilli, Roberto

2014-01-31

Four commercially available immobilized amylose-derived CSPs (Chiralpak IA-3, Chiralpak ID-3, Chiralpak IE-3 and Chiralpak IF-3) were used in the HPLC analysis of the chiral sulfoxides albendazole (ABZ-SO) and fenbendazole (FBZ-SO) and their in vivo sulfide precursor (ABZ and FBZ) and sulfone metabolite (ABZ-SO2 and FBZ-SO2) under organic-aqueous mode. U-shape retention maps, established by varying the water content in the acetonitrile- and ethanol-water mobile phases, were indicative of two retention mechanisms operating on the same CSP. The dual retention behavior of polysaccharide-based CSPs was exploited to design greener enantioselective and chemoselective separations in a short time frame. The enantiomers of ABZ-SO and FBZ-SO were baseline resolved with water-rich mobile phases (with the main component usually being 50-65% water in acetonitrile) on the IF-3 CSP and ethanol-water 100:5 mixture on the IA-3 and IE-3 CSPs. A simultaneous separation of ABZ (or FBZ), enantiomers of the corresponding sulfoxide and sulfone was achieved on the IA-3 using ethanol-water 100:60 (acetonitrile-water 100:100 for FBZ) as a mobile phase. Copyright © 2014 Elsevier B.V. All rights reserved.
Microstructure and phase transformation on milled and unmilled Ti induced by water quenching

CSIR Research Space (South Africa)

Bolokang, AS

2014-10-01

Full Text Available Materials Letters Vol. 132 Microstructure and phase transformation on milled and unmilled Ti induced by water quenching A.S.Bolokang a,b,n, M.J.Phasha c, D.E.Motaung b, F.R.Cummings a,d, T.F.G.Muller a, C.J.Arendse a a Department of...Physics,UniversityoftheWesternCape,PrivateBagx17,Bellville7535,SouthAfrica bDST/CSIR Nanotechnology InnovationCentre ,National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P.O.Box395, Pretoria 0001, SouthAfrica c Transnet Engineering, Product...
Three-phase solvent bar micro-extraction as an approach to silver ultra-traces speciation in estuarine water samples.

Science.gov (United States)

López-López, José Antonio; Herce-Sesa, Belén; Moreno, Carlos

2015-01-01

Silver ion inputs into the environment due to human activities have been increased in the last years because it has been used as a bactericide with application in medical, homecare and self-care products. In addition, it is toxic at low concentration for aquatic organisms. In estuarine waters, salinity and dissolved organic matter (DOM) regulate Ag(+) concentration by the formation of complexes as AgCln((n-1)-) and Ag-DOM. Difficulties of Ag(+) analysis in estuaries are associated to its low concentration level and interferences of sample matrix. Liquid and solid phase extraction methods have been used for speciation of silver in waters; however, miniaturized methods that offer a better environmental profile are desirable. Hollow fiber liquid phase micro-extraction (HFLPME) allows obtaining higher pre-concentration factors with a reduction of waste generation. Notwithstanding, some operational improvements are needed to permit their use as a routine method that can be afforded using a configuration of three-phase solvent bar micro-extraction (3PSBME). In this work, tri-isobutylphosphine sulphide (TIBPS) has been used as an extractant for Ag(+) pre-concentration in estuarine waters by 3PSBME. Under optimized conditions, Ag(+) has been pre-concentrated 60 times and the method presents a limit of detection of 1.53 ng L(-1). To evaluate which Ag species is transported by TIBPS, Cl(-) and DOM have been added to synthetic samples. As a result, a decrease in Ag pre-concentration efficiency after additions has been observed and quantified. Results showed that Ag(+) is selectively transported by TIBPS from estuarine water samples after comparison of the results with those obtained by the reference method of liquid extraction with APDC/DDDC. Copyright © 2014 Elsevier B.V. All rights reserved.
Responding to the challenges of water security: the Eighth Phase of the International Hydrological Programme, 2014–2021

Directory of Open Access Journals (Sweden)

B. Jimenez-Cisneros

2015-04-01

Full Text Available This paper presents the major water challenges at global, regional and local levels, including the need to adapt to climate change. It relates how the International Hydrological Programme (IHP – an intergovernmental scientific programme – will respond in its Eighth Phase to the water-related risks and seize potential opportunities, thereby contributing to ensure Water Security at all levels. The Member States of UNESCO IHP periodically define priorities for research, technological development, innovation and education. To implement the priorities in a coordinated manner, the Member States can count on the team and the projects of IHP based at UNESCO, as well as on the "UNESCO Water Family|, consisting to date of a Category 1 centre UNESCO-IHE located in the Netherlands; the World Water Assessment Programme, based in Italy, which produces the World Water Development Report of the United Nations; 30 Category 2 water centres under the auspices of UNESCO; and 35 water chairs in various parts of the world. Governments can access the powerful network of the UNESCO Water Family through IHP and its Intergovernmental Council.
An on-line push/pull perfusion-based hollow-fiber liquid-phase microextraction system for high-performance liquid chromatographic determination of alkylphenols in water samples.

Science.gov (United States)

Chao, Yu-Ying; Jian, Zhi-Xuan; Tu, Yi-Ming; Wang, Hsaio-Wen; Huang, Yeou-Lih

2013-06-07

In this study, we employed a novel on-line method, push/pull perfusion hollow-fiber liquid-phase microextraction (PPP-HF-LPME), to extract 4-tert-butylphenol, 2,4-di-tert-butylphenol, 4-n-nonylphenol, and 4-n-octylphenol from river and tap water samples; we then separated and quantified the extracted analytes through high-performance liquid chromatography (HPLC). Using this approach, we overcame the problem of fluid loss across the porous HF membrane to the donor phase, permitting on-line coupling of HF-LPME to HPLC. In our PPP-HF-LPME system, we used a push/pull syringe pump as the driving source to perfuse the acceptor phase, while employing a heating mantle and an ultrasonic probe to accelerate mass transfer. We optimized the experimental conditions such as the nature of the HF supported intermediary phase and the acceptor phase, the composition of the donor and acceptor phases, the sample temperature, and the sonication conditions. Our proposed method provided relative standard deviations of 3.1-6.2%, coefficients of determination (r(2)) of 0.9989-0.9998, and limits of detection of 0.03-0.2 ng mL(-1) for the analytes under the optimized conditions. When we applied this method to analyses of river and tap water samples, our results confirmed that this microextraction technique allows reliable monitoring of alkylphenols in water samples.
Modeling and Analysis of Magnetic Nanoparticles Injection in Water-Oil Two-Phase Flow in Porous Media under Magnetic Field Effect

KAUST Repository

El-Amin, Mohamed; Saad, Adel; Salama, Amgad; Sun, Shuyu

2017-01-01

In this paper, the magnetic nanoparticles are injected into a water-oil, two-phase system under the influence of an external permanent magnetic field. We lay down the mathematical model and provide a set of numerical exercises of hypothetical cases to show how an external magnetic field can influence the transport of nanoparticles in the proposed two-phase system in porous media. We treat the water-nanoparticles suspension as a miscible mixture, whereas it is immiscible with the oil phase. The magnetization properties, the density, and the viscosity of the ferrofluids are obtained based on mixture theory relationships. In the mathematical model, the phase pressure contains additional term to account for the extra pressures due to fluid magnetization effect and the magnetostrictive effect. As a proof of concept, the proposed model is applied on a countercurrent imbibition flow system in which both the displacing and the displaced fluids move in opposite directions. Physical variables, including waternanoparticles suspension saturation, nanoparticles concentration, and pore wall/throat concentrations of deposited nanoparticles, are investigated under the influence of the magnetic field. Two different locations of the magnet are studied numerically, and variations in permeability and porosity are considered.
Modeling and Analysis of Magnetic Nanoparticles Injection in Water-Oil Two-Phase Flow in Porous Media under Magnetic Field Effect

KAUST Repository

El-Amin, Mohamed

2017-08-28

In this paper, the magnetic nanoparticles are injected into a water-oil, two-phase system under the influence of an external permanent magnetic field. We lay down the mathematical model and provide a set of numerical exercises of hypothetical cases to show how an external magnetic field can influence the transport of nanoparticles in the proposed two-phase system in porous media. We treat the water-nanoparticles suspension as a miscible mixture, whereas it is immiscible with the oil phase. The magnetization properties, the density, and the viscosity of the ferrofluids are obtained based on mixture theory relationships. In the mathematical model, the phase pressure contains additional term to account for the extra pressures due to fluid magnetization effect and the magnetostrictive effect. As a proof of concept, the proposed model is applied on a countercurrent imbibition flow system in which both the displacing and the displaced fluids move in opposite directions. Physical variables, including waternanoparticles suspension saturation, nanoparticles concentration, and pore wall/throat concentrations of deposited nanoparticles, are investigated under the influence of the magnetic field. Two different locations of the magnet are studied numerically, and variations in permeability and porosity are considered.
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
Community shift of biofilms developed in a full-scale drinking water distribution system switching from different water sources.

Science.gov (United States)

Li, Weiying; Wang, Feng; Zhang, Junpeng; Qiao, Yu; Xu, Chen; Liu, Yao; Qian, Lin; Li, Wenming; Dong, Bingzhi

2016-02-15

The bacterial community of biofilms in drinking water distribution systems (DWDS) with various water sources has been rarely reported. In this research, biofilms were sampled at three points (A, B, and C) during the river water source phase (phase I), the interim period (phase II) and the reservoir water source phase (phase III), and the biofilm community was determined using the 454-pyrosequencing method. Results showed that microbial diversity declined in phase II but increased in phase III. The primary phylum was Proteobacteria during three phases, while the dominant class at points A and B was Betaproteobacteria (>49%) during all phases, but that changed to Holophagae in phase II (62.7%) and Actinobacteria in phase III (35.6%) for point C, which was closely related to its water quality. More remarkable community shift was found at the genus level. In addition, analysis results showed that water quality could significantly affect microbial diversity together, while the nutrient composition (e.g. C/N ration) of the water environment might determine the microbial community. Furthermore, Mycobacterium spp. and Pseudomonas spp. were detected in the biofilm, which should give rise to attention. This study revealed that water source switching produced substantial impact on the biofilm community. Copyright © 2015 Elsevier B.V. All rights reserved.
Numerical study of Tallinn storm-water system flooding conditions using CFD simulations of multi-phase flow in a large-scale inverted siphon

Science.gov (United States)

Kaur, K.; Laanearu, J.; Annus, I.

2017-10-01

The numerical experiments are carried out for qualitative and quantitative interpretation of a multi-phase flow processes associated with malfunctioning of the Tallinn storm-water system during rain storms. The investigations are focused on the single-line inverted siphon, which is used as under-road connection of pipes of the storm-water system under interest. A multi-phase flow solver of Computational Fluid Dynamics software OpenFOAM is used for simulating the three-phase flow dynamics in the hydraulic system. The CFD simulations are performed with different inflow rates under same initial conditions. The computational results are compared essentially in two cases 1) design flow rate and 2) larger flow rate, for emptying the initially filled inverted siphon from a slurry-fluid. The larger flow-rate situations are under particular interest to detected possible flooding. In this regard, it is anticipated that the CFD solutions provide an important insight to functioning of inverted siphon under a restricted water-flow conditions at simultaneous presence of air and slurry-fluid.
Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites

Science.gov (United States)

Plampin, Michael R.; Lassen, Rune N.; Sakaki, Toshihiro; Porter, Mark L.; Pawar, Rajesh J.; Jensen, Karsten H.; Illangasekare, Tissa H.

2014-12-01

A primary concern for geologic carbon storage is the potential for leakage of stored carbon dioxide (CO2) into the shallow subsurface where it could degrade the quality of groundwater and surface water. In order to predict and mitigate the potentially negative impacts of CO2 leakage, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2 concentration in the flowing water, the distance between the heterogeneity and the leakage location, and some fundamental properties of the porous media. Results also show that interfaces where a less permeable material overlies a more permeable material affect gas phase evolution more significantly than interfaces with the opposite layering.
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.
pH-induced inversion of water-in-oil emulsions to oil-in-water high internal phase emulsions (HIPEs) using core cross-linked star (CCS) polymer as interfacial stabilizer.

Science.gov (United States)

Chen, Qijing; Deng, Xiaoyong; An, Zesheng

2014-06-01

A pH-responsive core cross-linked star (CCS) polymer containing poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) arms was used as an interfacial stabilizer for emulsions containing toluene (80 v%) and water (20 v%). In the pH range of 12.1-9.3, ordinary water-in-oil emulsions were formed. Intermediate multiple emulsions of oil-in-water-in-oil and water-in-oil-in-water were formed at pH 8.6 and 7.5, respectively. Further lowering the pH resulted in the formation of gelled high internal phase emulsions of oil-in-water type in the pH range of 6.4-0.6. The emulsion behavior was correlated with interfacial tension, conductivity and configuration of the CCS polymer at different pH. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Thermal characteristics of non-edible oils as phase change materials candidate to application of air conditioning chilled water system

Science.gov (United States)

Irsyad, M.; Indartono, Y. S.; Suwono, A.; Pasek, A. D.

2015-09-01

The addition of phase change material in the secondary refrigerant has been able to reduce the energy consumption of air conditioning systems in chilled water system. This material has a high thermal density because its energy is stored as latent heat. Based on material melting and freezing point, there are several non-edible oils that can be studied as a phase change material candidate for the application of chilled water systems. Forests and plantations in Indonesia have great potential to produce non-edible oil derived from the seeds of the plant, such as; Calophyllum inophyllum, Jatropha curcas L, and Hevea braziliensis. Based on the melting temperature, these oils can further studied to be used as material mixing in the secondary refrigerant. Thermal characteristics are obtained from the testing of T-history, Differential Scanning Calorimetric (DSC) and thermal conductivity materials. Test results showed an increase in the value of the latent heat when mixed with water with the addition of surfactant. Thermal characteristics of each material of the test results are shown completely in discussion section of this article.
Determination of trace triazine and chloroacetamide herbicides in tile-fed drainage ditch water using solid-phase microextraction coupled with GC-MS

Energy Technology Data Exchange (ETDEWEB)

Rocha, Cleonice [Catholic University of Goias, Av. Universitaria, 1440 S. Universitario, Cx (Brazil); Pappas, Elizabeth A. [USDA ARS, National Soil Erosion Research Laboratory, 275 S. Russell Street, West Lafayette, IN 47907 (United States)], E-mail: bets@purdue.edu; Huang, C.-H. [USDA ARS, National Soil Erosion Research Laboratory, 275 S. Russell Street, West Lafayette, IN 47907 (United States)

2008-03-15

Solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) was used to analyze two triazine (atrazine and simazine) and three chloroacetamide herbicides (acetochlor, alachlor, and metolachlor) in water samples from a midwest US agricultural drainage ditch for two growing seasons. The effects of salt concentration, sample volume, extraction time, and injection time on extraction efficiency using a 100-{mu}m polydimethylsiloxane-coated fiber were investigated. By optimizing these parameters, ditch water detection limits of 0.5 {mu}g L{sup -1} simazine and 0.25 {mu}g L{sup -1} atrazine, acetochlor, alachlor, and metolachlor were achieved. The optimum salt concentration was found to be 83% NaCl, while sample volume (10 or 20 mL) negligibly affected analyte peak areas. The optimum extraction time was 40 min, and the optimum injection time was 15 min. Results indicated that atrazine levels in the ditch water exceeded the US maximum contaminant level for drinking water 12% of the time, and atrazine was the most frequently detected among studied analytes. - Solid-phase microextraction methods were successfully developed to quantify low levels of herbicides in tile-fed drain water by gas chromatography-mass spectrometry.
Solvent-assisted dispersive solid-phase extraction: A sample preparation method for trace detection of diazinon in urine and environmental water samples.

Science.gov (United States)

Aladaghlo, Zolfaghar; Fakhari, Alireza; Behbahani, Mohammad

2016-09-02

In this research, a sample preparation method termed solvent-assisted dispersive solid-phase extraction (SA-DSPE) was applied. The used sample preparation method was based on the dispersion of the sorbent into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was received by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the diazinon, the cloudy solution was centrifuged and diazinon in the sediment phase dissolved in ethanol and determined by gas chromatography-flame ionization detector. Under the optimized conditions (pH of solution=7.0, Sorbent: benzophenone, 2%, Disperser solvent: ethanol, 500μL, Centrifuge: centrifuged at 4000rpm for 3min), the method detection limit for diazinon was 0.2, 0.3, 0.3 and 0.3μgL(-1) for distilled water, lake water, waste water and urine sample, respectively. Furthermore, the pre-concentration factor was 363.8, 356.1, 360.7 and 353.38 in distilled water, waste water, lake water and urine sample, respectively. SA-DSPE was successfully used for trace monitoring of diazinon in urine, lake and waste water samples. Copyright © 2016 Elsevier B.V. All rights reserved.
Two-phase natural circulation experiments in a pressurized water loop with CANDU geometry

Energy Technology Data Exchange (ETDEWEB)

Ardron, K.H.; Krishnan, V.S.; McGee, G.R.; Anderson, J.W.D.; Hawley, E.H.

1984-07-01

A series of tests has been performed in the RD-12 loop, a 10-MPa pressurized-water loop containing two active boilers, two pumps, and two, or four, heated horizontal channels arranged in a symmetrical figure-of-eight configuration characteristic of the CANDU reactor primary heat-transport system. In the tests, single-phase natural circulation was established in the loop and void was introduced by controlled draining, with the surge tank (pressurizer) valved out of the system. Results indicate that a stable, two-phase, natural circulation flow can usually be established. However, as the void fraction in the loop is increased, large-amplitude flow oscillations can occur. The initial flow oscillations in the two halves of the loop are usually very nearly 180/sup 0/ out-of-phase. However, as the loop inventory is further decreased, an in-phase oscillation component is observed. In tests with two parallel, heated channels in each half-loop, oscillations associated with mass transfer between the channel pairs are also observed. Although flow oscillations can lead to intermittent dryout of the upper elements of the heater-rod assemblies in the horizontal channels, natural circulation cooling appears to be effective until about 50% of the loop inventory is drained; sustained flow stratification then occurs in the heated channels, leading to heater temperature excursions. The paper reviews the experimental results obtained and describes the evolution of natural circulation flow in particular cases as voidage is progressively increased. The stability behavior is discussed briefly with reference to a simple stability model.

Determination of the quaternary phase diagram of the water-ethylene glycol-sucrose-NaCl system and a comparison between two theoretical methods for synthetic phase diagrams.

Science.gov (United States)

Han, Xu; Liu, Yang; Critser, John K

2010-08-01

Characterization of the thermodynamic properties of multi-solute aqueous solutions is of critical importance for biological and biochemical research. For example, the phase diagrams of aqueous systems, containing salts, saccharides, and plasma membrane permeating solutes, are indispensible in the field of cryobiology and pharmacology. However, only a few ternary phase diagrams are currently available for these systems. In this study, an auto-sampler differential scanning calorimeter (DSC) was used to determine the quaternary phase diagram of the water-ethylene glycol-sucrose-NaCl system. To improve the accuracy of melting point measurement, a "mass-redemption" method was also applied for the DSC technique. Base on the analyses of these experimental data, a comparison was made between the two practical approaches to generate phase diagrams of multi-solute solutions from those of single-solute solutions: the summation of cubic polynomial melting point equations versus the use of osmotic virial equations with cross coefficients. The calculated values of the model standard deviations suggested that both methods are satisfactory for characterizing this quaternary system. (c) 2010 Elsevier Inc. All rights reserved.
Conformational preferences of γ-aminobutyric acid in the gas phase and in water

Science.gov (United States)

Song, Il Keun; Kang, Young Kee

2012-09-01

The conformational study of γ-aminobutyric acid (GABA) has been carried out at the M06-2X/cc-pVTZ level of theory in the gas phase and the SMD M06-2X/cc-pVTZ level of theory in water. In the gas phase, the folded conformation gG1 with gauche- and gauche+ conformations for the Cβsbnd Cα and Cγsbnd Cβ bonds, respectively, is found to be lowest in energy and enthalpy, which can be ascribed to the favored hyperconjugative n → π* interaction between the lone electron pair of the amine nitrogen atom and the Cdbnd O bond of the carboxylic group and the favored antiparallel dipole-dipole interaction between the Nsbnd H bond and the Cdbnd O bond. In addition, the intramolecular hydrogen bonds between the carboxylic group and the amine Nsbnd H group have contributed to stabilize some low-energy conformers. However, the most preferred conformation is found to be tG1 and more stable by 0.4 kcal/mol in ΔG than the conformer gG1, in which the favored entropic term due to the conformational flexibility and the other favored n → σ*, σ → σ*, and π → σ* interactions seem to play a role. The conformational preferences of the neutral GABA calculated by ΔG's are reasonably consistent with the populations deduced from FT microwave spectroscopy in supersonic jets combined with laser ablation. In water, the two folded conformers Gg and gG of the zwitterionic GABA are dominantly populated, each of which has the population of 47%, and the hydrogen bond between the ammonium Nsbnd H group and the lone electron pair of the Csbnd O- group seems to be crucial in stabilizing these conformers. Our calculated result that the folded conformers preferentially exist in water is consistent with the 1H NMR experiments in D2O.
Efficient sample preparation method based on solvent-assisted dispersive solid-phase extraction for the trace detection of butachlor in urine and waste water samples.

Science.gov (United States)

Aladaghlo, Zolfaghar; Fakhari, Alireza; Behbahani, Mohammad

2016-10-01

In this work, an efficient sample preparation method termed solvent-assisted dispersive solid-phase extraction was applied. The used sample preparation method was based on the dispersion of the sorbent (benzophenone) into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the butachlor, the cloudy solution was centrifuged and butachlor in the sediment phase dissolved in ethanol and determined by gas chromatography with flame ionization detection. Under the optimized conditions (solution pH = 7.0, sorbent: benzophenone, 2%, disperser solvent: ethanol, 500 μL, centrifuged at 4000 rpm for 3 min), the method detection limit for butachlor was 2, 3 and 3 μg/L for distilled water, waste water, and urine sample, respectively. Furthermore, the preconcentration factor was 198.8, 175.0, and 174.2 in distilled water, waste water, and urine sample, respectively. Solvent-assisted dispersive solid-phase extraction was successfully used for the trace monitoring of butachlor in urine and waste water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
CO2 saturated water as two-phase flow for fouling control in reverse electrodialysis.

Science.gov (United States)

Moreno, J; de Hart, N; Saakes, M; Nijmeijer, K

2017-11-15

When natural feed waters are used in the operation of a reverse electrodialysis (RED) stack, severe fouling on the ion exchange membranes and spacers occurs. Fouling of the RED stack has a strong influence on the gross power density output; which can decrease up to 50%. Moreover, an increase in the pressure loss occurs between the feed water inlet and outlet, increasing the pumping energy and thus decreasing the net power density that can be obtained. In this work, we extensively investigated the use of CO 2 saturated water as two-phase flow cleaning for fouling mitigation in RED using natural feed waters. Experiments were performed in the REDstack research facility located at the Afsluitdijk (the Netherlands) using natural feed waters for a period of 60 days. Two different gas combinations were experimentally investigated, water/air sparging and water/CO 2 (saturated) injection. Air is an inert gas mixture and induces air sparging in the stack. In the case of CO 2 , nucleation, i.e. the spontaneous formation of bubbles, occurs at the spacer filaments due to depressurization of CO 2 saturated water, inducing cleaning. Results showed that stacks equipped with CO 2 saturated water can produce an average net power density of 0.18 W/m 2 under real fouling conditions with minimal pre-treatment and at a low outside temperature of only 8 °C, whereas the stacks equipped with air sparging could only produce an average net power density of 0.04 W/m 2 . Electrochemical impedance spectroscopy measurements showed that the stacks equipped with air sparging increased in stack resistance due to the presence of stagnant bubbles remaining in the stack after every air injection. Furthermore, the introduction of CO 2 gas in the feed water introduces a pH decrease in the system (carbonated solution) adding an additional cleaning effect in the system, thus avoiding the use of environmentally unwanted cleaning chemicals. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All
Modeling and numerical simulation of oscillatory two-phase flows, with application to boiling water nuclear reactors

Energy Technology Data Exchange (ETDEWEB)

Rosa, M.P. [Instituto de Estudos Avancados - CTA, Sao Paolo (Brazil); Podowski, M.Z. [Rensselaer Polytechnic Institute, Troy, NY (United States)

1995-09-01

This paper is concerned with the analysis of dynamics and stability of boiling channels and systems. The specific objectives are two-fold. One of them is to present the results of a study aimed at analyzing the effects of various modeling concepts and numerical approaches on the transient response and stability of parallel boiling channels. The other objective is to investigate the effect of closed-loop feedback on stability of a boiling water reactor (BWR). Various modeling and computational issues for parallel boiling channels are discussed, such as: the impact of the numerical discretization scheme for the node containing the moving boiling boundary on the convergence and accuracy of computations, and the effects of subcooled boiling and other two-phase flow phenomena on the predictions of marginal stability conditions. Furthermore, the effects are analyzed of local loss coefficients around the recirculation loop of a boiling water reactor on stability of the reactor system. An apparent paradox is explained concerning the impact of changing single-phase losses on loop stability. The calculations have been performed using the DYNOBOSS computer code. The results of DYNOBOSS validation against other computer codes and experimental data are shown.
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.
Compositional evolution of particle-phase reaction products and water in the heterogeneous OH oxidation of model aqueous organic aerosols

Directory of Open Access Journals (Sweden)

M. M. Chim

2017-12-01

Full Text Available Organic compounds present at or near the surface of aqueous droplets can be efficiently oxidized by gas-phase OH radicals, which alter the molecular distribution of the reaction products within the droplet. A change in aerosol composition affects the hygroscopicity and leads to a concomitant response in the equilibrium amount of particle-phase water. The variation in the aerosol water content affects the aerosol size and physicochemical properties, which in turn governs the oxidation kinetics and chemistry. To attain better knowledge of the compositional evolution of aqueous organic droplets during oxidation, this work investigates the heterogeneous OH-radical-initiated oxidation of aqueous methylsuccinic acid (C5H8O4 droplets, a model compound for small branched dicarboxylic acids found in atmospheric aerosols, at a high relative humidity of 85 % through experimental and modeling approaches. Aerosol mass spectra measured by a soft atmospheric pressure ionization source (Direct Analysis in Real Time, DART coupled with a high-resolution mass spectrometer reveal two major products: a five carbon atom (C5 hydroxyl functionalization product (C5H8O5 and a C4 fragmentation product (C4H6O3. These two products likely originate from the formation and subsequent reactions (intermolecular hydrogen abstraction and carbon–carbon bond scission of tertiary alkoxy radicals resulting from the OH abstraction occurring at the methyl-substituted carbon site. Based on the identification of the reaction products, a kinetic model of oxidation (a two-product model coupled with the Aerosol Inorganic–Organic Mixtures Functional groups Activity Coefficients (AIOMFAC model is built to simulate the size and compositional changes of aqueous methylsuccinic acid droplets during oxidation. Model results show that at the maximum OH exposure, the droplets become slightly more hygroscopic after oxidation, as the mass fraction of water is predicted to increase from
Liquid chromatography tandem mass spectrometry method using solid-phase extraction and bead-beating-assisted matrix solid-phase dispersion to quantify the fungicide tebuconazole in controlled frog exposure study: analysis of water and animal tissue

DEFF Research Database (Denmark)

Hansen, Martin; Poulsen, Rikke; Luong, Xuan

2014-01-01

and on tissue from exposed and non-exposed adult X. laevis. Using solid-phase extraction (SPE), the analytical method allows for quantification of tebuconazole at concentrations as low as 3.89 pg mL(-1) in 10 mL water samples. Using bead-beating-assisted matrix solid-phase dispersion (MSPD), it was possible...
Dynamic fabric phase sorptive extraction for a group of pharmaceuticals and personal care products from environmental waters.

