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Sample records for membrane inlet mass

  1. Temperature-programmed desorption for membrane inlet mass spectrometry

    DEFF Research Database (Denmark)

    Ketola, R.A.; Grøn, C.; Lauritsen, F.R.

    1998-01-01

    We present a novel technique for analyzing volatile organic compounds in air samples using a solid adsorbent together with temperature-programmed desorption and subsequent detection by membrane inlet mass spectrometry (TPD-MIMS). The new system has the advantage of a fast separation of compounds...... to diffuse through the membrane into the mass spectrometer in a few seconds. In this fashion we could completely separate many similar volatile compounds, for example toluene from xylene and trichloroethene from tetrachloroethene. Typical detection limits were at low or sub-nanogram levels, the dynamic range...

  2. Membrane Inlet Mass Spectrometry for Homeland Security and Forensic Applications

    Science.gov (United States)

    Giannoukos, Stamatios; Brkić, Boris; Taylor, Stephen; France, Neil

    2015-02-01

    A man-portable membrane inlet mass spectrometer has been built and tested to detect and monitor characteristic odors emitted from the human body and also from threat substances. In each case, a heated membrane sampling probe was used. During human scent monitoring experiments, data were obtained for inorganic gases and volatile organic compounds emitted from human breath and sweat in a confined space. Volatile emissions were detected from the human body at low ppb concentrations. Experiments with compounds associated with narcotics, explosives, and chemical warfare agents were conducted for a range of membrane types. Test compounds included methyl benzoate (odor signature of cocaine), piperidine (precursor in clandestine phencyclidine manufacturing processes), 2-nitrotoluene (breakdown product of TNT), cyclohexanone (volatile signature of plastic explosives), dimethyl methylphosphonate (used in sarin and soman nerve agent production), and 2-chloroethyl ethyl sulfide (simulant compound for sulfur mustard gas). Gas phase calibration experiments were performed allowing sub-ppb LOD to be established. The results showed excellent linearity versus concentration and rapid membrane response times.

  3. A Method for Estimating Mass-Transfer Coefficients in a Biofilter from Membrane Inlet Mass Spectrometer Data

    DEFF Research Database (Denmark)

    Nielsen, Anders Michael; Nielsen, Lars Peter; Feilberg, Anders

    2009-01-01

    of a filter bed with a consortium of effective sulfur oxidizers, the most likely mechanism for incomplete removal of sulfur compounds from the exhaust air was elucidated. This was found to be insufficient mass transfer and not inadequate bacterial activity as anticipated by the manager of the BF. Thus......A membrane inlet mass spectrometer (MIMS) was used in combination with a developed computer model to study and improve management of a biofilter (BF) treating malodorous ventilation air from a meat rendering facility. The MIMS was used to determine percentage removal efficiencies (REs) of selected......, knowing the relationship between mass-transfer coefficients and air velocity for a given type of BF allows for an improved dimensioning and managing of this and similar BFs. This research demonstrates that it is possible to estimate mass-transfer coefficients and air velocity in BFs using MIMS...

  4. Quantifying contribution of synthrophic acetate oxidation to methane production in thermophilic anaerobic reactors by membrane inlet mass spectrometry

    DEFF Research Database (Denmark)

    Mulat, Daniel Girma; Ward, Alastair James; Adamsen, Anders Peter S

    2014-01-01

    A unique method was developed and applied for monitoring methanogenesis pathways based on isotope labeled substrates combined with online membrane inlet quadrupole mass spectrometry (MIMS). In our study, a fermentation sample from a full-scale biogas plant fed with pig and cattle manure, maize...

  5. Continuous monitoring of dissolved gases with membrane inlet mass spectrometry to fingerprint river biochemical activity

    Science.gov (United States)

    Vautier, Camille; Chatton, Eliot; Abbott, Benjamin; Harjung, Astrid; Labasque, Thierry; Guillou, Aurélie; Pannard, Alexandrine; Piscart, Christophe; Laverman, Anniet; Kolbe, Tamara; Massé, Stéphanie; de Dreuzy, Jean-Raynald; Thomas, Zahra; Aquilina, Luc; Pinay, Gilles

    2017-04-01

    Water quality in rivers results from biogeochemical processes in contributing hydrological compartments (soils, aquifers, hyporheic and riparian zones) and biochemical activity in the river network itself. Consequently, chemical fluxes fluctuate on multiple spatial and temporal scales, leading eventually to complex concentration signals in rivers. We characterized these fluctuations with innovative continuous monitoring of dissolved gases, to quantify transport and reaction processes occurring in different hydrological compartments. We performed stream-scale experiments in two headwater streams in Brittany, France. Factorial injections of inorganic nitrogen (NH4NO3), inorganic phosphate (P2O5) and multiple sources of labile carbon (acetate, tryptophan) were implemented in the two streams. We used a new field application of membrane inlet mass spectrometry to continuously monitor dissolved gases for multiple day-night periods (Chatton et al., 2016). Quantified gases included He, O2, N2, CO2, CH4, N2O, and 15N of dissolved N2 and N2O. We calibrated and assessed the methodology with well-established complementary techniques including gas chromatography and high-frequency water quality sensors. Wet chemistry and radon analysis complemented the study. The analyses provided several methodological and ecological insights and demonstrated that high frequency variations linked to background noise can be efficiently determined and filtered to derive effective fluxes. From a more fundamental point of view, the tested stream segments were fully characterized with extensive sampling of riverbeds and laboratory experiments, allowing scaling of point-level microbial and invertebrate diversity and activity on in-stream processing. This innovative technology allows fully-controlled in-situ experiments providing rich information with a high signal to noise ratio. We present the integrated nutrient demand and uptake and discuss limiting processes and elements at the reach and

  6. Estimating rates of denitrification enzyme activity in wetland soils and direct simultaneous quantification of nitrogen and nitrous oxide by membrane inlet mass spectrometry

    Science.gov (United States)

    Denitrification enzyme activity (DEA) was measured in short-term (4 h) anaerobic assays using Membrane Inlet Mass Spectrometry (MIMS) and electron capture gas chromatography (GC-ECD). Using MIMS, modifications of the instrument and sample handling allowed for the simultaneous me...

  7. Multiple inert gas elimination technique by micropore membrane inlet mass spectrometry--a comparison with reference gas chromatography.

    Science.gov (United States)

    Kretzschmar, Moritz; Schilling, Thomas; Vogt, Andreas; Rothen, Hans Ulrich; Borges, João Batista; Hachenberg, Thomas; Larsson, Anders; Baumgardner, James E; Hedenstierna, Göran

    2013-10-15

    The mismatching of alveolar ventilation and perfusion (VA/Q) is the major determinant of impaired gas exchange. The gold standard for measuring VA/Q distributions is based on measurements of the elimination and retention of infused inert gases. Conventional multiple inert gas elimination technique (MIGET) uses gas chromatography (GC) to measure the inert gas partial pressures, which requires tonometry of blood samples with a gas that can then be injected into the chromatograph. The method is laborious and requires meticulous care. A new technique based on micropore membrane inlet mass spectrometry (MMIMS) facilitates the handling of blood and gas samples and provides nearly real-time analysis. In this study we compared MIGET by GC and MMIMS in 10 piglets: 1) 3 with healthy lungs; 2) 4 with oleic acid injury; and 3) 3 with isolated left lower lobe ventilation. The different protocols ensured a large range of normal and abnormal VA/Q distributions. Eight inert gases (SF6, krypton, ethane, cyclopropane, desflurane, enflurane, diethyl ether, and acetone) were infused; six of these gases were measured with MMIMS, and six were measured with GC. We found close agreement of retention and excretion of the gases and the constructed VA/Q distributions between GC and MMIMS, and predicted PaO2 from both methods compared well with measured PaO2. VA/Q by GC produced more widely dispersed modes than MMIMS, explained in part by differences in the algorithms used to calculate VA/Q distributions. In conclusion, MMIMS enables faster measurement of VA/Q, is less demanding than GC, and produces comparable results.

  8. On-line monitoring of CO2 production in Lactococcus lactis during physiological pH decrease using membrane inlet mass spectrometry with dynamic pH calibration.

    Science.gov (United States)

    Andersen, Ann Zahle; Lauritsen, Frants Roager; Olsen, Lars Folke

    2005-12-20

    Monitoring CO2 production in systems, where pH is changing with time is hampered by the chemical behavior and pH-dependent volatility of this compound. In this article, we present the first method where the concentration and production rate of dissolved CO2 can be monitored directly, continuously, and quantitatively under conditions where pH changes rapidly ( approximately 2 units in 15 min). The method corrects membrane inlet mass spectrometry (MIMS) measurements of CO2 for pH dependency using on-line pH analysis and an experimentally established calibration model. It is valid within the pH range of 3.5 to 7, despite pH-dependent calibration constants that vary in a non-linear fashion with more than a factor of 3 in this interval. The method made it possible to determine the carbon dioxide production during Lactococcus lactis fermentations, where pH drops up to 3 units during the fermentation. The accuracy was approximately 5%. We used the method to investigate the effect of initial extracellular pH on carbon dioxide production during anarobic glucose fermentation by non-growing Lactocoocus lactis and demonstrated that the carbon dioxide production rate increases considerably, when the initial pH was increased from 6 to 6.8. (c) 2005 Wiley Periodicals, Inc.

  9. Simultaneous mass detection for direct inlet mass spectrometry

    International Nuclear Information System (INIS)

    Gordon, R.L.

    1979-05-01

    The evolution of analytical techniques for application in trace analysis has led to interest in practical methods for real-time monitoring. Direct inlet mass spectrometry (DIMS) has been the subject of considerable activity in recent years. A DIMS instrument is described which consists of an inlet system designed to permit particles entrained in the inlet air stream to strike a hot, oxidized rhenium filament which serves as a surface ionization source. A mass analyzer and detection system then permits identification of the elemental composition of particulates which strike the filament

  10. Silicon Microleaks for Inlets of Mass Spectrometers

    Science.gov (United States)

    Harpold, Dan; Hasso, Niemann; Jamieson, Brian G.; Lynch, Bernard A.

    2009-01-01

    Microleaks for inlets of mass spectrometers used to analyze atmospheric gases can be fabricated in silicon wafers by means of photolithography, etching, and other techniques that are commonly used in the manufacture of integrated circuits and microelectromechanical systems. The microleaks serve to limit the flows of the gases into the mass-spectrometer vacuums to specified very small flow rates consistent with the capacities of the spectrometer vacuum pumps. There is a need to be able to precisely tailor the dimensions of each microleak so as to tailor its conductance to a precise low value. (As used here, "conductance" signifies the ratio between the rate of flow in the leak and the pressure drop from the upstream to the downstream end of the leak.) To date, microleaks have been made, variously, of crimped metal tubes, pulled glass tubes, or frits. Crimped-metal and pulled-glass-tube microleaks cannot readily be fabricated repeatably to precise dimensions and are susceptible to clogging with droplets or particles. Frits tend to be differentially chemically reactive with various gas constituents and, hence, to distort the gas mixtures to be analyzed. The present approach involving microfabrication in silicon largely overcomes the disadvantages of the prior approaches.

  11. Cross contamination in dual inlet isotope ratio mass spectrometers

    NARCIS (Netherlands)

    Meijer, H.A.J.; Neubert, R.E.M.; Visser, G.H.

    2000-01-01

    Since the early days of geochemical isotope ratio mass spectrometry there has always been the problem of cross contamination, i.e. the contamination of the sample gas with traces of reference gas land vice versa) in a dual inlet system and the analyzer itself. This was attributable to valve leakages

  12. Mass independent kinetic energy reducing inlet system for vacuum environment

    Science.gov (United States)

    Reilly, Peter T. A. [Knoxville, TN

    2010-12-14

    A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.

  13. Effects of selected design variables on three ramp, external compression inlet performance. [boundary layer control bypasses, and mass flow rate

    Science.gov (United States)

    Kamman, J. H.; Hall, C. L.

    1975-01-01

    Two inlet performance tests and one inlet/airframe drag test were conducted in 1969 at the NASA-Ames Research Center. The basic inlet system was two-dimensional, three ramp (overhead), external compression, with variable capture area. The data from these tests were analyzed to show the effects of selected design variables on the performance of this type of inlet system. The inlet design variables investigated include inlet bleed, bypass, operating mass flow ratio, inlet geometry, and variable capture area.

  14. Biases in Ion Transmission Through an Electrospray Ionization-Mass Spectrometry Capillary Inlet

    Energy Technology Data Exchange (ETDEWEB)

    Page, Jason S.; Marginean, Ioan; Baker, Erin Shammel; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

    2009-12-01

    The standard heated capillary inlet of an electrospray ionization mass spectrometry (ESI-MS) interface was compared with shorter versions of the inlet to determine the effects on transmission and ionization efficiencies for low-flow electrosprays. The primary finding of the study was a large bias towards higher mobility species in the electrospray current losses to the inside walls of the inlet. The transmission efficiency increased with decreasing capillary length due to reduced losses along the capillary. A decrease in transmission efficiency was also confirmed for electrosprays of higher conductivity solvents. A direct correlation between mass spectrometry sensitivity and the transmitted electrospray current was not observed as some analytes showed little to no increase in sensitivity while others showed as high as a 15 – fold increase. The variation was shown to at least be partially dependent on the analytes’ mobilities. Higher mobility analytes demonstrated a larger increase in sensitivity when shorter inlets were used. The results indicate that considerable biases against higher mobility species can be produced by the use of long capillary inlets in the ESI-MS interface and strategies are provided to minimize the bias against higher mobility species for efficient ion transmission through the heated capillary interface.

  15. Phosphorus mass balance in a highly eutrophic semi-enclosed inlet near a big metropolis: a small inlet can contribute towards particulate organic matter production.

    Science.gov (United States)

    Asaoka, Satoshi; Yamamoto, Tamiji

    2011-01-01

    Terrigenous loading into enclosed water bodies has been blamed for eutrophic conditions marked by massive algal growth and subsequent hypoxia due to decomposition of dead algal cells. This study aims to describe the eutrophication and hypoxia processes in a semi-enclosed water body lying near a big metropolis. Phosphorus mass balance in a small inlet, Ohko Inlet, located at the head of Hiroshima Bay, Japan, was quantified using a numerical model. Dissolved inorganic phosphorous inflow from Kaita Bay next to the inlet was five times higher than that from terrigenous load, which may cause an enhancement of primary production. Therefore, it was concluded that not only the reduction of material load from the land and the suppression of benthic flux are needed, but also reducing the inflow of high phosphorus and oxygen depleted water from Kaita Bay will form a collective alternative measure to remediate the environmental condition of the inlet. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Numerical Calibration of Mass Flow Plug for Inlet Testing

    Science.gov (United States)

    Sasson, Jonathan; Barnhart, Paul; Davis, David O.

    2015-01-01

    A simple control volume model has been developed to calculate the discharge coefficient through a mass flow plug (MFP) and validated with a calibration experiment. The maximum error of the model within the operating region of the MFP is 0.54%. The control volume analysis developed work is comprised of a sequence of flow calculations through the MFP. The model uses the MFP geometry and operating pressure and temperature to couple continuity, momentum, energy, an equation of state, and wall shear. The discharge coefficient calculation also includes the effects of boundary layer growth, including the reduction in cross-sectional flow area as characterized by the boundary layer displacement thickness. The last calculation in the sequence uses an integral method to calculate the growth of the boundary layer, from which the displacement thickness is then determined. The result of these successive calculations is an accurate one-dimension model of the velocity, pressure, and temperature through the MFP. For comparison, a computational fluid dynamic (CFD) calibration is shown, which when compared to the presented numerical model, had a lower accuracy with a maximum error of 1.35% in addition to being slower by a factor of 100."

  17. Elimination of ``memory`` from sample handling and inlet system of a mass spectrometer

    Science.gov (United States)

    Chastgner, P.

    1991-05-08

    This paper describes a method for preparing the sample handling and inlet system of a mass spectrometer for analysis of a subsequent sample following analysis of a previous sample comprising the flushing of the system interior with supercritical CO{sub 2} and venting the interior. The method eliminates the effect of system ``memory`` on the subsequent analysis, especially following persistent samples such as xenon and krypton.

  18. Selective mass transfer in a membrane absorber

    Science.gov (United States)

    Okunev, A. Yu.; Laguntsov, N. I.

    2006-09-01

    A theoretical study of selective mass transfer in a plane-frame membrane absorber (contactor) has been made. A mathematical model of the process has been developed and the process of purification of a gas mixture depending on the flow parameters, the membrane, and the feeding-mixture composition has been studied with its help.

  19. Mass transport in thin supported silica membranes

    NARCIS (Netherlands)

    Benes, Nieck Edwin

    2000-01-01

    In this thesis multi-component mass transport in thin supported amorphous silica membranes is discussed. These membranes are micro-porous, with pore diameters smaller than 4Å and show high fluxes for small molecules (such as hydrogen) combined with high selectivities for these molecules with respect

  20. A Microchannel Inlet to Reduce High-Velocity Impact Fragmentation of Molecules in Orbital and Fly-by Mass Spectrometers

    Science.gov (United States)

    Turner, Brandon; Anupriya, Anupriya; Sevy, Eric; Austin, Daniel E.

    2017-10-01

    Closed source neutral mass spectrometers are often used on flyby missions to characterize the molecular components of planetary exospheres. In a typical closed source, neutrals are thermalized as they deflect off the walls within a spherical antechamber prior to ionization and mass analysis. However, the high kinetic energy of each molecule as it impacts the chamber can lead to fragmentation before the ionization region is reached. Due to this fragmentation, the original composition of the molecule can be altered, leading to ambiguous identification.Even knowing the fragmentation pathways that occur may not allow deconvolution of data to give the correct composition. Only stable, volatile fragments will be observed in the subsequent mass spectrometer and different organic compounds likely give similar fragmentation products. Simply detecting these products will not lead to unambiguous identication of the precursor molecules. Here, we present a hardware solution to this problem—an inlet that reduces the fragmentation of molecules that impact at high velocities.We present a microchannel inlet that reduces the impact fragmentation by allowing the molecules to dissipate kinetic energy faster than their respective dissociation lifetimes. Preliminary calculations indicate that impact-induced fragmentation will be reduced up to three orders of magnitude compared with conventional closed sources by using this inlet. The benefits of such an inlet apply to any orbital or flyby velocity. The microchannel inlet enables detection of semi-volatile molecules that were previously undetectable due to impact fragmentation.

  1. Stable Isotope Analyses of water and Aqueous Solutions by Conventional Dual-inlet Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Horita, Juske [ORNL; Kendall, C. [U.S. Geological Survey, Menlo Park, CA

    2004-01-01

    The foundation of various analytical methods for the stable isotope composition of water and other aqueous samples (natural abundance, {sup 1}H : {sup 2}H (D) = 99.985 : 0.015 atom%, and {sup 16}O : {sup 17}O : {sup 18}O = 99.762 : 0.038 : 0.200 atom%) was established during the Manhatten Project in the U.S.A., when large amounts of heavy water were produced for nuclear reactors (see Kirshenbaum, 1951, for a detailed account). From early on, there was great interest in the oxygen and hydrogen isotopic compositions of water, because they are the ideal tracers of water sources and reactions. The increased analytical precisions made possible by the subsequent development of modern gas-source isotope-ratio mass spectrometers with dual-inlets and multi-collectors, have caused the proliferation of new analytical methods and applications for the oxygen and hydrogen isotopic compositions of water. These stable isotopes have found wide applications in basic as well as applied sciences (chemistry, geology, hydrology, biology, medical sciences, and food sciences). This is because water is ubiquitous, is an essential and predominant ingredient of living organisms, and is perhaps the most reactive compound in the Earth.

  2. Direct determination of trace phthalate esters in alcoholic spirits by spray-inlet microwave plasma torch ionization tandem mass spectrometry.

    Science.gov (United States)

    Miao, Meng; Zhao, Gaosheng; Xu, Li; Dong, Junguo; Cheng, Ping

    2018-03-01

    A direct analytical method based on spray-inlet microwave plasma torch tandem mass spectrometry was applied to simultaneously determine 4 phthalate esters (PAEs), namely, benzyl butyl phthalate, diethyl phthalate, dipentyl phthalate, and dodecyl phthalate with extremely high sensitivity in spirits without sample treatment. Among the 4 brands of spirit products, 3 kinds of PAE compounds were directly determined at very low concentrations from 1.30 to 114 ng·g -1 . Compared with other online and off-line methods, the spray-inlet microwave plasma torch tandem mass spectrometry technique is extremely simple, rapid, sensitive, and high efficient, providing an ideal screening tool for PAEs in spirits. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Numerical simulation for the influence of laser-induced plasmas addition on air mass capture of hypersonic inlet

    Science.gov (United States)

    Zhao, Wei; Dou, Zhiguo; Li, Qian

    2012-03-01

    The theory of laser-induced plasmas addition to hypersonic airflow off a vehicle to increase air mass capture and improve the performance of hypersonic inlets at Mach numbers below the design value is explored. For hypersonic vehicles, when flying at mach numbers lower than the design one, we can increase the mass capture ratio of inlet through laser-induced plasmas injection to the hypersonic flow upstream of cowl lip to form a virtual cowl. Based on the theory, the model of interaction between laser-induced plasmas and hypersonic flow was established. The influence on the effect of increasing mass capture ratio was studied at different positions of laser-induced plasmas region for the external compression hypersonic inlet at Mach 5 while the design value is 6, the power of plasmas was in the range of 1-8mJ. The main results are as follows: 1. the best location of the plasma addition region is near the intersection of the nose shock of the vehicle with the continuation of the cowl line, and slightly below that line. In that case, the shock generated by the heating is close to the shock that is a reflection of the vehicle nose shock off the imaginary solid surface-extension of the cowl. 2. Plasma addition does increase mass capture, and the effect becomes stronger as more energy is added, the peak value appeared when the power of plasma was about 4mJ, when the plasma energy continues to get stronger, the mass capture will decline slowly.

  4. A homemade high-resolution orthogonal-injection time-of-flight mass spectrometer with a heated capillary inlet

    International Nuclear Information System (INIS)

    Guo Changjuan; Huang Zhengxu; Gao Wei; Nian Huiqing; Chen Huayong; Dong Junguo; Shen Guoying; Fu Jiamo; Zhou Zhen

    2008-01-01

    We describe a homemade high-resolution orthogonal-injection time-of-flight (O-TOF) mass spectrometer combing a heated capillary inlet. The O-TOF uses a heated capillary tube combined with a radio-frequency only quadrupole (rf-only quadrupole) as an interface to help the ion transmission from the atmospheric pressure to the low-pressure regions. The principle, configuration of the O-TOF, and the performance of the instrument are introduced in this paper. With electrospray ion source, the performances of the mass resolution, the sensitivity, the mass range, and the mass accuracy are described. We also include our results obtained by coupling atmospheric pressure matrix-assisted laser deporption ionization with this instrument

  5. Spray-inlet microwave plasma torch ionization tandem mass spectrometry for the direct detection of drug samples in liquid solutions.

    Science.gov (United States)

    Miao, Meng; Zhao, Gaosheng; Wang, Yaliang; Xu, Li; Dong, Junguo; Cheng, Ping

    2017-12-30

    Drug abuse or dependence results in a series of social problems, including crime and traffic accidents. Spray-inlet microwave plasma torch tandem mass spectrometry (MPT-MS/MS) was developed and used for the direct detection of such drugs in liquid solutions. Drug sample solutions were directly sprayed into the flame of an MPT by a sampling pump and the ions produced by Penning ionization and ion-molecule reactions were guided into a quadrupole time-of-flight (QTOF) tandem mass spectrometer for mass analysis. The MPT was operated at 40 W and 2.45 GHz in a 700 mL/min argon flow both for the inner and middle plasma. Intact quasi-molecular and molecular ions of various drugs were successfully characterized by spray-inlet MPT-MS/MS. The analysis of one sample was finished within 30 s. Furthermore, the method exhibited excellent efficiency, precision and sensitivity, and the limits of detection and limits of quantification of the samples in methanol were in the range of 5.25-60.0 and 17.5-200 ng g -1 , respectively. Excellent linearities with coefficients of determination (R 2 ) of 0.9627-0.9980 were verified in the range 0.05-50 μg g -1 . Four different beverages purchased locally were also analyzed with spray-inlet MPT-MS/MS, and caffeine was directly determined in two of the beverages. By adding six standard drug samples to sport drinks (each drug was 1 μg g -1 ) and Chinese spirit (each drug was 0.1 μg g -1 ), all the drugs except for caffeine were detected successfully. This study indicates that spay-inlet MPT-MS/MS is an effective method for direct and rapid identification of drug solutions, and it has substantial potential for fast and sensitive drug residue detection. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Influence of high range of mass transfer coefficient and convection heat transfer on direct contact membrane distillation performance

    KAUST Repository

    Lee, Jung Gil

    2017-11-03

    In order to improve water production of membrane distillation (MD), the development of high performance membrane having better mass transfer and enhancement of convection heat transfer in MD module have been continuously investigated. This paper presents the relationship between the heat and mass transfer resistance across the membrane and the performance improvement. Various ranges of mass transfer coefficient (MTC) from normal (0.3×10−6 to 2.1×10−6kg/m2sPa: currently available membranes) to high (>2.1×10−6kg/m2sPa: membranes under development) were simulated using an experimentally validated model at different ranges of convection heat transfer by varying the inlet flow rates and spacer enhancement factor. The effect of mass transfer and convection heat transfer on the MD performance parameters including temperature polarization coefficient (TPC), mean permeate flux, and specific energy consumption were investigated in a direct contact MD (DCMD) configuration. Results showed that improving the MTC at the low ranges is more important than that at the high ranges where the heat transfer resistance becomes dominant and hence the convection heat transfer coefficient must be increased. Therefore, an effort on designing MD modules using feed and permeate spacers and controlling the membrane surface roughness to increase the convection heat transfer and TPC in the channel aiming to enhance the flux is required because the currently developed mass transfer has almost reached the critical point.

  7. Membranes for nanometer-scale mass fast transport

    Science.gov (United States)

    Bakajin, Olgica [San Leandro, CA; Holt, Jason [Berkeley, CA; Noy, Aleksandr [Belmont, CA; Park, Hyung Gyu [Oakland, CA

    2011-10-18

    Nanoporous membranes comprising single walled, double walled, and multiwalled carbon nanotubes embedded in a matrix material were fabricated for fluid mechanics and mass transfer studies on the nanometer scale and commercial applications. Average pore size can be 2 nm to 20 nm, or seven nm or less, or two nanometers or less. The membrane can be free of large voids spanning the membrane such that transport of material such as gas or liquid occurs exclusively through the tubes. Fast fluid, vapor, and liquid transport are observed. Versatile micromachining methods can be used for membrane fabrication. A single chip can comprise multiple membranes. These membranes are a robust platform for the study of confined molecular transport, with applications in liquid and gas separations and chemical sensing including desalination, dialysis, and fabric formation.

  8. Measuring potential denitrification enzyme activity rates using the membrane inlet mass spectrometer

    Science.gov (United States)

    The denitrification enzyme activity (DEA) assay, provides a quantitative assessment of the multi enzyme, biological process of reactive nitrogen removal via the reduction of N03 to N2. Measured in soil, usually under non limiting carbon and nitrate concentrations, this short ter...

  9. Black hole mass formula in the membrane paradigm

    Science.gov (United States)

    Lemos, José P. S.; Zaslavskii, Oleg B.

    2018-03-01

    The membrane paradigm approach adopts a timelike surface, stretched out off the null event horizon, to study several important black hole properties. We use this powerful tool to give a direct derivation of the black hole mass formula in the static and stationary cases without and with electric field. Since here the membrane is a self-gravitating material system, we go beyond the usual applicability on test particles and test fields of the paradigm.

  10. RESEARCH OF THE MASS TRANSFER AT MEMBRANE CLEANING OF BIOGAZ

    Directory of Open Access Journals (Sweden)

    Marat SATAYEV

    2015-04-01

    Full Text Available Everyone has long known the benefits and effectiveness of biogas. Particularly, getting biogas from the agricultural waste is very promising. But, the question is if we can use such a useful and effective biogas at 100%. Today, we use only a half of the benefit, because to get the biogas we spend more energy than we get. In this regard, the work on the study of the biogas development is extremely important. The study of the biogas formation requires numerous experiments. This article analyzes the biogas mass transfer with the membrane purification and identification of the of mass transfer mechanisms through the membrane pores.

  11. Coastal Inlet Model Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Coastal Inlet Model Facility, as part of the Coastal Inlets Research Program (CIRP), is an idealized inlet dedicated to the study of coastal inlets and equipped...

  12. Tests of a mixed compression axisymmetric inlet with large transonic mass flow at Mach numbers 0.6 to 2.65

    Science.gov (United States)

    Smeltzer, D. B.; Sorensen, N. E.

    1972-01-01

    A 38.8-cm (15.28-in.) capture diameter model of a mixed-compression axisymmetric inlet system with a translating cowl was designed and tested. The internal contours, designed for Mach number 2.65, provided a throat area of 59 percent of the capture area when the cowl was retracted for transonic operation. Other model features included a boundary-layer removal system, vortex generators, an engine airflow bypass system, cowl support struts, and rotating rakes at the engine face. All tunnel testing was conducted at a tunnel total pressure of about 1 atm (a unit Reynolds number of about 8.53 million/m at Mach number 2.65) at angles of attack from 0 deg to 4 deg. Results for the following were obtained: total-pressure recovery and distortion at the engine face as a function of bleed mass-flow ratio, the effect of bleed and vortex generator configurations on pressure recovery and distortion, inlet tolerance to unstart due to changes in angle of attack or Mach number, surface pressure distributions, boundary-layer profiles, and transonic additive drag. At Mach number 2.65 and with the best bleed configurations, maximum total pressure recovery at the engine face ranged from 91 to 94.5 percent with bleed mass-flow ratios from 4 to 9 percent, respectively, and total-pressure distortion was less than 10 percent. At off-design supersonic Mach numbers above 1.70, maximum total-pressure recoveries and corresponding bleed mass flows were about the same as at Mach number 2.65, with about 10 to 15 percent distortion. In the transonic Mach number range, total pressure recovery was high (above 96 percent) and distortion was low (less than 15 percent) only when the inlet mass-flow ration was reduced 0.02 to 0.06 from the maximum theoretical value (0.590 at Mach number 1.0).

  13. Membrane introduction proton-transfer-reaction mass spectrometry

    International Nuclear Information System (INIS)

    Alexander, M.; Boscaini, E.; Maerk, T.; Lindinger, W.

    2002-01-01

    Proton-transfer-reaction mass spectrometry (PTR-MS) is a rapidly expanding field with multiple applications in ion physics, atmospheric chemistry, food chemistry, volatile organic compounds monitoring and biology. Initial studies that combine PTR-MS and membrane introduction mass spectrometry (MIMS) were researched and outlined. First using PTR-MS, certain fundamental physical properties of a poly-dimethylsiloxane (PDMS) membrane including solubilities and diffusion coefficients were measured. Second, it was shown how the chemical selectivity of the (PDMS) can be used to extend the capabilities of the PTR-MS instrument by eliminating certain isobaric interferences and excluding water from volatile organic compounds (VOCs). Experiments with mixtures of several VOCs (toluene, benzene, acetone, propanal, methanol) are presented. (nevyjel)

  14. Ultrananocrystalline Diamond Membranes for Detection of High-Mass Proteins

    Science.gov (United States)

    Kim, H.; Park, J.; Aksamija, Z.; Arbulu, M.; Blick, R. H.

    2016-12-01

    Mechanical resonators realized on the nanoscale by now offer applications in mass sensing of biomolecules with extraordinary sensitivity. The general idea is that perfect mechanical mass sensors should be of extremely small size to achieve zepto- or yoctogram sensitivity in weighing single molecules similar to a classical scale. However, the small effective size and long response time for weighing biomolecules with a cantilever restricts their usefulness as a high-throughput method. Commercial mass spectrometry (MS), on the other hand, such as electrospray ionization and matrix-assisted laser desorption and ionization (MALDI) time of flight (TOF) and their charge-amplifying detectors are the gold standards to which nanomechanical resonators have to live up to. These two methods rely on the ionization and acceleration of biomolecules and the following ion detection after a mass selection step, such as TOF. The principle we describe here for ion detection is based on the conversion of kinetic energy of the biomolecules into thermal excitation of chemical vapor deposition diamond nanomembranes via phonons followed by phonon-mediated detection via field emission of thermally emitted electrons. We fabricate ultrathin diamond membranes with large lateral dimensions for MALDI TOF MS of high-mass proteins. These diamond membranes are realized by straightforward etching methods based on semiconductor processing. With a minimal thickness of 100 nm and cross sections of up to 400 ×400 μ m2 , the membranes offer extreme aspect ratios. Ion detection is demonstrated in MALDI TOF analysis over a broad range from insulin to albumin. The resulting data in detection show much enhanced resolution as compared to existing detectors, which can offer better sensitivity and overall performance in resolving protein masses.

  15. Mass and Heat Transfer Analysis of Membrane Humidifier with a Simple Lumped Mass Model

    International Nuclear Information System (INIS)

    Lee, Young Duk; Bae, Ho June; Ahn, Kook Young; Yu, Sang Seok; Hwang, Joon Young

    2009-01-01

    The performance of proton exchange membrane fuel cell (PEMFC) is seriously changed by the humidification condition which is intrinsic characteristics of the PEMFC. Typically, the humidification of fuel cell is carried out with internal or external humidifier. A membrane humidifier is applied to the external humidification of residential power generation fuel cell due to its convenience and high performance. In this study, a simple static model is constructed to understand the physical phenomena of the membrane humidifier in terms of geometric parameters and operating parameters. The model utilizes the concept of shell and tube heat exchanger but the model is also able to estimate the mass transport through the membrane. Model is constructed with FORTRAN under Matlab/Simulink □ environment to keep consistency with other components model which we already developed. Results shows that the humidity of wet gas and membrane thickness are critical parameters to improve the performance of the humidifier

  16. Direct Analysis of Organic Compounds in Liquid Using a Miniature Photoionization Ion Trap Mass Spectrometer with Pulsed Carrier-Gas Capillary Inlet.

    Science.gov (United States)

    Lu, Xinqiong; Yu, Quan; Zhang, Qian; Ni, Kai; Qian, Xiang; Tang, Fei; Wang, Xiaohao

    2017-08-01

    A miniature ion trap mass spectrometer with capillary direct sampling and vacuum ultraviolet photoionization source was developed to conduct trace analysis of organic compounds in liquids. Self-aspiration sampling is available where the samples are drawn into the vacuum chamber through a capillary with an extremely low flow rate (less than 1 μL/min), which minimizes sample consumption in each analysis to tens of micrograms. A pulsed gas-assisted inlet was designed and optimized to promote sample transmission in the tube and facilitate the cooling of ions, thereby improving instrument sensitivity. A limit of detection of 2 ppb could be achieved for 2,4-dimethylaniline in a methanol solution. The sampling system described in the present study is specifically suitable for a miniature photoionization ion trap mass spectrometer that can perform rapid and online analysis for liquid samples. Graphical Abstract ᅟ.

  17. Plant Phosphoproteomics: Analysis of Plasma Membrane Transporters by Mass Spectrometry

    DEFF Research Database (Denmark)

    Ye, Juanying; Rudashevskaya, Elena; Young, Clifford

      Phosphorylation is a key regulatory factor in all aspects of eukaryotic biology including the regulation of plant membrane-bound transport proteins. To date, mass spectrometry (MS) has been introduced as powerful technology for study of post translational modifications (PTMs), including protein...... phosphorylation. Due to the low abundance of phosphoprotein, the specific enrichment prior to MS analysis is necessary. Plant proton pump (H+-ATPase) is an enzyme controls the major transport processes in the plant, such as root nutrient uptake. Moreover, this pump has been proposed to be involved in other...... important physiological functions, such as stomata aperture, cell elongation, or cellular pH regulation. It is known that the activity of plant plasma membrane H+-ATPase is regulated by phosphorylation. Therefore, we first investigated the phosphorylation profile of plant H+-ATPase by enriching...

  18. Characterization of Membrane Protein-Lipid Interactions by Mass Spectrometry Ion Mobility Mass Spectrometry

    Science.gov (United States)

    Liu, Yang; Cong, Xiao; Liu, Wen; Laganowsky, Arthur

    2017-04-01

    Lipids in the biological membrane can modulate the structure and function of integral and peripheral membrane proteins. Distinguishing individual lipids that bind selectively to membrane protein complexes from an ensemble of lipid-bound species remains a daunting task. Recently, ion mobility mass spectrometry (IM-MS) has proven to be invaluable for interrogating the interactions between protein and individual lipids, where the complex undergoes collision induced unfolding followed by quantification of the unfolding pathway to assess the effect of these interactions. However, gas-phase unfolding experiments for membrane proteins are typically performed on the entire ensemble ( apo and lipid bound species), raising uncertainty to the contribution of individual lipids and the species that are ejected in the unfolding process. Here, we describe the application of mass spectrometry ion mobility mass spectrometry (MS-IM-MS) for isolating ions corresponding to lipid-bound states of a model integral membrane protein, ammonia channel (AmtB) from Escherichia coli. Free of ensemble effects, MS-IM-MS reveals that bound lipids are ejected as neutral species; however, no correlation was found between the lipid-induced stabilization of complex and their equilibrium binding constants. In comparison to data obtained by IM-MS, there are surprisingly limited differences in stability measurements from IM-MS and MS-IM-MS. The approach described here to isolate ions of membrane protein complexes will be useful for other MS methods, such as surface induced dissociation or collision induced dissociation to determine the stoichiometry of hetero-oligomeric membrane protein complexes.

  19. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Viktor Johánek

    2016-01-01

    Full Text Available The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc. on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed subjected to a wide range of conditions.

  20. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells.

    Science.gov (United States)

    Johánek, Viktor; Ostroverkh, Anna; Fiala, Roman; Rednyk, Andrii; Matolín, Vladimír

    2016-01-01

    The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis) mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side) downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc.) on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein) polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed) subjected to a wide range of conditions.

  1. Performance Improvement of Membrane Stress Measurement Equipment through Evaluation of Added Mass of Membrane and Error Correction

    Directory of Open Access Journals (Sweden)

    Sang-Wook Jin

    2017-01-01

    Full Text Available One of the most important issues in keeping membrane structures in stable condition is to maintain the proper stress distribution over the membrane. However, it is difficult to determine the quantitative real stress level in the membrane after the completion of the structure. The stress relaxation phenomenon of the membrane and the fluttering effect due to strong wind or ponding caused by precipitation may cause severe damage to the membrane structure itself. Therefore, it is very important to know the magnitude of the existing stress in membrane structures for their maintenance. The authors have proposed a new method for separately estimating the membrane stress in two different directions using sound waves instead of directly measuring the membrane stress. The new method utilizes the resonance phenomenon of the membrane, which is induced by sound excitations given through an audio speaker. During such experiment, the effect of the surrounding air on the vibrating membrane cannot be overlooked in order to assure high measurement precision. In this paper, an evaluation scheme for the added mass of membrane with the effect of air on the vibrating membrane and the correction of measurement error is discussed. In addition, three types of membrane materials are used in the experiment in order to verify the expandability and accuracy of the membrane measurement equipment.

  2. Spray Inlet Proton Transfer Reaction Mass Spectrometry (SI-PTR-MS) for Rapid and Sensitive Online Monitoring of Benzene in Water.