Science.gov (United States)

Lakade, Sameer S; Borrull, Francesc; Furton, Kenneth G; Kabir, Abuzar; Marcé, Rosa Maria; Fontanals, Núria

2016-07-22

This paper describes for the first time the use of a new extraction technique, based on fabric phase sorptive extraction (FPSE). This new mode proposes the extraction of the analytes in dynamic mode in order to reduce the extraction time. Dynamic fabric phase sorptive extraction (DFPSE) followed by liquid chromatography-tandem mass spectrometry was evaluated for the extraction of a group of pharmaceuticals and personal care products (PPCPs) from environmental water samples. Different parameters affecting the extraction were optimized and best conditions were achieved when 50mL of sample at pH 3 was passed through 3 disks and analytes retained were eluted with 10mL of ethyl acetate. The recoveries were higher than 60% for most of compounds with the exception of the most polar ones (between 8% and 38%). The analytical method was validated with environmental samples such as river water and effluent and influent wastewater, and good performance was obtained. The analysis of samples revealed the presence of some PPCPs at low ngL(-1) concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.
Phase transformation of the brownmillerite SrCoO{sub 2.5} thin film through alkaline water electrolysis

Energy Technology Data Exchange (ETDEWEB)

Tambunan, Octolia Togibasa; Lee, Min Young; Kim, Deok Hyeon; Parwanta, Kadek Juliana; Jung, Chang Uk [Hankuk University of Foreign Studies, Yongin (Korea, Republic of)

2014-06-15

A phase transformation from insulating brownmillerite SrCoO{sub 2.5} to conducting perovskite SrCoO{sub 3} through electrochemical oxidation has been demonstrated for thin films of SrCoO{sub x} on a SrTiO{sub 3} (001) substrate. The cobalt-oxide film strongly favors the brownmillerite phase of SrCoO{sub 2.5} instead of the perovskite phase of SrCoO{sub 3} on a SrTiO{sub 3} (001) substrate due to its low lattice mismatch. Therefore, the phase transformation has its own retention. The alkaline water electrolysis occurs between the copper cathode and the SrCoO{sub 2.5} film anode. The H{sup +} ions are attracted to the cathode and generate H{sub 2} gas. The OH{sup -} ions are attracted to the film's surface and generate a rich amount of oxygen to fill the oxygen vacancy channel of brownmillerite SrCoO{sub 2.5}. The phase transformation was verified from the change in the out-of-plane lattice constant and the change in the resistivity of the electrolyzed film.
Temperature distributions in trapezoidal built in storage solar water heaters with/without phase change materials

International Nuclear Information System (INIS)

Tarhan, Sefa; Sari, Ahmet; Yardim, M. Hakan

2006-01-01

Built in storage solar water heaters (BSSWHs) have been recognized for their more compact constructions and faster solar gain than conventional solar water heaters, however, their water temperatures quickly go down during the cooling period. A trapezoidal BSSWH without PCM storage unit was used as the control heater (reference) to investigate the effect of two differently configured PCM storage units on the temperature distributions in water tanks. In the first design, myristic acid was filled into the PCM storage tank, which also served as an absorbing plate. In the second design, lauric acid was filled into the PCM storage tank, which also served as a baffle plate. The water temperature changes were followed by five thermocouples placed evenly and longitudinally into each of the three BSSWHs. The effects of the PCMs on the water temperature distributions depended on the configuration of the PCM storage unit and the longitudinal position in the water tanks. The use of lauric acid lowered the values of the peak temperatures by 15% compared to the control heater at the upper portion of the water tanks because of the low melting temperature of lauric acid, but it did not have any consistent effect on the retention of the water temperatures during the cooling period. The ability of the myristic acid storage unit to retain the water temperatures got more remarkable, especially at the middle portion of the water tank. The myristic acid storage increased the dip temperatures by approximately 8.8% compared to the control heater. In conclusion, lauric acid storage can be used to stabilize the water temperature during the day time, while the myristic acid storage unit can be used as a thermal barrier against heat loss during the night time because of its relatively high melting temperature and low heat conduction coefficient in its solid phase. The experimental results have also indicated that the thermal characteristics of the PCM and the configuration of the PCM storage
Experimental results of the effective water head in downcomer during reflood phase of a PWR LOCA

International Nuclear Information System (INIS)

Sudo, Yukio; Murao, Yoshio; Akimoto, Hajime

1980-08-01

The results and analysis of an experiment for the effective water head in downcomer with 50mm gap size are described. The main objective of the experiment was to clarify the effect of gap size on reflooding in a PWR LOCA. The effective water head in downcomer is the driving force for feeding emergency coolant into the core during reflood phase of a PWR LOCA. Discussions presented here follow those of a previous report in which experimental results and analysis were described for the case of 200mm gap size. Experimental Conditions were: Initial Wall Temperature = 200 -- 300 0 C, Back Pressure = 1 atm., Coolant Temperature = 71 -- 100 0 C, Extraction Water Velocity = 0 -- 2 cm/s, Gap Size = 50 mm. The effective water head history obtained in the experiment was compared with those predicted with Sudo's void fraction correlation. In the prediction, heat input to coolant was calculated from the response of measured wall temperature with heat condition analysis. The experimental results and analysis reveals that: (1) The effects of the gap size and initial wall temperature are evident, (2) The effect of extraction water velocity is negligible, and (3) The predicted history of effective water head is in good agreement with the experimental results except during the transient period in which the effective water head is descreasing. (author)
Gas chromatographic-mass spectrometric determination of hydrophilic compounds in environmental water by solid-phase extraction with activated carbon fiber felt.

Science.gov (United States)

Kawata, K; Ibaraki, T; Tanabe, A; Yagoh, H; Shinoda, A; Suzuki, H; Yasuhara, A

2001-03-09

Simple gas chromatographic-mass spectrometric determination of hydrophilic organic compounds in environmental water was developed. A cartridge containing activated carbon fiber felt was made by way of trial and was evaluated for solid-phase extraction of the compounds in water. The hydrophilic compounds investigated were acrylamide, N,N-dimethylacetamide, N,N-dimethylformamide, 1,4-dioxane, furfural, furfuryl alcohol, N-nitrosodiethylamine and N-nitrosodimethylamine. Overall recoveries were good (80-100%) from groundwater and river water. The relative standard deviations ranged from 4.5 to 16% for the target compounds. The minimum detectable concentrations were 0.02 to 0.03 microg/l. This method was successfully applied to several river water samples.
Hexagonal boron nitride nanosheets as adsorbents for solid-phase extraction of polychlorinated biphenyls from water samples

Energy Technology Data Exchange (ETDEWEB)

Jia, Shiliang; Wang, Zhenhua; Ding, Ning [Key Laboratory for Applied Technology of Sophisticated Analytical Instruments, Shandong Academy of Sciences, Jinan, Shandong (China); Elaine Wong, Y.-L. [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Chen, Xiangfeng, E-mail: xiangfchensdas@163.com [Key Laboratory for Applied Technology of Sophisticated Analytical Instruments, Shandong Academy of Sciences, Jinan, Shandong (China); Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Qiu, Guangyu [Department of Physics and Materials Science, City University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Dominic Chan, T.-W., E-mail: twdchan@cuhk.edu.hk [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong)

2016-09-14

The adsorptive potential of hexagonal boron nitride nanosheets (h-BNNSs) for solid-phase extraction (SPE) of pollutants was investigated for the first time. Seven indicators of polychlorinated biphenyls (PCBs) were selected as target analytes. The adsorption of PCBs on the surface of the h-BNNSs in water was simulated by the density functional theory and molecular dynamics. The simulation results indicated that the PCBs are adsorbed on the surface by π–π, hydrophobic, and electrostatic interactions. The PCBs were extracted with an h-BNNS-packed SPE cartridge, and eluted by dichloromethane. Gas chromatography–tandem mass spectrometry working in the multiple reaction monitor mode was used for the sample quantification. The effect of extraction parameters, including the flow rate, pH value, breakthrough volume, and the ionic strength, were investigated. Under the optimal working conditions, the developed method showed low limits of detection (0.24–0.50 ng L{sup −1}; signal-to-noise ratio = 3:1), low limits of quantification (0.79–1.56 ng L{sup −1}; signal-to-noise ratio = 10:1), satisfactory linearity (r > 0.99) within the concentration range of 2–1000 ng L{sup −1}, and good precision (relative standard deviation < 12%). The PCBs concentration in environmental water samples was determined by the developed method. This results demonstrate that h-BNNSs have high analytical potential in the enrichment of pollutants. - Highlights: • The hexagonal boron nitride nanosheets were synthesized. • The nanosheets were used as adsorbent for solid-phase extraction. • The h-BN demonstrates remarkable adsorption of PCBs from water samples. • The method was successfully applied in determination of PCBs in water samples.
Treatment of Produced Water Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

Energy Technology Data Exchange (ETDEWEB)

Lynn E. Katz; Kerry A. Kinney; Robert S. Bowman; Enid J. Sullivan; Soondong Kwon; Elaine B. Darby; Li-Jung Chen; Craig R. Altare

2006-01-31

Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. Produced waters typically contain a high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component as well as chemicals added during the oil-production process. It has been estimated that a total of 14 billion barrels of produced water were generated in 2002 from onshore operations (Veil, 2004). Although much of this produced water is disposed via reinjection, environmental and cost considerations can make surface discharge of this water a more practical means of disposal. In addition, reinjection is not always a feasible option because of geographic, economic, or regulatory considerations. In these situations, it may be desirable, and often necessary from a regulatory viewpoint, to treat produced water before discharge. It may also be feasible to treat waters that slightly exceed regulatory limits for re-use in arid or drought-prone areas, rather than losing them to reinjection. A previous project conducted under DOE Contract DE-AC26-99BC15221 demonstrated that surfactant modified zeolite (SMZ) represents a potential treatment technology for produced water containing BTEX. Laboratory and field experiments suggest that: (1) sorption of benzene, toluene, ethylbenzene and xylenes (BTEX) to SMZ follows linear isotherms in which sorption increases with increasing solute hydrophobicity; (2) the presence of high salt concentrations substantially increases the capacity of the SMZ for BTEX; (3) competitive sorption among the BTEX compounds is negligible; and, (4) complete recovery of the SMZ sorption capacity for BTEX can be achieved by air sparging the SMZ. This report summarizes research for a follow on project to optimize the regeneration process for multiple sorption/regeneration cycles, and to develop and incorporate a vapor phase bioreactor (VPB) system for treatment of the off-gas generated during
Comment on "Localized water reverberation phases and its impact on back-projection images" by Yue et al. [2017

Science.gov (United States)

Fan, W.; Shearer, P. M.

2017-12-01

Fan and Shearer [2016] analyzed the 2012 Mw 7.2 Sumatra earthquake and reported that the earthquake dynamically triggered early aftershock/aftershocks 150 km away from the mainshock and 50 s later. The early aftershock/aftershocks were detected with teleseismic P-wave back-projection, coincided with passing surface waves, and showed observable seismic waveforms in a wide frequency range (0.02—5 Hz). Recently, however, Yue et al. [2017] interpreted these coda arrivals as water reverberations from the mainshock, based mostly on EGF analysis of a nearby M6 earthquake and a water-phase synthetic test. Here, we show detailed back-projection and waveform analysis of three M6 earthquakes within 100km of the Mw 7.2 earthquake, including the EGF event analyzed in Yue et al. [2017]. In addition, we examine the waveforms of three M5.5 reverse faulting earthquakes close to our detected early aftershock landward of the trench. Our results show that the coda energy in question is more likely caused by a separate earthquake near the trench than by a mainshock water reverberation phase, thus supporting our earlier conclusion that the detected coherent radiators are likely to be dynamically triggered early aftershock/aftershocks.
SMART - IWRM : Integrated Water Resources Management in the Lower Jordan Rift Valley; Project Report Phase I (KIT Scientific Reports ; 7597)

OpenAIRE

Wolf, Leif; Hötzl, Heinz [Hrsg.

2011-01-01

This book provides an overview of the large scale Integrated Water Resources Management (IWRM) research program SMART at the Lower Jordan River Basin which aims at local implementation, knowledge & capacity building. The focus of the first phase is placed on decentralised wastewater treatment and reuse, water quality including emerging pollutants, management and modelling of groundwater systems, artificial recharge, socio-economic frameworks, a transboundary database and decision support tools.
Multi-Phase Modeling of Rainbird Water Injection

Science.gov (United States)

Vu, Bruce T.; Moss, Nicholas; Sampson, Zoe

2014-01-01

This paper describes the use of a Volume of Fluid (VOF) multiphase model to simulate the water injected from a rainbird nozzle used in the sound suppression system during launch. The simulations help determine the projectile motion for different water flow rates employed at the pad, as it is critical to know if water will splash on the first-stage rocket engine during liftoff.
Energetics of a hexagonal-lamellar-hexagonal-phase transition sequence in dioleoylphosphatidylethanolamine membranes

International Nuclear Information System (INIS)

Gawrisch, K.; Parsegian, V.A.; Hajduk, D.A.; Tate, M.W.; Gruner, S.M.; Fuller, N.L.; Rand, R.P.

1992-01-01

The phase diagram of DOPE/water dispersions was investigated by NMR and X-ray diffraction in the water concentration range from 2 to 20 water molecules per lipid and in the temperature range from -5 to +50C. At temperature above 22C, the dispersions form an inverse (H II ) phase at all water concentrations. Below 25C, an H II phase occurs at high water concentrations, an L α phase is formed at intermediate water concentrations, and finally the system switches back to an H II phase at low water concentrations. The enthalpy of the L α -H II -phase transition is +0.3 kcal/mol as measured by differential scanning calorimetry. Using 31 P and 2 H NMR and X-ray diffraction. The authors measured the trapped water volumes in H II and L α phases as a function of osmotic pressure. The change of the H II -phase free energy as a function of hydration was calculated by integrating the osmotic pressure vs trapped water volume curve. The phase diagram calculated on the basis of the known enthalpy of transition and the osmotic pressure vs water volume curves is in good agreement with the measured one. The H II -L α -H II double-phase transition at temperatures below 22C can be shown to be a consequence of (1) the greater degree of hydration of the H II phase in excess water and (2) the relative sensitivities with which the lamellar and hexagonal phases dehydrate with increasing osmotic pressure. These results demonstrate the usefulness of osmotic stress measurements to understand lipid-phase diagrams
Analysis of large two phase uranium dioxide bubble behavior in water and sodium pools

International Nuclear Information System (INIS)

Webb, R.L.

1984-05-01

An understanding of the behavior of large, two-phase UO 2 bubbles is important in assessing the consequences of a hypothetical core disruptive accident in a fast reactor. The UVABUBL II computer program was written to study the dynamics and heat and mass transfer in large UO 2 bubbles, and the code was used to analyze data from the underwater and undersodium FAST experiments conducted at Oak Ridge National Laboratory in which the behavior of UO 2 bubbles under a wide variety of conditions was examined. Significant understanding of the phenomena that govern UO 2 bubble behavior in both water and sodium was obtained by matching calculations of pressure, bubble size, and bubble growth and collapse rate to the experimental data. Heat and mass transfer included radiative heat losses and coolant entrainment. Larger heat transfer rates were calculated for the water tests with significant surface vaporization occurring. Because of the high thermal conductivity of sodium, no surface vaporization was calculated for the sodium tests. Entrainment was not found to be necessary for either the water or sodium tests, but calculations that included entrainment implied that it may be occurring. 38 references

Determination of butyltin species in natural waters using aqueous phase ethylation and off-line room temperature trapping

International Nuclear Information System (INIS)

Bowles, Karl C.; Apte, Simon C.; Hales, Leigh T.

2003-01-01

Monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) were determined in natural water samples by aqueous phase ethylation with sodium tetraethylborate (STEB), room temperature trapping of the resulting volatile derivatives on Tenax TA[reg], followed by gas chromatography-quartz furnace atomic absorption spectrometry (GC-QFAAS). Recoveries of butyltin spikes from natural water samples were 90-109% at concentrations of ∼100 ng Sn/l. The method precision at ∼100 ng Sn/l was ≤6% RSD for butyltins spiked into natural waters. The detection limits for 1 l water samples were <1 ng Sn/l for all butyltin species. Sample throughput of the method is high (greater than three samples per hour) due to the two-stage nature of the procedure, which allows derivatisation/trapping and GC-QFAAS quantitation to be performed separately. Off-line trapping is also advantageous as it extends the life of the GC column and quartz furnace to at least 12 months due to minimisation of carry-over of co-purged material
Two-phase flow experiments in a model of the hot leg of a pressurised water reactor. Technical report

Energy Technology Data Exchange (ETDEWEB)

Seidel, Tobias; Vallee, Christophe; Lucas, Dirk; Beyer, Matthias; Deendarlianto

2011-09-15

In order to investigate the two-phase flow behaviour in a complex reactor-typical geometry and to supply suitable data for CFD code validation, a model of the hot leg of a pressurised water reactor was built at FZD. The hot leg model is operated in the pressure chamber of the TOPFLOW test facility, which is used to perform high-pressure experiments under pressure equilibrium with the inside atmosphere of the chamber. This technique makes it possible to visualise the two-phase flow through large windows, also at reactor-typical pressure levels. In order to optimise the optical observation possibilities, the test section was designed with a rectangular cross-section. Experiments were performed with air and water at 1.5 and 3.0 bar at room temperature as well as with steam and water at 15, 30 and 50 bar and the corresponding saturation temperature (i.e. up to 264 C). The total of 194 runs are divided into 4 types of experiments covering stationary co-current flow, counter-current flow, flow without water circulation and transient counter-current flow limitation (CCFL) experiments. This report provides a detailed documentation of the experiments including information on the experimental setup, experimental procedure, test matrix and on the calibration of the measuring devices. The available data is described and data sheets were arranged for each experiment in order to give an overview of the most important parameters. For the cocurrent flow experiments, water level histograms were arranged and used to characterise the flow in the hot leg. In fact, the form of the probability distribution was found to be sensitive to the boundary conditions and, therefore, is useful for the CFD comparison. Furthermore, the flooding characteristics of the hot leg model plotted in terms of the classical Wallis parameter or Kutateladze number were found to fail to properly correlate the data of the air/water and steam/water series. Therefore, a modified Wallis parameter is proposed, which
Two-phase flow experiments in a model of the hot leg of a pressurised water reactor. Technical report

International Nuclear Information System (INIS)

Seidel, Tobias; Vallee, Christophe; Lucas, Dirk; Beyer, Matthias; Deendarlianto

2011-09-01

In order to investigate the two-phase flow behaviour in a complex reactor-typical geometry and to supply suitable data for CFD code validation, a model of the hot leg of a pressurised water reactor was built at FZD. The hot leg model is operated in the pressure chamber of the TOPFLOW test facility, which is used to perform high-pressure experiments under pressure equilibrium with the inside atmosphere of the chamber. This technique makes it possible to visualise the two-phase flow through large windows, also at reactor-typical pressure levels. In order to optimise the optical observation possibilities, the test section was designed with a rectangular cross-section. Experiments were performed with air and water at 1.5 and 3.0 bar at room temperature as well as with steam and water at 15, 30 and 50 bar and the corresponding saturation temperature (i.e. up to 264 C). The total of 194 runs are divided into 4 types of experiments covering stationary co-current flow, counter-current flow, flow without water circulation and transient counter-current flow limitation (CCFL) experiments. This report provides a detailed documentation of the experiments including information on the experimental setup, experimental procedure, test matrix and on the calibration of the measuring devices. The available data is described and data sheets were arranged for each experiment in order to give an overview of the most important parameters. For the cocurrent flow experiments, water level histograms were arranged and used to characterise the flow in the hot leg. In fact, the form of the probability distribution was found to be sensitive to the boundary conditions and, therefore, is useful for the CFD comparison. Furthermore, the flooding characteristics of the hot leg model plotted in terms of the classical Wallis parameter or Kutateladze number were found to fail to properly correlate the data of the air/water and steam/water series. Therefore, a modified Wallis parameter is proposed, which
A numerical study of the gas-liquid, two-phase flow maldistribution in the anode of a high pressure PEM water electrolysis cell

DEFF Research Database (Denmark)

Olesen, Anders Christian; Rømer, Carsten; Kær, Søren Knudsen

2016-01-01

In this work, the use of a circular-planar, interdigitated flow field for the anode of a high pressure proton exchange membrane (PEM) water electrolysis cell is investigated in a numerical study. While PEM fuel cells have separated flow fields for reactant transport and coolant, it is possible...... causes maldistribution, if land areas of equal width are applied. Moreover, below a water stoichiometry of 350, and at a current density of 1 A/cm2, flow and temperature maldistribution is adversely affected by the presence of the gas phase; particularly gas hold-up near outlet channels can cause......-phase flow model for establishing the effect of geometry and a two-phase flow model for studying the effect of dispersed gas bubbles. Both models account for turbulence and heat transport. By means of the developed models, it is elucidated that the circular-planar shape of the interdigitated flow field...
Determination of Triazine Herbicides in Drinking Water by Dispersive Micro Solid Phase Extraction with Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometric Detection.

Science.gov (United States)

Chen, Dawei; Zhang, Yiping; Miao, Hong; Zhao, Yunfeng; Wu, Yongning

2015-11-11

A novel dispersive micro solid phase extraction (DMSPE) method based on a polymer cation exchange material (PCX) was applied to the simultaneous determination of the 30 triazine herbicides in drinking water with ultrahigh-performance liquid chromatography-high-resolution mass spectrometric detection. Drinking water samples were acidified with formic acid, and then triazines were adsorbed by the PCX sorbent. Subsequently, the analytes were eluted with ammonium hydroxide/acetonitrile. The chromatographic separation was performed on an HSS T3 column using water (4 mM ammonium formate and 0.1% formic acid) and acetonitrile (0.1% formic acid) as the mobile phase. The method achieved LODs of 0.2-30.0 ng/L for the 30 triazines, with recoveries in the range of 70.5-112.1%, and the precision of the method was better than 12.7%. These results indicated that the proposed method had the advantages of convenience and high efficiency when applied to the analysis of the 30 triazines in drinking water.
Velocity and phase distribution measurements in vertical air-water annular flows

International Nuclear Information System (INIS)

Vassallo, P.

1997-07-01

Annular flow topology for three air-water conditions in a vertical duct is investigated through the use of a traversing double-sensor hot-film anemometry probe and differential pressure measurements. Near wall measurements of mean and fluctuating velocities, as well as local void fraction, are taken in the liquid film, with the highest turbulent fluctuations occurring for the flow condition with the largest pressure drop. A modified law-of-the-wall formulation for wall shear is presented which, using near wall values of mean velocity and kinetic energy, agrees reasonably well with the average stress obtained from direct pressure drop measurements. The linear profile using wall coordinates in the logarithmic layer is preserved in annular flow; however, the slope and intercept of the profile differ from the single-phase values for the annular flow condition which has a thicker, more turbulent, liquid film
Multi-dimensional Mixing Behavior of Steam-Water Flow in a Downcomer Annulus during LBLOCA Reflood Phase with a DVI Injection Mode

International Nuclear Information System (INIS)

Kwon, T.S.; Yun, B.J.; Euh, D.J.; Chu, I.C.; Song, C.H.