    Science.gov (United States)

    Zou, Xue; Kang, Meng; Li, Aiyue; Shen, Chengyin; Chu, Yannan

    2016-03-15

    Rapid and sensitive monitoring of benzene in water is very important to the health of people and for environmental protection. A novel and online detection method of spray inlet proton transfer reaction mass spectrometry (SI-PTR-MS) was introduced for rapid and sensitive monitoring of trace benzene in water. A spraying extraction system was coupled with the self-developed PTR-MS. The benzene was extracted from the water sample in the spraying extraction system and continuously detected with PTR-MS. The flow of carrier gas and salt concentration in water were optimized to be 50 sccm and 20% (w/v), respectively. The response time and the limit of detection of the SI-PTR-MS for detection of benzene in water were 55 s and 0.14 μg/L at 10 s integration time, respectively. The repeatability of the SI-PTR-MS was evaluated, and the relative standard deviation of five replicate determinations was 4.3%. The SI-PTR-MS system was employed for monitoring benzene in different water matrices, such as tap water, lake water, and wastewater. The results indicated that the online SI-PTR-MS can be used for rapid and sensitive monitoring of trace benzene in water.

  3. Inlet stratification device

    DEFF Research Database (Denmark)

    2014-01-01

    An inlet stratification (5) is adapted to be arranged vertically in a tank (1) during operation. The stratification device (5) comprises an inlet pipe (6) formed of a flexible porous material and having a lower and upper end. The lower end of the inlet pipe (6) is connected to a bottom cap (10......) with an inlet passage way (16). The upper end of the inlet pipe (6) is connected with a top cap (9). The top cap (9) and the bottom cap (10) are mutually connected by means of a wire (8) and the top cap (9) is configured as a floating device providing a buoyancy force larger than the downwardly directed force...... due to the wire (8), the inlet pipe (6) and any deposited on the above pass during operation....

  4. Analysis of mass transfer characteristics in a tubular membrane using CFD modeling.

    Science.gov (United States)

    Yang, Jixiang; Vedantam, Sreepriya; Spanjers, Henri; Nopens, Ingmar; van Lier, Jules B

    2012-10-01

    In contrast to the large amount of research into aerobic membrane bioreactors, little work has been reported on anaerobic membrane bioreactors (AMBRs). As to the application of membrane bioreactors, membrane fouling is a key issue. Membrane fouling generally occurs more seriously in AMBRs than in aerobic membrane bioreactors. However, membrane fouling could be managed through the application of suitable shear stress that can be introduced by the application of a two-phase flow. When the two-phase flow is applied in AMBRs, little is known about the mass transfer characteristics, which is of particular importance, in tubular membranes of AMBRs. In our present work, we have employed fluid dynamic modeling to analyze the mass transfer characteristics in the tubular membrane of a side stream AMBR in which, gas-lift two-phase flow was applied. The modeling indicated that the mass transfer capacity at the membrane surface at the noses of gas bubbles was higher than the mass transfer capacity at the tails of the bubbles, which is in contrast to the results when water instead of sludge is applied. At the given mass transfer rate, the filterability of the sludge was found to have a strong influence on the transmembrane pressure at a steady flux. In addition, the model also showed that the shear stress in the internal space of the tubular membrane was mainly around 20 Pa but could be as high as about 40 Pa due to gas bubble movements. Nonetheless, at these shear stresses a stable particle size distribution was found for sludge particles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. INLET STRATIFICATION DEVICE

    DEFF Research Database (Denmark)

    2006-01-01

    formed of a flexible porous material and having an inlet (19) and outlets formed of the pores of the porous material. The stratification device (5) further comprises at least one outer pipe (7) surrounding the inlet pipe (6) in spaced relationship thereto and being at least partially formed of a porous......An inlet stratification device (5) for a circuit circulating a fluid through a tank (1 ) and for providing and maintaining stratification of the fluid in the tank (1 ). The stratification de- vice (5) is arranged vertically in the tank (1) and comprises an inlet pipe (6) being at least partially...

  6. Sodium laurate, a novel protease- and mass spectrometry-compatible detergent for mass spectrometry-based membrane proteomics.

    Directory of Open Access Journals (Sweden)

    Yong Lin

    Full Text Available The hydrophobic nature of most membrane proteins severely complicates their extraction, proteolysis and identification. Although detergents can be used to enhance the solubility of the membrane proteins, it is often difficult for a detergent not only to have a strong ability to extract membrane proteins, but also to be compatible with the subsequent proteolysis and mass spectrometric analysis. In this study, we made evaluation on a novel application of sodium laurate (SL to the shotgun analysis of membrane proteomes. SL was found not only to lyse the membranes and solubilize membrane proteins as efficiently as SDS, but also to be well compatible with trypsin and chymotrypsin. Furthermore, SL could be efficiently removed by phase transfer method from samples after acidification, thus ensuring not to interfere with the subsequent CapLC-MS/MS analysis of the proteolytic peptides of proteins. When SL was applied to assist the digestion and identification of a standard protein mixture containing bacteriorhodoposin and the proteins in rat liver plasma membrane-enriched fractions, it was found that, compared with other two representative enzyme- and MS-compatible detergents RapiGest SF (RGS and sodium deoxycholate (SDC, SL exhibited obvious superiority in the identification of membrane proteins particularly those with high hydrophobicity and/or multiple transmembrane domains.

  7. Variable geometry for supersonic mixed-compression inlets

    Science.gov (United States)

    Sorensen, N. E.; Latham, E. A.; Smeltzer, D. B.

    1974-01-01

    Study of two-dimensional and axisymmetric supersonic mixed-compression inlet systems has shown that the geometry of both systems can be varied to provide adequate transonic airflow to satisfy the airflow demand of most jet engines. Collapsing geometry systems for both types of inlet systems provide a generous amount of transonic airflow for any design Mach number inlet system. However, the mechanical practicality of collapsing centerbodies for axisymmetric inlet systems is doubtful. Therefore, translating centerbody axisymmetric inlets with auxiliary airflow systems to augment the transonic airflow capability are an attractive alternative. Estimates show that the capture mass-flow ratio at Mach number 1.0 can be increased approximately 0.20 for a very short axisymmetric inlet system designed for Mach number 2.37. With this increase in mass-flow ratio, even variable-cycle engine transonic airflow demand can be matched without oversizing the inlet at the design Mach number.

  8. Novel spacers for mass transfer enhancement in membrane separations

    NARCIS (Netherlands)

    Li, F.; Meindersma, G.W.; de Haan, A.B.; Reith, T.

    2005-01-01

    The optimal flow pattern for mass transfer enhancement in spacer-filled channels is characterized by the coexistence of transversal and longitudinal vortices in the flow close to the channel walls and minimal cross-flow power consumption in the middle of the channel. The mass transfer enhancement of

  9. Amplified CPEs enhancement of chorioamnion membrane mass transport by encapsulation in nano-sized PLGA particles.

    Science.gov (United States)

    Azagury, Aharon; Amar-Lewis, Eliz; Appel, Reut; Hallak, Mordechai; Kost, Joseph

    2017-08-01

    Chemical penetration enhancers (CPEs) have long been used for mass transport enhancement across membranes. Many CPEs are used in a solution or gel and could be a solvent. The use of CPEs is mainly limited due to their toxicity/irritation levels. This study presents the evaluation of encapsulated CPEs in nano-sized polymeric particles on the chorioamnion (CA) membrane mass transport. CPEs' mass encapsulated in nanoparticles was decreased by 10,000-fold. Interestingly, this approach resulted in a 6-fold increase in mass transport across the CA. This approach may also be used with other CPEs' base applications necessitating lower CPE concentration. Applying Ultrasound (US) has shown to increase the release rate of and also the mass transport across the CA membrane. It is proposed that encapsulated CPEs penetrate into the CA membrane thus prolonging their exposure, possibly extending their penetration into the CA membrane, while insonation also deepens their penetration into the CA membrane. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The mass balance of a Proton Exchange Membrane Fuel Cell (PEMFC)

    International Nuclear Information System (INIS)

    Miloud, S.; Kamaruzzaman Sopian; Wan Ramli Wan Daud

    2006-01-01

    A Proton Exchange Membrane Fuel Cell (PEMFC), operating at low temperature uses a simple chemical process to combine hydrogen and oxygen into water, producing electric current and heat during the electrochemical reaction. This work concern on the theoretical consideration of the mass balance has been evaluated to predict the mass flow rate of the both gases (hydrogen/oxygen), the water mass balance, and the heat transfer in order to design a single cell PEMFC stack with a better flow field distributor on the performance of Polymer Electrolyte membrane fuel cells

  11. Statistical analysis of the effect of temperature and inlet humidities on the parameters of a semiempirical model of the internal resistance of a polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Giner-Sanz, J. J.; Ortega, E. M.; Pérez-Herranz, V.

    2018-03-01

    The internal resistance of a PEM fuel cell depends on the operation conditions and on the current delivered by the cell. This work's goal is to obtain a semiempirical model able to reproduce the effect of the operation current on the internal resistance of an individual cell of a commercial PEM fuel cell stack; and to perform a statistical analysis in order to study the effect of the operation temperature and the inlet humidities on the parameters of the model. First, the internal resistance of the individual fuel cell operating in different operation conditions was experimentally measured for different DC currents, using the high frequency intercept of the impedance spectra. Then, a semiempirical model based on Springer and co-workers' model was proposed. This model is able to successfully reproduce the experimental trends. Subsequently, the curves of resistance versus DC current obtained for different operation conditions were fitted to the semiempirical model, and an analysis of variance (ANOVA) was performed in order to determine which factors have a statistically significant effect on each model parameter. Finally, a response surface method was applied in order to obtain a regression model.

  12. Versatile inlet system for on-line compound-specific deltaD and delta13C gas chromatography-oxidation/reduction-isotope ratio mass spectrometry analysis of gaseous mixtures.

    Science.gov (United States)

    Henning, Mark; Strapoć, Dariusz; Lis, Grzegorz P; Sauer, Peter; Fong, Jon; Schimmelmann, Arndt; Pratt, Lisa M

    2007-01-01

    Compound-specific deltaD and delta13C analyses of gas mixtures are useful indicators of geochemical and environmental factors. However, the relative concentrations of individual components in gas mixtures (e.g., H2, CO2, methane, ethane, propane, i-butane, n-butane) may vary over several orders of magnitude. The determination of hydrogen and carbon compound-specific stable isotope ratios requires that the hydrogen and carbon dioxide produced from each separated component has a concentration adjusted to match the dynamic range of the stable isotope mass spectrometer. We present a custom-built gas sampling and injection system (GASIS) linked with a Delta Plus XP mass spectrometer that provides flexibility, ease of operation, and economical use of small gas samples with wide ranges of analyte concentrations. The overall on-line GC-ox/red-IRMS (Gas Chromatography - oxidation/reduction - Isotope Ratio Mass Spectrometry) system consists of (i) a customized GASIS inlet system and (ii) two alternative reactors, namely an oxidative Cu-Ni-Pt reactor at 950 degrees C for production of CO2 and a reductive graphitized Al2O3 reactor at 1420 degrees C for production of H2. In addition, the system is equipped with (iii) a liquid nitrogen spray-cooling unit for cryo-GC-focusing at -20 degrees C, and (iv) a Nafion dryer for removal of water vapor from product CO2. The three injection loops of the GASIS inlet allow flexibility in the volume of injected analyte gas (e.g., from 0.06 to 500 microL) in order to measure reproducible deltaD and delta13C values for gases at concentrations ranging from 100% down to 10 ppm. We calibrate our GC-ox/red-IRMS system with two isotopically distinct methane references gases that are combusted off-line and characterized using dual-inlet IRMS. Copyright 2007 John Wiley & Sons, Ltd.

  13. Early Detection of Biofouling on Water Purification Membranes by Ambient Ionization Mass Spectrometry Imaging.

    Science.gov (United States)

    Jakka Ravindran, Swathy; Kumar, Ramesh; Srimany, Amitava; Philip, Ligy; Pradeep, Thalappil

    2018-01-02

    By direct analysis of water purification membranes using ambient ionization mass spectrometry, an attempt has been made to understand the molecular signatures of bacterial fouling. Membrane based purification methods are used extensively in water treatment, and a major challenge for them is biofouling. The buildup of microbes and their extracellular polymeric matrix clog the purification membranes and reduce their efficiency. To understand the early stages of bacterial fouling on water purification membranes, we have used desorption electrospray ionization mass spectrometry (DESI MS), where ion formation occurs in ambient conditions and the ionization event is surface sensitive. Biosurfactants at the air-water interface generated by microorganisms as a result of quorum sensing, influence the water-membrane interface and are important for the bacterial attachment. We show that these biosurfactants produced by bacteria can be indicator molecular species signifying initiation of biofilms on membrane surfaces, demonstrated by specific DESI MS signatures. In Pseudomonas aeruginosa, one of the best studied models for biofilm formation, this process is mediated by rhamnolipids forewarning bacterial fouling. Species dependent variation of such molecules can be used for the precise identification of the microorganisms, as revealed by studies on P. aeroginosa (ATCC 25619). The production of biosurfactants is tightly regulated at the transcriptional level by the quorum-sensing (QS) response. Thus, secretion of these extracellular molecules across the membrane surface allows rapid screening of the biofilm community. We show that, the ambient ionization mass spectrometry can detect certain toxic heavy metals present in water, using surfactant-metal complexes as analytes. We believe that such studies conducted on membranes in various input water streams will help design suitable membrane processes specific to the input streams.

  14. Heat-And-Mass Transfer Relationship to Determine Shear Stress in Tubular Membrane Systems

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Nopens, Ingmar

    2012-01-01

    The main drawback of Membrane Bioreactors (MBRs) is the fouling of the membrane. One way to reduce this fouling is through controlling the hydrodynamics of the two-phase slug flow near the membrane surface. It has been proven in literature that the slug flow pattern has a higher scouring effect...... measurements are required. Therefore, this work proposes an alternative method that uses already existing heat transfer relationships for two phase flow and links them through a dimensionless number to the mass transfer coefficient (Sherwood number) to obtain an empirical relationship which can be used...

  15. Theoretical studies on membrane-based gas separation using computational fluid dynamics (CFD) of mass transfer

    International Nuclear Information System (INIS)

    Sohrabi, M.R.; Marjani, A.; Davallo, M.; Moradi, S.; Shirazian, S.

    2011-01-01

    A 2D mass transfer model was developed to study carbon dioxide removal by absorption in membrane contactors. The model predicts the steady state absorbent and carbon dioxide concentrations in the membrane by solving the conservation equations. The continuity equations for three sub domains of the membrane contactor involving the tube; membrane and shell were obtained and solved by finite element method (FEM). The model was based on 'non-wetted mode' in which the gas phase filled the membrane pores. Laminar parabolic velocity profile was used for the liquid flow in the tube side; whereas, the gas flow in the shell side was characterized by Happel's free surface model. Axial and radial diffusion transport inside the shell, through the membrane, and within the tube side of the contactor was considered in the mass transfer model. The predictions of percent CO/sub 2/ removal obtained by modeling were compared with the experimental values obtained from literature. They were the experimental results for CO/sub 2/ removal from CO/sub 2//N/sub 2/ gas mixture with amines aqueous solutions as the liquid solvent using polypropylene membrane contactor. The modeling predictions were in good agreement with the experimental values for different values of gas and liquid flow rates. (author)

  16. Definition of the mitochondrial proteome by measurement of molecular masses of membrane proteins

    Science.gov (United States)

    Carroll, Joe; Fearnley, Ian M.; Walker, John E.

    2006-01-01

    The covalent structure of a protein is incompletely defined by its gene sequence, and mass spectrometric analysis of the intact protein is needed to detect the presence of any posttranslational modifications. Because most membrane proteins are purified in detergents that are incompatible with mass spectrometric ionization techniques, this essential measurement has not been made on many hydrophobic proteins, and so proteomic data are incomplete. We have extracted membrane proteins from bovine mitochondria and detergent-purified NADH:ubiquinone oxidoreductase (complex I) with organic solvents, fractionated the mixtures by hydrophilic interaction chromatography, and measured the molecular masses of the intact membrane proteins, including those of six subunits of complex I that are encoded in mitochondrial DNA. These measurements resolve long-standing uncertainties about the interpretation of the mitochondrial genome, and they contribute significantly to the definition of the covalent composition of complex I. PMID:17060615

  17. 3D Topography Design of Membranes for Enhanced Mass Transport

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Godinho, M.H.; Brogueira, P.; Figueirinhas, J.L.; Crespo, J.G.

    2008-01-01

    Roč. 321, č. 2 (2008), s. 337-343 ISSN 0376-7388 R&D Projects: GA ČR GA104/08/0600 Grant - others:SFRH(PT) BPD/9470/2002; POCTI(PT) EQU/35437/2000; POCTI(PT) CTM/56382/2004 Institutional research plan: CEZ:AV0Z40720504 Keywords : Ionic liquids * mass transport * pervaporation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.247, year: 2008

  18. Determination of membrane degradation products in the product water of polymer electrolyte membrane fuel cells using liquid chromatography mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zedda, Marco

    2011-05-12

    The predominant long term failure of polymer electrolyte membranes (PEM) is caused by hydroxyl radicals generated during fuel cell operation. These radicals attack the polymer, leading to chain scission, unzipping and consequently to membrane decomposition products. The present work has investigated decomposition products of novel sulfonated aromatic hydrocarbon membranes on the basis of a product water analysis. Degradation products from the investigated membrane type and the possibility to detect these compounds in the product water for diagnostic purposes have not been discovered yet. This thesis demonstrates the potential of solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) for the extraction, separation, characterization, identification and quantification of membrane degradation products in the product water of fuel cells. For this purpose, several polar aromatic hydrocarbons with different functional groups were selected as model compounds for the development of reliable extraction, separation and detection methods. The results of this thesis have shown that mixed mode sorbent materials with both weak anion exchange and reversed phase retention properties are well suited for reproducible extraction of both molecules and ions from the product water. The chromatographic separation of various polar aromatic hydrocarbons was achieved by means of phase optimized liquid chromatography using a solvent gradient and on a C18 stationary phase. Sensitive and selective detection of model compounds could be successfully demonstrated by the analysis of the product water using tandem mass spectrometry. The application of a hybrid mass spectrometer (Q Trap) for the characterization of unknown polar aromatic hydrocarbons has led to the identification and confirmation of 4-hydroxybenzoic acid in the product water. In addition, 4-HBA could be verified as a degradation product resulting from PEM decomposition by hydroxyl radicals using an

  19. Evaluation of vapor mass transfer in various membrane distillation configurations: an experimental study

    Science.gov (United States)

    Mannella, G. A.; La Carrubba, V.; Brucato, V.

    2012-06-01

    Vapor mass transfer phenomena in four different membrane distillation (MD) configurations were examined through a self-built laboratory scale experimental apparatus: Air Gap MD, Sweeping Gas MD, Vacuum Sweeping Gas MD and Vacuum MD. Vapor fluxes were measured and compared with those predicted by various models, showing that MD performance under usual processing conditions is severely controlled by the permeate side resistance to mass transfer.

  20. Experimental study on mass transfer of contaminants through an enthalpy recovery unit with polymer membrane foils

    DEFF Research Database (Denmark)

    Nie, Jinzhe; Fang, Lei

    2014-01-01

    Laboratory experimental studies were conducted to investigate the mass transfer of contaminants through a total heat recovery unit with polymer membranes foils. The studies were conducted in twin climate chambers which simulated outdoor and indoor thermal climates. One manufacturd total heat...... recovery unit with polymer membrane foils was used as refeering unit in this study. The experiments were conducted with different outdoor thermal climates e.g. warm-humid and cold-dry climates; isothermal and non isothermal as well as equal humidity and non equal humidity with indoor climate. Three...... membrane or due to both reasons. The results indicated that polymer membrane foils may be a choice for producing total heat recovering equipment in ventilation systems....