2002-01-01

Multi-dimensional thermal-hydraulic behavior in the downcomer annulus of a pressurized water reactor vessel with a Direct Vessel Injection (DVI) mode is presented based on the experimental observation in the MIDAS (Multi-dimensional Investigation in Downcomer Annulus Simulation) steam-water test facility. From the steady-state test results to simulate the late reflood phase of a Large Break Loss-of-Coolant Accidents(LBLOCA), isothermal lines show the multidimensional phenomena of a phasic interaction between steam and water in the downcomer annulus very well. MIDAS is a steam-water separate effect test facility, which is 1/4.93 linearly scaled-down of 1400 MWe PWR type of a nuclear reactor, focused on understanding multi-dimensional thermalhydraulic phenomena in downcomer annulus with various types of safety injection during the refill or reflood phase of a LBLOCA. The initial and the boundary conditions are scaled from the pre-test analysis based on the preliminary calculation using the TRAC code. The superheated steam with a superheating degree of 80 K at a given downcomer pressure of 180 kPa is injected equally through three intact cold legs into the downcomer. (authors)
General Mechanism of Morphology Transition and Spreading Area-dependent Phase Diagram of Block Copolymer Self-assembly at the Air/Water Interface

Science.gov (United States)

Kim, Dong Hyup; Kim, So Youn

Block copolymers (BCPs) can be self-assembled forming periodic nanostructures, which have been employed in many applications. While general agreements exist for the phase diagrams of BCP self-assembly in bulk or thin films, a fundamental understanding of BCP structures at the air/water interface still remain elusive. The current study explains morphology transition of BCPs with relative fraction of each block at the air/water interface: block fraction is the only parameter to control the morphology. In this study, we show morphology transitions from spherical to cylindrical and planar structures with neat polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) via reducing the spreading area of BCP solution at the air/water interface. For example, PS-b-P2VP in a fixed block fraction known to form only spheres can experience sphere to cylinder or lamellar transitions depending on the spreading area at the air/water interface. Suggesting a new parameter to control the interfacial assembly of BCPs, a complete phase diagram is drawn with two paramters: relative block fraction and spreading area. We also explain the morphology transition with the combinational description of dewetting mechanism and spring effect of hydrophilic block.
CFD Analyses for Water-Air Flow With the Euler-Euler Two-Phase Model in the Fluent4 CFD Code

International Nuclear Information System (INIS)

Miettinen, Jaakko; Schmidt, Holger

2002-01-01

Framatome ANP develops a new boiling water reactor called SWR 1000. For the case of a hypothetical core melt accident it is designed in such a way that the core melt is retained in the Reactor Pressure Vessel (RPV) at low pressure owing to cooling of the RPV exterior and high reliable depressurization devices. Framatome ANP performs - in co-operation with VTT - tests to quantify the safety margins of the exterior cooling concept for the SWR 1000, for determining the limits to avoid the critical heat fluxes (CHFs). The three step procedure has been set up to investigate the phenomenon: 1. Water-air study for a 1:10 scaled global model, with the aim to investigate the global flow conditions 2. Water-air study for a 1:10 scaled, 10 % sector model, with the aim to find a flow sector with almost similar flow conditions as in the global model. 3. Final CHF experiments for a 1:1-scaled, 10 % sector., the boarders of this model have been selected based on the first two steps. The instrumentation for the water/air experiments included velocity profiles, the vertically averaged average void fraction and void fraction profiles in selected positions. The experimental results from the air-water experiments have been analyzed at VTT using the Fluent-4.5.2 code with its Eulerian multiphase flow modeling capability. The aim of the calculations was to learn how to model complex two-phase flow conditions. The structural mesh required by Fluent-4 is a strong limitation in the complex geometry, but modeling of the 1/4 sector from the facility was possible, when the GAMBIT pre-processor was used for the mesh generation. The experiments were analyzed with the 150 x 150 x 18 grid for the geometry. In the analysis the fluid viscosity was the main dials for adjusting the vertical liquid velocity profiles and the bubble diameter for adjusting the phase separation. The viscosity ranged between 1 to 10000 times the molecular viscosity, and bubble diameter between 3 to 100 mm, when the
Advanced Mars Water Acquisition System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The Advanced Mars Water Acquisition System (AMWAS) recovers and purifies water from Mars soils for oxygen and fuel production, life support, food production, and...
Phase equilibria at low temperature for light hydrocarbons-methanol-water-acid gases mixtures: measurements and modelling; Equilibres de phases a basse temperature de systemes complexes CO{sub 2} - hydrocarbures legers - methanol - eau: mesures et modelisation

Energy Technology Data Exchange (ETDEWEB)

Ruffine, L.

2005-10-15

The need to develop and improve natural gas treatment processes is real. The petroleum industry usually uses separation processes which require phase equilibrium phenomena. Yet, the complexity of the phase equilibria involved results in a lack of data, which in turn limits the development of thermodynamic models. The first part of this work is devoted to experimental investigations for systems containing light hydrocarbons, methanol, water and acid gases. We present a new apparatus that was developed to measure vapor-liquid and vapor-liquid-liquid equilibria. It allowed us to obtain new phase composition data for the methanol-ethane binary system and different mixtures, and also to determine a part of the three phases equilibrium envelope of the same systems. In the second part of this work, we have developed a thermodynamic model based on the CPA equation of state. This choice may be justified by the presence of associating components like methanol, hydrogen sulfide and water in the systems. Such model is necessary for the design of gas treatment plants. Our model provides good results for phase equilibrium calculations for binaries systems without binary interaction parameter in many cases, and describes correctly the vapour-liquid and vapor-liquid-liquid equilibria for complex mixtures. (author)
Influence of aqueous phase on electrochemical biocorrosion tests in diesel/water systems

Energy Technology Data Exchange (ETDEWEB)

Bento, F.M. [Dept. of Soils, Faculty of Agronomy, UFRGS, 7712 Bento Goncalves Avenue, CEP: 91540-001, POA, RS (Brazil); Englert, G.E.; Muller, I.L. [Dept. of Metallurgy, Biocorrosion and Biofilms Lab, UFRGS, 99 Osvaldo Aranha Avenue s.615D, CEP: 90035-190, POA, RS (Brazil); Gaylarde, C.C. [Dept. of Biophisics, UFRGS POA, RS (Brazil)

2004-08-01

Storage tanks containing microbially contaminated diesel oil are susceptible to corrosion. This process may be evaluated electrochemically in the laboratory using simulated storage systems containing diesel oil and an aqueous phase. The simulated aqueous phase must supply mineral nutrients for microbial growth, together with adequate electrical conductivity, without, however, being too corrosive, so as to allow the aggressive nature of the microbial metabolites to be detected. In this investigation, microbial growth was measured in six electrically conductive media overlaid with metropolitan diesel oil containing an additive package. The microorganisms were the filamentous fungi, Hormoconis resinae, Paecilomyces variotii and Aspergillus fumigatus, the bacterium Bacillus subtilis and the yeast Candida silvicola, all previously isolated from contaminated diesel oil. After 60 days incubation with pure or mixed inocula of these microorganisms, pH, conductivity and viable microorganisms were measured. The electrochemical behaviour of carbon steel ASTM 283-93-C was determined in each of the six media (uninoculated) and in selected inoculated medium via measurements of open circuit potential and potentiostatic polarization curves. The uptake of phosphate (corrosion inhibitor), microbial growth, pH, conductivity and anodic and cathodic polarization curves were assessed in the water phase after 30 and 60 days of incubation with each single species Aspergillus fumigatus and Hormoconis resinae and with the consortium. The medium which proved most appropriate was Bushnell-Haas medium modified by the omission of chlorides, which allowed satisfactory microbial growth and had low aggressivity towards the steel. The performance of electrochemical tests in aerated, rather than deaerated, electrolyte solutions is suggested to be important to allow the detection of microbial influence on passive film formation and stability. (Abstract Copyright [2004], Wiley Periodicals, Inc.)
Effects of rolling on characteristics of single-phase water flow in narrow rectangular ducts

International Nuclear Information System (INIS)

Xing Dianchuan; Yan Changqi; Sun Licheng; Xu Chao

2012-01-01

Highlights: ► Mass flow rate and friction pressure drop with different pressure head are compared. ► The effect of pressure head on flow fluctuation is considered theoretically. ► Time-mean and real-time friction pressure drop in different rolling motion are studied. ► Rolling motion influences the fluctuation of friction pressure drop in two aspects. ► New correlation for frictional coefficient in rolling motion is achieved. - Abstract: Experimental and theoretical studies of rolling effects on characteristics of single-phase water flow in narrow rectangular ducts are performed under ambient temperature and pressure. Two types of pressure head are supplied by elevate water tank and pump respectively. The results show that the frictional pressure drop under rolling condition fluctuates periodically, with its amplitude decaying as mean Reynolds number increase and the rolling amplitude decrease, while the amplitude is nearly invariable with rolling period. Rolling motion influences the fluctuation amplitude of frictional pressure drop in two aspects, on the one hand, rolling reduced periodical pulsing flow leads to the fluctuation of the frictional pressure drop, on the other hand, additional force acting on fluid near the wall due to the rolling motion makes local frictional resistance oscillate periodically. The mass flow rate oscillates periodically in rolling motion with the pressure head supplied by water tank, while its fluctuation is so weak that could be neglected for the case of the pressure head supplied by pump. An empirical correlation for the frictional coefficient under rolling condition is achieved, and the experimental data is well correlated. A mathematical model is also developed to study the effect of pressure head on mass flow rate fluctuation in rolling motion. The fluctuation amplitude of the mass flow rate decreases rapidly with a higher pressure head. Comparing with the vertical condition, rolling motion nearly has no effects on
Identification, measurement, and assessment of water cycle of unhusked rice agricultural phases: Case study at Tangerang paddy field, Indonesia

Science.gov (United States)

Hartono, N.; Laurence; Johannes, H. P.

2017-11-01

According to one of UN reports, water scarcity has happened all around the world, including Indonesia. Irrigation sector takes up 70% of world water consumption and potentially increases 20% due to the population explosion. Rice is accounted for 69% of agricultural products contributions in Indonesia’s water footprint. Therefore, evaluation of water cycle was essential to raise awareness among practitioners. Data collections were conducted in the functional unit of one-hectare rice field located in Tangerang. This study used CropWat 8.0 and SimaPro software. Identification involved data such as climate, crop, and soil. Nursery became the highest water consumed phase, requiring 419 mm in height. Measurement through water footprint resulted in consumption of green water footprint for 8,183,618.5 liters (62.9%), followed by grey for 4,805,733.2 liters (36.9%) and blue for 23,902.36 liters (0.2%). The grey consumption was exceeding the average, which indicated high doses of pesticides. Life Cycle Assessment showed negative impacts of fertilizers that caused damages like fossil depletion, respiratory health, and eutrophication.
Thermal performance of an integrated collector storage solar water heater (ICSSWH) with phase change materials (PCM)

International Nuclear Information System (INIS)

Chaabane, Monia; Mhiri, Hatem; Bournot, Philippe

2014-01-01

Highlights: • We study the effect of phase change materials integration on the thermal performances of an ICSSWH. • Two kinds and tree radiuses of the PCM layer are studied and the most appropriate design is presented. • The use of phase change materials in ICSSWH is determined to reduce the night thermal losses. • Myristic acid is the most appropriate PCM for this application regarding the daily and night operation. - Abstract: In this paper, we propose a numerical study of an integrated collector storage solar water heater (ICSSWH). Two numerical models in three-dimensional modeling are developed. The first one which describes a sensible heat storage unit (SHSU), allowing validating the numerical model. Based on the good agreement between numerical results and experimental data from literature, and as this type of solar water heater presents the disadvantage of its high night losses, we propose to integrate a phase change material (PCM) directly in the collector and to study its effect on the ICSSWH thermal performance. Indeed, a second 3D CFD model is developed and series of numerical simulations are conducted for two kind (myristic acid and RT42-graphite) and three radiuses (R = 0.2 m, R = 0.25 m and R = 0.3 m) of this PCM layer. Numerical results show that during the day-time, the latent heat storage unit (LHSU) performs better than the sensible one when myristic acid is used as PCM. Regarding the night operating of this solar system, it is found that the LHSU is more effective for both PCMs as it allows lower thermal losses and better heat preservation
Analytical description of thermodynamic properties of steam, water and the phase interface for use in CFD

OpenAIRE

Hrubý Jan; Duška Michal

2014-01-01

We present a system of analytical equations for computation of all thermodynamic properties of dry steam and liquid water (undesaturated, saturated and metastable supersaturated) and properties of the liquid-vapor phase interface. The form of the equations is such that it enables computation of all thermodynamic properties for independent variables directly related to the balanced quantities - total mass, liquid mass, energy, momenta. This makes it suitable for the solvers of fluid dynamics e...
Thin-layer chromatography with stationary phase gradient as a method for separation of water-soluble vitamins.

Science.gov (United States)

Cimpoiu, Claudia; Hosu, Anamaria; Puscas, Anitta

2012-02-03

The group of hydrophilic vitamins play an important role in human health, and their lack or excess produces specific diseases. Therefore, the analysis of these compounds is indispensable for monitoring their content in pharmaceuticals and food in order to prevent some human diseases. TLC was successfully applied in the analysis of hydrophilic vitamins, but the most difficult problem in the simultaneous analysis of all these compounds is to find an optimum stationary phase-mobile phase system due to different chemical characteristics of analytes. Unfortunately structural analogues are difficult to separate in one chromatographic run, and this is the case in hydrophilic vitamins investigations. TLC gives the possibility to perform two-dimensional separations by using stationary phase gradient achieving the highest resolution by combining two systems with different selectivity. The goal of this work was to develop a method of analysis enabling separation of hydrophilic vitamins using TLC with adsorbent gradient. The developed method was used for identifying the water-soluble vitamins in alcoholic extracts of Hippophae rhamnoides and of Ribes nigrum. Copyright © 2011 Elsevier B.V. All rights reserved.
Simultaneous determination of polycyclic aromatic hydrocarbons and their chlorination by-products in drinking water and the coatings of water pipes by automated solid-phase microextraction followed by gas chromatography-mass spectrometry.

Science.gov (United States)

Tillner, Jocelyn; Hollard, Caroline; Bach, Cristina; Rosin, Christophe; Munoz, Jean-François; Dauchy, Xavier

2013-11-08

In this study, an automated method for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) and their chlorination by-products in drinking water was developed based on online solid-phase microextraction-gas chromatography-mass spectrometry. The main focus was the optimisation of the solid-phase microextraction step. The influence of the agitation rate, type of fibre, desorption time, extraction time, extraction temperature, desorption temperature, and solvent addition was examined. The method was developed and validated using a mixture of 17 PAHs, 11 potential chlorination by-products (chlorinated and oxidised PAHs) and 6 deuterated standards. The limit of quantification was 10 ng/L for all target compounds. The validated method was used to analyse drinking water samples from three different drinking water distribution networks and the presumably coal tar-based pipe coatings of two pipe sections. A number of PAHs were detected in all three networks although individual compositions varied. Several PAH chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also found, their presence correlating closely with that of their respective parent compounds. Their concentrations were always below 100 ng/L. In the coatings, all PAHs targeted were detected although concentrations varied between the two coatings (76-12,635 mg/kg and 12-6295 mg/kg, respectively). A number of chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also detected (from 40 to 985 mg/kg), suggesting that the reaction of PAHs with disinfectant agents takes place in the coatings and not in the water phase after migration. Copyright © 2013 Elsevier B.V. All rights reserved.
Separation of the components of the binary mixture ethanol-water by steam flux in solid phase column; Separacao dos componentes da mistura binaria etanol-agua por passagem do vapor em coluna de fase solida

Energy Technology Data Exchange (ETDEWEB)

Terrones, M G.H.; Brune, W; Souza Barcellos, E de; Almeida, P G.V. de [Vicosa Univ., MG (Brazil). Dept. de Quimica; Fabris, J D [EMBRAPA, Sete Lagoas, MG (Brazil)

1988-12-31

This paper deals with the energy required to separate ethanol from an aqueous solution in a distillation column containing a solid phase. The solid phases evaluated consisted of either an amylatious (ground corn) or a cellulose (sugar cane bagasse) absorber whit particle sizes smaller than 4 mm. The water-retention capacity of each solid phase was measured by passing vapors or ethanol-water mixtures through the solid phase. When starting with initial concentrations bellow the azeotropic point, ethanol concentrations up to 99,5% (on corn) and 97,2% (on sugar cane) were achieved. The water content was evaluated potentiometrically (Karl`Fischer). Regarding the 2-4 mm ground corn solid phase column, the energy consumed was estimated to be reduced by 15,6% and 60% (by weight) ethanol-water mixture respectively. (author) 11 refs., 2 figs., 2 tabs
High pressure study of water-salt systems, phase equilibria, partitioning, thermodynic properties and implication for large icy worlds hydrospheres.

Science.gov (United States)

Journaux, B.; Brown, J. M.; Abramson, E.; Petitgirard, S.; Pakhomova, A.; Boffa Ballaran, T.; Collings, I.

2017-12-01

Water salt systems are predicted to be present in deep hydrosphere inside water-rich planetary bodies, following water/rock chemical interaction during early differentiation stages or later hydrothermal activity. Unfortunately the current knowledge of the thermodynamic and physical properties of aqueous salt mixtures at high pressure and high temperature is still insufficient to allow realistic modeling of the chemical or dynamic of thick planetary hydrospheres. Recent experimental results have shown that the presence of solutes, and more particularly salts, in equilibrium with high pressure ices have large effects on the stability fields, buoyancy and chemistry of all the phases present at these extreme conditions. Effects currently being investigated by our research group also covers ice melting curve depressions that depend on the salt species and incorporation of solutes inside the crystallographic lattice of high pressure ices. Both of these could have very important implication at the planetary scale, enabling thicker/deeper liquid oceans, and allowing chemical transportation through the high pressure ice layer in large icy worlds. We will present the latest results obtained in-situ using diamond anvil cell, coupled with Synchrotron X-Ray diffraction, Raman Spectroscopy and optical observations, allowing to probe the crystallographic structure, equations of state, partitioning and phase boundary of high pressure ice VI and VII in equilibrium with Na-Mg-SO4-Cl ionic species at high pressures (1-10 GPa). The difference in melting behavior depending on the dissolved salt species was characterized, suggesting differences in ionic speciation at liquidus conditions. The solidus P-T conditions were also measured as well as an increase of lattice volumes interpreted as an outcome of ionic incorporation in HP ice during incongruent crystallization. The measured phase diagrams, lattice volumes and important salt incorporations suggest a more complex picture of the

Phase equilibrium condition measurements in nitrogen and air clathrate hydrate forming systems at temperatures below freezing point of water

International Nuclear Information System (INIS)

Yasuda, Keita; Oto, Yuya; Shen, Renkai; Uchida, Tsutomu; Ohmura, Ryo

2013-01-01

Highlights: • Phase equilibrium conditions in the nitrogen and modelled air hydrate forming systems are measured. • Measurements are conducted at temperatures below the freezing point of water. • Results have relevance to the air hydrate formation in the ice sheets. • Measured data are quantitatively compared with the previously reported values. • Range of the equilibrium measurements was from (242 to 268) K. -- Abstract: Contained in this paper are the three phase equilibrium conditions of the (ice + clathrate hydrate + guest-rich) vapour in the (nitrogen + water) and the modelled (air + water) systems at temperatures below the freezing point of water. The precise determination of the equilibrium conditions in those systems are of importance for the analysis of the past climate change using the cored samples from the ice sheets at Antarctica and Greenland because the air hydrates keep the ancient climate signals. The mole ratio of the modelled air composed of nitrogen and oxygen is 0.790:0.210. The equilibrium conditions were measured by the batch, isochoric procedure. The temperature range of the measurements in the nitrogen hydrate forming system is (244.05 < T < 266.55) K and the corresponding equilibrium pressure range is (7.151 < p < 12.613) MPa. The temperature range of the measurements in the modelled air hydrate forming system is (242.55 < T < 267.85) K, and the corresponding equilibrium pressure range is (6.294 < p < 12.144) MPa. The data obtained quantitatively compared with the previously reported data
Life and water

International Nuclear Information System (INIS)

Rosu, H.

1992-08-01

Many living organisms on Earth are strongly dependent on water, the natural liquid of the planet. A possible reason for that could be the conjecture of Ryoji Takahashi that water microdrops release negenetropy through a phase transition to a phase with zero surface tension. Biological cells could make use of such a phase transition in their duty cycle. We comment on the relative merit of this conjecture, and present it in wider theoretical context. (author). 10 refs
Numerical investigation on effect of riser diameter and inclination on system parameters in a two-phase closed loop thermosyphon solar water heater

International Nuclear Information System (INIS)

Aung, Nay Zar; Li, Songjing

2013-01-01

Highlights: • Optimum inclination for maximum heat flux changes with latitude of location. • Optimum inclination for maximum heat flux also changes local solar time. • Maximum flow rate increases with increasing of riser tube size. • Maximum mass flow rate is obtained at different inclinations for different risers. • Length of two-phase region depends on inclination angles but not riser tube size. - Abstract: In this work, the effect of riser diameter and its inclination angle on system parameters in a two-phase closed loop thermosyphon solar water heater has been numerically investigated. Here, receivable heat flux by the collector, circulating mass flow rate, driving pressure, total pressure drop, heat transfer coefficient in risers and collector efficiency are defined as system parameters. For this aim, a model of two-phase thermosyphon solar water heater that is acceptable for various inclinations is presented and variations of riser diameter and inclination are considered. The riser tube size is varied from 1.25 cm to 2.5 cm with inclination range 2–75°. The system absolute pressure is set as 3567 Pa and water is chosen as working fluid. The results show that higher inclination angle is required for higher latitude location to obtain maximum solar heat flux. At local solar noon of 21.996 north latitude, the optimum inclination angle increases in the range of 24–44° with increasing of riser diameter giving maximum circulating mass flow rate from 0.02288 kg/s to 0.03876 kg/s. The longer two-phase heat transfer characteristics can be obtained at smaller inclination angles and mass flow rate for all riser tube sizes. Therefore, it is observed that the optimum inclination angles and diameters for solar heat flux, circulating mass flow rate and heat transfer coefficient in two-phase thermosyphon systemdo not coincide. From this work, better understanding and useful information are provided for constructing two-phase thermosyphon solar heaters
A 2H nuclear magnetic resonance study of the state of water in neat silica and zwitterionic stationary phases and its influence on the chromatographic retention characteristics in hydrophilic interaction high-performance liquid chromatography.

Science.gov (United States)

Wikberg, Erika; Sparrman, Tobias; Viklund, Camilla; Jonsson, Tobias; Irgum, Knut

2011-09-23

2H NMR has been used as a tool for probing the state of water in hydrophilic stationary phases for liquid chromatography at temperatures between -80 and +4 °C. The fraction of water that remained unfrozen in four different neat silicas with nominal pore sizes between 60 and 300 Å, and in silicas with polymeric sulfobetaine zwitterionic functionalities prepared in different ways, could be determined by measurements of the line widths and temperature-corrected integrals of the 2H signals. The phase transitions detected during thawing made it possible to estimate the amount of non-freezable water in each phase. A distinct difference was seen between the neat and modified silicas tested. For the neat silicas, the relationship between the freezing point depression and their pore size followed the expected Gibbs-Thomson relationship. The polymeric stationary phases were found to contain considerably higher amounts of non-freezable water compared to the neat silica, which is attributed to the structural effect that the sulfobetaine polymers have on the water layer close to the stationary phase surface. The sulfobetaine stationary phases were used alongside the 100 Å silica to separate a number of polar compounds in hydrophilic interaction (HILIC) mode, and the retention characteristics could be explained in terms of the surface water structure, as well as by the porous properties of the stationary phases. This provides solid evidence supporting a partitioning mechanism, or at least of the existence of an immobilized layer of water into which partitioning could be occurring. Copyright © 2011 Elsevier B.V. All rights reserved.
Experimental investigation of void distribution in suppression pool over the duration of a loss of coolant accident using steam–water two-phase mixture

International Nuclear Information System (INIS)

Rassame, Somboon; Griffiths, Matthew; Yang, Jun; Ju, Peng; Sharma, Subash; Hibiki, Takashi; Ishii, Mamoru

2015-01-01

Highlights: • Experiments were conducted to study void fraction distribution in SP during blowdown. • 3 Experimental phases, namely, an initial and a quasi-steady phase, chugging were observed. • The maximum void penetration depth was experienced during the initial phase. • The quasi-steady phase provided less void penetration depth with oscillations. • The chugging phase was experienced at the end of experimental phase. - Abstract: Studies are underway to determine if a large amount gas discharged through the downcomer pipes in the pressure suppression chamber during the blowdown of Loss of Coolant Accident (LOCA) can potentially be entrained into the Emergency Core Cooling System (ECCS) suction piping of BWR. This may result in degraded ECCS pumps performance which could affect the ability to maintain or recover the water inventory level in the Reactor Pressure Vessel (RPV) during a LOCA. Therefore, it is very important to understand the void behavior in the pressure suppression chamber during the blowdown period of a LOCA. To address this issue, a set of experiments is conducted using the Purdue University Multi-Dimensional Integral Test Assembly for ESBWR applications (PUMA-E) facility. The geometry of the test apparatus is determined based on the basic geometrical scaling analysis from a prototypical BWR containment (MARK I) with a consideration of downcomer size, downcomer water submergence depth and Suppression Pool (SP) water level. Several instruments are installed in the test facility to measure the required experimental data such as the steam mass flow rate, void fraction, pressure and temperature. In the experiments, sequential flows of air, steam–air mixture and pure steam-each with the various flow rate conditions are injected from the Drywell (DW) through a downcomer pipe in the SP. Eight tests with two different downcomer sizes, various initial gas volumetric fluxes at the downcomer, and two different initial non-condensable gas
Monitoring of Trichloroethene and Tetrachloroethene Content in Soil-Water Environment in Third Phase of Ecological Audit of Land

Directory of Open Access Journals (Sweden)

Pusz Agnieszka

2014-07-01

Full Text Available Trichloroethene (TCE and tetrachloroethene (PCE are chemical compounds which pose a serious threat for human health. Their specific properties make it possible that these substances may linger in soil and water for many years. These are the reasons why wells with water designed for drinking purposes have been subject of monitoring since 2006. This paper presents the results of monitoring research conducted in the soil-water environment within the framework in third phase of an ecological audit of land. The ecological audit of land made it possible to identify the cause and degree of the degradation, and helped formulate rationale for remedy decisions pertaining to the land (remediation/reclamation. The objective of the paper was to determine the pollution status of the soil-water environment and, subsequently, monitor (in years 2008-2010 the contents of the hazardous substances, namely trichloroethene and tetrachloroethene, within the area of the potential impact of metallurgical plant located in borders of the Main Underground Water Reservoir Wierzbica-Ostrowiec (GZWP 420 in in voivodeship Świętokrzyskie.
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.
Concentration of organic compounds in natural waters with solid-phase dispersion based on advesicle modified silica prior to liquid chromatography.