  1. Innovative use of membrane contactor as condenser for heat recovery in carbon capture.

    Science.gov (United States)

    Yan, Shuiping; Zhao, Shuaifei; Wardhaugh, Leigh; Feron, Paul H M

    2015-02-17

    The gas-liquid membrane contactor generally used as a nonselective gas absorption enhancement device is innovatively proposed as a condenser for heat recovery in liquid-absorbent-based carbon capture. The membrane condenser is used as a heat exchanger to recover the latent heat of the exiting vapor from the desorber, and it can help achieve significant energy savings when proper membranes with high heat-transfer coefficients are used. Theoretical thermodynamic analysis of mass and heat transfer in the membrane condensation system shows that heat recovery increases dramatically as inlet gas temperature rises and outlet gas temperature falls. The optimal split mass flow rate is determined by the inlet gas temperature and the overall heat-transfer coefficient in the condensation system. The required membrane area is also strongly dependent on the overall heat-transfer coefficient, particularly at higher inlet gas temperatures. Mass transfer across the membrane has an insignificant effect on heat transfer and heat recovery, suggesting that membrane wetting may not be an issue when a membrane condenser is used for heat recovery. Our analysis provides important insights into the energy recovery performance of the membrane condensation system as well as selection of operational parameters, such as split mass flow rate and membrane area, thickness, and thermal conductivity.

  2. Laser-activated membrane introduction mass spectrometry for high-throughput evaluation of bulk heterogeneous catalysts.

    Science.gov (United States)

    Nayar, Amit; Liu, Renxuan; Allen, Robert J; McCall, Michael J; Willis, Richard R; Smotkin, Eugene S

    2002-05-01

    Laser-activated membrane introduction mass spectrometry (LAMIMS), a high-throughput screening method, evaluates heterogeneous catalysts under realistic reactor conditions. It is a precise, versatile system requiring no moving parts. The catalyst array is supported on carbon paper overlaid upon a silicone rubber membrane configured in a variation of membrane introduction mass spectrometry as introduced by Cooks. The carbon paper serves as a heat-dissipating gas diffusion layer that permits laser heating of catalyst samples far above the decomposition temperature of the polymer membrane that separates the array from the mass spectrometer vacuum chamber. A computer-controlled CO2 bar code writing laser is used for fine-tune heating of the catalyst spots above the base temperature of the LAMIMS reactor. The detailed design and performance of LAMIMS is demonstrated on arrays of "real world" bulk water-gas shift catalysts using natural and isotopically labeled reactor feed streams. A bulk catalyst array spot can be evaluated for activity and selectivity in as little as 1.5 min. All array screening results were confirmed by industrial microreactor evaluations.

  3. Submicrometer Emitter ESI Tips for Native Mass Spectrometry of Membrane Proteins in Ionic and Nonionic Detergents

    Science.gov (United States)

    Susa, Anna C.; Lippens, Jennifer L.; Xia, Zijie; Loo, Joseph A.; Campuzano, Iain D. G.; Williams, Evan R.

    2018-01-01

    Native mass spectrometry (native-MS) of membrane proteins typically requires a detergent screening protocol, protein solubilization in the preferred detergent, followed by protein liberation from the micelle by collisional activation. Here, submicrometer nano-ESI emitter tips are used for native-MS of membrane proteins solubilized in both nonionic and ionic detergent solutions. With the submicrometer nano-ESI emitter tips, resolved charge-state distributions of membrane protein ions are obtained from a 150 mM NaCl, 25 mM Tris-HCl with 1.1% octyl glucoside solution. The relative abundances of NaCl and detergent cluster ions at high m / z are significantly reduced with the submicrometer emitters compared with larger nano-ESI emitters that are commonly used. This technique is beneficial for significantly decreasing the abundances (by two to three orders of magnitude compared with the larger tip size: 1.6 μm) of detergent cluster ions formed from aqueous ammonium acetate solutions containing detergents that can overlap with the membrane protein ion signal. Resolved charge-state distributions of membrane protein ions from aqueous ammonium acetate solutions containing ionic detergents were obtained with the submicrometer nano-ESI emitters; this is the first report of native-MS of membrane proteins solubilized by ionic detergents. [Figure not available: see fulltext.

  4. Mass transfer ranking of polylysine, poly-ornithine and poly-methylene-co-guanidine microcapsule membranes using a single low molecular mass marker

    Directory of Open Access Journals (Sweden)

    Rosinski Stefan

    2003-01-01

    Full Text Available On the long way to clinical transplantable hybrid systems, comprising of cells, acting as immuno-protected bioreactors microencapsulated in a polymeric matrix and delivering desired factors (proteins, hormones, enzymes etc to the patient's body, an important step is the optimization of the microcapsule. This topic includes the selection of a proper coating membrane which could fulfil, first of all, the mass transfer as well as biocompatibility, stability and durability requirements. Three different membranes from polymerised aminoacids, formed around exactly identical alginate gel cores, were considered, concerning their mass transport properties, as potential candidates in this task. The results of the evaluation of the mass ingress and mass transfer coefficient h for the selected low molecular mass marker, vitamin B12, in poly-L-lysine (HPLL poly-L-ornithine (HPLO and poly-methylene-co-guanidine hydrochloride (HPMCG membrane alginate microcapsules demonstrate the advantage of using the mass transfer approach to a preliminary screening of various microcapsule formulations. Applying a single marker and evaluating mass transfer coefficients can help to quickly rank the investigated membranes and microcapsules according to their permeability. It has been demonstrated that HPLL, HPLO and HPMCG microcapsules differ from each other by a factor of two concerning the rate of low molecular mass marker transport. Interesting differences in mass transfer through the membrane in both directions in-out was also found, which could possibly be related to the membrane asymmetry.

  5. Mass spectrometric study of rhamnolipid biosurfactants and their interactions with cell membrane phospholipids

    Directory of Open Access Journals (Sweden)

    Pashynska V. A.

    2009-12-01

    Full Text Available Aim. To examine the formation of supramolecular complexes of biogenous rhamnolipids with membrane phospholipids that is considered as a molecular mechanism of the biosurfactants antimicrobial action. Method. In the present work rhamnolipid biosurfactant samples produced by Pseudomonas sp. PS-17 strain have been investigated by electrospray ionization mass spectrometry for the first time. Results. As a result of the study, characteristic mass spectra of the rhamnolipid samples were obtained, that can be used as reference spectra for mass spectrometric identification of the compounds in any biological or industrial samples. At the next stage of the experiments the pair systems, containing the biosurfactants and a membrane phospholipid dipalmitoylphosphatidylcholine, have been tested. The cationized noncovalent complexes of the rhamnolipids with the phospholipid were observed in the spectra. Conclusions. The results obtained testify to the consideration that rhamnolipids (similar to other membranotropic agents can form stable supramolecular complexes with membrane phospholipids that are able to evoke the biosurfactants antimicrobial action. A great potential of electrospray ionization mass spectrometry for the biosurfactants identification and study has been demonstrated in the work.

  6. Spiral inlets for steam turbines

    Science.gov (United States)

    Škach, Radek; Uher, Jan

    2017-09-01

    This paper deals with the design process of special nozzle blades for spiral inlets. Spiral inlets are used for the first stages of high pressure and intermediate pressure steam turbines with both reaction and impulse blades when throttling or sliding pressure control is applied. They improve the steam flow uniformity from the inlet pipe and thus decrease the aerodynamic losses. The proposed evaluation of the inlet angle is based on the free vortex law.

  7. Trace level analysis of VOCs and semi-VOCs in aqueous solution using a direct insertion membrane probe and trap and release membrane introduction mass spectrometry

    OpenAIRE

    Mendes, MA; Eberlin, MN

    2000-01-01

    A new design for a trap and release membrane introduction mass spectrometry (T&R-MIMS) system using a removable direct insertion membrane probe (DIMP) for combined trace level analysis (low or sub ppb range) of volatile (VOC) and semi-volatile organic compounds (SVOCs) is reported. The system differs from the original T&R-MIMS system (M. Leth and F. R. Lauritsen, Rapid Commun. Mass Spectrom., 1995, 9, 591) as it uses a removable DIMP probe to place a capillary membrane loop inside the ion sou...

  8. Performance evaluation and mass transfer study of CO{sub 2} absorption in flat sheet membrane contactor using novel porous polysulfone membrane

    Energy Technology Data Exchange (ETDEWEB)

    Nabian, Nima; Ghoreyshi, Ali Asghar; Rahimpour, Ahmad; Shakeri, Mohsen [Babol University of Technology, Babol (Iran, Islamic Republic of)

    2015-11-15

    The performance of gas-liquid membrane contactor for CO{sub 2} capture was investigated using a novel polysulfone (PSF) flat membrane prepared via non-solvent phase inversion method. Polyvinyl pyrrolidone (PVP) was used as an additive in the dope solution of PSF membranes. Morphological studies by scanning electron microscopy (SEM) analysis revealed that PSF membrane with PVP has a finger-like structure, but the PSF membrane without PVP has a sponge-like structure. Also, characterization results through atomic force microscopy (AFM) and contact angle measurement demonstrated that the porosity, surface roughness and hydrophobicity of the PSF membrane increased with addition of PVP to the dope solution. Mass transfer resistance analysis, based on CO{sub 2} absorption flux, displayed that addition of PVP to the dope solution of PSF membrane decreased membrane mass transfer resistance, and significantly improved CO{sub 2} absorption flux up to 2.7 and 1.8 times of absorption fluxes of PSF membrane without PVP and commercial PVDF, respectively.

  9. Mass diffusion-based separation of sugars in a microfluidic contactor with nanofiltration membranes.

    Science.gov (United States)

    Kolfschoten, Ruben C; Janssen, Anja E M; Boom, Remko M

    2011-06-01

    Processes such as chromatographic separation and nanofiltration can remove low molecular weight sugars from liquid mixtures of oligosaccharides. As an alternative for the separation of such liquid mixtures, we studied mass diffusion separation of such sugars in a microfluidic device with incorporated nanofiltration membranes. This separation method is based on differences between diffusivities of components and does not require high transmembrane pressures. The effects of channel depth and flow rate were studied in experiments. The key parameters selectivity and rejection increased with increasing channel depth due to increased external mass transfer limitations. Among the studied membranes, the obtained selectivities and rejections correlated to the specified retention values by the manufacturers. Compared to more conventional nanofiltration where high pressure forces solutes through membranes, we obtained corresponding selectivities and fluxes of only an order of magnitude smaller. Simulated results indicated that with optimized microchannel and membrane dimensions, the presented separation process can compete with currently available separation technologies. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Intensification of heat and mass transfer by ultrasound: application to heat exchangers and membrane separation processes.

    Science.gov (United States)

    Gondrexon, N; Cheze, L; Jin, Y; Legay, M; Tissot, Q; Hengl, N; Baup, S; Boldo, P; Pignon, F; Talansier, E

    2015-07-01

    This paper aims to illustrate the interest of ultrasound technology as an efficient technique for both heat and mass transfer intensification. It is demonstrated that the use of ultrasound results in an increase of heat exchanger performances and in a possible fouling monitoring in heat exchangers. Mass transfer intensification was observed in the case of cross-flow ultrafiltration. It is shown that the enhancement of the membrane separation process strongly depends on the physico-chemical properties of the filtered suspensions. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Profiling of integral membrane proteins and their post translational modifications using high-resolution mass spectrometry

    Science.gov (United States)

    Souda, Puneet; Ryan, Christopher M.; Cramer, William A.; Whitelegge, Julian

    2011-01-01

    Integral membrane proteins pose challenges to traditional proteomics approaches due to unique physicochemical properties including hydrophobic transmembrane domains that limit solubility in aqueous solvents. A well resolved intact protein molecular mass profile defines a protein’s native covalent state including post-translational modifications, and is thus a vital measurement toward full structure determination. Both soluble loop regions and transmembrane regions potentially contain post-translational modifications that must be characterized if the covalent primary structure of a membrane protein is to be defined. This goal has been achieved using electrospray-ionization mass spectrometry (ESI-MS) with low-resolution mass analyzers for intact protein profiling, and high-resolution instruments for top-down experiments, toward complete covalent primary structure information. In top-down, the intact protein profile is supplemented by gas-phase fragmentation of the intact protein, including its transmembrane regions, using collisionally activated and/or electroncapture dissociation (CAD/ECD) to yield sequence-dependent high-resolution MS information. Dedicated liquid chromatography systems with aqueous/organic solvent mixtures were developed allowing us to demonstrate that polytopic integral membrane proteins are amenable to ESI-MS analysis, including top-down measurements. Covalent post-translational modifications are localized regardless of their position in transmembrane domains. Top-down measurements provide a more detail oriented high-resolution description of post-transcriptional and post-translational diversity for enhanced understanding beyond genomic translation. PMID:21982782

  12. [Analysis of mass minimization of Thermoelectric Integrated Membrane Evaporation Subsystem in waste water processing].

    Science.gov (United States)

    Ren, J X; Ji, C Y; Zhang, X R; Wang, S; Liang, X G; Guo, Z Y

    2001-02-01

    To minimize in the system level the designed mass of Thermoelectric Integrated Membrane Evaporation Subsystem (TIMES) of Environment Control Life Support System (ECLSS) in manned spacecraft, when the requirement of the production rate of fresh water and its hygiene is fulfilled. According to the characteristics of the operational process of TIMES, the physical and mathematical model for fluid flow, heat transfer and mass composition in its main parts were established to investigate numerically the relation between the system mass and those parameters associated with the structure and operation of the system. The system mass depended not only on the structural parameters and operational parameters of TIMES, but also on the operational characteristics of power subsystem and thermal control subsystem. The relative mass covered a large part of the system mass. There existed an optimum of the number of thermoelectric cooling parts and flow rate of circular waste water of the TIMES when the designed system mass was minimum. Moreover, higher condensation pressure in the system contributed to lower system mass.

  13. Nanodisc-based Co-immunoprecipitation for Mass Spectrometric Identification of Membrane-interacting Proteins

    DEFF Research Database (Denmark)

    Borch-Jensen, Jonas; Roepstorff, Peter; Møller-Jensen, Jakob

    2011-01-01

    Proteomic identification of protein interactions with membrane associated molecules in their native membrane environment pose a challenge because of technical problems of membrane handling. We investigate the possibility of employing membrane nanodiscs for harboring the membrane associated molecu...

  14. Identification of membrane proteins by tandem mass spectrometry of protein ions

    Science.gov (United States)

    Carroll, Joe; Altman, Matthew C.; Fearnley, Ian M.; Walker, John E.

    2007-01-01

    The most common way of identifying proteins in proteomic analyses is to use short segments of sequence (“tags”) determined by mass spectrometric analysis of proteolytic fragments. The approach is effective with globular proteins and with membrane proteins with significant polar segments between membrane-spanning α-helices, but it is ineffective with other hydrophobic proteins where protease cleavage sites are either infrequent or absent. By developing methods to purify hydrophobic proteins in organic solvents and by fragmenting ions of these proteins by collision induced dissociation with argon, we have shown that partial sequences of many membrane proteins can be deduced easily by manual inspection. The spectra from small proteolipids (1–4 transmembrane α-helices) are dominated usually by fragment ions arising from internal amide cleavages, from which internal sequences can be obtained, whereas the spectra from larger membrane proteins (5–18 transmembrane α-helices) often contain fragment ions from N- and/or C-terminal parts yielding sequences in those regions. With these techniques, we have, for example, identified an abundant protein of unknown function from inner membranes of mitochondria that to our knowledge has escaped detection in proteomic studies, and we have produced sequences from 10 of 13 proteins encoded in mitochondrial DNA. They include the ND6 subunit of complex I, the last of its 45 subunits to be analyzed. The procedures have the potential to be developed further, for example by using newly introduced methods for protein ion dissociation to induce fragmentation of internal regions of large membrane proteins, which may remain partially folded in the gas phase. PMID:17720804

  15. Determining Membrane Protein-Lipid Binding Thermodynamics Using Native Mass Spectrometry.

    Science.gov (United States)

    Cong, Xiao; Liu, Yang; Liu, Wen; Liang, Xiaowen; Russell, David H; Laganowsky, Arthur

    2016-04-06

    Membrane proteins are embedded in the biological membrane where the chemically diverse lipid environment can modulate their structure and function. However, the thermodynamics governing the molecular recognition and interaction of lipids with membrane proteins is poorly understood. Here, we report a method using native mass spectrometry (MS), to determine thermodynamics of individual ligand binding events to proteins. Unlike conventional methods, native MS can resolve individual ligand binding events and, coupled with an apparatus to control the temperature, determine binding thermodynamic parameters, such as for protein-lipid interactions. We validated our approach using three soluble protein-ligand systems (maltose binding protein, lysozyme, and nitrogen regulatory protein) and obtained similar results to those using isothermal titration calorimetry and surface plasmon resonance. We also determined for the first time the thermodynamics of individual lipid binding to the ammonia channel (AmtB), an integral membrane protein from Escherichia coli. Remarkably, we observed distinct thermodynamic signatures for the binding of different lipids and entropy-enthalpy compensation for binding lipids of variable chain length. Additionally, using a mutant form of AmtB that abolishes a specific phosphatidylglycerol (PG) binding site, we observed distinct changes in the thermodynamic signatures for binding PG, implying these signatures can identify key residues involved in specific lipid binding and potentially differentiate between specific lipid binding sites.

  16. Mass spectrometric characterization of the sarcoplasmic reticulum from rabbit skeletal muscle by on-membrane digestion.

    Science.gov (United States)

    Staunton, Lisa; Ohlendieck, Kay

    2012-03-01

    The sarcoplasmic reticulum from skeletal muscle constitutes an elaborate membrane system that contains a considerable number of integral and very large proteins that exist in highly complex supramolecular clusters. Conventional proteomics using two-dimensional gel electrophoresis greatly underestimates the presence of these proteins. Here, we have applied one-dimensional gradient gels and on-membrane digestion to overcome this technical problem. Mass spectrometric analysis has determined the presence of 31 distinct protein species in the sarcoplasmic reticulum, including key Ca2+-handling proteins such as the ryanodine receptor, Ca2+-ATPase, calsequestrin and sarcalumenin. Immunoblotting confirmed the relative position of these Ca2+-regulatory elements in analytical gel replicas. Interestingly, aldolase and phosphofructokinase were found to be present in the purified sarcoplasmic reticulum, supporting the idea of a close physical coupling between the glycolytic pathway and the energy-dependent sarcoplasmic reticulum. Hence, on-membrane digestion is highly suitable as the method of choice for studying integral and high-molecular-mass proteins in proteomic studies.

  17. Application of the mass-based UNIQUAC model to membrane systems: A critical revision

    International Nuclear Information System (INIS)

    Chovau, S.; Van der Bruggen, B.; Luis, P.

    2012-01-01

    Highlights: ► UNIQUAC model in mass-based terms is considered for the description of sorption equilibria in membrane systems. ► Model validation of molar and mass-based model is performed on simple (vapor + liquid) equilibrium. ► Discrepancy is found between molar and mass-based model, which is attributed to an incorrect conversion. ► Novel model based on correct thermodynamics is provided for future research. - Abstract: The UNIQUAC model is very suitable in describing (liquid + liquid) as well as (vapor + liquid) equilibrium for a wide range of systems. It can be extended to (solvent + polymer) systems for describing sorption equilibria. The original model is expressed in molar-based terms, but requires knowledge of structural parameters and molar masses of all components. Since these cannot always be easily determined for membranes, a conversion to mass-based terms is often performed, which eliminates this issue. Many studies use this model to calculate sorption equilibria in (solvent + polymer) systems. Nevertheless, in this work the conversion from molar to mass-based parameters is postulated to be erroneous. This even leads to an incorrect description of simple (vapor + liquid) equilibrium of pure liquid mixtures and hence it is advised not to use this model for further modeling of sorption equilibrium in (solvent + polymer) systems. In this paper, the errors in the conversion are pinpointed, and the effects it can have on the description of (vapor + liquid) equilibrium, if used improvident, are demonstrated. Furthermore, it is shown that in fact a simple and straightforward conversion can be performed. Finally, in the case when polymers are involved, an adaption and simplification to the model was successfully applied.