Science.gov (United States)

Parisis, Nikolaos A; Giokas, Dimosthenis L; Vlessidis, Athanasios G; Evmiridis, Nicholaos P

2005-12-02

The ability of vesicle-coated silica to aid the extraction of organic compounds from water prior to liquid chromatographic analysis is presented for the first time. The method is based on the formation of silica supported cationic multi-lamellar vesicles of gemini surfactants inherently ensuring the presence of hydrophilic and hydrophobic sites for the partitioning of analytes bearing different properties. Method development is illustrated by studying the adsolubilization of UV absorbing chemicals from swimming pool water. Due to the requirement for external energy input (intense shearing) a method based on solid-phase dispersion (SPD) was applied producing better results than off-line solid-phase extraction (SPE). Meticulous investigation of the experimental parameters was conducted in order to elucidate the mechanisms behind the proposed extraction pattern. Analyte recoveries were quantitative under the optimum experimental conditions offering recoveries higher than 96% with RSD values below 5%.
A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

Science.gov (United States)

Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

2013-11-15

A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry). Copyright © 2013 Elsevier B.V. All rights reserved.
Experimental study of centrifugal pump performance under steam-water two-phase flow conditions at elevated pressures

International Nuclear Information System (INIS)

Chan, A.M.C.; Barreca, S.L.; Hartlen, R.T.

1991-01-01

The performance of a centrifugal pump under two-phase flow conditions was studied in a closed loop. System voids of increasing magnitude were attained by draining water from the loop in steps. The operating temperature/pressure were varied from 110 degrees C/0.15 MPa to 260 degrees C/4.7 MPa. Only tests in the first quadrant were conducted. In this paper the head-flow characteristics and pump head degradation data are presented and discussed
Lower critical solution temperature (LCST) phase separation of glycol ethers for forward osmotic control.

Science.gov (United States)

Nakayama, Daichi; Mok, Yeongbong; Noh, Minwoo; Park, Jeongseon; Kang, Sunyoung; Lee, Yan

2014-03-21

Lower critical solution temperature (LCST) phase transition of glycol ether (GE)-water mixtures induces an abrupt change in osmotic pressure driven by a mild temperature change. The temperature-controlled osmotic change was applied for the forward osmosis (FO) desalination. Among three GEs evaluated, di(ethylene glycol) n-hexyl ether (DEH) was selected as a potential FO draw solute. A DEH-water mixture with a high osmotic pressure could draw fresh water from a high-salt feed solution such as seawater through a semipermeable membrane at around 10 °C. The water-drawn DEH-water mixture was phase-separated into a water-rich phase and a DEH-rich phase at around 30 °C. The water-rich phase with a much reduced osmotic pressure released water into a low-salt solution, and the DEH-rich phase was recovered into the initial DEH-water mixture. The phase separation behaviour, the residual GE concentration in the water-rich phase, the osmotic pressure of the DEH-water mixture, and the osmotic flux between the DEH-water mixture and salt solutions were carefully analysed for FO desalination. The liquid-liquid phase separation of the GE-water mixture driven by the mild temperature change between 10 °C and 30 °C is very attractive for the development of an ideal draw solute for future practical FO desalination.
Extração em fase sólida (SPE e micro extração em fase sólida (SPME de piretróides em água Solid-phase extraction (SPE and solid-phase microextraction of pyrethroids in water

Directory of Open Access Journals (Sweden)

Wilma Regina Barrionuevo

2001-04-01

Full Text Available The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE and solid phase microextraction (SPME. The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD. Octadecil Silano-C18, Florisil and Silica stationary phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10 pg ml-1. Although the data showed that the two extraction methods were able to isolate the pesticide residues from water samples, the best results were obtained by using SPME which is more sensitive, faster, cheeper, being a more useful technique for the analysis of pyrethroids in drinking water.
Structure of two-phase air-water flows. Study of average void fraction and flow patterns

International Nuclear Information System (INIS)

Roumy, R.

1969-01-01

This report deals with experimental work on a two phase air-water mixture in vertical tubes of different diameters. The average void fraction was measured in a 2 metre long test section by means of quick-closing valves. Using resistive probes and photographic techniques, we have determined the flow patterns and developed diagrams to indicate the boundaries between the various patterns: independent bubbles, agglomerated bubbles, slugs, semi-annular, annular. In the case of bubble flow and slug flow, it is shown that the relationship between the average void fraction and the superficial velocities of the phases is given by: V sg = f( ) * g(V sl ). The function g(V sl ) for the case of independent bubbles has been found to be: g(V sl ) = V sl + 20. For semi-annular and annular flow conditions; it appears that the average void fraction depends, to a first approximation only on the ratio V sg /V sl . (author) [fr
Numerical analysis of solid–liquidtwo-phase turbulent flow in Francis turbine runner with splitter bladesin sandy water

Directory of Open Access Journals (Sweden)

Hua Hong

2015-03-01

Full Text Available As the key component of a hydroelectric power generation system, hydraulic turbine plays a decisive role in the overall performance of the system. There are many sandy rivers in the world, and turbines working in these rivers are seriously damaged. Therefore, the research of flow in sandy water has great theoretical significance and practical value. Based on the specific hydrological conditions of a hydropower station, the solid–liquid two-phase flow in the whole flow passage of a Francis turbine with splitter blades in sandy water was numerically studied. A geometric model of the whole flow passage of the Francis turbine was established on the basis of given design parameters. The solid–liquid two-phase turbulent flows in Francis turbine runner under three different loads were numerically analyzed by using this model. The three different loads are as follows: Condition 1: single unit with 1/4 load, Condition 2: single unit with 1/2 load, and Condition 3: single unit with full load. The distributions of pressure and sand concentration on the leading side and the suction side of the runner blades, as well as the velocity vector distribution of water and sand on the horizontal section of the runner, were obtained under different load conditions. Therefore, the damages to various flow passage components by sand can be qualitatively predicated under various conditions. To guarantee the safety and stability of the unit, the adverse conditions shall be avoided, which can provide certain reference for plant operation.
Local gas- and liquid-phase measurements for air-water two-phase flows in a rectangular channel

International Nuclear Information System (INIS)

Zhou, X.; Sun, X.; Williams, M.; Fu, Y.; Liu, Y.

2014-01-01

Local gas- and liquid-phase measurements of various gas-liquid two-phase flows, including bubbly, cap-bubbly, slug, and churn-turbulent flows, were performed in an acrylic vertical channel with a rectangular cross section of 30 mm x 10 mm and height of 3.0 m. All the measurements were carried out at three measurement elevations along the flow channel, with z/D h = 9, 72, and 136, respectively, to study the flow development. The gas-phase velocity, void fraction, and bubble number frequency were measured using a double-sensor conductivity probe. A high-speed imaging system was utilized to perform the flow regime visualization and to provide additional quantitative information of the two-phase flow structure. An image processing scheme was developed to obtain the gas-phase velocity, void fraction, Sauter mean diameter, bubble number density, and interfacial area concentration. The liquid-phase velocity and turbulence measurements were conducted using a particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system, which enables whole-field and high-resolution data acquisition. An optical phase separation method, which uses fluorescent particles and optical filtration technique, is adopted to extract the velocity information of the liquid phase. An image pre-processing scheme is imposed on the raw PIV images acquired to remove noises due to the presence of bubble residuals and optically distorted particles in the images captured by the PIV-PLIF system. Due to the better light access and less bubble distortion in the narrow rectangular channel, the PIV-PLIF system were able to perform reasonably well in flows of even higher void fractions as compared to the situations with circular pipe test sections. The flow conditions being studied covered various flow regime transitions, void fractions, and liquid-phase flow Reynolds numbers. The obtained experimental data can also be used to validate two-phase CFD results. (author)
Relationship between myocardial flow reserve by oxygen-15 water positron emission tomography in the subacute phase of myocardial infarction and left ventricular remodeling in the chronic phase

International Nuclear Information System (INIS)

Ohara, Minako; Yukiiri, Kazushi; Masugata, Hisashi

2008-01-01

The purposes of this study were to examine the effects of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) on myocardial flow reserve in patients with acute myocardial infarction (AMI) in the subacute phase using oxygen-15 positron emission tomography (PET) and to elucidate the relationship between the myocardial flow reserve and remodeling in the chronic phase. Sixty patients who had been treated with coronary angioplasty within 12 h after the onset of AMI were enrolled. Patients were divided into an enalapril (ACEI) group and a candesartan (ARB) group. The myocardial flow reserve was measured by oxygen-15 water PET in the subacute phase from the 20th to the 30th day after the onset of AMI. Left ventriculography was performed to measure the left ventricular ejection fraction in the chronic phase about 6 months after the onset. Ten patients (33%) in the enalapril group and 4 patients (13%) in the candesartan group stopped taking their respective medications within a few days of starting, because of side effects such as cough or hypotension. Thus, the prevalence of medication intolerance was higher in the enalapril group. The myocardial flow reserve in the subacute phase and the left ventricular ejection fraction in the chronic phase were lower in the enalapril group (2.08±0.30 and 42±6%) than in the candesartan group (2.25±0.20 and 49±5%) (p<0.05). The myocardial flow reserve significantly correlated with the left ventricular ejection fraction in all patients (r=0.45, p<0.01). The myocardial flow reserve assessed by PET in the subacute phase after AMI was found to be related to left ventricular remodeling in the chronic phase. (author)
Liquid-phase and vapor-phase dehydration of organic/water solutions

Science.gov (United States)

Huang, Yu [Palo Alto, CA; Ly, Jennifer [San Jose, CA; Aldajani, Tiem [San Jose, CA; Baker, Richard W [Palo Alto, CA

2011-08-23

Processes for dehydrating an organic/water solution by pervaporation or vapor separation using fluorinated membranes. The processes are particularly useful for treating mixtures containing light organic components, such as ethanol, isopropanol or acetic acid.
Flow characteristics of centrifugal gas-liquid separator. Investigation with air-water two-phase flow experiment

International Nuclear Information System (INIS)

Yoneda, Kimitoshi; Inada, Fumio

2004-01-01

Air-water two-phase flow experiment was conducted to examine the basic flow characteristics of a centrifugal gas-liquid separator. Vertical transparent test section, which is 4 m in height, was used to imitate the scale of a BWR separator. Flow rate conditions of gas and liquid were fixed at 0.1 m 3 /s and 0.033 m 3 /s, respectively. Radial distributions of two-phase flow characteristics, such as void fraction, gas velocity and bubble chord length, were measured by traversing dual optical void probes in the test section, horizontally. The flow in the standpipe reached to quasi-developed state within the height-to-diameter aspect ratio H/D=10, which in turn can mean the maximum value for an ideal height design of a standpipe. The liquid film in the barrel showed a maximum thickness at 0.5 to 1 m in height from the swirler exit, which was a common result for three different standpipe length conditions, qualitatively and quantitatively. The empirical database obtained in this study would contribute practically to the validation of numerical analyses for an actual separator in a plant, and would also be academically useful for further investigations of two-phase flow in large-diameter pipes. (author)
Cold Heat Storage Characteristics of O/W-type Latent Heat Emulsion Including Continuum Phase of Water Treated with a Freezing Point Depression

Science.gov (United States)

Inaba, Hideo; Morita, Shin-Ichi

This paper deals with flow and cold heat storage characteristics of the oil (tetradecane, C14H30, freezing point 278.9 K, Latent heat 229 kJ/kg)/water emulsion as a latent heat storage material having a low melting point. The test emulsion includes a water-urea solution as a continuum phase. The freezing point depression of the continuum phase permits enhancement of the heat transfer rate of the emulison, due to the large temperature difference between the latent heat storage material and water-urea solution. The velocity of emulsion flow and the inlet temperature of coolant in a coiled double tube heat exchanger are chosen as the experimental parameters. The pressure drop, the heat transfer coefficient of the emulsion in the coiled tube are measured in the temperture region over solid and liquid phase of the latent heat storage material. The finishing time of the cold heat storage is defined experimentally in the range of sensible and latent heat storage. It is clarified that the flow behavior of the emulsion as a non-Newtonian fluid has an important role in cold heat storage. The useful nondimentional correlation equations for the additional pressure loss coefficient, the heat transfer coefficient and the finishing time of the cold heat storage are derived in terms of Dean number and heat capacity ratio.
Determination of submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples by solid-phase extraction and liquid chromatography

Science.gov (United States)

Burkhardt, M.R.; Soliven, P.P.; Werner, S.L.; Vaught, D.G.

1999-01-01

A method for determining submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples has been developed. Caffeine is extracted from a 1 L water sample with a 0.5 g graphitized carbon-based solid-phase cartridge, eluted with methylene chloride-methanol (80 + 20, v/v), and analyzed by liquid chromatography with photodiode-array detection. The single-operator method detection limit for organic-free water samples was 0.02 ??g/L. Mean recoveries and relative standard deviations were 93 ?? 13% for organicfree water samples fortified at 0.04 ??g/L and 84 ?? 4% for laboratory reagent spikes fortified at 0.5 ??g/L. Environmental concentrations of caffeine ranged from 0.003 to 1.44 ??g/L in surface water samples and from 0.01 to 0.08 ??g/L in groundwater samples.

Determination of Low Concentrations of Acetochlor in Water by Automated Solid-Phase Extraction and Gas Chromatography with Mass-Selective Detection

Science.gov (United States)

Lindley, C.E.; Stewart, J.T.; Sandstrom, M.W.

1996-01-01

A sensitive and reliable gas chromatographic/mass spectrometric (GC/MS) method for determining acetochlor in environmental water samples was developed. The method involves automated extraction of the herbicide from a filtered 1 L water sample through a C18 solid-phase extraction column, elution from the column with hexane-isopropyl alcohol (3 + 1), and concentration of the extract with nitrogen gas. The herbicide is quantitated by capillary/column GC/MS with selected-ion monitoring of 3 characteristic ions. The single-operator method detection limit for reagent water samples is 0.0015 ??g/L. Mean recoveries ranged from about 92 to 115% for 3 water matrixes fortified at 0.05 and 0.5 ??g/L. Average single-operator precision, over the course of 1 week, was better than 5%.
Analytical description of thermodynamic properties of steam, water and the phase interface for use in CFD

Science.gov (United States)

Hrubý, Jan; Duška, Michal

2014-03-01

We present a system of analytical equations for computation of all thermodynamic properties of dry steam and liquid water (undesaturated, saturated and metastable supersaturated) and properties of the liquid-vapor phase interface. The form of the equations is such that it enables computation of all thermodynamic properties for independent variables directly related to the balanced quantities - total mass, liquid mass, energy, momenta. This makes it suitable for the solvers of fluid dynamics equations in the conservative form. Thermodynamic properties of dry steam and liquid water are formulated in terms of special thermodynamic potentials and all properties are obtained as analytical derivatives. For the surface tension, the IAPWS formula is used. The interfacial internal energy is derived from the surface tension and it is used in the energy balance. Unlike common models, the present one provides real (contrary to perfect gas approximation) properties of steam and water and reflects the energetic effects due to the surface tension. The equations are based on re-fitting the reference formulation IAPWS-95 and selected experimental data. The mathematical structure of the equations is optimized for fast computation.
Construction of a Direct Water-Injected Two-Stroke Engine for Phased Direct Fuel Injection-High Pressure Charging Investigations

Science.gov (United States)

Somsel, James P.

1998-01-01

The development of a water injected Orbital Combustion Process (OCP) engine was conducted to assess the viability of using the powerplant for high altitude NASA aircraft and General Aviation (GA) applications. An OCP direct fuel injected, 1.2 liter, three cylinder, two-stroke engine has been enhanced to independently inject water directly into the combustion chamber. The engine currently demonstrates low brake specific fuel consumption capability and an excellent power to weight ratio. With direct water injection, significant improvements can be made to engine power, to knock limits/ignition advance timing, and to engine NO(x) emissions. The principal aim of the testing was to validate a cyclic model developed by the Systems Analysis Branch at NASA Ames Research Center. The work is a continuation of Ames' investigations into a Phased Direct Fuel Injection Engine with High Pressure Charging (PDFI-ITPC).
Releasing intracellular product to prepare whole cell biocatalyst for biosynthesis of Monascus pigments in water-edible oil two-phase system.

Science.gov (United States)

Hu, Minglue; Zhang, Xuehong; Wang, Zhilong

2016-11-01

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

Energy Technology Data Exchange (ETDEWEB)

Baquerizo, Luis G., E-mail: luis.baquerizoibarra@holcim.com [Innovation, Holcim Technology Ltd., CH-5113 Holderbank (Switzerland); Matschei, Thomas [Innovation, Holcim Technology Ltd., CH-5113 Holderbank (Switzerland); Scrivener, Karen L. [Laboratory of Construction Materials, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Saeidpour, Mahsa; Wadsö, Lars [Building Materials, Lund University, Box 124, 221 000 Lund (Sweden)

2015-07-15

The AFm phase, one of the main products formed during the hydration of Portland and calcium aluminate cement based systems, belongs to the layered double hydrate (LDH) family having positively charged layers and water plus charge-balancing anions in the interlayer. It is known that these phases present different hydration states (i.e. varying water content) depending on the relative humidity (RH), temperature and anion type, which might be linked to volume changes (swelling and shrinkage). Unfortunately the stability conditions of these phases are insufficiently reported. This paper presents novel experimental results on the different hydration states of the most important AFm phases: monocarboaluminate, hemicarboaluminate, strätlingite, hydroxy-AFm and monosulfoaluminate, and the thermodynamic properties associated with changes in their water content during absorption/desorption. This data opens the possibility to model the response of cementitious systems during drying and wetting and to engineer systems more resistant to harsh external conditions.
Analysis of macrolide antibiotics in water by magnetic solid-phase extraction and liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Pérez, Rosa Ana; Albero, Beatriz; Férriz, Macarena; Tadeo, José Luis

2017-11-30

Macrolides are one of the most commonly used families of antibiotics employed in human and veterinary treatment. These compounds are considered emerging contaminants with potential ecological and human health risks that could be present in surface water. This paper describes the development and application of a simple and efficient extraction procedure for the determination of tilmicosin; erythromycin, tylosin and erythromycin-H 2 O from water samples. Sample extraction was carried out using magnetic solid-phase extraction using oleate functionalized magnetic nanoparticles followed by LC-MS/MS analysis. The effects of several parameters on the extraction efficiency of MLs from water were evaluated. The recovery results obtained were >84% for most of the compounds, except for erytromycin. The LOD and LOQ values ranged from 11.5 to 26ngL -1 and from 34 to 77ngL -1 , respectively. The selected method was applied to monitor these contaminants in water samples from different sources. Tilmicosin and tylosin were not detected in any of the samples, but erythromycin and erythromycin-H 2 O were found in 50% of the surface water samples at levels from
Novel amide polar-embedded reversed-phase column for the fast liquid chromatography-tandem mass spectrometry method to determine polyether ionophores in environmental waters.

Science.gov (United States)

Herrero, P; Borrull, F; Pocurull, E; Marcé, R M

2012-11-09

A fast chromatographic method has been developed that takes less than 5 min per run to determine five polyether ionophores with a novel amide polar-embedded reversed-phase column coupled to a triple quadrupole mass spectrometer. A comparison between Oasis HLB and Oasis MAX sorbents for the solid-phase extraction was done. Oasis HLB sorbent gave recoveries close to 90% and the repeatability (%RSD, 25-100 ng/L, n=3) of the method was less than 7% for all compounds in all matrices. The presence of polyether ionophores in environmental waters such as river water and sewage was investigated. Monensin and narasin were frequently determined in influent and effluent sewage at concentrations from 10 ng/L to 47 ng/L in influents and from 6 ng/L to 34 ng/L in effluents. In river waters, polyether ionophores were not detected in any sample. Copyright © 2012 Elsevier B.V. All rights reserved.
Experimental test of a hot water storage system including a macro-encapsulated phase change material (PCM)

Science.gov (United States)

Mongibello, L.; Atrigna, M.; Bianco, N.; Di Somma, M.; Graditi, G.; Risi, N.

2017-01-01

Thermal energy storage systems (TESs) are of fundamental importance for many energetic systems, essentially because they permit a certain degree of decoupling between the heat or cold production and the use of the heat or cold produced. In the last years, many works have analysed the addition of a PCM inside a hot water storage tank, as it can allow a reduction of the size of the storage tank due to the possibility of storing thermal energy as latent heat, and as a consequence its cost and encumbrance. The present work focuses on experimental tests realized by means of an indoor facility in order to analyse the dynamic behaviour of a hot water storage tank including PCM modules during a charging phase. A commercial bio-based PCM has been used for the purpose, with a melting temperature of 58°C. The experimental results relative to the hot water tank including the PCM modules are presented in terms of temporal evolution of the axial temperature profile, heat transfer and stored energy, and are compared with the ones obtained by using only water as energy storage material. Interesting insights, relative to the estimation of the percentage of melted PCM at the end of the experimental test, are presented and discussed.
Experimental research on density wave oscillation of steam-water two-phase flow in parallel inclined internally ribbed pipes

International Nuclear Information System (INIS)

Gao Feng; Chen Tingkuan; Luo Yushan; Yin Fei; Liu Weimin

2005-01-01

At p=3-10 MPa, G=300-600 kg/(m 2 ·s), Δt sub =30-90 degree C, and q=0-190 kW/m 2 , the experiments on steam-water two-phase flow instabilities have been performed. The test sections are parallel inclined internally ribbed pipes with an outer diameter of φ38.1 mm, a wall thinkness of 7.5 mm, a obliquity of 19.5 and a length more than 15 m length. Based on the experimental results, the effects of pressure, mass velocity, inlet subcooling and asymmetrical heat flux on steam-water two-phase flow density wave oscillation were analyzed. The experimental results showed that the flow system were more stable as pressure increased. As an increase in mass velocity, critical heat flux increased but critical steam quality decreased. Inlet subcooling had a monotone effect on density wave oscillation, when inlet subcooling decreased, critical heat flux decreased. Under a certain working condition, critical heat flux on asymmetrically heating parallel pipes is higher than that on symmetrically heating parallel pipes, that means the system with symmetrically heating parallel pips was more stable. (authors)
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.
Recent experiences with ultrasonic inservice inspection systems with phased array probes on spherical bottoms of boiling water reactors

International Nuclear Information System (INIS)

Wustenberg, H.; Brekow, G.; Erhard, A.; Hein, E.

1988-01-01

The special geometry of the spherical bottom of boiling water reactors with control rods and measuring nozzles requires a very special surveillance technique during the in-service inspection. Reside visual inspection an ultrasonic inspection has been established due to the requirements of German authorities. A first application of a new phased array system took place August 1987. The 100% inspection of a spherical bottom had been enabled by the application of phased array probes with electronically controlled skewing angles. The data acquisition had been based on the storage of whole A-scans, which had been pixellized into 256 points. This A-scan storage procedure makes possible the application of a simple and fast algorithm to present the data as TD-(time displacement)-scans. Defect reconstruction by echotomographique approaches are under development. This paper presents the ultrasonic technique applied including the phased array probes, the electronic system, as well as the software package used for the control of the inspection parameters depending on the probe position
Evaluation of Water Security in Kathmandu Valley before and after Water Transfer from another Basin

OpenAIRE

Bhesh Raj Thapa; Hiroshi Ishidaira; Vishnu Prasad Pandey; Tilak Mohan Bhandari; Narendra Man Shakya

2018-01-01

Kathmandu Upatyaka Khanepani Limited (KUKL) has planned to harness water from outside the valley from Melamchi as an inter-basin project to supply water inside the ring road (core valley area) of the Kathmandu Valley (KV). The project, called the “Melamchi Water Supply Project (MWSP)”, is expected to have its first phase completed by the end of September 2018 and its second phase completed by the end of 2023 to supply 170 MLD (million liters a day) through the first phase and an additional 34...
Multiwalled carbon nanotubes as solid-phase extraction materials for the gas chromatographic determination of organophosphorus pesticides in waters.