  18. Ice Protection of Turbojet Engines by Inertia Separation of Water III : Annular Submerged Inlets

    Science.gov (United States)

    Von Glahn, Uwe

    1948-01-01

    Aerodynamic and icing studies were conducted on a one-half-scale model of an annular submerged inlet for use with axial-flow turbojet engines. Pressure recoveries, screen radial-velocity profiles, circumferential mass-flow variations, and icing characteristics were determined at the compressor inlet. In order to be effective in maintaining water-free induction air, the inlet gap must be extremely small and ram-pressure recoveries consequently are low, the highest achieved being 65 percent at inlet-velocity ratio of 0.86. All inlets exhibited considerable screen icing. Severe mass-flow shifts occurred at angles of attack.

  19. Indirect evaporative cooler using membrane-contained, liquid desiccant for dehumidification

    Science.gov (United States)

    Kozubal, Eric Joseph

    2016-12-13

    An indirect evaporative cooler for cooling inlet supply air from a first temperature to a second, lower temperature using a stream of liquid coolant and a stream of exhaust or purge air. The cooler includes a first flow channel for inlet supply air and a second flow channel adjacent the first for exhaust air. The first and second flow channels are defined in part by sheets of a membrane permeable to water vapor such that mass is transferred as a vapor through the membrane from the inlet supply air to a contained liquid desiccant for dehumidification and also to the exhaust air as heat is transferred from the inlet supply air to the liquid coolant. A separation wall divides the liquid desiccant and the coolant but allows heat to be transferred from the supply air to the coolant which releases water vapor to the counter or cross flowing exhaust air.

  20. Experimental study on mass transfer of contaminants through an enthalpy recovery unit with polymer membrane foils

    DEFF Research Database (Denmark)

    Nie, Jinzhe; Fang, Lei

    2014-01-01

    unit tested was little to do with their molecule sizes and water solubility. The contaminants transfer of 5-9% in the total heat recovery unit tested is to be investigated further to determine the reasons e.g. due to air leakage in the unit or due to diffusion of the contaminants through the polymer......Laboratory experimental studies were conducted to investigate the mass transfer of contaminants through a total heat recovery unit with polymer membranes foils. The studies were conducted in twin climate chambers which simulated outdoor and indoor thermal climates. One manufacturd total heat...... recovery unit with polymer membrane foils was used as refeering unit in this study. The experiments were conducted with different outdoor thermal climates e.g. warm-humid and cold-dry climates; isothermal and non isothermal as well as equal humidity and non equal humidity with indoor climate. Three...

  1. Chemical crosslinking and mass spectrometry studies of the structure and dynamics of membrane proteins and receptors.

    Energy Technology Data Exchange (ETDEWEB)

    Haskins, William E.; Leavell, Michael D.; Lane, Pamela; Jacobsen, Richard B.; Hong, Joohee; Ayson, Marites J.; Wood, Nichole L.; Schoeniger, Joseph S.; Kruppa, Gary Hermann; Sale, Kenneth L.; Young, Malin M.; Novak, Petr

    2005-03-01

    Membrane proteins make up a diverse and important subset of proteins for which structural information is limited. In this study, chemical cross-linking and mass spectrometry were used to explore the structure of the G-protein-coupled photoreceptor bovine rhodopsin in the dark-state conformation. All experiments were performed in rod outer segment membranes using amino acid 'handles' in the native protein sequence and thus minimizing perturbations to the native protein structure. Cysteine and lysine residues were covalently cross-linked using commercially available reagents with a range of linker arm lengths. Following chemical digestion of cross-linked protein, cross-linked peptides were identified by accurate mass measurement using liquid chromatography-fourier transform mass spectrometry and an automated data analysis pipeline. Assignments were confirmed and, if necessary, resolved, by tandem MS. The relative reactivity of lysine residues participating in cross-links was evaluated by labeling with NHS-esters. A distinct pattern of cross-link formation within the C-terminal domain, and between loop I and the C-terminal domain, emerged. Theoretical distances based on cross-linking were compared to inter-atomic distances determined from the energy-minimized X-ray crystal structure and Monte Carlo conformational search procedures. In general, the observed cross-links can be explained by re-positioning participating side-chains without significantly altering backbone structure. One exception, between C3 16 and K325, requires backbone motion to bring the reactive atoms into sufficient proximity for cross-linking. Evidence from other studies suggests that residues around K325 for a region of high backbone mobility. These findings show that cross-linking studies can provide insight into the structural dynamics of membrane proteins in their native environment.

  2. The influence of polymeric membrane gas spargers on hydrodynamics and mass transfer in bubble column bioreactors

    DEFF Research Database (Denmark)

    Tirunehe, Gossay; Norddahl, B.

    2016-01-01

    Gas sparging performances of a flat sheet and tubular polymeric membranes were investigated in 3.1 m bubble column bioreactor operated in a semi batch mode. Air–water and air–CMC (Carboxymethyl cellulose) solutions of 0.5, 0.75 and 1.0 % w/w were used as interacting gas–liquid mediums. CMC...... solutions were employed in the study to simulate rheological properties of bioreactor broth. Gas holdup, bubble size distribution, interfacial area and gas–liquid mass transfer were studied in the homogeneous bubbly flow hydrodynamic regime with superficial gas velocity (UG) range of 0.0004–0.0025 m...

  3. Mathematical modeling of water mass balance for proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Wan Ramli Wan Daud; Kamaruzzaman Sopian; Jaafar Sahari; Nik Suhaimi Mat Hassan

    2006-01-01

    Gas and water management are key to achieving good performance from a proton exchange membrane fuel cell (PEMFC) stack. Water plays a critical role in PEMFC. The proton conductivity is increase with the water content. In order to achieve enough hydration, water is normally introduced into the cell externally by a variety of methods such as liquid injection, steam introduction, and humidification of reactants by passing them through humidifiers before entering the cell. In this paper, mathematical modeling of water mass balance for PEMFC at anode and cathode side are proposed by using external humidification and assume that steady state, constant pressure, constant temperature and gases distribution are uniform

  4. Comparison of Theoretical and Experimental Mass Transfer Coefficients of Gases in Supported Ionic Liquid Membranes

    Czech Academy of Sciences Publication Activity Database

    Kárászová, Magda; Šimčík, Miroslav; Friess, K.; Randová, A.; Jansen, J. C.; Růžička, Marek; Sedláková, Zuzana; Izák, Pavel

    2013-01-01

    Roč. 118, 30 OCT (2013), s. 255-263 ISSN 1383-5866 R&D Projects: GA ČR GAP106/10/1194; GA MŠk(CZ) 7C11009 Grant - others:RFCS(XE) RFCR-CT-2010-00009; INP(IT) PON01_01840; HA MŠk(CZ) CZ.1.05/2.1.00/03.0071 Institutional support: RVO:67985858 Keywords : biogas purification * supported ionic liquid membranes * mass transfer coefficients Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.065, year: 2013

  5. Quantifying the loss of methane through secondary gas mass transport (or 'slip') from a micro-porous membrane contactor applied to biogas upgrading.

    Science.gov (United States)

    McLeod, Andrew; Jefferson, Bruce; McAdam, Ewan J

    2013-07-01

    Secondary gas transport during the separation of a binary gas with a micro-porous hollow fibre membrane contactor (HMFC) has been studied for biogas upgrading. In this application, the loss or 'slip' of the secondary gas (methane) during separation is a known concern, specifically since methane possesses the intrinsic calorific value. Deionised (DI) water was initially used as the physical solvent. Under these conditions, carbon dioxide (CO2) and methane (CH4) absorption were dependent upon liquid velocity (V(L)). Whilst the highest CO2 flux was recorded at high V(L), selectivity towards CO2 declined due to low residence times and a diminished gas-side partial pressure, and resulted in slip of approximately 5.2% of the inlet methane. Sodium hydroxide was subsequently used as a comparative chemical absorption solvent. Under these conditions, CO2 mass transfer increased by increasing gas velocity (VG) which is attributed to the excess of reactive hydroxide ions present in the solvent, and the fast conversion of dissolved CO2 to carbonate species reinitiating the concentration gradient at the gas-liquid interface. At high gas velocities, CH4 slip was reduced to 0.1% under chemical conditions. Methane slip is therefore dependent upon whether the process is gas phase or liquid phase controlled, since methane mass transport can be adequately described by Henry's law within both physical and chemical solvents. The addition of an electrolyte was found to further retard CH4 absorption via the salting out effect. However, their applicability to physical solvents is limited since electrolytic concentration similarly impinges upon the solvents' capacity for CO2. This study illustrates the significance of secondary gas mass transport, and furthermore demonstrates that gas-phase controlled systems are recommended where greater selectivity is required. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Coastal inlets and tidal basins

    NARCIS (Netherlands)

    De Vriend, H.J.; Dronkers, J.; Stive, M.J.F.; Van Dongeren, A.; Wang, J.H.

    2002-01-01

    lecture note: Tidal inlets and their associated basins (lagoons) are a common feature of lowland coasts all around the world. A significant part ofthe world's coastlines is formed by barrier island coasts, and most other tidal coasts are interrupted by estuaries and lagoon inlets. These tidal

  7. Combined Magnetohydrodynamic and Geometric Optimization of a Hypersonic Inlet

    Directory of Open Access Journals (Sweden)

    Kamesh Subbarao

    2009-01-01

    Full Text Available This paper considers the numerical optimization of a double ramp scramjet inlet using magnetohydrodynamic (MHD effects together with inlet ramp angle changes. The parameter being optimized is the mass capture at the throat of the inlet, such that spillage effects for less than design Mach numbers are reduced. The control parameters for the optimization include the MHD effects in conjunction with ramp angle changes. To enhance the MHD effects different ionization scenarios depending upon the alignment of the magnetic field are considered. The flow solution is based on the Advection Upstream Splitting Method (AUSM that accounts for the MHD source terms as well. A numerical Broyden-Flecher-Goldfarb-Shanno- (BFGS- based procedure is utilized to optimize the inlet mass capture. Numerical validation results compared to published results in the literature as well as the outcome of the optimization procedure are summarized to illustrate the efficacy of the approach.

  8. Quantitative Imaging of Cell Membrane-associated Effective Mass Density Using Photonic Crystal Enhanced Microscopy (PCEM)

    Science.gov (United States)

    Zhuo, Yue; Choi, Ji Sun; Marin, Thibault; Yu, Hojeong; Harley, Brendan A.; Cunningham, Brian T.

    2017-01-01

    Adhesion is a critical cellular process that contributes to migration, apoptosis, differentiation, and division. It is followed by the redistribution of cellular materials at the cell membrane or at the cell-surface interface for cells interacting with surfaces, such as basement membranes. Dynamic and quantitative tracking of changes in cell adhesion mass redistribution is challenging because cells are rapidly moving, inhomogeneous, and nonequilibrium objects, whose physical and mechanical properties are difficult to measure or predict. Here, we report a novel biosensor based microscopy approach termed Photonic Crystal Enhanced Microscopy (PCEM) that enables the movement of cellular materials at the plasma membrane of individual live cells to be dynamically monitored and quantitatively imaged. PCEM utilizes a photonic crystal biosensor surface, which can be coated with arbitrary extracellular matrix materials to facilitate cellular interactions, within a modified brightfield microscope with a low intensity non-coherent light source. Benefiting from the high sensitivity, narrow resonance peak, and tight spatial confinement of the evanescent field atop the photonic crystal biosensor, PCEM enables label-free live cell imaging with high sensitivity and high lateral and axial spatial-resolution, thereby allowing dynamic adhesion phenotyping of single cells without the use of fluorescent tags or stains. We apply PCEM to investigate adhesion and the early stage migration of different types of stem cells and cancer cells. By applying image processing algorithms to analyze the complex spatiotemporal information generated by PCEM, we offer insight into how the plasma membrane of anchorage dependent cells is dynamically organized during cell adhesion. The imaging and analysis results presented here provide a new tool for biologists to gain a deeper understanding of the fundamental mechanisms involved with cell adhesion and concurrent or subsequent migration events. PMID

  9. Sound Attenuation of Membranes Loaded with Square Frame-Shaped Masses

    Directory of Open Access Journals (Sweden)

    J. S. Chen

    2016-01-01

    Full Text Available This study examines sound transmission of thin membranes with square frame-shaped masses. Numerical results indicate that multiple transmission loss peaks can be generated by adding more frame mass inclusions. The number and the location of the peaks are controlled by the number of frames, the frame distribution, and the frame width. Near the transmission loss peak frequencies, the dynamic effective mass density turns from positive to negative. The validity of the present model has been verified by comparing the analytical results with FE results. Two types of cell arrangements are also considered in this study, namely, cells in series and cells in array. It is seen that either the stacked or array configurations can produce better sound attenuation than single-celled structures. Moreover, the frequency band where sound wave is blocked can be broadened by stacking more layers with different mass magnitudes. Furthermore, additional frequency bands due to the periodicity of the structure are found in the stacked configurations.

  10. Assessment of Mass Transfer Coefficients in Coalescing Slug Flow in Vertical Pipes and Applications to Tubular Airlift Membrane Bioreactors

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Berube, P.R.; Nopens, I.

    2011-01-01

    One of the operational challenges associated with membrane bioreactors (MBRs) is the fouling of the membranes. In tubular side-stream MBRs, fouling reduction can be achieved through controlling the hydrodynamics of the two-phase slug flow near the membrane surface. The two-phase slug flow induces......) cannot be applied directly. As an alternative, in this work, a multidisciplinary approach was selected, by exploiting dimensionless analysis using the Sherwood number. Mass transfer coefficients were measured at various superficial velocities of gas and liquid flow in a tubular system. Due...... to the variability of the mass transfer coefficient obtained for each experimental condition, the results were compiled into, mass transfer coefficient histograms (MTH) for analysis. A bimodal MTH was observed, with one peak corresponding to the mass transfer induced by the liquid flow, and the other peak induced...

  11. MALDI Imaging Mass Spectrometry of Integral Membrane Proteins from Ocular Lens and Retinal Tissue

    Science.gov (United States)

    Grey, Angus C.; Chaurand, Pierre; Caprioli, Richard M.; Schey, Kevin L.

    2009-01-01

    A tissue preparation protocol for MALDI (Matrix-Assisted Laser Desorption/Ionization) imaging mass spectrometry of an integral membrane protein was developed using ocular lens and retina tissues as model samples. Frozen bovine and human lenses were cryosectioned equatorially or axially at −20 °C into 20 μm-thick tissue sections. Lens sections were mounted onto gold-coated MALDI targets by methanol soft-landing to maintain tissue integrity. Tissue sections underwent extensive water washing to deplete the samples of highly abundant water-soluble proteins. Automated matrix deposition was achieved using an acoustic reagent multispotter, with sinapinic acid as matrix and high percentage acetonitrile as solvent, with a center-to-center spot spacing of 200–300 μm. Molecular images of full-length Aquaporin-0 (AQP0) and its most abundant truncation products were obtained from mass spectral data acquired across whole bovine and human lens sections. In equatorial and axial sections of bovine lenses, full-length AQP0 was detected throughout the lens. A truncation product corresponding to AQP0 (1–260) was detected in the bovine lens core at low abundance. In axial lens sections, no antero-posterior variation was detected. In 11 year-old human lens sections, full-length AQP0 was most abundant in the lens periphery, but was detected throughout the lens. The major truncation product, consisting of AQP0 residues 1–246, was absent from the lens periphery and increased in abundance in the lens core. This tissue preparation protocol was then applied to image the distribution of the G-protein coupled receptor, opsin, in the rabbit retina. This protocol has expanded the variety of target analytes which can be detected by MALDI imaging mass spectrometry to include integral membrane proteins. PMID:19326924

  12. A quantitative evaluation of ethylene production in the recombinant cyanobacterium Synechocystis sp PCC 6803 harboring the ethylene-forming enzyme by membrane inlet mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Zavřel, Tomáš; Knoop, H.; Steuer, R.; Jones, P. R.; Červený, Jan; Trtílek, M.

    2016-01-01

    Roč. 202, feb (2016), s. 142-151 ISSN 0960-8524 R&D Projects: GA MŠk(CZ) LO1415; GA ČR(CZ) GA15-17367S Institutional support: RVO:67179843 Keywords : biofuels * cyanobacteria * photobioreactor * MIMS * biotechnology Subject RIV: EH - Ecology, Behaviour Impact factor: 5.651, year: 2016

  13. Membrane introduction/laser photoionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Oser, Harald; Coggiola, Michael J; Young, Steven E; Crosley, David R; Hafer, Virginia; Grist, Gregory

    2007-04-01

    Two-photon resonance enhanced multiphoton ionization (REMPI) has been shown to be a unique ionization method for mass spectrometry, exhibiting both high sensitivity and chemical selectivity. Because REMPI is a gas-phase method, its applications have been limited either to direct analysis of vapor phase samples, or in conjunction with an initial laser desorption or other vaporization step. We describe here for the first time a combination of membrane introduction mass spectrometry (MIMS) and REMPI with time-of-flight mass spectrometry (TOF-MS), which allows for the direct analysis of trace amounts of organic compounds in water samples. The objective of our research was the detection of very low levels of aromatic contaminants, particularly benzene, toluene, and xylene (BTX), in aqueous solutions without interference due to the water. We have measured limits of detection (LOD) for selected aromatics in water below 1 part-per-trillion with an averaging time of less than 10 s using a continuous sample flow.

  14. Membrane funnel-based spray ionization for protein/peptide analysis by Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Yeung, Hoi Sze; Li, Wan; Wang, Ze; Wong, Y L Elaine; Chen, Xiangfeng; Chan, T-W Dominic

    2015-02-28

    Samples analyzed in proteomic studies by nanoelectrospray ionization (nanoESI) are extremely limited in quantity requiring careful sample handling to prevent loss upon transfer and to maintain sample concentration. To alleviate the operational process and reduce the cost of nanoESI, it is essential to develop more robust, simple and sensitive analytical variants of the process. Membrane funnel-based spray was developed for analysis of proteins/peptides in this study. The membrane funnel was fabricated from thin flexible membrane by a punching method using a homemade device. The performance of the membrane funnel-based spray was demonstrated by analyzing peptides, proteins and trypsin-digested samples in comparison of nanoESI and the Teflon sheet based microfunnel. Compared with the microfunnel, the membrane funnel can be fabricated easily by punching a thin flexible membrane using a sharp needle. Only 50 nL of sample was required for an analysis. The membrane funnel enhanced the spray sensitivity 100-fold. A total of 5 amol of on-spot sample loading was sufficient to provide a measurable signal on a 9.4 Tesla Fourier transform ion cyclotron resonance mass spectrometry system. High-mass proteins (up to 66 kDa) could be analyzed using this funnel-based spray system. Good sequence coverage was obtained for tryptic digested samples. A rapid, simple and cheap membrane funnel-based sample plate fabrication method was developed. The membrane funnel-based spray is a promising new variant of nanoESI capable of fast and sensitive analysis of peptides/proteins with great potential that could be extended to other applications, including quantitative analysis at high throughput and imaging mass spectrometry. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Pulsed hydrogen/deuterium exchange mass spectrometry for time-resolved membrane protein folding studies.

    Science.gov (United States)

    Khanal, Anil; Pan, Yan; Brown, Leonid S; Konermann, Lars

    2012-12-01

    Kinetic folding experiments by pulsed hydrogen/deuterium exchange (HDX) mass spectrometry (MS) are a well-established tool for water-soluble proteins. To the best of our knowledge, the current study is the first that applies this approach to an integral membrane protein. The native state of bacteriorhodopsin (BR) comprises seven transmembrane helices and a covalently bound retinal cofactor. BR exposure to sodium dodecyl sulfate (SDS) induces partial unfolding and retinal loss. We employ a custom-built three-stage mixing device for pulsed-HDX/MS investigations of BR refolding. The reaction is triggered by mixing SDS-denatured protein with bicelles. After a variable folding time (10 ms to 24 h), the protein is exposed to excess D(2) O buffer under rapid exchange conditions. The HDX pulse is terminated by acid quenching after 24 ms. Subsequent off-line analysis is performed by size exclusion chromatography and electrospray MS. These measurements yield the number of protected backbone N-H sites as a function of folding time, reflecting the recovery of secondary structure. Our results indicate that much of the BR secondary structure is formed quite late during the reaction, on a time scale of 10 s and beyond. It is hoped that in the future it will be possible to extend the pulsed-HDX/MS approach employed here to membrane proteins other than BR. Copyright © 2012 John Wiley & Sons, Ltd.

  16. On-chip electro membrane extraction with online ultraviolet and mass spectrometric detection

    DEFF Research Database (Denmark)

    Petersen, Nickolaj Jacob; Foss, Sunniva Taule; Jensen, Henrik

    2011-01-01

    Electro membrane extraction was demonstrated in a microfluidic device. The device was composed of a 25 μm thick porous polypropylene membrane bonded between two poly(methyl methacrylate) (PMMA) substrates, each having 50 μm deep channel structures facing the membrane. The supported liquid membran...

  17. Microporous hollow fibre membrane modules as gas-liquid contactors. Part 1: Physical mass transfer processes. A specific application: mass transfer in highly viscous liquids

    NARCIS (Netherlands)

    Kreulen, H.; Kreulen, H.; Versteeg, Geert; Smolders, C.A.; Smolders, C.A.; van Swaaij, Willibrordus Petrus Maria

    1993-01-01

    Gas-liquid mass transfer has been studied in a membrane module with non-wetted microporous fibres in the laminar flow regime. This new type of gas/liquid contactor can be operated stabily over a large range of gas and liquid flows because gas and liquid phase do not influence each other directly.

  18. Systematic cyanobacterial membrane proteome analysis by combining acid hydrolysis and digestive enzymes with nano-liquid chromatography-Fourier transform mass spectrometry.

    Science.gov (United States)

    Kwon, Joseph; Oh, Jeehyun; Park, Chiyoul; Cho, Kun; Kim, Seung Il; Kim, Soohyun; Lee, Sunghoon; Bhak, Jong; Norling, Birgitta; Choi, Jong-Soon

    2010-01-15

    The identification of membrane proteins is currently under-represented since the trans-membrane domains of membrane proteins have a hydrophobic property. Membrane proteins have mainly been analyzed by cleaving and identifying exposed hydrophilic domains. We developed the membrane proteomics method for targeting integral membrane proteins by the following sequential process: in-solution acid hydrolysis, reverse phase chromatographic separation, trypsin or chymotrypsin digestion and nano-liquid chromatography-Fourier transform mass spectrometry. When we employed total membrane proteins of Synechocystis sp. PCC 6803, 155 integral membrane proteins out of a predictable 706 were identified in a single application, corresponding to 22% of a genome. The combined methods of acid hydrolysis-trypsin (AT) and acid hydrolysis-chymotrypsin (AC) identified both hydrophilic and hydrophobic domains of integral membrane proteins, respectively. The systematic approach revealed a more concrete data in mapping the repertoire of cyanobacterial membrane and membrane-linked proteome. 2009 Elsevier B.V. All rights reserved.

  19. Evaluation of clayey masses compositions starting from the residue incorporation of the red ceramic industry to obtain tubular ceramic membranes

    International Nuclear Information System (INIS)

    Silva, Adriano Lima da; Chaves, Alexsandra Cristina; Luna, Carlos Bruno Barreto; Neves, Gelmires de Araujo; Lira, Helio de Lucena

    2017-01-01

    The inappropriate residue disposal of red ceramic industry is very high. Nowadays, one of the major challenges is the investigation of processes to obtain alternative materials, enabling the use of these residues to manufacture new materials. This work's objective is to study clayey masses' compositions starting from the residue incorporation of the red ceramic industry to be used in tubular ceramic membranes. Two compositions of ceramic masses were established, composition A (50% of residue) and composition B (70% of residue). Granulometric analysis of the ceramic masses presented an average size of particles, what indicates membranes in the microfiltration scale. Another observed factor is related to the increase of residue amount, what favored a decrease in the ceramic mass' plasticity. A rise in the apparent porosity was also observed, probably because of a possible growing in the bigger pores numbers, due to the sintering high temperature and the elevation of residue quantity itself. (author)

  20. High-performance liquid chromatography separation and intact mass analysis of detergent-solubilized integral membrane proteins

    Science.gov (United States)

    Berridge, Georgina; Chalk, Rod; D’Avanzo, Nazzareno; Dong, Liang; Doyle, Declan; Kim, Jung-In; Xia, Xiaobing; Burgess-Brown, Nicola; deRiso, Antonio; Carpenter, Elisabeth Paula; Gileadi, Opher

    2011-01-01

    We have developed a method for intact mass analysis of detergent-solubilized and purified integral membrane proteins using liquid chromatography–mass spectrometry (LC–MS) with methanol as the organic mobile phase. Membrane proteins and detergents are separated chromatographically during the isocratic stage of the gradient profile from a 150-mm C3 reversed-phase column. The mass accuracy is comparable to standard methods employed for soluble proteins; the sensitivity is 10-fold lower, requiring 0.2–5 μg of protein. The method is also compatible with our standard LC–MS method used for intact mass analysis of soluble proteins and may therefore be applied on a multiuser instrument or in a high-throughput environment. PMID:21093405

  1. Real time optimization of solar powered direct contact membrane distillation based on multivariable extremum seeking

    KAUST Repository

    Karam, Ayman M.

    2015-09-21

    This paper presents a real time optimization scheme for a solar powered direct contact membrane distillation (DCMD) water desalination system. The sun and weather conditions vary and are inconsistent throughout the day. Therefore, the solar powered DCMD feed inlet temperature is never constant, which influences the distilled water flux. The problem of DCMD process optimization has not been studied enough. In this work, the response of the process under various feed inlet temperatures is investigated, which demonstrates the need for an optimal controller. To address this issue, we propose a multivariable Newton-based extremum seeking controller which optimizes the inlet feed and permeate mass flow rates as the feed inlet temperature varies. Results are presented and discussed for a realistic temperature profile.

  2. Microporous hollow fibre membrane modules as gas-liquid contactors. Part 1. Physical mass transfer processes : A specific application

    NARCIS (Netherlands)

    Kreulen, H.; Versteeg, G.F.; Swaaij, W.P.M. van

    1993-01-01

    Gas-liquid mass transfer has been studied in a membrane module with non-wetted microporous fibres in the laminar flow regime. This new type of gas/liquid contactor can be operated stabily over a large range of gas and liquid flows because gas and liquid phase do not influence each other directly.

  3. Novel protein phosphorylation site identification in spinach stroma membranes by titanium dioxide microcolumns and tandem mass spectrometry

    DEFF Research Database (Denmark)

    Rinalducci, Sara; Larsen, Martin Røssel; Mohammed, Shabaz

    2006-01-01

    In this work, spinach stroma membrane, instead of thylakoid, has been investigated for the presence of phosphorylated proteins. We identified seven previously unknown phosphorylation sites by taking advantage of TiO(2) phosphopeptides enrichment coupled to mass spectrometric analysis. Upon illumi...

  4. Mass transfer in corrugated-plate membrane modules. II. Ultrafiltration experiments

    NARCIS (Netherlands)

    van der Waal, M.J.; Stevanovic, S.; Racz, I.G.

    1989-01-01

    The application of corrugations as turbulence promoters in membrane filtration was studied. In ultrafiltration experiments with polysulfone membranes using Dextran T70 as solute, it was found that the corrugations result in reduced energy consumption or pressure drop compared with flat membranes at

  5. Performance study for inlet installations

    Science.gov (United States)

    Bingaman, Donald C.

    1992-01-01

    A conceptual design trade study was conducted by McDonnell Aircraft Company (MCAIR) and NASA LARC PAB to determine the impact of inlet design features incorporated for reduced detectability on inlet performance, weight, and cost, for both fighter and attack-type aircraft. Quality Function Deployment (QFD) techniques were used to prioritize trade study issues, and select 'best' air induction system configurations for each of two notional aircraft, the Multi-Role Fighter (MRF) and the Advanced Medium Attack (AMA) bomber. Database deficiencies discovered in the trade study process were identified, and technology roadmaps were developed to address these deficiencies. Finally, two high speed inlet wind tunnel model concepts were developed for follow-on wind tunnel investigations.

  6. Rapid determination of bacterial aminoglycoside resistance in environmental samples using membrane electrospray ionization mass spectrometry.

    Science.gov (United States)

    Fan, Liusheng; Ke, Ming; Yuan, Min; Pu, Ji; Li, Juan; Lu, Jinxing; Xu, Jianguo; Zhang, Mei; Xu, Wei

    2016-08-01

    Antibiotic resistance in pathogenic bacteria is becoming a global public health problem, such as aminoglycoside resistance encoded by the armA gene. Although many methods have been reported, rapid analysis of environmental samples is still challenging. A rapid analytical method was developed in this study to determine bacterial aminoglycoside resistance using membrane electrospray ionization mass spectrometry (MESI-MS). Precursor/product-ion pairs of ArmA unique peptides were detected with minimal sample preparation. Standard peptides were synthesized and used for developing and validating the methodology, and then the method was verified by both ArmA positive and ArmA negative simulated environmental samples. A rapid method for determination of bacterial aminoglycoside resistance was developed using MESI-MS/MS. The bacterial cultural time was optimized to 2 hours, and the precision, accuracy and recovery of this method were investigated. The peptide IHSSTNER (IR-8) unique to ArmA in simulated environmental samples can be successfully identified within 3 hours. The novel assay offered a rapid method to determine bacterial aminoglycoside resistance with high sensitivity, accuracy and precision in simulated environmental samples. This method could also be applied to identify other drug-resistance proteins in clinical/environmental samples. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Exploring membrane protein structural features by oxidative labeling and mass spectrometry.

    Science.gov (United States)

    Konermann, Lars; Pan, Yan

    2012-10-01

    Despite their biological importance, the structural characterization of integral membrane proteins (IMPs) by x-ray crystallography and NMR spectroscopy remains challenging. Hence, there is a need for complementary approaches that are capable of probing IMP conformational features in a robust fashion. Covalent labeling relies on the principle that solvent accessible regions can be modified by reactive species, whereas buried segments are protected. The readout of the labeling pattern is conducted by mass spectrometry. Hydroxyl radical (·OH) introduces oxidative modifications at amino acid side chains. In this article, the authors discuss the application of ·OH labeling for the structural interrogation of IMPs. Kyte-Doolittle hydropathy analyses are widely used for generating IMP topology models. The validation of these models by mutational techniques is labor intensive. ·OH labeling can readily distinguish transmembrane elements from solvent-exposed loops, thereby providing an alternative topology validation tool. For IMPs with published crystal structures, oxidative modifications can report on functionally relevant dynamic features that are invisible in the static x-ray data. The coupling of pulsed ·OH labeling with rapid mixing techniques represents a novel approach for studying IMP folding kinetics. In conclusion, ·OH labeling is a versatile tool that can provide insights into the structure and dynamics of IMPs.

  8. Transmission geometry laserspray ionization vacuum using an atmospheric pressure inlet.

    Science.gov (United States)

    Lutomski, Corinne A; El-Baba, Tarick J; Inutan, Ellen D; Manly, Cory D; Wager-Miller, James; Mackie, Ken; Trimpin, Sarah

    2014-07-01

    This represents the first report of laserspray ionization vacuum (LSIV) with operation directly from atmospheric pressure for use in mass spectrometry. Two different types of electrospray ionization source inlets were converted to LSIV sources by equipping the entrance of the atmospheric pressure inlet aperture with a customized cone that is sealed with a removable glass plate holding the matrix/analyte sample. A laser aligned in transmission geometry (at 180° relative to the inlet) ablates the matrix/analyte sample deposited on the vacuum side of the glass slide. Laser ablation from vacuum requires lower inlet temperature relative to laser ablation at atmospheric pressure. However, higher inlet temperature is required for high-mass analytes, for example, α-chymotrypsinogen (25.6 kDa). Labile compounds such as gangliosides and cardiolipins are detected in the negative ion mode directly from mouse brain tissue as intact doubly deprotonated ions. Multiple charging enhances the ion mobility spectrometry separation of ions derived from complex tissue samples.

  9. Method for Determining Optimum Injector Inlet Geometry

    Science.gov (United States)

    Trinh, Huu P. (Inventor); Myers, W. Neill (Inventor)

    2015-01-01

    A method for determining the optimum inlet geometry of a liquid rocket engine swirl injector includes obtaining a throttleable level phase value, volume flow rate, chamber pressure, liquid propellant density, inlet injector pressure, desired target spray angle and desired target optimum delta pressure value between an inlet and a chamber for a plurality of engine stages. The method calculates the tangential inlet area for each throttleable stage. The method also uses correlation between the tangential inlet areas and delta pressure values to calculate the spring displacement and variable inlet geometry of a liquid rocket engine swirl injector.

  10. Key factors regulating the mass delivery of macromolecules to model cell membranes

    DEFF Research Database (Denmark)

    Campbell, Richard A.; Watkins, Erik B.; Jagalski, Vivien

    2014-01-01

    We show that both gravity and electrostatics are key factors regulating interactions between model cell membranes and self-assembled liquid crystalline aggregates of dendrimers and phospholipids. The system is a proxy for the trafficking of reservoirs of therapeutic drugs to cell membranes for sl...... of the aggregates to activate endocytosis pathways on specific cell types is discussed in the context of targeted drug delivery applications.......We show that both gravity and electrostatics are key factors regulating interactions between model cell membranes and self-assembled liquid crystalline aggregates of dendrimers and phospholipids. The system is a proxy for the trafficking of reservoirs of therapeutic drugs to cell membranes for slow...

  11. Low molecular weight components in an aquatic humic substance as characterized by membrane dialysis and orbitrap mass spectrometry.

    Science.gov (United States)

    Remucal, Christina K; Cory, Rose M; Sander, Michael; McNeill, Kristopher

    2012-09-04

    Suwannee River fulvic acid (SRFA) was dialyzed through a 100-500 molecular weight cutoff dialysis membrane, and the dialysate and retentate were analyzed by UV-visible absorption and high-resolution Orbitrap mass spectrometry (MS). A significant fraction (36% based on dissolved organic carbon) of SRFA passed through the dialysis membrane. The fraction of SRFA in the dialysate had a different UV-visible absorption spectrum and was enriched in low molecular weight molecules with a more aliphatic composition relative to the initial SRFA solution. Comparison of the SRFA spectra collected by Orbitrap MS and Fourier transform ion cyclotron resonance MS (FT-ICR MS) demonstrated that the mass accuracy of the Orbitrap MS is sufficient for determination of unique molecular formulas of compounds with masses masses detected by Orbitrap MS were found in the 100-200 Da mass range. Many of these low molecular masses corresponded to molecular formulas of previously identified compounds in organic matter, lignin, and plants, and the use of the standard addition method provided an upper concentration estimate of selected target compounds in SRFA. Collectively, these results provide evidence that SRFA contains low molecular weight components that are present individually or in loosely bound assemblies.

  12. Mass and Heat Transfer in Ion-Exchange Membranes Applicable to Solid Polymer Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Otteroey, M.

    1996-04-01

    In this doctoral thesis, an improved emf method for determination of transference numbers of two counter ions in ion-exchange membranes is presented. Transference numbers were obtained as a continuous function of the composition. The method avoids problems with diffusion by using a stack of membranes. Water transference coefficients in ion-exchange membranes is discussed and reversible and irreversible water transfer is studied by emf methods. Efforts were made to get data relevant to the solid polymer fuel cell. The results support the findings of other researchers that the reversible water transfer is lower than earlier predicted. A chapter on the conductivity of ion-exchange membranes establishes a method to separate the very thin liquid layers surrounding the membranes in a stack. Using the method it was found that the conductivity is obtained with high accuracy and that the liquid layer in a membrane stack can contribute significantly to the total measured resistance. A four point impedance method was tested to measure the conductivity of membranes under fuel cell conditions. Finally, there is a discussion of reversible heat effects and heat transfer in ion-exchange membranes. 155 refs., 45 figs., 13 tabs.

  13. Large-scale analysis of in Vivo phosphorylated membrane proteins by immobilized metal ion affinity chromatography and mass spectrometry

    DEFF Research Database (Denmark)

    Nühse, Thomas S; Stensballe, Allan; Jensen, Ole N

    2003-01-01

    Global analyses of protein phosphorylation require specific enrichment methods because of the typically low abundance of phosphoproteins. To date, immobilized metal ion affinity chromatography (IMAC) for phosphopeptides has shown great promise for large-scale studies, but has a reputation for poor...... specificity. We investigated the potential of IMAC in combination with capillary liquid chromatography coupled to tandem mass spectrometry for the identification of plasma membrane phosphoproteins of Arabidopsis. Without chemical modification of peptides, over 75% pure phosphopeptides were isolated from...... plasma membrane digests and detected and sequenced by mass spectrometry. We present a scheme for two-dimensional peptide separation using strong anion exchange chromatography prior to IMAC that both decreases the complexity of IMAC-purified phosphopeptides and yields a far greater coverage...

  14. Osmotic Power Generation by Inner Selective Hollow Fiber Membranes: An investigation of thermodynamics, mass transfer, and module scale modelling

    KAUST Repository

    Xiong, Jun Ying

    2016-12-29

    A comprehensive analysis of fluid motion, mass transport, thermodynamics and power generation during pressure retarded osmotic (PRO) processes was conducted. This work aims to (1) elucidate the fundamental relationship among various membrane properties and operation parameters and (2) analyse their individual and combined impacts on PRO module performance. A state-of-the-art inner-selective thin-film composite (TFC) hollow fiber membrane was employed in the modelling. The analyses of mass transfer and Gibbs free energy of mixing indicate that the asymmetric nature of hollow fibers results in more significant external concentration polarization (ECP) in the lumen side of the inner-selective hollow fiber membranes. In addition, a trade-off relationship exists between the power density (PD) and the specific energy (SE). The PD vs. SE trade-off upper bound may provide a useful guidance whether the flowrates of the feed and draw solutions should be further optimized in order to (1) minimize the boundary thickness and (2) maximize the osmotic power generation. Two new terms, mass transfer efficiency and power harvesting efficiency for osmotic power generation, have been proposed. This work may provide useful insights to design and operate PRO modules with enhanced performance so that the PRO process becomes more promising in real applications in the near future.

  15. Morphodynamic modelling for Thuan An inlet, Vietnam

    NARCIS (Netherlands)

    Lam, T.N.; Stive, M.J.; Verhagen, H.J.; Wang, Z.B.

    2006-01-01

    Thuan An is a tidal inlet located in Vietnam in a tropical monsoon area. The inlet is very dynamic and variable under the influences of not only tides and waves from the sea but also flows and floods from upstream rivers. Therefore, morphodynamic behaviour of the inlet is very complicated and not

  16. Analytical and experimental evaluation of a 3-D hypersonic fixed-geometry, swept, mixed compression inlet

    Science.gov (United States)

    Agnone, Anthony M.

    1987-01-01

    The performance of a fixed-geometry, swept, mixed compression hypersonic inlet is presented. The experimental evaluation was conducted for a Mach number of 6.0 and for several angles of attack. The measured surface pressures and pitot pressure surveys at the inlet throat are compared to computations using a three-dimensional Euler code and an integral boundary layer theory. Unique features of the intake design, including the boundary layer control, insure a high inlet performance. The experimental data show the inlet has a high mass averaged total pressure recovery, a high mass capture and nearly uniform flow diffusion. The swept inlet exhibits excellent starting characteristics, and high flow stability at angle of attack.