Science.gov (United States)

Ravelo-Pérez, Lidia M; Hernández-Borges, Javier; Angel Rodríguez-Delgado, Miguel

2008-10-01

In the present work, a GC method with nitrogen-phosphorus detection (NPD) was developed for the simultaneous determination of eight organophosphorus pesticide (OPP) residues (i.e., ethoprofos, diazinon, chlorpyrifos-methyl, fenitrothion, malathion, chlorpyrifos, fenamiphos, and buprofezin) in water samples. Preconcentration of the water samples was carried out using an SPE procedure with multiwalled carbon nanotubes (MWCNTs) of 10-15 nm od, 2-6 nm id, and 0.1-10 microm length as stationary phase. Extraction parameters, such as the amount of MWCNTs, sample volume, pH, and type and amount of the eluent were optimized. The most favorable conditions were as follows: 40 mg MWCNTs, 800 mL water, pH 6.0, and 20 mL dichloromethane, respectively. The MWCNTs-SPE-GC-NPD method was applied to the determination of these pesticides in real water samples: mineral and ground water as well as run-off water from an agricultural area collected shortly before opening out onto the sea. A recovery study was developed with five consecutive extractions of the three types of water spiked at three concentration levels (n = 15). Mean recovery values were in the range of 75-116% for mineral water (RSD water (RSD waters (RSDs waters, RSDs waters). The proposed method was also applied to the analysis of six water samples (two of each type: mineral, ground, and run-off waters) in which no residues of the selected pesticides were found. Results show that the MWCNTs used in this work have a high adsorbability of the pesticides under study. The main advantage of the use of these MWCNTs is their low cost when compared with those MWCNTs previously used in the literature and with conventional SPE cartridges.
Ion-pair in-tube solid-phase microextraction and capillary liquid chromatography using a titania-based column: application to the specific lauralkonium chloride determination in water.

Science.gov (United States)

Prieto-Blanco, M C; Moliner-Martínez, Y; López-Mahía, P; Campíns-Falcó, P

2012-07-27

A quick, miniaturized and on-line method has been developed for the determination in water of the predominant homologue of benzalkonium chloride, dodecyl dimethyl benzyl ammonium chloride or lauralkonium chloride (C(12)-BAK). The method is based on the formation of an ion-pair in both in-tube solid-phase microextraction (IT-SPME) and capillary liquid chromatography. The IT-SPME optimization required the study of the length and nature of the stationary phase of capillary and the processed sample volume. Because to the surfactant character of the analyte both, the extracting and replacing solvents, have played a decisive role in the IT-SPME optimized procedure. Conditioning the capillary with the mobile phase which contains the counter ion (acetate), using an organic additive (tetrabutylammonium chloride) added to the sample and a mixture water/methanol as replacing solvent (processed just before the valve is switched to the inject position), allowed to obtain good precision of the retention time and a narrow peak for C(12)-BAK. A reversed-phase capillary based TiO(2) column and a mobile phase containing ammonium acetate at pH 5.0 for controlling the interactions of cationic surfactant with titania surface were proposed. The optimized procedure provided adequate linearity, accuracy and precision at the concentrations interval of 1.5-300 μg L(-1) .The limit of detection (LOD) was 0.5 μg L(-1) using diode array detection (DAD). The applicability of proposed IT-SPME-capillary LC method has been assessed in several water samples. Copyright © 2012 Elsevier B.V. All rights reserved.
On-Going Bentonite Pore Water Studies by NMR and SAXS

International Nuclear Information System (INIS)

Carlsson, Torbjoern; Muurinen, Arto; Root, Andrew

2013-01-01

Compacted water-saturated MX-80 bentonite is presently being studied by SAXS and NMR in order to quantify the major pore water phases in the bentonite. The SAXS and NMR measurements gave very similar results indicating that the pore water is mainly distributed between two major phases (interlayer and non-interlayer water) and also indicate how these phases depend on the bentonite dry density. The results from the SAXS and NMR studies at VTT indicate the same thing: - The pore water in water-saturated compacted (?dry = 0.7-1.6 g/cm 3 ) bentonite is divided into two main phases: interlayer water and non-interlayer water. - The amounts of these pore water phases can be determined quantitatively with the above methods. (authors)
Extraction of actinide and lanthanide complexonates in two-phase aqueous system potassium carbonate-polyethylene glycol-water

International Nuclear Information System (INIS)

Molochnikova, N.P.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.; Myasoedov, B.F.

1988-01-01

Extraction system on the basis of polyethylene glycol for the concentration, isolation and separation of actinides is suggested. Extraction of actinides and lanthanides in two-phase aqueous system: potassium carbonate - polyethylene glycol - water in the presence of different complexones is investigated. Trivalent actinides are extracted quantitatively by polyethylene glycol from potassium carbonate solutions in the system with xylenol orange and alizarin-complexone. Under the conditions uranium (6) and plutonium (4) are extracted into the phase, enriched by polyethylene glycol, quite insignificantly, which permits to separate them from trivalent actinides with the separation factor of 10 2 - 10 3 . For actinide and lanthanide separation two complexones were introduced into the system, one of them being extractant, the other one - camouflaging reactant. The best results are obtained for the mixture of xylenol orange and hydroxyethylenediphosphonic acid. Separation coefficients for americium and europium constitute 4.5 - 5.6
Simultaneous detection of nine cyanotoxins in drinking water using dual solid-phase extraction and liquid chromatography-mass spectrometry.

Science.gov (United States)

Yen, Hung-Kai; Lin, Tsair-Fuh; Liao, Pao-Chi

2011-08-01

A solid-phase extraction (SPE)-liquid chromatography (LC)-mass spectrometry (MS) method was developed to concentrate and detect nine cyanotoxins simultaneously, including six microcystins (MCs) congeners, nodularin (NOD), anatoxin-a (ATX) and cylindrospermopsin (CYN), in pure and natural waters. A dual cartridge SPE assembly was tested for the operating parameters of cyanotoxin extraction. A surrogate standard (SS), 1,9-diaminononane, was spiked in all the samples before the SPE extraction, and an internal standard (IS), 2,3,5-trimethylphenyl methyl carbamate, was spiked before LC/MS analysis. The method detection limit (MDL) was 2-100 ng/L for nine cyanotoxins in pure water and was increased by a factor of three to ten in a more complicated water matrix. The recoveries based on SS were between 83 and 104%, while those based on IS were 80-120%. The developed method was successfully employed in analyzing 33 water samples collected from eutrophic lakes, water treatment plants and distribution taps. MCs, NOD, and CYN were detected in the reservoir water, with concentrations as high as 36 μg/L. In addition, for the first time in Taiwan's tap water, CYN was detected at concentrations as high as 8.6 μg/L. Quality control data for the field samples shows that the analytical scheme developed is appropriate for monitoring cyanotoxins. Copyright © 2011 Elsevier Ltd. All rights reserved.
Film boiling from spheres in single- and two-phase flow

International Nuclear Information System (INIS)

Liu, C.; Theofanous, T.G.; Yuen, W.W.

1992-01-01

Experimental data on film boiling heat transfer from single, inductively heated, spheres in single- and two-phase flow (saturated water and steam, respectively) are presented. In the single-phase-flow experiments water velocities ranged from 0.1 to 2.0 m/s; in the two-phase-flow experiments superficial water and steam velocities covered 0.1 to 0.6 m/s and 4 to 10 m/s, respectively. All experiments were run at atmospheric pressure and with sphere temperatures from 900C down to quenching. Limited interpretations of the single-phase- flow data are possible, but the two-phase-flow data are new and unique
Method development for the analysis of 1,4-dioxane in drinking water using solid-phase extraction and gas chromatography-mass spectrometry.

Science.gov (United States)

Grimmett, Paul E; Munch, Jean W

2009-01-01

1,4-Dioxane has been identified as a probable human carcinogen and an emerging contaminant in drinking water. The United States Environmental Protection Agency's (U.S. EPA) National Exposure Research Laboratory (NERL) has developed a method for the analysis of 1,4-dioxane in drinking water at ng/L concentrations. The method consists of an activated carbon solid-phase extraction of 500-mL or 100-mL water samples using dichloromethane as the elution solvent. The extracts are analyzed by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. In the NERL laboratory, recovery of 1,4-dioxane ranged from 94-110% in fortified laboratory reagent water and recoveries of 96-102% were demonstrated for fortified drinking water samples. The relative standard deviations for replicate analyses were less than 6% at concentrations exceeding the minimum reporting level.
Two-phase flow models in unbounded two-phase critical flows

International Nuclear Information System (INIS)

Celata, G.P.; Cumo, M.; Farello, G.E.

1985-01-01

With reference to a Loss-of-Coolant Accident in Light Water Reactors, an analysis of the unbounded two-phase critical flow (i.e. the issuing two-phase jet) has been accomplished. Considering jets external shape, obtained by means of photographic pictures; pressure profiles inside the jet, obtained by means of a movable ''Pitot;'' and jet phases distribution information, obtained by means of X-rays pictures; a characterization of the flow pattern in the unbounded region of a two-phase critical flow is given. Jets X-ray pictures show the existence of a central high density ''core'' gradually evaporating all around, which gives place to a characteristic ''dartflow'' the length of which depends on stagnation thermodynamic conditions

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.
Phase equilibrium condition of marine carbon dioxide hydrate

International Nuclear Information System (INIS)

Sun, Shi-Cai; Liu, Chang-Ling; Ye, Yu-Guang

2013-01-01

Highlights: ► CO 2 hydrate phase equilibrium was studied in simulated marine sediments. ► CO 2 hydrate equilibrium temperature in NaCl and submarine pore water was depressed. ► Coarse-grained silica sand does not affect CO 2 hydrate phase equilibrium. ► The relationship between equilibrium temperature and freezing point was discussed. - Abstract: The phase equilibrium of ocean carbon dioxide hydrate should be understood for ocean storage of carbon dioxide. In this paper, the isochoric multi-step heating dissociation method was employed to investigate the phase equilibrium of carbon dioxide hydrate in a variety of systems (NaCl solution, submarine pore water, silica sand + NaCl solution mixture). The experimental results show that the depression in the phase equilibrium temperature of carbon dioxide hydrate in NaCl solution is caused mainly by Cl − ion. The relationship between the equilibrium temperature and freezing point in NaCl solution was discussed. The phase equilibrium temperature of carbon dioxide hydrate in submarine pore water is shifted by −1.1 K to lower temperature region than that in pure water. However, the phase equilibrium temperature of carbon dioxide hydrate in mixture samples of coarsed-grained silica sand and NaCl solution is in agreement with that in NaCl solution with corresponding concentrations. The relationship between the equilibrium temperature and freezing point in mixture samples was also discussed.
Facile Fabrication of Superhydrophobic Paper with Excellent Water Repellency and Moisture Resistance by Phase Separation

Directory of Open Access Journals (Sweden)

Pan Li

2016-06-01

Full Text Available A simple but effective method of fabricating superhydrophobic paper with excellent moisture resistance was developed by precipitating carnauba wax onto the surface of cellulose fibers using a phase separation method. Response surface methodology (RSM was used to optimize the effects of the preparation variables on the water contact angle (WCA of the paper surface. The four independent variables were carnauba wax concentration, immersion time, coagulation bath ratio (water/ethanol, and coagulation bath time. The optimal treatment conditions were as follows: wax concentration, 3.78% (wax/chloroform, w/v; immersion time, 1.46 h; coagulation bath ratio, 13/87 (water/ethanol, v/v; and coagulation bath time, 2.63 h. Under these conditions, the experimental WCA reached 152.7°, which agreed closely with the predicted value of 154.1°. The surface morphology of the superhydrophobic paper was characterized by scanning electron microscopy (SEM and atomic force microscopy (AFM, and the images showed that cluster-like carnauba wax aggregation completely covered the fiber surface, resulting in increased roughness. Moreover, the moisture resistance of the obtained superhydrophobic paper was evaluated. The results demonstrated that under high relative humidity conditions, the moisture resistance of the superhydrophobic paper significantly improved, and its tensile strength remained high.
Metal-organic framework based in-syringe solid-phase extraction for the on-site sampling of polycyclic aromatic hydrocarbons from environmental water samples.

Science.gov (United States)

Zhang, Xiaoqiong; Wang, Peiyi; Han, Qiang; Li, Hengzhen; Wang, Tong; Ding, Mingyu

2018-04-01

In-syringe solid-phase extraction is a promising sample pretreatment method for the on-site sampling of water samples because of its outstanding advantages of portability, simple operation, short extraction time, and low cost. In this work, a novel in-syringe solid-phase extraction device using metal-organic frameworks as the adsorbent was fabricated for the on-site sampling of polycyclic aromatic hydrocarbons from environmental waters. Trace polycyclic aromatic hydrocarbons were effectively extracted through the self-made device followed by gas chromatography with mass spectrometry analysis. Owing to the excellent adsorption performance of metal-organic frameworks, the analytes could be completely adsorbed during one adsorption cycle, thus effectively shortening the extraction time. Moreover, the adsorbed analytes could remain stable on the device for at least 7 days, revealing the potential of the self-made device for on-site sampling of degradable compounds in remote regions. The limit of detection ranged from 0.20 to 1.9 ng/L under the optimum conditions. Satisfactory recoveries varying from 84.4 to 104.5% and relative standard deviations below 9.7% were obtained in real samples analysis. The results of this study promote the application of metal-organic frameworks in sample preparation and demonstrate the great potential of in-syringe solid-phase extraction for the on-site sampling of trace contaminants in environmental waters. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Water-soluble phosphine-protected Au9 clusters: Electronic structures and nuclearity conversion via phase transfer

Science.gov (United States)

Yao, Hiroshi; Tsubota, Shuhei

2017-08-01

In this article, isolation, exploration of electronic structures, and nuclearity conversion of water-soluble triphenylphosphine monosulfonate (TPPS)-protected nonagold (Au9) clusters are outlined. The Au9 clusters are obtained by the reduction of solutions containing TPPS and HAuCl4 and subsequent electrophoretic fractionation. Mass spectrometry and elemental analysis reveal the formation of [Au9(TPPS)8]5- nonagold cluster. UV-vis absorption and magnetic circular dichroism (MCD) spectra of aqueous [Au9(TPPS)8]5- are quite similar to those of [Au9(PPh3)8]3+ in organic solvent, so the solution-phase structures are likely similar for both systems. Simultaneous deconvolution analysis of absorption and MCD spectra demonstrates the presence of some weak electronic transitions that are essentially unresolved in the UV-vis absorption. Quantum chemical calculations for a model compound [Au9(pH3)8]3+ show that the possible (solution-phase) skeletal structure of the nonagold cluster has D2h core symmetry rather than C4-symmetrical centered crown conformation, which is known as the crystal form of the Au9 compound. Moreover, we find a new nuclearity conversion route from Au9 to Au8; that is, phase transfer of aqueous [Au9(TPPS)8]5- into chloroform using tetraoctylammonium bromide yields [Au8(TPPS)8]6- clusters in the absence of excess phosphine.
Membrane solid-phase extraction: Field application for isolation of polycyclic aromatic hydrocarbons from water samples

International Nuclear Information System (INIS)

Furlong, E.T.; Koleis, J.C.; Gates, P.M.

1995-01-01

Solid-phase extraction (SPE) membranes (M-SPE) were used to isolate microgram-per-liter to nanogram-per-liter quantities of polycyclic aromatic hydrocarbons (PAH) in 4- to 8-liter ground-water samples from a crude-oil-contaminated ground-water site near Bemidji, Minnesota. The M-SPE method was evaluated (1) under laboratory conditions using reagent water fortified with individual PAH at 1.23 micrograms per liter, and (2) at the Bemidji site. At the site, ground-water samples were processed and PAH isolated using a M-SPE system connected directly to the well pump. Following sample isolation, all M-SPE samples were extracted using dichloromethane and analyzed by gas chromatography-mass spectrometry with selected-ion monitoring. Operationally, the M-SPE method provided a simple means to isolate PAH on site at the wellhead, particularly for anoxic water samples. Acceptable recoveries, ranging from 56 to over 100 percent, were observed for lower molecular weight PAH (naphthalene to pyrene) using the M-SPE method. Recoveries using M-SPE were somewhat lower, but reproducible, for higher molecular weight PAH (chrysene to benzo[ghi]perylene), ranging from 18 to 56 percent. M-SPE provides the capability to collect and field isolate PAH from a sufficiently large number of samples to identify environmental chemical processes occurring at individual compound concentrations of 50 to 1,200 nanograms per liter. Using M-SPE, the potential for facilitated transport of PAH by in situ-derived dissolved organic carbon (DOC) was evaluated at the site. Plots comparing DOC and PAH concentrations indicate that PAH concentrations increase exponentially with linear increases in DOC concentrations
Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part II: Multi-layered cloud

Energy Technology Data Exchange (ETDEWEB)

Morrison, H; McCoy, R B; Klein, S A; Xie, S; Luo, Y; Avramov, A; Chen, M; Cole, J; Falk, M; Foster, M; Genio, A D; Harrington, J; Hoose, C; Khairoutdinov, M; Larson, V; Liu, X; McFarquhar, G; Poellot, M; Shipway, B; Shupe, M; Sud, Y; Turner, D; Veron, D; Walker, G; Wang, Z; Wolf, A; Xu, K; Yang, F; Zhang, G

2008-02-27

Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a deep, multi-layered, mixed-phase cloud system observed during the ARM Mixed-Phase Arctic Cloud Experiment. This cloud system was associated with strong surface turbulent sensible and latent heat fluxes as cold air flowed over the open Arctic Ocean, combined with a low pressure system that supplied moisture at mid-level. The simulations, performed by 13 single-column and 4 cloud-resolving models, generally overestimate the liquid water path and strongly underestimate the ice water path, although there is a large spread among the models. This finding is in contrast with results for the single-layer, low-level mixed-phase stratocumulus case in Part I of this study, as well as previous studies of shallow mixed-phase Arctic clouds, that showed an underprediction of liquid water path. The overestimate of liquid water path and underestimate of ice water path occur primarily when deeper mixed-phase clouds extending into the mid-troposphere were observed. These results suggest important differences in the ability of models to simulate Arctic mixed-phase clouds that are deep and multi-layered versus shallow and single-layered. In general, models with a more sophisticated, two-moment treatment of the cloud microphysics produce a somewhat smaller liquid water path that is closer to observations. The cloud-resolving models tend to produce a larger cloud fraction than the single-column models. The liquid water path and especially the cloud fraction have a large impact on the cloud radiative forcing at the surface, which is dominated by the longwave flux for this case.
Aqueous Two-Phase Systems: A New Approach for the Determination of Brilliant Blue FCF in Water and Food Samples

Directory of Open Access Journals (Sweden)

Sabah Shiri

2013-01-01

Full Text Available A novel, simple, and more sensitive spectrophotometric procedure has been developed for the determination of brilliant blue FCF in water and food samples by an aqueous two-phase system (ATPS. In this method, adequate amount of polyethylene glycol/ sodium carbonate (PEG-4000/Na2CO3 was added to aqueous solution for formation of a homogeneous solution. To the mixture solution, suitable amount of Na2CO3 was added, the mixture solution was shaken until the salt was dissolved, and then it was separated into two clear phases easily and rapidly. The target analyte in the water sample was extracted into the polyethylene glycol phase. After extraction, measuring the absorbance at 634 nm was done. The effects of different parameters such as polyethylene glycol (type and concentration, pH, salt (type and amount, centrifuge time, and temperature on the ATPS of dye was investigated and optimum conditions were established. Linear calibration curves were obtained in the range of 0.25–750 ng/mL for brilliant blue FCF under optimum conditions. Detection limit based on three times the standard deviation of the blank (3Sb was 0.12 ng/mL. The relative standard deviation (RSD for 400 ng/mL was 3.14%. The method was successfully applied to the determination of brilliant blue FCF in spiked samples with satisfactory results. The relative recovery was between 96.0 and 102.2%.
New data on two-phase water-air hydrodynamics in vertical upward and downward tubes

Energy Technology Data Exchange (ETDEWEB)

Lau, V [Atomic Energy of Canada Ltd., Saskatoon, SK (Canada); Rezkallah, K S [Saskatchewan Univ., Saskatoon (Canada). Mechanical Engineering Dept.

1996-12-31

The three key parameters involved in the analysis of the hydrodynamic characteristics of a two-phase system (i.e. pressure drop, void fraction, and flow pattern associated with the flow) are taken in vertical upward and downward tubes, using water-air mixture at atmospheric pressure. The acquired data set covers a wide range of liquid and gas flow rates, as well as void fractions. Using the acquired data set, two sets of flow pattern maps, for both upward and downward flows, are developed in the present study. Furthermore, a set of correlations for predicting the frictional pressure drop in both upward and downward flow were also developed. (author). 16 refs., 13 figs.
Comparison of the solid-phase extraction efficiency of a bounded and an included cyclodextrin-silica microporous composite for polycyclic aromatic hydrocarbons determination in water samples.

Science.gov (United States)

Mauri-Aucejo, Adela; Amorós, Pedro; Moragues, Alaina; Guillem, Carmen; Belenguer-Sapiña, Carolina

2016-08-15

Solid-phase extraction is one of the most important techniques for sample purification and concentration. A wide variety of solid phases have been used for sample preparation over time. In this work, the efficiency of a new kind of solid-phase extraction adsorbent, which is a microporous material made from modified cyclodextrin bounded to a silica network, is evaluated through an analytical method which combines solid-phase extraction with high-performance liquid chromatography to determine polycyclic aromatic hydrocarbons in water samples. Several parameters that affected the analytes recovery, such as the amount of solid phase, the nature and volume of the eluent or the sample volume and concentration influence have been evaluated. The experimental results indicate that the material possesses adsorption ability to the tested polycyclic aromatic hydrocarbons. Under the optimum conditions, the quantification limits of the method were in the range of 0.09-2.4μgL(-1) and fine linear correlations between peak height and concentration were found around 1.3-70μgL(-1). The method has good repeatability and reproducibility, with coefficients of variation under 8%. Due to the concentration results, this material may represent an alternative for trace analysis of polycyclic aromatic hydrocarbons in water trough solid-phase extraction. Copyright © 2016 Elsevier B.V. All rights reserved.
In-Flight Water Quality Monitoring on the International Space Station (ISS): Measuring Biocide Concentrations with Colorimetric Solid Phase Extraction (CSPE)

Science.gov (United States)

Gazda, Daniel B.; Schultz, John R.; Siperko, Lorraine M.; Porter, Marc D.; Lipert, Robert J.; Flint, Stephanie M.; McCoy, J. Torin

2011-01-01

The colorimetric water quality monitoring kit (CWQMK) was delivered to the International Space Station (ISS) on STS-128/17A and was initially deployed in September 2009. The kit was flown as a station development test objective (SDTO) experiment to evaluate the acceptability of colorimetric solid phase extraction (CSPE) technology for routine water quality monitoring on the ISS. During the SDTO experiment, water samples from the U.S. water processor assembly (WPA), the U.S. potable water dispenser (PWD), and the Russian system for dispensing ground-supplied water (SVO-ZV) were collected and analyzed with the CWQMK. Samples from the U.S. segment of the ISS were analyzed for molecular iodine, which is the biocide added to water in the WPA. Samples from the SVOZV system were analyzed for ionic silver, the biocide used on the Russian segment of the ISS. In all, thirteen in-flight analysis sessions were completed as part of the SDTO experiment. This paper provides an overview of the experiment and reports the results obtained with the CWQMK. The forward plan for certifying the CWQMK as operational hardware and expanding the capabilities of the kit are also discussed.
Study on Solid Phase Extraction and Spectrophotometric Determination of Nickel in Waters and Biological Samples

International Nuclear Information System (INIS)

Hu, Qiufen; Yang, Guangyu; Huang, Zhangjie; Yin, Jiayuan

2004-01-01

A sensitive, selective and rapid method for the determination of nickel based on the rapid reaction of nickel(II) with QADMAA and the solid phase extraction of the Ni(II)-QADMAA chelate with C 18 membrane disks has been developed. In the presence of pH 6.0 buffer solution and sodium dodecyl sulfonate (SDS) medium, QADMAA reacts with nickel to form a violet complex of a molar ratio of 1 : 2 (nickel to QADMAA). This chelate was enriched by solid phase extraction with C 18 membrane disks. An enrichment factor of 50 was obtained by elution of the chelates form the disks with the minimal amount of isopentyl alcohol. The molar absorptivity of the chelate was 1.32 x 10 5 L mol -1 cm -1 at 590 nm in the measured solution. Beer's law was obeyed in the range of 0.01-0.6 μg/mL. This method was applied to the determination of nickel in water and biological samples with good results
Supercooling of aqueous dimethylsulfoxide solution at normal and high pressures: Evidence for the coexistence of phase-separated aqueous dimethylsulfoxide solutions of different water structures

Science.gov (United States)

Kanno, H.; Kajiwara, K.; Miyata, K.