  17. Euler Calculations at Off-Design Conditions for an Inlet of Inward Turning RBCC-SSTO Vehicle

    Science.gov (United States)

    Takashima, N.; Kothari, A. P.

    1998-01-01

    The inviscid performance of an inward turning inlet design is calculated computationally for the first time. Hypersonic vehicle designs based on the inward turning inlets have been shown analytically to have increased effective specific impulse and lower heat load than comparably designed vehicles with two-dimensional inlets. The inward turning inlets are designed inversely from inviscid stream surfaces of known flow fields. The computational study is performed on a Mach 12 inlet design to validate the performance predicted by the design code (HAVDAC) and calculate its off-design Mach number performance. The three-dimensional Euler equations are solved for Mach 4, 8, and 12 using a software package called SAM, which consists of an unstructured mesh generator (SAMmesh), a three-dimensional unstructured mesh flow solver (SAMcfd), and a CAD-based software (SAMcad). The computed momentum averaged inlet throat pressure is within 6% of the design inlet throat pressure. The mass-flux at the inlet throat is also within 7 % of the value predicted by the design code thereby validating the accuracy of the design code. The off-design Mach number results show that flow spillage is minimal, and the variation in the mass capture ratio with Mach number is comparable to an ideal 2-D inlet. The results from the inviscid flow calculations of a Mach 12 inward turning inlet indicate that the inlet design has very good on and off-design performance which makes it a promising design candidate for future air-breathing hypersonic vehicles.

  18. Comparative analysis of the uropathogenic Escherichia coli surface proteome by tandem mass-spectrometry of artificially induced outer membrane vesicles.

    Science.gov (United States)

    Wurpel, Daniël J; Moriel, Danilo G; Totsika, Makrina; Easton, Donna M; Schembri, Mark A

    2015-02-06

    Uropathogenic Escherichia coli (UPEC) are the major cause of urinary tract infections. For successful colonisation of the urinary tract, UPEC employ multiple surface-exposed or secreted virulence factors, including adhesins and iron uptake systems. Whilst individual UPEC strains and their virulence factors have been the focus of extensive research, there have been no outer membrane (OM) proteomic studies based on large clinical UPEC collections, primarily due to limitations of traditional methods. In this study, a high-throughput method based on tandem mass-spectrometry of EDTA heat-induced outer membrane vesicles (OMVs) was developed for the characterisation of the UPEC surface-associated proteome. The method was applied to compare the OM proteome of fifty-four UPEC isolates, resulting in the identification of 8789 proteins, consisting of 619 unique proteins, which were subsequently interrogated for their subcellular origin, prevalence and homology to characterised virulence factors. Multiple distinct virulence-associated proteins were identified, including two novel putative iron uptake proteins, an uncharacterised type of chaperone-usher fimbriae and various highly prevalent hypothetical proteins. Our results give fundamental insight into the physiology of UPEC and provide a framework for understanding the composition of the UPEC OM proteome. In this study a high-throughput method based on tandem mass-spectrometry of EDTA heat-induced outer membrane vesicles was used to define the outer membrane proteome of a large uropathogenic E. coli (UPEC) collection. Our results provide an inventory of proteins expressed on the surface of UPEC, and provide a framework for understanding the composition of the UPEC OM proteome. The method enables the rapid characterisation of the E. coli surface proteome and could easily be applied to the large-scale outer membrane protein profiling of other Gram-negative bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. A one-step strategy for ultra-fast and low-cost mass production of plastic membrane microfluidic chips.

    Science.gov (United States)

    Hu, Chong; Lin, Sheng; Li, Wanbo; Sun, Han; Chen, Yangfan; Chan, Chiu-Wing; Leung, Chung-Hang; Ma, Dik-Lung; Wu, Hongkai; Ren, Kangning

    2016-10-05

    An ultra-fast, extremely cost-effective, and environmentally friendly method was developed for fabricating flexible microfluidic chips with plastic membranes. With this method, we could fabricate plastic microfluidic chips rapidly (within 12 seconds per piece) at an extremely low cost (less than $0.02 per piece). We used a heated perfluoropolymer perfluoroalkoxy (often called Teflon PFA) solid stamp to press a pile of two pieces of plastic membranes, low density polyethylene (LDPE) and polyethylene terephthalate (PET) coated with an ethylene-vinyl acetate copolymer (EVA). During the short period of contact with the heated PFA stamp, the pressed area of the membranes permanently bonded, while the LDPE membrane spontaneously rose up at the area not pressed, forming microchannels automatically. These two regions were clearly distinguishable even at the micrometer scale so we were able to fabricate microchannels with widths down to 50 microns. This method combines the two steps in the conventional strategy for microchannel fabrication, generating microchannels and sealing channels, into a single step. The production is a green process without using any solvent or generating any waste. Also, the chips showed good resistance against the absorption of Rhodamine 6G, oligonucleotides, and green fluorescent protein (GFP). We demonstrated some typical microfluidic manipulations with the flexible plastic membrane chips, including droplet formation, on-chip capillary electrophoresis, and peristaltic pumping for quantitative injection of samples and reagents. In addition, we demonstrated convenient on-chip detection of lead ions in water samples by a peristaltic-pumping design, as an example of the application of the plastic membrane chips in a resource-limited environment. Due to the high speed and low cost of the fabrication process, this single-step method will facilitate the mass production of microfluidic chips and commercialization of microfluidic technologies.

  20. Microporous hollow fibre membrane modules as gas-liquid contactors. Part 1: Physical mass transfer processes. A specific application: mass transfer in highly viscous liquids

    OpenAIRE

    Kreulen, H.; Kreulen, H.; Versteeg, Geert; Smolders, C.A.; Smolders, C.A.; van Swaaij, Willibrordus Petrus Maria

    1993-01-01

    Gas-liquid mass transfer has been studied in a membrane module with non-wetted microporous fibres in the laminar flow regime. This new type of gas/liquid contactor can be operated stabily over a large range of gas and liquid flows because gas and liquid phase do not influence each other directly. Therefore foam is not formed in the module, gas bubbles are not entrained in the liquid flowing out of the reactor and the separation of both phases can be achieved very easily. These phenomena often...

  1. Relative abundance of integral plasma membrane proteins in Arabidopsis leaf and root tissue determined by metabolic labeling and mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Katja Bernfur

    Full Text Available Metabolic labeling of proteins with a stable isotope ((15N in intact Arabidopsis plants was used for accurate determination by mass spectrometry of differences in protein abundance between plasma membranes isolated from leaves and roots. In total, 703 proteins were identified, of which 188 were predicted to be integral membrane proteins. Major classes were transporters, receptors, proteins involved in membrane trafficking and cell wall-related proteins. Forty-one of the integral proteins, including nine of the 13 isoforms of the PIP (plasma membrane intrinsic protein aquaporin subfamily, could be identified by peptides unique to these proteins, which made it possible to determine their relative abundance in leaf and root tissue. In addition, peptides shared between isoforms gave information on the proportions of these isoforms. A comparison between our data for protein levels and corresponding data for mRNA levels in the widely used database Genevestigator showed an agreement for only about two thirds of the proteins. By contrast, localization data available in the literature for 21 of the 41 proteins show a much better agreement with our data, in particular data based on immunostaining of proteins and GUS-staining of promoter activity. Thus, although mRNA levels may provide a useful approximation for protein levels, detection and quantification of isoform-specific peptides by proteomics should generate the most reliable data for the proteome.

  2. Application of zwitterionic detergents to the solubilization of integral membrane proteins for two-dimensional gel electrophoresis and mass spectrometry.

    Science.gov (United States)

    Henningsen, Robert; Gale, Brenda L; Straub, Kenneth M; DeNagel, Diane C

    2002-11-01

    Comparative analysis has long been utilized in biological research to interpret protein interactions in both drug naïve versus drug challenged and normal versus diseased tissues. The technology of proteomics today allows researchers to provide insight into old and still open questions related to biological mechanisms while offering the opportunity to discover novel details in cellular lifecycles. Perhaps the most powerful way to execute these differential displays is in the combination of two-dimensional (2-D) gel electrophoresis and mass spectrometry. While these two techniques together are well suited for abundant and soluble proteins found in cells, rare proteins and integral membrane proteins are still problematic. Recently, a series of novel zwitterionic detergents has been reported in the literature that shows a substantial improvement in solubilizing integral membrane proteins. We show that the amidosulfobetaine, 4-octylbenzol amidosulfobetaine, is better than 3-[(3-cholamidopropyl)dimethylamino]-1-propanesulfonate (CHAPS) at solubilizing both an ion channel and a G-protein coupled receptor (GPCR), while another amidosulfobetaine, myristic amidosulfobetaine (ASB-14), was better than CHAPS at solubilizing a GPCR. Neither membrane protein was visible after staining with colloidal Coomassie blue, silver nor Sypro Ruby. However, a comparison against a duplicate immunoblot allowed for the localization and identification of the ion channel from a 2-D gel by liquid chromatography-tandem mass spectrometry.

  3. Modeling the Transverse Shell-side Mass Transfer in Hollow Fiber Membrane Contactors at Low Reynolds Numbers

    Science.gov (United States)

    Kirsch, V. A.; Volkov, V. V.; Bildukevich, A. V.

    A method for calculating the external mass transfer in a contactor with a transverse confined flow of a viscous incompressible liquid (gas) past hollow fibers at low Reynolds numbers is proposed. The method is based on the concept of regular arrays of parallel fibers with a well-defined flowfield. As a simplest model system, a row of parallel fibers is considered, for which dependences of a drag force and an efficiency of a solute retention on the inter-fiber distance, membrane mass transfer coefficient, Peclet and Reynolds numbers are computed. The influence of the fluid inertia on the mass transport is studied. It is shown that a linear Stokes equations can be used for as higher Re numbers, as denser is the fiber array. In this case the flow field is independent on the Re number, and analytical solutions for the flowfield and fiber sorption efficiency (fiber Sherwood number) can be used.

  4. Stimulation of Slack K+ Channels Alters Mass at the Plasma Membrane by Triggering Dissociation of a Phosphatase-Regulatory Complex

    Directory of Open Access Journals (Sweden)

    Matthew R. Fleming

    2016-08-01

    Full Text Available Human mutations in the cytoplasmic C-terminal domain of Slack sodium-activated potassium (KNa channels result in childhood epilepsy with severe intellectual disability. Slack currents can be increased by pharmacological activators or by phosphorylation of a Slack C-terminal residue by protein kinase C. Using an optical biosensor assay, we find that Slack channel stimulation in neurons or transfected cells produces loss of mass near the plasma membrane. Slack mutants associated with intellectual disability fail to trigger any change in mass. The loss of mass results from the dissociation of the protein phosphatase 1 (PP1 targeting protein, Phactr-1, from the channel. Phactr1 dissociation is specific to wild-type Slack channels and is not observed when related potassium channels are stimulated. Our findings suggest that Slack channels are coupled to cytoplasmic signaling pathways and that dysregulation of this coupling may trigger the aberrant intellectual development associated with specific childhood epilepsies.

  5. Measurement of Membrane Characteristics Using the Phenomenological Equation and the Overall Mass Transport Equation in Ion-Exchange Membrane Electrodialysis of Saline Water

    Directory of Open Access Journals (Sweden)

    Yoshinobu Tanaka

    2012-01-01

    Full Text Available The overall membrane pair characteristics included in the overall mass transport equation are understandable using the phenomenological equations expressed in the irreversible thermodynamics. In this investigation, the overall membrane pair characteristics (overall transport number , overall solute permeability , overall electro-osmotic permeability and overall hydraulic permeability were measured by seawater electrodialysis changing current density, temperature and salt concentration, and it was found that occasionally takes minus value. For understanding the above phenomenon, new concept of the overall concentration reflection coefficient ∗ is introduced from the phenomenological equation. This is the aim of this investigation. ∗ is defined for describing the permselectivity between solutes and water molecules in the electrodialysis system just after an electric current interruption. ∗ is expressed by the function of and . ∗ is generally larger than 1 and is positive, but occasionally ∗ becomes less than 1 and becomes negative. Negative means that ions are transferred with water molecules (solvent from desalting cells toward concentrating cells just after an electric current interruption, indicating up-hill transport or coupled transport between water molecules and solutes.

  6. A Solution of the Convective-Diffusion Equation for Solute Mass Transfer inside a Capillary Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    B. Godongwana

    2010-01-01

    Full Text Available This paper presents an analytical model of substrate mass transfer through the lumen of a membrane bioreactor. The model is a solution of the convective-diffusion equation in two dimensions using a regular perturbation technique. The analysis accounts for radial-convective flow as well as axial diffusion of the substrate specie. The model is applicable to the different modes of operation of membrane bioreactor (MBR systems (e.g., dead-end, open-shell, or closed-shell mode, as well as the vertical or horizontal orientation. The first-order limit of the Michaelis-Menten equation for substrate consumption was used to test the developed model against available analytical results. The results obtained from the application of this model, along with a biofilm growth kinetic model, will be useful in the derivation of an efficiency expression for enzyme production in an MBR.

  7. The SC3 hydrophobin self-assembles into a membrane with distinct mass transfer properties

    NARCIS (Netherlands)

    Wang, [No Value; Shi, FX; Wosten, HAB; Hektor, H; Poolman, B; Robillard, GT; Wang, X.; Shi, Fuxin

    Hydrophobins are a class of small proteins that fulfill a wide spectrum of functions in fungal growth and development. They do so by self-assembling into an amphipathic membrane at hydrophilic-hydrophobic interfaces. The SC3 hydrophobin of Schizophyllum commune is the best-studied hydrophobin. It

  8. Single particle electron microscopy in combination with mass spectrometry to investigate novel complexes of membrane proteins

    NARCIS (Netherlands)

    Arteni, Ana A.; Nowaczyk, Marc; Lax, Julia; Rögner, Matthias; Boekema, Egbert J.; Kouril, R.; Rogner, M.

    2005-01-01

    Large data sets of molecular projections of the membrane proteins Photosystem I and Photosystem II from cyanobacteria were analyzed by single particle electron microscopy (EM). Analysis resulted in the averaging of 2D projections from the purified complexes but also in the simultaneous detection and

  9. Modelling of cross-flow membrane contactors : Physical mass transfer processes

    NARCIS (Netherlands)

    Dindore, V. Y.; Brilman, D. W. F.; Versteeg, G. F.

    2005-01-01

    Traditionally, hollow fiber membrane contactors used for gas-liquid contacting were designed in a shell and tube configuration with shell-side fluid flowing parallel to the fiber-side fluid, either in co-current or counter-current pattern. The primary limitations of these so-called 'parallel flow'

  10. Molecularly imprinted polymer (MIP) membrane assisted direct spray ionization mass spectrometry for agrochemicals screening in foodstuffs.

    Science.gov (United States)

    Pereira, Igor; Rodrigues, Marcella Ferreira; Chaves, Andréa Rodrigues; Vaz, Boniek Gontijo

    2018-02-01

    Paper spray ionization (PSI) has some limitations such as low sensitivity and ionization suppression when complex samples are analyzed. The use of sample preparation devices directly coupled to MS can avoid these restrictions. Molecularly imprinted polymers (MIPs) are materials widely used as adsorbent in sample preparation methods such as solid-phase extraction and solid-phase microextraction, and they can provide specifics cavities with affinity to a target molecule. Here, we introduce a new MIP membrane spray ionization method combining MIP and PSI. MIP was synthesized directly on a cellulose membrane. Monuron and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) were used as template molecules in MIP synthesis for diuron and 2,4-D (2,4-dichlorophenoxyacetic acid) analyte sequesters, respectively. Apple, banana and grape methanolic extracts were used as matrices. The MIP membrane spray showed signal intensities of diuron and 2,4-D that were much higher compared to those obtained by non-imprinted polymers(NIP). Calibration curves exhibited R 2 > 0.99 for diuron and 2,4-D in all fruit extracts analyzed. LODs were found less than 0.60µgL -1 and LLOQs were found less than 2.00µgL -1 . The coefficients of variation and relative errors were less than 15% for almost all analyses. The apparent recovery test results ranged between 92,5% and 116.9%. Finally, the MIP membrane spray method was employed for the quantification of diuron and 2,4-D in real samples. Diuron contents were only found in three bananas (4.0, 6.5, and 9.9µgL -1 ). The proposed MIP membrane spray ionization method was straightforward, fast to carry out and provided satisfactory results for analyses of diuron and 2,4-D in apple, banana and grape samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Microporous hollow fibre membrane modules as gas-liquid contactors. Part 1. Physical mass transfer processes: A specific application

    OpenAIRE

    Kreulen, H.; Versteeg, G.F.; Swaaij, W.P.M. van

    1993-01-01

    Gas-liquid mass transfer has been studied in a membrane module with non-wetted microporous fibres in the laminar flow regime. This new type of gas/liquid contactor can be operated stabily over a large range of gas and liquid flows because gas and liquid phase do not influence each other directly. Therefore foam is not formed in the module, gas bubbles are not entrained in the liquid flowing out of the reactor and the separation of both phases can be achieved very easily. These phenomena often...

  12. Mass-charge-heat coupled transfers in a single cell of a proton exchange membrane fuel cell; Transferts couples masse-charge-chaleur dans une cellule de pile a combustible a membrane polymere

    Energy Technology Data Exchange (ETDEWEB)

    Ramousse, J.

    2005-11-15

    Understanding and modelling of coupled mass, charges and heat transfers phenomena are fundamental to analyze the electrical behaviour of the system. The aim of the present model is to describe electrical performances of a PEFMC according to the fluidic and thermal operating conditions. The water content of the membrane and the water distribution in the single cell are estimated according to the coupled simulations of mass transport in the thickness of the single cell and in the feeding channels of the bipolar plates. A microscopic model of a Gas Diffusion Electrode is built up to describe charges transfer phenomena occurring at the electrodes. Completed by a study of heat transfer in the Membrane Electrode Assembly, conditions and preferential sites of water vapor condensation can be highlighted. A set of measurements of the effective thermal conductivity of carbon felts used in fuel cells as porous backing layers have also been performed. Although the value of this parameter is essential for the study of heat transfer, it is still under investigation because of the strong thermal anisotropy of the medium. (author)

  13. PENGARUH SIMULASI PENGARUH KONSENTRASI SOLID DAN GEOMETRI BIOREAKTOR MEMBRAN TERENDAM TERHADAP PERPINDAHAN MASSA GAS-LIQUID DAN FLUKS MELALUI MEMBRAN

    Directory of Open Access Journals (Sweden)

    Aisyah Endah Palupi

    2012-09-01

    Full Text Available Abstract: Hydrodynamics characteristic for the mixing of gas-solid-liquid in membrane bioreactor submerged (MBRs and its influence on mass transfer was studied computationally at various solid concentration, incoming gas rate, and the baffle distance. Computational method was conducted by using software GAMBIT 2.1.6. for the making of the grid which represents the calculation domain and conduct the simulation using CFD software FLUENT commercial code 6.2.16. Multiphase flow in reactor was simulated with mixture model, while to model the turbulence characteristic of the flow standard k-ε model was used. The geometrical system investigate is bioreactor in the form of box with flat bottom, 2 baffles, submerged membrane and air passage through the reactor bottom. The membrane type used is hollow fiber, the liquid used is water, and the solid is activated sludge, and air acts as gas phase. The result indicates that closer the baffle to the membrane, the liquid dispersion process goes faster, so that fluid in tank can be mixed perfectly and it can increase the gas-liquid mass transfer rate and the flux at MBRs. The increase of the solid concentration does not significantly affect the change of gas-liquid mass transfer rate and flux through the membrane, but the increase of air flow rate can accelerate the gas-liquid mass transfer and the flux. The position of baffle 9 cm from tank wall is the best position among the others because the amount of air flow is balanced with the circulating fluid flow. Consider from the solid distribution, double inlet MBRs is better compared to that of single inlet. Flux obtained does not show significant difference. From the both approach of the membrane model, membrane model as porous media give the simulation results closer to the experimental data.