2010-05-01

Supercooling behavior of aqueous dimethylsulfoxide (DMSO) solution was investigated as a function of DMSO concentration and at high pressures. A linear relationship was observed for TH (homogeneous ice nucleation temperature) and Tm (melting temperature) for the supercooling of aqueous DMSO solution at normal pressure. Analysis of the DTA (differential thermal analysis) traces for homogeneous ice crystallization in the bottom region of the TH curve for a DMSO solution of R =20 (R: moles of water/moles of DMSO) at high pressures supported the contention that the second critical point (SCP) of liquid water should exist at Pc2=˜200 MPa and at Tc2pressure of SCP, Tc2: temperature of SCP). The presence of two TH peaks for DMSO solutions (R =15, 12, and 10) suggests that phase separation occurs in aqueous DMSO solution (R ≤15) at high pressures and low temperatures (pressure dependence of the two TH curves for DMSO solutions of R =10 and 12 indicates that the two phase-separated components in the DMSO solution of R =10 have different liquid water structures [LDL-like and HDL-like structures (LDL: low-density liquid water, HDL: high-density liquid water)] in the pressure range of 120-230 MPa.
Box-Behnken design in modeling of solid-phase tea waste extraction for the removal of uranium from water samples

Energy Technology Data Exchange (ETDEWEB)

Khajeh, Mostafa; Jahanbin, Elham; Ghaffari-Moghaddam, Mansour; Moghaddam, Zahra Safaei [Zabol Univ. (Iran, Islamic Republic of). Dept. of Chemistry; Bohlooli, Mousa [Zabol Univ. (Iran, Islamic Republic of). Dept. of Biology

2015-07-01

In this study, the solid-phase tea waste procedure was used for separation, preconcentration and determination of uranium from water samples by UV-Vis spectrophotometer. In addition, Box-Behnken experimental design was employed to investigated the influence of six variables including pH, mass of adsorbent, eluent volume, amount of 1-(2-pyridylazo)-2-naphthol (PAN); and sample and eluent flow rates on the extraction of analyte. High determination coefficient (R{sup 2}) of 0.972 and adjusted-R{sup 2} of 0.943 showed the satisfactory adjustment of the polynomial regression model. This method was used for the extraction of uranium from real water samples.
Box-Behnken design in modeling of solid-phase tea waste extraction for the removal of uranium from water samples

International Nuclear Information System (INIS)

Khajeh, Mostafa; Jahanbin, Elham; Ghaffari-Moghaddam, Mansour; Moghaddam, Zahra Safaei; Bohlooli, Mousa

2015-01-01

In this study, the solid-phase tea waste procedure was used for separation, preconcentration and determination of uranium from water samples by UV-Vis spectrophotometer. In addition, Box-Behnken experimental design was employed to investigated the influence of six variables including pH, mass of adsorbent, eluent volume, amount of 1-(2-pyridylazo)-2-naphthol (PAN); and sample and eluent flow rates on the extraction of analyte. High determination coefficient (R 2 ) of 0.972 and adjusted-R 2 of 0.943 showed the satisfactory adjustment of the polynomial regression model. This method was used for the extraction of uranium from real water samples.
Solid-phase extraction with slurry injection of the resin into ETAAS for trace determination of thallium in natural water

International Nuclear Information System (INIS)

Isoshi, Nukatsuka; Hiroyuki, Seitoh; Kunio, Ohzeki

2004-01-01

Thallium in natural water samples was determined by electrothermal atomic absorption spectrometry after 1000-fold enrichment by mini solid-phase extraction from a 100-mL sample solution. A TI-pyrrolidine-1-carbodithioate complex formed in a sample solution of pH 1.6 was extracted on fine particles of a cellulose nitrate resin dispersed in the sample solution. The cellulose nitrate resin was then collected on a membrane filter (25 mm ) by filtration under suction using a glass funnel with an effective filtration area of 0.64 cm 2 . As a result, a circular thin layer of the resin phase with a diameter of 9 mm was obtained. Then the resin phase was carved out by an acrylate resin puncher with a 10-mm hole to put it into a sample cup containing 100 μL of 10 mM HNO 3 containing 0.5 mM NaCl. The resin phase was suspended in the solution by ultrasonication. 1000-fold enrichment was thus attained within 15 min, and the suspension was delivered to electrothermal atomic absorption spectrometry. The linear calibration graph was obtained in the range of 0-4 ng of TI in 100 mL of a sample solution. The detection limit obtained by 3 σ method was 0.19 ng. The proposed method was applied to the determination of TI in natural water samples. The results showed the concentration of TI in seawater was 12.1 ± 1.8 pg mL -1 for the calibration graph method and 12.6 ± 1.4 pg mL -1 for the standard addition method. A snowmelt sample contained 20.7 ± 1.0 pg mL -1 of TI. (author)
Analysis of trace dicyandiamide in stream water using solid phase extraction and liquid chromatography UV spectrometry.

Science.gov (United States)

Qiu, Huidong; Sun, Dongdi; Gunatilake, Sameera R; She, Jinyan; Mlsna, Todd E

2015-09-01

An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase extraction. The extraction procedure (including loading, washing, and eluting) used a flow rate of 1.0mL/min, and dicyandiamide was eluted with 20mL of a methanol/acetonitrile mixture (V/V=2:3), followed by pre-concentration using nitrogen evaporation and analysis with high performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV). Sample extraction was carried out using a Waters Sep-Pak AC-2 Cartridge (with activated carbon). Separation was achieved on a ZIC(®)-Hydrophilic Interaction Liquid Chromatography (ZIC-HILIC) (50mm×2.1mm, 3.5μm) chromatography column and quantification was accomplished based on UV absorbance. A reliable linear relationship was obtained for the calibration curve using standard solutions (R(2)>0.999). Recoveries for dicyandiamide ranged from 84.6% to 96.8%, and the relative standard deviations (RSDs, n=3) were below 6.1% with a detection limit of 5.0ng/mL for stream water samples. Copyright © 2015. Published by Elsevier B.V.
Analytical description of thermodynamic properties of steam, water and the phase interface for use in CFD

Directory of Open Access Journals (Sweden)

Hrubý Jan

2014-03-01

Full Text Available We present a system of analytical equations for computation of all thermodynamic properties of dry steam and liquid water (undesaturated, saturated and metastable supersaturated and properties of the liquid-vapor phase interface. The form of the equations is such that it enables computation of all thermodynamic properties for independent variables directly related to the balanced quantities - total mass, liquid mass, energy, momenta. This makes it suitable for the solvers of fluid dynamics equations in the conservative form. Thermodynamic properties of dry steam and liquid water are formulated in terms of special thermodynamic potentials and all properties are obtained as analytical derivatives. For the surface tension, the IAPWS formula is used. The interfacial internal energy is derived from the surface tension and it is used in the energy balance. Unlike common models, the present one provides real (contrary to perfect gas approximation properties of steam and water and reflects the energetic effects due to the surface tension. The equations are based on re-fitting the reference formulation IAPWS-95 and selected experimental data. The mathematical structure of the equations is optimized for fast computation.
Preconcentration of Arsenic in Water Samples Using the Composition-Induced Phase Separation Method and Determination by ETAAS

Directory of Open Access Journals (Sweden)

Güçoğlu M.

2013-04-01

Full Text Available A new phase transition microextraction method was developed for determination of trace amount of arsenic ions in water samples in this work. The method is based on the critical point of miscibility of solvents. In this method the mixed solution of sample and organic solvent is initially homogeneous but is separated into two phases by adding a secondary solvent (modifier. In acidic medium As(V was complexed with ammonium molybdate, this complex was quantitatively extracted to the mixture of organic solvent (acetonitrile/methyl isobutyl ketone before ETAAS determination. Total inorganic arsenic (III, V was extracted similarly after oxidation of As(III to As(V with nitric acid. Concentration of As(III was calculated by difference in the concentration between total arsenic and As(V. Optimization of the experimental conditions and instrumental parameters was investigated in detail. A detection limit of 0.05 μgL−1 with enrichment factor of 85 was achieved for only 5 mL of sample. The analytical curve was linear in the concentration range of 0.25-4.00 μgL−1. Relative standard deviation (RSD for 10 replicate determinations of 2.0 μgL−1 of As(V was 4,1%. The method was successfully applied to preconcentration and determination of arsenic in real water samples.
Determination of trace labile copper in environmental waters by magnetic nanoparticle solid phase extraction and high-performance chelation ion chromatography.

Science.gov (United States)

Wei, Z; Sandron, S; Townsend, A T; Nesterenko, P N; Paull, B

2015-04-01

Cobalt magnetic nanoparticles surface functionalised with iminodiacetic acid were evaluated as a nano-particulate solid phase extraction absorbent for copper ions (Cu(2+)) from environmental water samples. Using an external magnetic field, the collector nanoparticles could be separated from the aqueous phase, and adsorbed ions simply decomplexed using dilute HNO3. Effects of pH, buffer concentration, sample and sorbent volume, extraction equilibrium time, and interfering ion concentration on extraction efficiency were investigated. Optimal conditions were then applied to the extraction of Cu(2+) ions from natural water samples, prior to their quantitation using high-performance chelation ion chromatography. The limits of detection (LOD) of the combined extraction and chromatographic method were ~0.1 ng ml(-1), based upon a 100-fold preconcentration factor (chromatographic performance; LOD=9.2 ng ml(-1) Cu(2+)), analytical linear range from 20 to 5000 ng mL(-1), and relative standard deviations=4.9% (c=1000 ng ml(-1), n=7). Accuracy and precision of the combined approach was verified using a certified reference standard estuarine water sample (SLEW-2) and comparison of sample determinations with sector field inductively coupled plasma mass spectrometry. Recoveries from the addition of Cu(2+) to impacted estuarine and rain water samples were 103.5% and 108.5%, respectively. Coastal seawater samples, both with and without prior UV irradiation and dissolved organic matter removal were also investigated using the new methodology. The effect of DOM concentration on copper availability was demonstrated. Copyright © 2015. Published by Elsevier B.V.

TiO{sub 2} nanoparticles obtained by laser ablation in water: Influence of pulse energy and duration on the crystalline phase

Energy Technology Data Exchange (ETDEWEB)

Giorgetti, E., E-mail: emilia.giorgetti@fi.isc.cnr.it [Istituto dei Sistemi Complessi (ISC) CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Muniz Miranda, M.; Caporali, S. [Dipartimento di Chimica “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); Canton, P. [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari, Via Torino, 30170 Venezia-Mestre (Italy); Marsili, P. [Istituto dei Sistemi Complessi (ISC) CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Dipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa (Italy); Vergari, C.; Giammanco, F. [Dipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa (Italy)

2015-09-15

Highlights: • Laser ablation of Ti in water at 1064 nm and comparison of ns and ps temporal regimes. • Structural and spectroscopic characterization of the colloids: TiO{sub 2} is the predominant phase. • Determination of an energy window where ps ablation produces more anatase than rutile. • Modelling of the experimental dependence of anatase/rutile yield on pulse length and energy. - Abstract: We fabricated Ti oxide nanoparticles by laser ablation of a Ti target in doubly deionized water with ps or ns pulses at a laser wavelength of 1064 nm. Electron microscopy, Raman, X-ray diffraction and X-ray photoelectron spectroscopy showed that, while with ns pulses the dominant oxide phase is rutile, with ps pulses anatase is the most abundant form in an intermediate energy window centered around 25 mJ per pulse. This experimental behavior can be described by a theoretical model which calculates the pressure and temperature evolution of the ablated material and, from this, the rutile and anatase yield.
Phase transitions

CERN Document Server

Sole, Ricard V; Solé, Ricard V; SolÃ©, Ricard V; Sol, Ricard V; Solé, Ricard V

2011-01-01

Phase transitions--changes between different states of organization in a complex system--have long helped to explain physics concepts, such as why water freezes into a solid or boils to become a gas. How might phase transitions shed light on important problems in biological and ecological complex systems? Exploring the origins and implications of sudden changes in nature and society, Phase Transitions examines different dynamical behaviors in a broad range of complex systems. Using a compelling set of examples, from gene networks and ant colonies to human language and the degradation of diverse ecosystems, the book illustrates the power of simple models to reveal how phase transitions occur. Introductory chapters provide the critical concepts and the simplest mathematical techniques required to study phase transitions. In a series of example-driven chapters, Ricard Solé shows how such concepts and techniques can be applied to the analysis and prediction of complex system behavior, including the origins of ...
Gas hydrate phase equilibria measurement techniques and phase rule considerations

International Nuclear Information System (INIS)

Beltran, Juan G.; Bruusgaard, Hallvard; Servio, Phillip

2012-01-01

Highlights: → Inconsistencies found in hydrate literature. → Clarification to the number of variables needed to satisfy and justify equilibrium data. → Application of phase rule to mixed hydrate systems. → Thermodynamically consistent format to present data. - Abstract: A brief review of the Gibbs phase rule for non-reacting systems and its correct application to clathrate hydrates is presented. Clarification is provided for a common mistake found in hydrate phase-equilibria literature, whereby initial compositions are used as intensive variables to satisfy the Gibbs phase rule instead of the equilibrium values. The system of (methane + carbon dioxide + water) under (hydrate + liquid + vapor) equilibrium is used as a case study to illustrate key points and suggestions to improve experimental techniques are proposed.
Detailed pressure drop measurements in single-and two-phase adiabatic air-water turbulent flows in realistic BWR fuel assembly geometry with spacer grids

International Nuclear Information System (INIS)

Caraghiaur, Diana; Frid, Wiktor; Tillmark, Nils

2004-01-01

In recent years, advance numerical simulation tools based on CFD methods have been increasingly used in various multi-phase flow applications. One of these is two-phase flow in fuel assemblies of Boiling Water Reactors. The important and often missing aspect of this development is validation of CFD codes against proper experimental data. The purpose of the current paper is to present detailed pressure measurements over a spacer grid in low pressure adiabatic single- and bubbly two-phase flow, which will be used to further develop a CFD code for BWR fuel bundle analysis. The experiments have been carried out in a n asymmetric 24-rod sub-bundle, representing one quarter of a Westinghouse SVEA-96 nuclear reactor fuel assembly. Single-phase flow measurements have been performed at superficial velocities between 0.90-4.50 m/s and in the two-phase flow, which was simulated by air-water mixture, measurements have been performed at void fractions ranging from 4 to 12% and liquid superficial velocity of 4.50 m/s. In order to increase the number of measuring points, five pressure taps were drilled in one of the rods, which was easily moved vertically by a traversing system, covering most of the points in axial direction. Any of the rods in the bundle could be substitute by the pressure sensing rod and the measurements were made for five pressure taps facing-angles. A detailed pressure distribution comparison between single- and two-phase flows for different sub-channel positions and different flow conditions was performed over one of the spacers. In addition, single-phase pressure drop measurements in the upper part of the test section comprising two spacer grids have been carried out. (author)
High temperature pressure water's blowdown into water. Experimental results

International Nuclear Information System (INIS)

Ishida, Toshihisa; Kusunoki, Tsuyoshi; Kasahara, Yoshiyuki; Iida, Hiromasa

1994-01-01

The purpose of the present experimental study is to clarify the phenomena in blowdown of high temperature and pressure water in pressure vessel into the containment water for evaluation of design of an advanced marine reactor(MRX). The water blown into the containment water flushed and formed steam jet plume. The steam jet condensed in the water, but some stream penetrated to gas phase of containment and contributed to increase of containment pressure. (author)
Salicylic acid determination in estuarine and riverine waters using hollow fiber liquid-phase microextraction and capillary zone electrophoresis.

Science.gov (United States)

da Silva, Gilmar Silvério; Lima, Diana L D; Esteves, Valdemar Inocêncio

2017-06-01

A low-cost methodology using hollow fiber liquid-phase microextraction (HF-LPME) and capillary zone electrophoresis (CZE) with UV-Vis detector was developed to analyze the salicylic acid (SA) in estuarine and riverine waters. The technique is easy-to-use and rapid, and demands little volume of organic solvent. The extraction was carried out using a polypropylene membrane supporting into octan-1-ol. HF-LPME under optimized conditions (donor solution sample pH 2, acceptor solution pH 14, sample volume 25 mL, fiber length 10 cm, acceptor volume 25 μL, extraction time 3 h and stirring speed 350 rpm) presented high enrichment factor (407 times) and good recovery in real water samples (from 88 to 110%). A limit of detection of 2.6 μg L -1 was achieved using CZE with UV-Vis detector as quantification method. The method was applied to direct quantification of SA in environmental complex estuarine and riverine water matrices.
Two-phase water hammer in nuclear power plants

International Nuclear Information System (INIS)

Kim, J.H.

1987-01-01

Water hammer events keep recurring in nuclear power plants. In the mid-1970s, water hammer was designated to be an unresolved safety issue (USI A-1) due to its high frequency of occurrence and the severity of the attendant damages. Between 1969 and 1981, a significant number of water hammer incidents (more than 12 events per year) involving BWRs and PWRs have been reported and evaluated. After intensive evaluations of the events, in late 1983, the U.S. Nuclear Regulatory Commission staff concluded that water hammer was not a serious contributor to the degradation of plant safety and it has been taken off the list of the unresolved safety issues. The frequency decreased to around 11 events per year between 1981 and 1985. Nevertheless, 11 events per year are still unacceptable high, especially in light of the financial losses caused by most events. Some events are not required to be reported. The number of the unreported events are estimated to be five to ten times as many as the reported events. The implication is that water hammer in nuclear power plants still needs attention and is a problem that has not been fundamentally resolved
Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of pesticides in water by graphitized carbon-based solid-phase extraction and high-performance liquid chromatography/mass spectrometry

Science.gov (United States)

Furlong, Edward T.; Anderson, Bruce D.; Werner, Stephen L.; Soliven, Paul P.; Coffey, Laura J.; Burkhardt, Mark R.

2001-01-01

In 1996, the U.S. Geological Survey National Water Quality Laboratory (NWQL) developed and implemented a graphitized carbon-based solid-phase extraction and high-performance liquid chromatographic analytical method to determine polar pesticide concentrations in surface- and ground-water samples. Subsequently, the NWQL developed a complementary analysis that uses high-performance liquid chromatography/mass spectrometry to detect, identify, and quantify polar pesticides and pesticide metabolites in filtered water at concentrations as low as 10 nanograms per liter. This new method was designed to improve sensitivity and selectivity over the prior method, and to reduce known interferences from natural organic matter.In this new method, pesticides are extracted from filtered water samples by useing a 0.5-gram graphitized carbon-based solid-phase extraction cartridge, eluted from the cartridge, and concentrations determined by using high-performance liquid chromatography with electrospray ionization-mass spectrometry. The upper concentration limit is 1.000 microgram per liter (μg/L) for most compounds. Single-operator method detection limits in organic-free water samples fortified with pesticides at a concentration of 0.025 μg/L ranged from 0.0019 to 0.022 μg/L for all compounds in the method. The grand mean (mean of mean recoveries for individual compounds) recoveries in organic-free water samples ranged from 72 to 89 percent, fortified with pesticides at three concentrations between 0.025 and 0.5 μg/L. Grand mean recoveries in ground- and surface-water samples ranged from 46 to 119 percent, also fortified with pesticides at three concentrations between 0.025 and 0.5 μg/L. Long-term recoveries from reagent water spikes were used to demonstrate that 38 of 65 compounds can be reported without qualification of the quantitative result across the analytical range of the method. The remaining 27 are reported with qualified estimates of concentration because of greater
Investigations of the reflood-phase after a loss-of-coolant-accident of an advanced pressurized water reactor (APWR)

International Nuclear Information System (INIS)

Schumann, S.; Oldekop, W.

1983-01-01

Differences between a high converting advanced pressurized-water reactor (APWR) and a conventional PWR, which are relevant to the reflood-phase after LOCA are presented. The used code and its verification by PWR-reflood experiments is explained. Comparative calculations for APWR and PWR with several conservative assumptions for example cold-leg-injection only, yield nearly the same maximum midplane-temperatures for the average-channel. For the APWR, however, the upper half of the rod shows higher temperatures. Quenchfront and core-water-level increase more slowly. The differences in the reflood-thermohydraulics are analysed in detail. A conservative hot-channel calculation shows maximum temperatures of about 920 0 C. Finally the influence of conservative assumptions is described and the necessity of experiments pointed out. (orig.)
Analysis of trace levels of sulfonamide and tetracycline antimicrobials in groundwater and surface water using solid-phase extraction and liquid chromatography/mass spectrometry

Science.gov (United States)

Lindsey, M.E.; Meyer, M.; Thurman, E.M.

2001-01-01

A method has been developed for the trace analysis of two classes of antimicrobials consisting of six sulfonamides (SAs) and five tetracyclines (TCs), which commonly are used for veterinary purposes and agricultural feed additives and are suspected to leach into ground and surface water. The method used solid-phase extraction and liquid chromatography/mass spectrometry (LC/MS) with positive ion electrospray. The unique combination of a metal chelation agent (Na2EDTA) with a macroporous copolymer resulted in quantitative recoveries by solid-phase extraction (mean recovery, 98 ?? 12%) at submicrogram-per-liter concentrations. An ammonium formate/formic acid buffer with a methanol/water gradient was used to separate the antimicrobials and to optimize the signal intensity. Mass spectral fragmentation and ionization characteristics were determined for each class of compounds for unequivocal identification. For all SAs, a characteristic m/z 156 ion representing the sulfanilyl fragment was identified. TCs exhibited neutral losses of 17 amu resulting from the loss of ammonia and 35 amu from the subsequent loss of water. Unusual matrix effects were seen only for TCs in this first survey of groundwater and surface water samples from sites around the United States, requiring that TCs be quantitated using the method of standard additions.
Aqueous-Phase Acetic Acid Ketonization over Monoclinic Zirconia

Energy Technology Data Exchange (ETDEWEB)

Cai, Qiuxia [Institute for Integrated Catalysis, Pacific Northwest; College; Lopez-Ruiz, Juan A. [Institute for Integrated Catalysis, Pacific Northwest; Cooper, Alan R. [Institute for Integrated Catalysis, Pacific Northwest; Wang, Jian-guo [College; Albrecht, Karl O. [Institute for Integrated Catalysis, Pacific Northwest; Mei, Donghai [Institute for Integrated Catalysis, Pacific Northwest

2017-12-13

The effect of aqueous phase on the acetic acid ketonization over monoclinic zirconia has been investigated using first-principles based density functional theory (DFT) calculations. To capture the aqueous phase chemistry over the solid zirconia catalyst surface, the aqueous phase is represented by 111 explicit water molecules with a liquid water density of 0.93 g/cm3 and the monoclinic zirconia is modeled by the most stable surface structure . The dynamic nature of aqueous phase/ interface was studied using ab initio molecular dynamics simulation, indicating that nearly half of the surface Zr sites are occupied by either adsorbed water molecules or hydroxyl groups at 550 K. DFT calculations show that the adsorption process of acetic acid from the liquid water phase to the surface is nearly thermodynamically neutral with a Gibbs free energy of -2.3 kJ/mol although the adsorption strength of acetic acid on the surface in aqueous phase is much stronger than in vapor phase. Therefore it is expected that the adsorption of acetic acid will dramatically affects aqueous phase ketonization reactivity over the monoclinic zirconia catalyst. Using the same ketonization mechanism via the β-keto acid intermediate, we have compared acetic acid ketonization to acetone in both vapor and aqueous phases. Our DFT calculation results show although the rate-determining step of the β-keto acid formation via the C-C coupling is not pronouncedly affected, the presence of liquid water molecules will dramatically affect dehydrogenation and hydrogenation steps via proton transfer mechanism. This work was financially supported by the United States Department of Energy (DOE)’s Bioenergy Technologies Office (BETO) and performed at the Pacific Northwest National Laboratory (PNNL). PNNL is a multi-program national laboratory operated for DOE by Battelle Memorial Institute. Computing time and advanced catalyst characterization use was granted by a user proposal at the William R. Wiley
Characterising Dynamic Instability in High Water-Cut Oil-Water Flows Using High-Resolution Microwave Sensor Signals

Science.gov (United States)

Liu, Weixin; Jin, Ningde; Han, Yunfeng; Ma, Jing

2018-06-01

In the present study, multi-scale entropy algorithm was used to characterise the complex flow phenomena of turbulent droplets in high water-cut oil-water two-phase flow. First, we compared multi-scale weighted permutation entropy (MWPE), multi-scale approximate entropy (MAE), multi-scale sample entropy (MSE) and multi-scale complexity measure (MCM) for typical nonlinear systems. The results show that MWPE presents satisfied variability with scale and anti-noise ability. Accordingly, we conducted an experiment of vertical upward oil-water two-phase flow with high water-cut and collected the signals of a high-resolution microwave resonant sensor, based on which two indexes, the entropy rate and mean value of MWPE, were extracted. Besides, the effects of total flow rate and water-cut on these two indexes were analysed. Our researches show that MWPE is an effective method to uncover the dynamic instability of oil-water two-phase flow with high water-cut.
Phased Startup Initiative Phase 3 and 4 Test Procedure (OCRWM)

International Nuclear Information System (INIS)

PAJUNEN, A.L.

2000-01-01

The purpose of this test procedure is to safely operate the Fuel Retrieval System (FRS) and Integrated Water Treatment System (IWTS) with specific fuel canisters, and show that canisters containing fuel can be retrieved from the canister queue, decapped in the Canister Decapper, and loaded into the Primary Clean Machine (PCM) for fuel cleaning; and that fuel can be sorted on the Process Table, then loaded back into fuel canisters and relocated in basin storage. An option is included to load selected elements into multi-canister overpack (MCO) Fuel Baskets. Additional Data are collected during this test, beyond that collected during production operations. These data support qualifying the cleaning performance of the PCM, assessing the quantity of scrap generated during the cleaning, and evaluating the impact of fuel retrieval operations on the Basin water quality. The additional data collected primarily consist of weighing fuel and scrap at selected points in the operation, as well as photographing fuel and scrap as it is processed. The time to perform operations is also monitored for comparison with design predictions. Water quality data are collected to establish a baseline to predict the effectiveness of equipment design for control of contamination and visibility during production operation. The scope of this test procedure is to validate the operation of FRS and IWTS components as a complete system. Fuel canisters shall be processed in accordance with this test procedure such that fuel inspection results are clearly attributed to a particular set of PCM operating parameters. The Phase 3 test sequence processes a minimum of six canisters. Twenty-four contingency canisters have been identified, and will be processed if additional performance data are required. The Phase 4 test sequence processes a minimum of 29 specific canisters. Twenty-nine contingency canisters have been identified for Phase 4 activities and will be processed to complete process validation, if
Correlation of phase equilibria for water + hydrocarbon systems at high temperatures and pressures by cubic equation of state

Energy Technology Data Exchange (ETDEWEB)

Haruki, Masashi; Yahiro, Yukihito; Higashi, Hidenori; Iwai, Yoshio; Arai, Yasuhiko [Kyushu University, FUkuoka (Japan). Graduate School of Engineering

1999-08-01

A modified-Soave-Redlich-Kwong (MSRK) equation of state with an exponent-type mixing rule for the energy parameter and a conventional rule for the size parameter is applied to correlate the phase equilibria for four binary mixtures of water + hydrocarbon (benzene, hexane, decane, and dodecane) systems at high temperatures and pressures. It is noted that good correlation results are obtained by using the mixing rules with interaction parameters between unlike molecules. (author)
Water vapour tomography using GPS phase observations: Results from the ESCOMPTE experiment

Science.gov (United States)

Nilsson, T.; Gradinarsky, L.; Elgered, G.

2007-10-01

Global Positioning System (GPS) tomography is a technique for estimating the 3-D structure of the atmospheric water vapour using data from a dense local network of GPS receivers. Several current methods utilize estimates of slant wet delays between the GPS satellites and the receivers on the ground, which are difficult to obtain with millimetre accuracy from the GPS observations. We present results of applying a new tomographic method to GPS data from the Expériance sur site pour contraindre les modèles de pollution atmosphérique et de transport d'emissions (ESCOMPTE) experiment in southern France. This method does not rely on any slant wet delay estimates, instead it uses the GPS phase observations directly. We show that the estimated wet refractivity profiles estimated by this method is on the same accuracy level or better compared to other tomographic methods. The results are in agreement with earlier simulations, for example the profile information is limited above 4 km.
Subchannel analysis program for boiling water reactor fuel bundles based on five conservation equations of two-phase flow

International Nuclear Information System (INIS)

Bessho, Y.; Uchikawa, S.

1985-01-01

A subchannel analysis program, MENUETT, is developed for evaluation of thermal-hydraulic characteristics in boiling water reactor fuel bundles. This program is based on five conservation equations of two-phase flow with the drift-flux correlation. The cross flows are calculated separately for liquid and vapor phases from the lateral momentum conservation equation. The effects of turbulent mixing and void drift are accounted for in the program. The conservation equations are implicitly differentiated with the convective terms by the donor-cell method, and are solved iteratively in the axial and lateral directions. Data of the 3 X 3 rod bundle experiments are used for program verification. The lateral distributions of equilibrium quality and mass flow rate at the bundle exit calculated by the program compare satisfactorily with the experimental results
Determination of haloacetic acids in water using layered double hydroxides as a sorbent in dispersive solid-phase extraction followed by liquid chromatography with tandem mass spectrometry.

Science.gov (United States)

Alsharaa, Abdulnaser; Sajid, Muhammad; Basheer, Chanbasha; Alhooshani, Khalid; Lee, Hian Kee

2016-09-01

In the present study, highly efficient and simple dispersive solid-phase extraction procedure for the determination of haloacetic acids in water samples has been established. Three different types of layered double hydroxides were synthesized and used as a sorbent in dispersive solid-phase extraction. Due to the interesting behavior of layered double hydroxides in an acidic medium (pH˂4), the analyte elution step was not needed; the layered double hydroxides are simply dissolved in acid immediately after extraction to release the analytes which are then directly introduced into a liquid chromatography with tandem mass spectrometry system for analysis. Several dispersive solid-phase extraction parameters were optimized to increase the extraction efficiency of haloacetic acids such as temperature, extraction time and pH. Under optimum conditions, good linearity was achieved over the concentration range of 0.05-100 μg/L with detection limits in the range of 0.006-0.05 μg/L. The relative standard deviations were 0.33-3.64% (n = 6). The proposed method was applied to different water samples collected from a drinking water plant to determine the concentrations of haloacetic acids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Determination of diphenylether herbicides in water samples by solid-phase microextraction coupled to liquid chromatography.

Science.gov (United States)

Sheu, Hong-Li; Sung, Yu-Hsiang; Melwanki, Mahaveer B; Huang, Shang-Da

2006-11-01

Solid-phase microextraction (SPME) coupled to LC for the analysis of five diphenylether herbicides (aclonifen, bifenox, fluoroglycofen-ethyl, oxyfluorfen, and lactofen) is described. Various parameters of extraction of analytes onto the fiber (such as type of fiber, extraction time and temperature, pH, impact of salt and organic solute) and desorption from the fiber in the desorption chamber prior to separation (such as type and composition of desorption solvent, desorption mode, soaking time, and flush-out time) were studied and optimized. Four commercially available SPME fibers were studied. PDMS/divinylbenzene (PDMS/DVB, 60 microm) and carbowax/ templated resin (CW/TPR, 50 microm) fibers were selected due to better extraction efficiencies. Repeatability (RSD, 0.994), and detection limit (0.33-1.74 and 0.22-1.94 ng/mL, respectively, for PDMS/DVB and CW/TPR) were investigated. Relative recovery (81-104% for PDMS/DVB and 83-100% for CW/TPR fiber) values have also been calculated. The developed method was successfully applied to the analysis of river water and water collected from a vegetable garden.
Technical description of the test section SUCOT to investigate a water/steam two-phase flow

International Nuclear Information System (INIS)

Daubner, M.; Janssens-Maenhout, G.; Knebel, J.U.

2002-02-01

Within the POOLTHY Project of the European Union (Euratom Fourth Framework Programme contract FJ4J-CT95-0003) an active/passive concept (SUCO-Programme) was investigated which controls the heat removal after a potential core melt-down accident in an evolutionary light water reactor by spreading and stabilising the core melt in the reactor sump and flooding the melt with sump water from above. The experiments were performed in the test facility SUCOT which was designed and erected at the Institute for Nuclear and Energy Technologies (IKET). The report gives an overview on the SUCO-Programme and the scaling analysis, which was applied to design the test facility SUCOT. A detailed technical description of the test facility SUCOT is given, in which the natural circulation driven two-phase flow within the reactor sump and relevant phenomena such as flow boiling, disperse bubbly flow with and without mass transfer, and geysering are investigated. The major components of the test facility, the three-loop system and the instrumentation are described. Finally, a perspective for future application of the gained knowledge is given. (orig.) [de
A combined single-multiphase flow formulation of the premixing phase using the level set method

International Nuclear Information System (INIS)

Leskovar, M.; Marn, J.

1999-01-01

The premixing phase of a steam explosion covers the interaction of the melt jet or droplets with the water prior to any steam explosion occurring. To get a better insight of the hydrodynamic processes during the premixing phase beside hot premixing experiments, where the water evaporation is significant, also cold isothermal premixing experiments are performed. The specialty of isothermal premixing experiments is that three phases are involved: the water, the air and the spheres phase, but only the spheres phase mixes with the other two phases whereas the water and air phases do not mix and remain separated by a free surface. Our idea therefore was to treat the isothermal premixing process with a combined single-multiphase flow model. In this combined model the water and air phase are treated as a single phase with discontinuous phase properties at the water air interface, whereas the spheres are treated as usually with a multiphase flow model, where the spheres represent the dispersed phase and the common water-air phase represents the continuous phase. The common water-air phase was described with the front capturing method based on the level set formulation. In the level set formulation, the boundary of two-fluid interfaces is modeled as the zero set of a smooth signed normal distance function defined on the entire physical domain. The boundary is then updated by solving a nonlinear equation of the Hamilton-Jacobi type on the whole domain. With this single-multiphase flow model the Queos isothermal premixing Q08 has been simulated. A numerical analysis using different treatments of the water-air interface (level set, high-resolution and upwind) has been performed for the incompressible and compressible case and the results were compared to experimental measurements.(author)

Two-phase flow induced parametric vibrations in structural systems

International Nuclear Information System (INIS)

Hara, Fumio

1980-01-01

This paper is divided into two parts concerning piping systems and a nuclear fuel pin system. The significant experimental results concerning the random vibration induced in an L-shaped pipe by air-water two-phase flow and the theoretical analysis of the vibration are described in the first part. It was clarified for the first time that the parametric excitation due to the periodic changes of system mass, centrifugal force and Coriolis force was the mechanism of exciting the vibration. Moreover, the experimental and theoretical analyses of the mechanism of exciting vibration by air-water two-phase flow in a straight, horizontal pipe were carried out, and the first natural frequency of the piping system was strongly related to the dominant frequency of void signals. The experimental results on the vibration of a nuclear fuel pin model in parallel air-water two-phase flow are reported in the latter part. The relations between vibrational strain variance and two-phase flow velocity or pressure fluctuation, and the frequency characteristics of vibrational strain variance were obtained. The theoretical analysis of the dynamic interaction between air-water two-phase flow and a fuel pin structure, and the vibrational instability of fuel pins in alternate air and water slugs or in large bubble flow are also reported. (Kako, I.)
Microporous Carbon Spheres Solid Phase Membrane Tip Extraction for the Analysis of Nitrosamines in Water Samples

International Nuclear Information System (INIS)

Mohammed Salisu Musa; Wan Aini Wan Ibrahim

2015-01-01

A simple solid phase membrane tip extraction (SPMTE) utilizing microporous carbon spheres (MCS) was developed for the analysis of nitrosamines in aqueous samples. The method termed MCS-SPMTE was optimized for various important extraction parameters namely conditioning organic solvent, extraction time, effects of salt addition and pH change, desorption time, desorption solvent and sample volume. Under the optimized conditions, the method indicated good linearity in the range of 10-100 μg/ L with coefficients of determination, r 2 ≥0.9984. The method also demonstrated good reproducibility with % RSDs values ranging from 2.2 - 8.9 (n = 3). Limit of detection (LOD) and limit of quantification (LOQ) for the method ranged from 3.2 - 4.8 μg/ L and 10.9 - 15.9 μg/L respectively. Recoveries for both tap-water and lake water samples spiked at 10 μg/L were in the range of 83.2 - 107.5 %. (author)
Semi-permeable surface analytical reversed-phase column for the improved trace analysis of acidic pesticides in water with coupled-column reversed-phase liquid chromatography with UV detection. Determination of bromoxynil and bentazone in surface water.

Science.gov (United States)

Hogendoorn, E A; Westhuis, K; Dijkman, E; Heusinkveld, H A; den Boer, A C; Evers, E A; Baumann, R A

1999-10-08

The coupled-column (LC-LC) configuration consisting of a 3 microm C18 column (50 x 4.6 mm I.D.) as the first column and a 5 microm C18 semi-permeable-surface (SPS) column (150 x 4.6 mm I.D.) as the second column appeared to be successful for the screening of acidic pesticides in surface water samples. In comparison to LC-LC employing two C18 columns, the combination of C18/SPS-C18 significantly decreased the baseline deviation caused by the hump of the co-extracted humic substances when using UV detection (217 nm). The developed LC-LC procedure allowed the simultaneous determination of the target analytes bentazone and bromoxynil in uncleaned extracts of surface water samples to a level of 0.05 microg/l in less than 15 min. In combination with a simple solid-phase extraction step (200 ml of water on a 500 mg C18-bonded silica) the analytical procedure provides a high sample throughput. During a period of about five months more than 200 ditch-water samples originating from agricultural locations were analyzed with the developed procedure. Validation of the method was performed by randomly analyzing recoveries of water samples spiked at levels of 0.1 microg/l (n=10), 0.5 microg/l (n=7) and 2.5 microg/l (n=4). Weighted regression of the recovery data showed that the method provides overall recoveries of 95 and 100% for bentazone and bromoxynil, respectively, with corresponding intra-laboratory reproducibilities of 10 and 11%, respectively. Confirmation of the analytes in part of the samples extracts was carried out with GC-negative ion chemical ionization MS involving a derivatization step with bis(trifluoromethyl)benzyl bromide. No false negatives or positives were observed.
Sensing of phase transition in medium with terahertz pulsed spectroscopy

International Nuclear Information System (INIS)

Zaytsev, Kirill I; Fokina, Irina N; Fedorov, Aleksey K; Yurchenko, Stanislav O

2014-01-01

Phase state identification and phase transition registration in condensed matter are significant applications of terahertz spectroscopy. A set of fundamental and applied problems are associated with the phase state problem. Our report is devoted to the experimental analysis of the spectral characteristics of water and water solution during the phase transition from the solid state to the liquid state via the method of terahertz pulsed spectroscopy. In this work transformation of the sample spectral characteristics during the phase transition were observed and discussed. Possible application of terahertz pulsed spectroscopy as an effective instrument for phase transition sensing was considered
SINGLE-PHASE AND TWO-PHASE SECONDARY COOLANTS: SIMULATION AND EVALUATION OF THEIR THERMOPHYSICAL PROPERTIES

Directory of Open Access Journals (Sweden)

Pedro Samuel Gomes Medeiros

2011-09-01

Full Text Available This paper makes a comparative analysis of the thermophysical properties of ice slurry with conventional single-phase secondary fluids used in thermal storage cooling systems. The ice slurry is a two-phase fluid consisting of water, antifreeze and ice crystals. It is a new technology that has shown great energy potential. In addition to transporting energy as a heat transfer fluid, it has thermal storage properties due to the presence of ice, storing coolness by latent heat of fusion. The single-phase fluids analyzed are water-NaCl and water-propylene glycol solutions, which also operate as carrier fluids in ice slurry. The presence of ice changes the thermophysical properties of aqueous solutions and a number of these properties were determined: density, thermal conductivity and dynamic viscosity. Data were obtained by software simulation. The results show that the presence of 10% by weight of ice provides a significant increase in thermal conductivity and dynamic viscosity, without causing changes in density. The rheological behavior of ice slurries, associated with its high viscosity, requires higher pumping power; however, this was not significant because higher thermal conductivity allows a lower mass flow rate without the use of larger pumps. Thus, the ice slurry ensures its high potential as a secondary fluid in thermal storage cooling systems, proving to be more efficient than single-phase secondary fluids.
A Thermomechanical Transport Approach and Application in Soil-Water System of Polluted Mining Areas considering the Three-Phase Coupling

Directory of Open Access Journals (Sweden)

Xuan Guo

2016-01-01

Full Text Available The thermomechanical transport approach includes the process of diffusing or the condition of being diffused, absorption/desorption, swell/shrink, equilibrium/nonequilibrium, and thermomechanical transport of contaminant in three phases of polluted mining soil which are discussed. The thermomechanical transport model of the contaminants transport in polluted soil is established, and its basic equations are given. Based on that, the distribution regularities of the contaminant seepage in water-soil system are discussed in detail and the sensitivities of parameters are analyzed. The study shows that the parameter has important influence on the contamination distribution and transportation in polluted soil-water system. The influence degree is also related to the action of seepage force directly.
Two-phase flow characterisation by nuclear magnetic resonance

International Nuclear Information System (INIS)

Leblond, J.; Javelot, S.; Lebrun, D.; Lebon, L.

1998-01-01

The results presented in this paper demonstrate the performance of the PFGSE-NMR to obtain a complete characterisation of two-phase flows. Different methods are proposed to characterise air-water flows in different regimes: stationary two-phase flows and flows in transient condition. Finally a modified PFGSE is proposed to analyse the turbulence of air-water bubbly flow. (author)
Evaluation of Water Security in Kathmandu Valley before and after Water Transfer from another Basin

Directory of Open Access Journals (Sweden)

Bhesh Raj Thapa

2018-02-01

Full Text Available Kathmandu Upatyaka Khanepani Limited (KUKL has planned to harness water from outside the valley from Melamchi as an inter-basin project to supply water inside the ring road (core valley area of the Kathmandu Valley (KV. The project, called the “Melamchi Water Supply Project (MWSP”, is expected to have its first phase completed by the end of September 2018 and its second phase completed by the end of 2023 to supply 170 MLD (million liters a day through the first phase and an additional 340 MLD through the second phase. The area has recently faced a severe water deficit and KUKL’s existing infrastructure has had a limited capability, supplying only 19% of the water that is demanded in its service areas during the dry season and 31% during the wet season. In this context, this study aims to assess the temporal trends and spatial distribution of household water security index (WSI, defined as a ratio of supply to demand for domestic water use for basic human water requirements (50 L per capita per day (lpcd and economic growth (135 lpcd as demand in pre- and post-MWSP scenarios. For this purpose, data on water demand and supply with infrastructure were used to map the spatial distribution of WSI and per capita water supply using ArcMap. Results show a severe water insecurity condition in the year 2017 in all KUKL service areas (SAs, which is likely to improve after completion of the MWSP. It is likely that recent distribution network and strategies may lead to inequality in water distribution within the SAs. This can possibly be addressed by expanding existing distribution networks and redistributing potable water, which can serve an additional 1.21 million people in the area. Service providers may have to develop strategies to strengthen a set of measures including improving water supply infrastructures, optimizing water loss, harnessing additional water from hills, and managing water within and outside the KUKL SAs in the long run to cover
Hollow fiber based liquid-phase microextraction for the determination of mercury traces in water samples by electrothermal atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Lopez-Garcia, Ignacio; Rivas, Ricardo E. [Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence ' Campus Mare Nostrum' , University of Murcia, E-30071 Murcia (Spain); Hernandez-Cordoba, Manuel, E-mail: hcordoba@um.es [Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence ' Campus Mare Nostrum' , University of Murcia, E-30071 Murcia (Spain)

2012-09-19

Highlight: Black-Right-Pointing-Pointer Hg (II) traces are preconcentrated by means of a three-phase liquid microextraction system. Black-Right-Pointing-Pointer PAN and ammonium iodide are used in the donor and acceptor phase, respectively. Black-Right-Pointing-Pointer Hollow-fiber pores are continuously fed with toluene placed in the lumen. Black-Right-Pointing-Pointer Mercuric ions can be measured in waters below the {mu}g L{sup -1} level. - Abstract: A three-phase liquid microextraction procedure for the determination of mercury at low concentrations is discussed. To the aqueous sample placed at pH 7 by means of a phosphate buffer, 0.002% (m/v) 1-(2-pyridylazo)-2-naphthol (PAN) is incorporated, and the mixture submitted to microextraction with a hollow-fiber impregnated with toluene and whose lumen contains a 0.05 mol L{sup -1} ammonium iodide solution. The final measurement of the extract is carried out by electrothermal atomic absorption spectrometry (300 Degree-Sign C and 1100 Degree-Sign C for the calcination and atomization temperatures, respectively). The pyrolytic graphite atomizer is coated electrolytically with palladium. An enrichment factor of 270, which results in a 0.06 {mu}g L{sup -1} mercury for the detection limit is obtained. The relative standard deviation at the 1 {mu}g L{sup -1} mercury level is 3.2% (n = 5). The reliability of the procedure is verified by analyzing waters as well as six certified reference materials.
New definition of Regulated Deficit Irrigation phases in pistachio: more sustainable, more efficient

Science.gov (United States)

Pérez-López, David; Moreno, Marta M.; Memmi, Houssem; Guerrero, Julián; Galindo, Alejandro; Centeno, Ana; Corell, Mireilla; Giron, Ignacio; José Martín-Palomo, María; Gijón, Mª Carmen; Moreno, Carmen; Torrecillas, Arturo; Moriana, Alfonso

2017-04-01

Regulated Deficit Irrigation (RDI) is an irrigation methodology in which a water stress is imposed by irrigation withholding in function of fruit growth phases. The objective of this method is to found phases where water stress has no effect on yield or only a slight effect. RDI in pistachio has been demonstrated as an efficient tool to save water without negative effect on yield, or even the contrary, a slight water stress has produced pistachios more appreciated by consumers opposite to well irrigated. Phases of fruit growth are widely defined as: Phase I, from leaf out to full shell expansion; Phase II, from full shell expansion to the onset of rapid kernel growth; Phase III, from rapid growth to harvest. Water stress applied in Phase II does not affect yield. Traditionally Phase II had been considered interchangeable with shell hardening; however, recent studies have showed that shell hardening extends for two weeks from the beginning of the kernel growth. In this assay, conducted in Ciudad Real (Spain) in 2015 and 2016, different irrigation treatments were applied on a pistachio crop in order to check if shell hardening can be considered as phase II instead the previous definition. The T1 treatment consisted of water stress during the shell hardening, always trying to maintain a stem water potential (SWP) of -1.5 MPa during this phase. The T2 treatment was severely water stressed, in this case trying to maintain -2 MPa during the phase II, as previous definition. In the rest of the season, both treatments were irrigated in order to have no water stress. Additionally, a control treatment (T0), irrigated following FAO methodology, was stablished to evaluate the loss of yield. Water irrigation applied in T0 was 596 and 505 mm in 2015 and 2016, respectively. In T1, 317 and 245 mm were applied, respectively, which means an average water save about 270 mm year-1. In T2, water irrigation was 396 and 272 mm, respectively, higher amounts than in T1, which an average
Preconcentration of uranium in water samples using dispersive liquid-liquid micro- extraction coupled with solid-phase extraction and determination with inductively coupled plasma-optical emission spectrometry

Directory of Open Access Journals (Sweden)

M. Rezaee,

2015-10-01

Full Text Available A new liquid phase microextraction method based on the dispersion of an extraction solvent into aqueous phase coupled with solid-phase extraction was investigated for the extraction, preconcentration and determination of uranium in water samples. 1-(2-Pyridylazo-2-naphthol reagent (PAN at pH 6.0 was used as a chelating agent prior to extraction. After concentration and purification of the samples in SPE C18 sorbent, 1.5 mL elution sample containing 40.0 µL chlorobenzene was injected into the 5.0 mL pure water. After extraction and centrifuging, the sedimented phase was evaporated and the residue was dissolved in nitric acid (0.5 M and was injected by injection valve into the ICP-OES. Some important extraction parameters, such as sample solution flow rate, sample pH, type and volume of extraction and disperser solvents as well as the salt addition were studied and optimized. Under the optimum conditions, the calibration graph was linear in the range of 0.5-500 µg L-1. The detection limit was 0.1 µg L-1. The relative standard deviation (RSD at 5.0 µg L-1 concentration level was 6.6%. Finally, the developed method was successfully applied to the extraction and determination of uranium in the well, river, mineral, waste and tap water samples and satisfactory results were obtained.DOI: http://dx.doi.org/10.4314/bcse.v29i3.4
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.
Determining octanol-water partition coefficients for extremely hydrophobic chemicals by combining "slow stirring" and solid-phase microextraction.

Science.gov (United States)

Jonker, Michiel T O

2016-06-01

Octanol-water partition coefficients (KOW ) are widely used in fate and effects modeling of chemicals. Still, high-quality experimental KOW data are scarce, in particular for very hydrophobic chemicals. This hampers reliable assessments of several fate and effect parameters and the development and validation of new models. One reason for the limited availability of experimental values may relate to the challenging nature of KOW measurements. In the present study, KOW values for 13 polycyclic aromatic hydrocarbons were determined with the gold standard "slow-stirring" method (log KOW 4.6-7.2). These values were then used as reference data for the development of an alternative method for measuring KOW . This approach combined slow stirring and equilibrium sampling of the extremely low aqueous concentrations with polydimethylsiloxane-coated solid-phase microextraction fibers, applying experimentally determined fiber-water partition coefficients. It resulted in KOW values matching the slow-stirring data very well. Therefore, the method was subsequently applied to a series of 17 moderately to extremely hydrophobic petrochemical compounds. The obtained KOW values spanned almost 6 orders of magnitude, with the highest value measuring 10(10.6) . The present study demonstrates that the hydrophobicity domain within which experimental KOW measurements are possible can be extended with the help of solid-phase microextraction and that experimentally determined KOW values can exceed the proposed upper limit of 10(9) . Environ Toxicol Chem 2016;35:1371-1377. © 2015 SETAC. © 2015 SETAC.
Simultaneous separation and analysis of water- and fat-soluble vitamins on multi-modal reversed-phase weak anion exchange material by HPLC-UV.

Science.gov (United States)

Dabre, Romain; Azad, Nazanin; Schwämmle, Achim; Lämmerhofer, Michael; Lindner, Wolfgang

2011-04-01

Several methods for the separation of vitamins on HPLC columns were already validated in the last 20 years. However, most of the techniques focus on separating either fat- or water-soluble vitamins and only few methods are intended to separate lipophilic and hydrophilic vitamins simultaneously. A mixed-mode reversed-phase weak anion exchange (RP-WAX) stationary phase was developed in our laboratory in order to address such mixture of analytes with different chemical characteristics, which are difficult to separate on standard columns. The high versatility in usage of the RP-WAX chromatographic material allowed a baseline separation of ten vitamins within a single run, seven water-soluble and three fat-soluble, using three different chromatographic modes: some positively charged vitamins are eluted in ion exclusion and ion repulsion modes whereas the negatively charged molecules are eluted in the ion exchange mechanism. The non-charged molecules are eluted in a classical reversed-phase mode, regarding their polarities. The method was validated for the vitamin analysis in tablets, evaluating selectivity, robustness, linearity, accuracy, and precision. The validated method was finally employed for the analysis of the vitamin content of some commercially available supplement tablets. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Pre-Service Primary Science Teachers' Understandings of the Effect of Temperature and Pressure on Solid-Liquid Phase Transition of Water

Science.gov (United States)

Yalcin, Fatma Aggul

2012-01-01

The aim of this study was to explore pre-service primary teachers' understandings of the effect of temperature and pressure on the solid-liquid phase transition of water. In the study a survey approach was used, and the sample consisted of one-hundred and three, third year pre-service primary science teachers. As a tool for data collection, a test…
Phase I of the Kissimmee River restoration project, Florida, USA: impacts of construction on water quality.

Science.gov (United States)

Colangelo, David J; Jones, Bradley L

2005-03-01

Phase I of the Kissimmee River restoration project included backfilling of 12 km of canal and restoring flow through 24 km of continuous river channel. We quantified the effects of construction activities on four water quality parameters (turbidity, total phosphorus flow-weighted concentration, total phosphorus load and dissolved oxygen concentration). Data were collected at stations upstream and downstream of the construction and at four stations within the construction zone to determine if canal backfilling and construction of 2.4 km of new river channel would negatively impact local and downstream water quality. Turbidity levels at the downstream station were elevated for approximately 2 weeks during the one and a half year construction period, but never exceeded the Florida Department of Environmental Protection construction permit criteria. Turbidity levels at stations within the construction zone were high at certain times. Flow-weighted concentration of total phosphorus at the downstream station was slightly higher than the upstream station during construction, but low discharge limited downstream transport of phosphorus. Total phosphorus loads at the upstream and downstream stations were similar and loading to Lake Okeechobee was not significantly affected by construction. Mean water column dissolved oxygen concentrations at all sampling stations were similar during construction.
Stable water isotope simulation by current land-surface schemes:Results of IPILPS phase 1

Energy Technology Data Exchange (ETDEWEB)

Henderson-Sellers, A.; Fischer, M.; Aleinov, I.; McGuffie, K.; Riley, W.J.; Schmidt, G.A.; Sturm, K.; Yoshimura, K.; Irannejad, P.

2005-10-31

Phase 1 of isotopes in the Project for Intercomparison of Land-surface Parameterization Schemes (iPILPS) compares the simulation of two stable water isotopologues ({sup 1}H{sub 2} {sup 18}O and {sup 1}H{sup 2}H{sup 16}O) at the land-atmosphere interface. The simulations are off-line, with forcing from an isotopically enabled regional model for three locations selected to offer contrasting climates and ecotypes: an evergreen tropical forest, a sclerophyll eucalypt forest and a mixed deciduous wood. Here we report on the experimental framework, the quality control undertaken on the simulation results and the method of intercomparisons employed. The small number of available isotopically-enabled land-surface schemes (ILSSs) limits the drawing of strong conclusions but, despite this, there is shown to be benefit in undertaking this type of isotopic intercomparison. Although validation of isotopic simulations at the land surface must await more, and much more complete, observational campaigns, we find that the empirically-based Craig-Gordon parameterization (of isotopic fractionation during evaporation) gives adequately realistic isotopic simulations when incorporated in a wide range of land-surface codes. By introducing two new tools for understanding isotopic variability from the land surface, the Isotope Transfer Function and the iPILPS plot, we show that different hydrological parameterizations cause very different isotopic responses. We show that ILSS-simulated isotopic equilibrium is independent of the total water and energy budget (with respect to both equilibration time and state), but interestingly the partitioning of available energy and water is a function of the models' complexity.
Water, water everywhere

International Nuclear Information System (INIS)

Moxon, Suzanne

1999-01-01

Although there is an abundance of water in Lesotho, it is argued that future development of the Lesotho Highlands water project is not yet required. Lesotho exports water to arid regions in South Africa. However, some South Africans believe that further development of the scheme is unnecessary and they argue that Gauteng Province has enough water for the immediate future provided the demand is managed effectively - this being the case, there would be no urgency for completing what is termed phase 1B. It is argued that if 1B is completed before the water is required, then costs to the consumer would increase. It was also argued that proceeding with 1B would give South Africa greater flexibility in augmenting supply to the Vaal river system. Some disadvantages to Lesotho if 1B does not proceed would be loss of royalties and job opportunities and a curb on development of its infrastructure
Preconcentration and Determination of Perfluoroalkyl Substances (PFASs in Water Samples by Bamboo Charcoal-Based Solid-Phase Extraction Prior to Liquid Chromatography–Tandem Mass Spectrometry

Directory of Open Access Journals (Sweden)

Ze-Hui Deng

2018-04-01

Full Text Available In this work, bamboo charcoal was used as solid-phase extraction adsorbent for the enrichment of six perfluoroalkyl acids (PFAAs in environmental water samples before liquid chromatography–tandem mass spectrometry analysis. The specific porous structure, high specific surface area, high porosity, and stability of bamboo charcoal were characterized. Several experimental parameters which considerably affect extraction efficiency were investigated and optimized in detail. The experimental data exhibited low limits of detection (LODs (0.01–1.15 ng/L, wide linear range (2–3 orders of magnitude and R ≥ 0.993 within the concentration range of 0.1–1000 ng/L, and good repeatability (2.7–5.0%, n = 5 intraday and 4.8–8.3%, n = 5 interday and reproducibility (5.3–8.0%, n = 3. Bamboo charcoal was successfully used for the enrichment and determination of PFAAs in real environmental water samples. The bamboo charcoal-based solid-phase extraction coupled with liquid chromatography–tandem mass spectrometry analysis possessed great potential in the determination of trace PFAA levels in environmental water samples.
Tritium distribution ratios between the 30 % tributyl phosphate(TBP)-normal dodecane(nDD) organic phase and uranyl nitrate-nitric acid aqueous phase

International Nuclear Information System (INIS)

Fujine, Sachio; Uchiyama, Gunzou; Sugikawa, Susumu; Maeda, Mitsuru; Tsujino, Takeshi.

1989-10-01

Tritium distribution ratios between the organic and aqueous phases were measured for the system of 30 % tributyl phosphate(TBP)-normal dodecane(nDD)/uranyl nitrate-nitric acid water. It was confirmed that tritium is extracted by TBP into the organic phase in both chemical forms of tritiated water (HTO) and tritiated nitric acid (TNO 3 ). The value of tritium distribution ratio ranged from 0.002 to 0.005 for the conditions of 0-6 mol/L nitric acid, 0.5-800 mCi/L tritium in aqueous phase, and 0-125 g-U/L uranium in organic phase. Isotopic distribution coefficient of tritium between the organic and aqueous phases was observed to be about 0.95. (author)

Solution phase and membrane immobilized iron-based free radical reactions: Fundamentals and applications for water treatment

Science.gov (United States)

Lewis, Scott Romak

Membrane-based separation processes have been used extensively for drinking water purification, wastewater treatment, and numerous other applications. Reactive membranes synthesized through functionalization of the membrane pores offer enhanced reactivity due to increased surface area at the polymer-solution interface and low diffusion limitations. Oxidative techniques utilizing free radicals have proven effective for both the destruction of toxic organics and non-environmental applications. Most previous work focuses on reactions in the homogeneous phase; however, the immobilization of reactants in membrane pores offers several advantages. The use of polyanions immobilized in a membrane or chelates in solution prevents ferric hydroxide precipitation at near-neutral pH, a common limitation of iron(Fe(II/III))-catalyzed hydrogen peroxide (H 2O2) decomposition. The objectives of this research are to develop a membrane-based platform for the generation of free radicals, degrade toxic organic compounds using this and similar solution-based reactions, degrade toxic organic compounds in droplet form, quantify hydroxyl radical production in these reactions, and develop kinetic models for both processes. In this study, a functionalized membrane containing poly(acrylic acid) (PAA) was used to immobilize iron ions and conduct free radical reactions by permeating H2O2 through the membrane. The membrane's responsive behavior to pH and divalent cations was investigated and modeled. The conversion of Fe(II) to Fe(III) in the membrane and its effect on the decomposition of hydrogen peroxide were monitored and used to develop kinetic models for predicting H2O2 decomposition in these systems. The rate of hydroxyl radical production, and hence contaminant degradation can be varied by changing the residence time, H2O2 concentration, and/or iron loading. Using these membrane-immobilized systems, successful removal of toxic organic compounds, such as pentachlorophenol (PCP), from water
Three-phase flow analysis of dense nonaqueous phase liquid infiltration in horizontally layered porous media

NARCIS (Netherlands)

Wipfler, E.L.; Dijke, van M.I.J.; Zee, van der S.E.A.T.M.

2004-01-01

We considered dense nonaqueous phase liquid (DNAPL) infiltration into a water-unsaturated porous medium that consists of two horizontal layers, of which the top layer has a lower intrinsic permeability than the bottom layer. DNAPL is the intermediate-wetting fluid with respect to the wetting water
Phase transitions and dynamics of bulk and interfacial water

International Nuclear Information System (INIS)

Franzese, G; Hernando-Martinez, A; Kumar, P; Mazza, M G; Stokely, K; Strekalova, E G; Stanley, H E; De los Santos, F

2010-01-01

New experiments on water at the surface of proteins at very low temperature display intriguing dynamic behaviors. The extreme conditions of these experiments make it difficult to explore the wide range of thermodynamic state points needed to offer a suitable interpretation. Detailed simulations suffer from the same problem, where equilibration times at low temperature become extremely long. We show how Monte Carlo simulations and mean field calculations using a tractable model of water help interpret the experimental results. Here we summarize the results for bulk water and investigate the thermodynamic and dynamic properties of supercooled water at an interface.
Phase transitions and dynamics of bulk and interfacial water

Energy Technology Data Exchange (ETDEWEB)

Franzese, G; Hernando-Martinez, A [Departament de Fisica Fonamental, Universitat de Barcelona, Diagonal 647, Barcelona 08028 (Spain); Kumar, P [Center for Studies in Physics and Biology, Rockefeller University, 1230 York Avenue, New York, NY 10021 (United States); Mazza, M G; Stokely, K; Strekalova, E G; Stanley, H E [Center for Polymer Studies and Department of Physics, Boston University, Boston, MA 02215 (United States); De los Santos, F, E-mail: gfranzese@ub.ed [Departamento de Electromagnetismo y Fisica de la Materia, Universidad de Granada, Fuentenueva s/n, 18071 Granada (Spain)

2010-07-21

New experiments on water at the surface of proteins at very low temperature display intriguing dynamic behaviors. The extreme conditions of these experiments make it difficult to explore the wide range of thermodynamic state points needed to offer a suitable interpretation. Detailed simulations suffer from the same problem, where equilibration times at low temperature become extremely long. We show how Monte Carlo simulations and mean field calculations using a tractable model of water help interpret the experimental results. Here we summarize the results for bulk water and investigate the thermodynamic and dynamic properties of supercooled water at an interface.
Three dimensional turbulence structure measurements in air/water two phase flow

International Nuclear Information System (INIS)

Wang, S.K.L.

1986-01-01

The phenomena of turbulent air/water two phase upward and downward flows in a circular test section were investigated. Important flow quantities such as void fraction, liquid velocity, and Reynolds stresses were measured by using both single sensor and three sensor hot film probes. A digital data processing technique based on combined derivative and level thresholding was developed to determine the local void fraction from hot-film anemometer signals. The measured local void fraction was integrated and the result was compared with the chordal averaged void fraction measured by a gamma ray densitometer. It was found that the local measurement underestimated local void fraction due to surface tension effects and bubble deflection by the probe. A correlation based on local parameters characterizing probe/bubble interaction was developed, and it corrected the measured void fraction successfully. The measured void fraction profiles in upward flow and downward flow showed two distinct patterns. In upward flow, bubbles tend to migrate toward the wall and the void fraction profile shows a sharp peak near the wall. In downward flow, as the liquid velocity increases, the wall peaking phenomenon fades out and bubbles tend to migrate toward the center of the pipe
Long Term Field Development of a Surfactant Modified Zeolite/Vapor Phase Bioreactor System for Treatment of Produced Waters for Power Generation

Energy Technology Data Exchange (ETDEWEB)

Lynn Katz; Kerry Kinney; Robert Bowman; Enid Sullivan; Soondong Kwon; Elaine Darby; Li-Jung Chen; Craig Altare

2007-12-31

The main goal of this research was to investigate the feasibility of using a combined physicochemical/biological treatment system to remove the organic constituents present in saline produced water. In order to meet this objective, a physical/chemical adsorption process was developed and two separate biological treatment techniques were investigated. Two previous research projects focused on the development of the surfactant modified zeolite adsorption process (DE-AC26-99BC15221) and development of a vapor phase biofilter (VPB) to treat the regeneration off-gas from the surfactant modified zeolite (SMZ) adsorption system (DE-FC26-02NT15461). In this research, the SMZ/VPB was modified to more effectively attenuate peak loads and to maintain stable biodegradation of the BTEX constituents from the produced water. Specifically, a load equalization system was incorporated into the regeneration flow stream. In addition, a membrane bioreactor (MBR) system was tested for its ability to simultaneously remove the aromatic hydrocarbon and carboxylate components from produced water. The specific objectives related to these efforts included the following: (1) Optimize the performance VPBs treating the transient loading expected during SMZ regeneration: (a) Evaluate the impact of biofilter operating parameters on process performance under stable operating conditions. (b) Investigate how transient loads affect biofilter performance, and identify an appropriate technology to improve biological treatment performance during the transient regeneration period of an SMZ adsorption system. (c) Examine the merits of a load equalization technology to attenuate peak VOC loads prior to a VPB system. (d) Evaluate the capability of an SMZ/VPB to remove BTEX from produced water in a field trial. (2) Investigate the feasibility of MBR treatment of produced water: (a) Evaluate the biodegradation of carboxylates and BTEX constituents from synthetic produced water in a laboratory-scale MBR. (b
Water in the Gas Phase.

Science.gov (United States)

1998-06-01

Valentin, Ch. Claveau A.D. Bykov, N.N. Lavrentieva, VN. Saveliev , L.N. Sinitsa « THE TCPE MANY-BODY MODEL FOR WATER » 79 M. Masella and J-P. Flament...Laboratoire de Physique Moleculaire et Applications, CNRS Universite Pierre et Marie Curie, Paris, France. A.D. Bykov, N.N. Lavrentieva, V.N. Saveliev , L.N...T19 Lozada M. T4 Rothman L.S. T22 Lutz B. L. T33 Ruiz J. P24 Lynch R. P3 Sadlej A. T5 Lynden-Bell R. M. P8 Saveliev V.N. P4 Maemets V. P18 Saykally
Investigation of two-phase flow structure in model of draught pipe of water boiling reactor VK-300

International Nuclear Information System (INIS)

Efanov, A.D.; Kuznetzov, Y.N.; Kaliakin, S.G.; Lisitza, F.D.; Remizov, O.V.; Serdun, N.P.

2001-01-01

VK-300 reactor represents a vessel-type boiling reactor with integral arrangement of assemblies and in-vessel steam separation at one-circuit scheme. The circuit consists of core, draught pipes, and separation facilities. The vessel of VK-300 reactor is chosen on the base of the dimensions of that of VVER-1000 reactor. The following thermal-hydraulic parameters of nuclear power plant (NPP) were investigated experimentally: dependence of void fraction upon the steam quality in mixing chamber (on the draught section input); pressure losses at different, specific zones of up-flow and down-flow sections of the circuit with free circulation; degree of steam separation in the separating chamber (at the first step of phase separation) and its dependence upon steam quality; structure of steam-water flow in draught pipes (distribution of phases over the draught pipe cross- section); presence of steam hovering and height of this hovering in inter-pipe space of draught section. (author)
Design of a surface-based factory for the production of life support and technology support products. Phase 2: Integrated water system for a space colony

Science.gov (United States)

1989-01-01

Phase 2 of a conceptual design of an integrated water treatment system to support a space colony is presented. This includes a breathable air manufacturing system, a means of drilling for underground water, and storage of water for future use. The system is to supply quality water for biological consumption, farming, residential and industrial use and the water source is assumed to be artesian or subsurface and on Mars. Design criteria and major assumptions are itemized. A general block diagram of the expected treatment system is provided. The design capacity of the system is discussed, including a summary of potential users and the level of treatment required; and, finally, various treatment technologies are described.
Process for removing sulfate anions from waste water

Science.gov (United States)

Nilsen, David N.; Galvan, Gloria J.; Hundley, Gary L.; Wright, John B.

1997-01-01

A liquid emulsion membrane process for removing sulfate anions from waste water is disclosed. The liquid emulsion membrane process includes the steps of: (a) providing a liquid emulsion formed from an aqueous strip solution and an organic phase that contains an extractant capable of removing sulfate anions from waste water; (b) dispersing the liquid emulsion in globule form into a quantity of waste water containing sulfate anions to allow the organic phase in each globule of the emulsion to extract and absorb sulfate anions from the waste water and (c) separating the emulsion including its organic phase and absorbed sulfate anions from the waste water to provide waste water containing substantially no sulfate anions.
Polymers as reference partitioning phase: polymer calibration for an analytically operational approach to quantify multimedia phase partitioning

DEFF Research Database (Denmark)

Gilbert, Dorothea; Witt, Gesine; Smedes, Foppe

2016-01-01

Polymers are increasingly applied for the enrichment of hydrophobic organic chemicals (HOCs) from various types of samples and media in many analytical partitioning-based measuring techniques. We propose using polymers as a reference partitioning phase and introduce polymer-polymer partitioning......-air) and multimedia partition coefficients (lipid-water, air-water) were calculated by applying the new concept of a polymer as reference partitioning phase and by using polymer-polymer partition coefficients as conversion factors. The present study encourages the use of polymer-polymer partition coefficients...
Determination of polycyclic aromatic hydrocarbons in drinking water samples by solid-phase nanoextraction and high-performance liquid chromatography.

Science.gov (United States)

Wang, Huiyong; Campiglia, Andres D

2008-11-01

A novel alternative is presented for the extraction and preconcentration of polycyclic aromatic hydrocarbons (PAH) from water samples. The new approachwhich we have named solid-phase nanoextraction (SPNE)takes advantage of the strong affinity that exists between PAH and gold nanoparticles. Carefully optimization of experimental parameters has led to a high-performance liquid chromatography method with excellent analytical figures of merit. Its most striking feature correlates to the small volume of water sample (500 microL) for complete PAH analyses. The limits of detection ranged from 0.9 (anthracene) to 58 ng.L (-1) (fluorene). The relative standard deviations at medium calibration concentrations vary from 3.2 (acenaphthene) to 9.1% (naphthalene). The analytical recoveries from tap water samples of the six regulated PAH varied from 83.3 +/- 2.4 (benzo[ k]fluoranthene) to 95.7 +/- 4.1% (benzo[ g,h,i]perylene). The entire extraction procedure consumes less than 100 microL of organic solvents per sample, which makes it environmentally friendly. The small volume of extracting solution makes SPNE a relatively inexpensive extraction approach.
Photoionization-induced water migration in the amide group of trans-acetanilide-(H2O)1 in the gas phase.

Science.gov (United States)

Sakota, Kenji; Harada, Satoshi; Shimazaki, Yuiga; Sekiya, Hiroshi

2011-02-10

IR-dip spectra of trans-acetanilide-water 1:1 cluster, AA-(H(2)O)(1), have been measured for the S(0) and D(0) state in the gas phase. Two structural isomers, where a water molecule binds to the NH group or the CO group of AA, AA(NH)-(H(2)O)(1) and AA(CO)-(H(2)O)(1), are identified in the S(0) state. One-color resonance-enhanced two-photon ionization, (1 + 1) RE2PI, of AA(NH)-(H(2)O)(1) via the S(1)-S(0) origin generates [AA(NH)-(H(2)O)(1)](+) in the D(0) state, however, photoionization of [AA(CO)-(H(2)O)(1)] does not produce [AA(CO)-(H(2)O)(1)](+), leading to [AA(NH)-(H(2)O)(1)](+). This observation explicitly indicates that the water molecule in [AA-(H(2)O)(1)](+) migrates from the CO group to the NH group in the D(0) state. The reorganization of the charge distribution from the neutral to the D(0) state of AA induces the repulsive force between the water molecule and the CO group of AA(+), which is the trigger of the water migration in [AA-(H(2)O)(1)](+).
An example of transition from a corrosion process in gaseous phase to corrosion in aqueous environment: the case of Z2CN18-10 stainless steel by iodine and water in vapour phase

International Nuclear Information System (INIS)

Mathieu, Bruno

1990-01-01

This research thesis addresses an example of transition of a corrosion process in gaseous phase towards corrosion in aqueous environment, specifically in the case of the corrosion of the Z2CN18-10 stainless steel by gaseous iodine in presence of water vapour (and possibly nitrogen dioxide). This transition occurs in two steps: initiation in gaseous phase and growth in aqueous environment. This transition is due to hygroscopic properties of mostly chromium iodides and, to a lesser extent, iron iodides. Morphological, electrochemical and thermogravimetry studies have been performed by varying different parameters governing corrosion processes: corrosion temperature, iodine concentration, relative humidity, and reaction time [fr
Equations of State and Phase Diagrams of Ammonia

Science.gov (United States)

Glasser, Leslie

2009-01-01

We present equations of state relating the phases and a three-dimensional phase diagram for ammonia with its solid, liquid, and vapor phases, based on fitted authentic experimental data and including recent information on the high-pressure solid phases. This presentation follows similar articles on carbon dioxide and water published in this…
New theoretical model for two-phase flow discharged from stratified two-phase region through small break

International Nuclear Information System (INIS)

Yonomoto, Taisuke; Tasaka, Kanji

1988-01-01

A theoretical and experimental study was conducted to understand two-phase flow discharged from a stratified two-phase region through a small break. This problem is important for an analysis of a small break loss-of-coolant accident (LOCA) in a light water reactor (LWR). The present theoretical results show that a break quality is a function of h/h b , where h is the elevation difference between a bulk water level in the upstream region and break and b the suffix for entrainment initiation. This result is consistent with existing eperimental results in literature. An air-water experiment was also conducted changing a break orientation as an experimental parameter to develop and assess the model. Comparisons between the model and the experimental results show that the present model can satisfactorily predict the flow rate and the quality at the break without using any adjusting constant when liquid entrainment occurs in a stratified two-phase region. When gas entrainment occurs, the experimental data are correlated well by using a single empirical constant. (author)
A multi-residue method for the analysis of pesticides and pesticide degradates in water using HLB solid-phase extraction and gas chromatography-ion trap mass spectrometry

Science.gov (United States)

Hladik, M.L.; Smalling, K.L.; Kuivila, K.M.

2008-01-01

A method was developed for the analysis of over 60 pesticides and degradates in water by HLB solid-phase extraction and gas-chromatography/mass spectrometry. Method recoveries and detection limits were determined using two surface waters with different dissolved organic carbon (DOC) concentrations. In the lower DOC water, recoveries and detection limits were 80%-108% and 1-12 ng/L, respectively. In the higher DOC water, the detection limits were slightly higher (1-15 ng/L). Additionally, surface water samples from four sites were analyzed and 14 pesticides were detected with concentrations ranging from 4 to 1,200 ng/L. ?? 2008 Springer Science+Business Media, LLC.
[State of Fungal Lipases of Rhizopus microsporus, Penicillium sp. and Oospora lactis in Border Layers Water-Solid Phase and Factors Affecting Catalytic Properties of Enzymes].

Science.gov (United States)

Khasanov, Kh T; Davranov, K; Rakhimov, M M

2015-01-01

We demonstrated that a change in the catalytic activity of fungal lipases synthesized by Rhizopus microsporus, Penicillium sp. and Oospora lactis and their ability to absorb on different sorbents depended on the nature of groups on the solid phase surface in the model systems water: lipid and water: solid phase. Thus, the stability of Penicillium sp. lipases increased 85% in the presence ofsorsilen or DEAE-cellulose, and 55% of their initial activity respectively was preserved. In the presence of silica gel and CM-cellulose, a decreased rate of lipid hydrolysis by Pseudomonas sp. enzymes was observed in water medium, and the hydrolysis rate increased by 2.4 and 1.5 times respectively in the presence of aminoaerosil and polykefamid. In an aqueous-alcohol medium, aminoaerosil and polykefamid decreased the rate of substrate hydrolysis by more than 30 times. The addition of aerosil to aqueous and aqueous-alcohol media resulted in an increase in the hydrolysis rate by 1.2-1.3 times. Sorsilen stabilized Penicillium sp. lipase activity at 40, 45, 50 and 55 degrees C. Either stabilization or inactivation of lipases was observed depending on the pH of the medium and the nature of chemical groups localized on the surface of solid phase. The synthetizing activity of lipases also changed depending on the conditions.
Exchange of Na+ and K+ between water vapor and feldspar phases at high temperature and low vapor pressure

Science.gov (United States)

Fournier, R.O.

1976-01-01

In order to determine whether gas (steam) containing a small amount of dissolved alkali chloride is effective in promoting base exchange of Na+ and K+ among alkali feldspars and coexisting brine or brine plus solid salt, experiments were carried out at 400-700??C and steam densities ranging down to less than 0.05. For bulk compositions rich in potassium, the low pressure results are close to previous high-pressure results in composition of the fluid and coexisting solid phase. However, when the bulk composition is more sodic, alkali feldspars are relatively richer in potassium at low pressure than at high pressure. This behaviour corresponds to enrichment of potassium in the gas phase relative to coexisting brine and precipitation of solid NaCl when the brine plus gas composition becomes moderately sodic. The gas phase is very effective in promoting base exchange between coexisting alkali feldspars at high temperature and low water pressure. This suggests that those igneous rocks which contain coexisting alkali feldspars out of chemical equilibrium either remained very dry during the high-temperature part of their cooling history or that the pore fluid was a gas containing very little potassium relative to sodium. ?? 1976.
Ecological evaluation of proposed discharge of dredged material from Oakland Harbor into ocean waters (Phase 3 B of -42-foot project)

Energy Technology Data Exchange (ETDEWEB)

Kohn, N.P.; Ward, J.A.; Mayhew, H.L.; Word, J.Q.; Barrows, E.S.; Goodwin, S.M.; Lefkovitz, L.F. (Battelle/Marine Sciences Lab., Sequim, WA (United States))

1992-06-01

The Water Resources Development Act of 1986 (Public Law 99-662) authorized the US Army Corps of Engineers (USACE) San Francisco District, to deepen and widen the navigational channels of the Oakland Inner and Outer Harbors to accommodate deeper-draft vessels. The USACE is considering several disposal options for the dredged material removed during these channel improvements including open-water disposal. Dredged material proposed for open-water disposal must be evaluated to determine the potential impacts of the disposal activity on the water column and disposal site environments. The USACE requested that Battelle/Marine Sciences Laboratory (MSL) conduct studies to evaluate open-water disposal options for Oakland Harbor sediments. This request developed into the Oakland Harbor Phase III Program. This is Volume 2 of a two-volume report that presents information gathered to determine the suitability of ocean disposal of sediments dredged from Oakland Harbor. This volume contains the Appendixes (A through N), which provide details of the data analyses and full presentation of the data and results.

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