  14. One dimensional transient numerical study of the mass heat and charge transfer in a proton exchange membrane for PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Djamel; Benmoussa, Hocine [Laboratory (LESEI), Faculty of Engineering, University of Batna (Algeria); Bourmada, Noureddine; Oulmi, Kafia [Laboratory LCCE, Faculty of Science, University of Batna (Algeria); Mahmah, Bouziane; Belhamel, Maiouf [CDER, BP, 62 Avenue-Observatoire, Bouzareah, Alger (Algeria)

    2009-06-15

    The objective of our study is to quantify the mass water transferred by various modes: diffusion, convection and migration. For the water transfer, the principal forces considered in the model are, the convection force, the osmotic force (i.e. diffusion) and the electric force (migration). The first of these forces results from a pressure gradient, the second of a concentration gradient and the third of a protons' migration from the anode to the cathode, which has an effect on the dipole of the water molecules (resistance force to the advancement). The numerical tool used to solve the equations' system is the finite element method. The results obtained numerically considering this method are concentration profiles and concentration variation with time and membrane thickness. These results illustrate the contribution of each mass transfer mode. (author)

  15. Assessing the Mitochondrial Membrane Potential in Cells and In Vivo using Targeted Click Chemistry and Mass Spectrometry.

    Science.gov (United States)

    Logan, Angela; Pell, Victoria R; Shaffer, Karl J; Evans, Cameron; Stanley, Nathan J; Robb, Ellen L; Prime, Tracy A; Chouchani, Edward T; Cochemé, Helena M; Fearnley, Ian M; Vidoni, Sara; James, Andrew M; Porteous, Carolyn M; Partridge, Linda; Krieg, Thomas; Smith, Robin A J; Murphy, Michael P

    2016-02-09

    The mitochondrial membrane potential (Δψm) is a major determinant and indicator of cell fate, but it is not possible to assess small changes in Δψm within cells or in vivo. To overcome this, we developed an approach that utilizes two mitochondria-targeted probes each containing a triphenylphosphonium (TPP) lipophilic cation that drives their accumulation in response to Δψm and the plasma membrane potential (Δψp). One probe contains an azido moiety and the other a cyclooctyne, which react together in a concentration-dependent manner by "click" chemistry to form MitoClick. As the mitochondrial accumulation of both probes depends exponentially on Δψm and Δψp, the rate of MitoClick formation is exquisitely sensitive to small changes in these potentials. MitoClick accumulation can then be quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This approach enables assessment of subtle changes in membrane potentials within cells and in the mouse heart in vivo. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Automated SDS Depletion for Mass Spectrometry of Intact Membrane Proteins though Transmembrane Electrophoresis.

    Science.gov (United States)

    Kachuk, Carolyn; Faulkner, Melissa; Liu, Fang; Doucette, Alan A

    2016-08-05

    Membrane proteins are underrepresented in proteome analysis platforms because of their hydrophobic character, contributing to decreased solubility. Sodium dodecyl sulfate is a favored denaturant in proteomic workflows, facilitating cell lysis and protein dissolution; however, SDS impedes MS detection and therefore must be removed prior to analysis. Although strategies exist for SDS removal, they provide low recovery, purity, or reproducibility. Here we present a simple automated device, termed transmembrane electrophoresis (TME), incorporating the principles of membrane filtration, but with an applied electric current to ensure near-complete (99.9%) removal of the surfactant, including protein-bound SDS. Intact proteins are recovered in solution phase in high yield (90-100%) within 1 h of operation. The strategy is applied to protein standards and proteome mixtures, including an enriched membrane fraction from E. coli, resulting in quality MS spectra free of SDS adducts. The TME platform is applicable to both bottom-up MS/MS as well as LC-ESI-MS analysis of intact proteins. SDS-depleted fractions reveal a similar number of protein identifications (285) compared wit a non-SDS control (280), being highly correlated in terms of protein spectral counts. This fully automated approach to SDS removal presents a viable tool for proteome sample processing ahead of MS analysis. Data are available via ProteomeXchange, identifier PXD003941.

  17. Interactions Between Wetlands and Tidal Inlets

    National Research Council Canada - National Science Library

    Sanchez, Alejandro

    2008-01-01

    This Coastal and Hydraulics Engineering Technical Note (CHETN) presents numerical simulations investigating how the loss of wetlands in estuaries modifies tidal processes in inlet navigation channels...

  18. Unsteady flow characteristic analysis of turbine based combined cycle (TBCC inlet mode transition

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2015-09-01

    Full Text Available A turbine based combined cycle (TBCC propulsion system uses a turbine-based engine to accelerate the vehicle from takeoff to the mode transition flight condition, at which point, the propulsion system performs a “mode transition” from the turbine to ramjet engine. Smooth inlet mode transition is accomplished when flow is diverted from one flowpath to the other, without experiencing unstart or buzz. The smooth inlet mode transition is a complex unsteady process and it is one of the enabling technologies for combined cycle engine to become a functional reality. In order to unveil the unsteady process of inlet mode transition, the research of over/under TBCC inlet mode transition was conducted through a numerical simulation. It shows that during the mode transition the terminal shock oscillates in the inlet. During the process of inlet mode transition mass flow rate and Mach number of turbojet flowpath reduce with oscillation. While in ramjet flowpath the flow field is non-uniform at the beginning of inlet mode transition. The speed of mode transition and the operation states of the turbojet and ramjet engines will affect the motion of terminal shock. The result obtained in present paper can help us realize the unsteady flow characteristic during the mode transition and provide some suggestions for TBCC inlet mode transition based on the smooth transition of thrust.

  19. Staged membrane oxidation reactor system

    Science.gov (United States)

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2012-09-11

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  20. Model mass spectrometric study of competitive interactions of antimicrobial bisquaternary ammonium drugs and aspirin with membrane phospholipids

    Directory of Open Access Journals (Sweden)

    Vekey K.

    2013-03-01

    Full Text Available The aim of the study is to reveal molecular mechanisms of possible activity modulation of antimicrobial bis-quaternary ammonium compounds (BQAC and aspirin (ASP through noncovalent competitive complexation under their combined introduction into the model systems with membrane phospholipids. Methods. Binary and triple systems containing either decamethoxinum or ethonium, or thionium and aspirin, as well as dipalmitoyl-phosphatidylcholine (DPPC have been investigated by electrospray ionization mass spectrometry. Results. Basing on the analysis of associates recorded in the mass spectra, the types of nonocovalent complexes formed in the systems studied were determined and the supposed role of the complexation in the BQAC and ASP activity modulation was discussed. The formation of associates of BQAC dications with ASP anion is considered as one of the possible ways of deactivation of ionic forms of the medications. The formation of stable complexes of BQAC with DPPC and ASP with DPPC in binary systems as well as the complexes distribution in triple-components systems BQAC:ASP:DPPC point to the existence of competition between drugs of these two types for the binding to DPPC. Conclusions. The results obtained point to the competitive complexation in the model molecular systems containing the BQAC, aspirin and membrane phospholipids. The observed phenomenon testifies to the possibility of modulating the activity of bisquaternary antimicrobial agents and aspirin under their combined usage, due to the competition between the drugs for binding to the target membrane phospholipid molecules and also due to the formation of stable noncovalent complexes between BQAC and ASP.

  1. Aerosol Inlet Characterization Experiment Report

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Robert L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kuang, Chongai [Brookhaven National Lab. (BNL), Upton, NY (United States); Uin, Janek [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Springston, Stephen R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-05-01

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility Aerosol Observation System inlet stack was characterized for particle penetration efficiency from 10 nm to 20 μm in diameter using duplicate scanning mobility particle sizers (10 nm-450 nm), ultra-high-sensitivity aerosol spectrometers (60 nm-μm), and aerodynamic particle sizers (0.5 μm-20 μm). Results show good model-measurement agreement and unit transmission efficiency of aerosols from 10 nm to 4 μm in diameter. Large uncertainties in the measured transmission efficiency exist above 4 μm due to low ambient aerosol signal in that size range.

  2. Modelling Complex Inlet Geometries in CFD

    DEFF Research Database (Denmark)

    Skovgaard, M.; Nielsen, Peter V.

    field. In order to apply CFD for this purpose it is essential to be able to model the inlet conditions precisely and effectively, in a way which is comprehensible to the manufacturer of inlet devices and in a way which can be coped with by the computer. In this paper a universal method is presented...

  3. Morphodynamics of Hue tidal inlets, Vietnam

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Verhagen, H.J.; Wang, Z.B.

    2007-01-01

    Morphodynamics of a tidal inlet system on a micro-tidal coast in a tropical monsoon influenced region is modelled and discussed. Effects of tides, waves, river flows and system configuration on the inlet morphologies are investigated with the aid of process-based state-of-the-art numerical models.

  4. Influence of Capillary Condensation Effects on Mass Transport through Porous Membranes

    Czech Academy of Sciences Publication Activity Database

    Uchytil, Petr; Petričkovič, Roman; Thomas, S.; Siedel-Morgenstern, A.

    2003-01-01

    Roč. 33, č. 3 (2003), s. 273-281 ISSN 1383-5866 R&D Projects: GA ČR GA104/01/0945 Institutional research plan: CEZ:AV0Z4072921 Keywords : capillary condensation * mass transport * gas separation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.355, year: 2003

  5. Label-free quantitative mass spectrometry for analysis of protein antigens in a meningococcal group B outer membrane vesicle vaccine.

    Science.gov (United States)

    Dick, Lawrence W; Mehl, John T; Loughney, John W; Mach, Anna; Rustandi, Richard R; Ha, Sha; Zhang, Lan; Przysiecki, Craig T; Dieter, Lance; Hoang, Van M

    2015-01-01

    The development of a multivalent outer membrane vesicle (OMV) vaccine where each strain contributes multiple key protein antigens presents numerous analytical challenges. One major difficulty is the ability to accurately and specifically quantitate each antigen, especially during early development and process optimization when immunoreagents are limited or unavailable. To overcome this problem, quantitative mass spectrometry methods can be used. In place of traditional mass assays such as enzyme-linked immunosorbent assays (ELISAs), quantitative LC-MS/MS using multiple reaction monitoring (MRM) can be used during early-phase process development to measure key protein components in complex vaccines in the absence of specific immunoreagents. Multiplexed, label-free quantitative mass spectrometry methods using protein extraction by either detergent or 2-phase solvent were developed to quantitate levels of several meningococcal serogroup B protein antigens in an OMV vaccine candidate. Precision was demonstrated to be less than 15% RSD for the 2-phase extraction and less than 10% RSD for the detergent extraction method. Accuracy was 70 to 130% for the method using a 2-phase extraction and 90-110% for detergent extraction. The viability of MS-based protein quantification as a vaccine characterization method was demonstrated and advantages over traditional quantitative methods were evaluated. Implementation of these MS-based quantification methods can help to decrease the development time for complex vaccines and can provide orthogonal confirmation of results from existing antigen quantification techniques.

  6. Internal Shock Interactions in Propulsion/Airframe Integrated Three-Dimensional Sidewall Compression Scramjet Inlets

    Science.gov (United States)

    Holland, Scott D.; Perkins, John N.

    1992-01-01

    The advantages and design requirements of propulsion/airframe integration for high Mach number flight have led to extensive study of the three-dimensional sidewall compression scramjet inlet in recent years. Recent research publications have indicated testing over a broad range of Mach number (2 to 18) in a variety of test gases, such as air, helium, and tetrafluoromethane. Multiple experimental techniques have been employed to obtain detailed internal shock interaction data, performance data, and inlet starting limits. Computational fluid dynamics has been effectively used for preliminary parametric studies as well as in parallel with experiments to aid in the explanation of unusual or unexpected flow phenomena. Inlets of this genre afford a relatively simple, generic geometry while producing a highly complex, three-dimensional flow field dominated by shock/shock and shock/boundary layer interactions. While the importance of the viscous effects in high speed inlet interactions is recognized, the present work addresses in a parametric fashion the inviscid effects of leading edge sweep, sidewall compression, and inflow Mach number on the internal shock structure in terms of inlet compression and mass capture. In the process, the source of the of the Mach number invariance with leading edge sweep for a constant sidewall compression class of inlet is identified, and a previously undocumented spillage phenomenon in a constant effective wedge angle class of inlets is discussed.

  7. Inlet Distortion Generation for a Transonic Compressor

    National Research Council Canada - National Science Library

    Papamarkos, Ioannis

    2004-01-01

    ... (and therefore engine) stall. Auxiliary injection was examined as a technique for generating distortion in inlet stagnation pressure, or temperature, or to simulate the more complex effects of engine, steam ingestion from a catapult launch...

  8. Bechevin Bay, Alaska, Inlet Stability Study.

    Science.gov (United States)

    1985-05-01

    Krenitzin. Bechevin Inlet, Bechevin Bay, and Isanotski Strait form an inlet system which * separates Unimak Island from the Alaska Peninsula. This...from the North Pacific must travel around Unimak Island through Unimak Pass. This route is 100-150 miles longer than the route through the Bechevin...period was semidiurnal, while the tidal flow at Unimak Pass (not too far southwest from the study area) was, interestingly, diurnal. Second, the phase

  9. JET ENGINE INLET DISTORTION SCREEN AND DESCRIPTOR EVALUATION

    Directory of Open Access Journals (Sweden)

    Jiří Pečinka

    2017-02-01

    Full Text Available Total pressure distortion is one of the three basic flow distortions (total pressure, total temperature and swirl distortion that might appear at the inlet of a gas turbine engine (GTE during operation. Different numerical parameters are used for assessing the total pressure distortion intensity and extent. These summary descriptors are based on the distribution of total pressure in the aerodynamic interface plane. There are two descriptors largely spread around the world, however, three or four others are still in use and can be found in current references. The staff at the University of Defence decided to compare the most common descriptors using basic flow distortion patterns in order to select the most appropriate descriptor for future department research. The most common descriptors were identified based on their prevalence in widely accessible publications. The construction and use of these descriptors are reviewed in the paper. Subsequently, they are applied to radial, angular, and combined distortion patterns of different intensities and with varied mass flow rates. The tests were performed on a specially designed test bench using an electrically driven standalone industrial centrifugal compressor, sucking air through the inlet of a TJ100 small turbojet engine. Distortion screens were placed into the inlet channel to create the desired total pressure distortions. Of the three basic distortions, only the total pressure distortion descriptors were evaluated. However, both total and static pressures were collected using a multi probe rotational measurement system.

  10. A membrane cell for on-line hydrogen/deuterium exchange to study protein folding and protein-protein interactions by mass spectrometry.

    Science.gov (United States)

    Astorga-Wells, Juan; Landreh, Michael; Johansson, Jan; Bergman, Tomas; Jörnvall, Hans

    2011-09-01

    A membrane cell for hydrogen and deuterium exchange on-line with mass spectrometry has been developed to monitor protein-protein interactions and protein conformations. It consists of two channels separated by a semipermeable membrane, where one channel carries the protein sample and the other deuterium oxide. The membrane allows transfer of deuterium oxide into the sample flow. The labeling time is controlled via the flow rate in the sample channel. This cell was validated against three models commonly used in hydrogen-deuterium exchange mass spectrometry: monitoring of folded and unfolded states in a protein, mapping the protein secondary structure at the peptide level, and detection of protein and antibody interactions. The system avoids the conventionally used sample dilution and handling, allowing for potential automation.

  11. A Membrane Cell for On-line Hydrogen/Deuterium Exchange to Study Protein Folding and Protein-Protein Interactions by Mass Spectrometry*

    Science.gov (United States)

    Astorga-Wells, Juan; Landreh, Michael; Johansson, Jan; Bergman, Tomas; Jörnvall, Hans

    2011-01-01

    A membrane cell for hydrogen and deuterium exchange on-line with mass spectrometry has been developed to monitor protein-protein interactions and protein conformations. It consists of two channels separated by a semipermeable membrane, where one channel carries the protein sample and the other deuterium oxide. The membrane allows transfer of deuterium oxide into the sample flow. The labeling time is controlled via the flow rate in the sample channel. This cell was validated against three models commonly used in hydrogen-deuterium exchange mass spectrometry: monitoring of folded and unfolded states in a protein, mapping the protein secondary structure at the peptide level, and detection of protein and antibody interactions. The system avoids the conventionally used sample dilution and handling, allowing for potential automation. PMID:21610101

  12. ATP-Mediated Compositional Change in Peripheral Myelin Membranes: A Comparative Raman Spectroscopy and Time-Of-Flight Secondary Ion Mass Spectrometry Study.

    Directory of Open Access Journals (Sweden)

    Nikolay Kutuzov

    Full Text Available In the present paper we addressed a mechanism of the myelin reorganization initiated by extracellular ATP and adenosine in sciatic nerves of the frog Rana temporaria. In combination with Raman microspectroscopy, allowing noninvasive live-cell measurements, we employed time-of-flight secondary ion mass spectrometry (TOF-SIMS to follow the underlying changes in chemical composition of myelin membranes triggered by the purinergic agents. The simultaneous increase in lipid ordering degree, decrease in membrane fluidity and the degree of fatty acid unsaturation were induced by both ATP and adenosine. Mass spectrometry measurements revealed that ATP administration also led to the marked elevation of membrane cholesterol and decrease of phosphotidylcholine amounts. Vesicular lipid transport pathways are considered as possible mechanisms of compositional and structural changes of myelin.

  13. ATP-Mediated Compositional Change in Peripheral Myelin Membranes: A Comparative Raman Spectroscopy and Time-Of-Flight Secondary Ion Mass Spectrometry Study.

    Science.gov (United States)

    Kutuzov, Nikolay; Gulin, Alexander; Lyaskovskiy, Vladimir; Nadtochenko, Victor; Maksimov, Georgy

    2015-01-01

    In the present paper we addressed a mechanism of the myelin reorganization initiated by extracellular ATP and adenosine in sciatic nerves of the frog Rana temporaria. In combination with Raman microspectroscopy, allowing noninvasive live-cell measurements, we employed time-of-flight secondary ion mass spectrometry (TOF-SIMS) to follow the underlying changes in chemical composition of myelin membranes triggered by the purinergic agents. The simultaneous increase in lipid ordering degree, decrease in membrane fluidity and the degree of fatty acid unsaturation were induced by both ATP and adenosine. Mass spectrometry measurements revealed that ATP administration also led to the marked elevation of membrane cholesterol and decrease of phosphotidylcholine amounts. Vesicular lipid transport pathways are considered as possible mechanisms of compositional and structural changes of myelin.

  14. Mass

    International Nuclear Information System (INIS)

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  15. 77 FR 420 - Drawbridge Operation Regulation; Corson Inlet, Stathmere, NJ

    Science.gov (United States)

    2012-01-05

    ... Operation Regulation; Corson Inlet, Stathmere, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... Corson Inlet, mile 0.9 in Strathmere, NJ. The deviation is necessary to facilitate the replacement of the... provided. The Corson Inlet Bridge (CR-619) at mile 0.9, across Corson Inlet in Strathmere, NJ has a...

  16. High energy efficiency and high power density proton exchange membrane fuel cells: Electrode kinetics and mass transport

    Science.gov (United States)

    Srinivasan, Supramaniam; Velev, Omourtag A.; Parthasathy, Arvind; Manko, David J.; Appleby, A. John

    1991-01-01

    The development of proton exchange membrane (PEM) fuel cell power plants with high energy efficiencies and high power densities is gaining momentum because of the vital need of such high levels of performance for extraterrestrial (space, underwater) and terrestrial (power source for electric vehicles) applications. Since 1987, considerable progress has been made in achieving energy efficiencies of about 60 percent at a current density of 200 mA/sq cm and high power densities (greater than 1 W/sq cm) in PEM fuel cells with high (4 mg/sq cm) or low (0.4 mg/sq cm) platinum loadings in electrodes. The following areas are discussed: (1) methods to obtain these high levels of performance with low Pt loading electrodes - by proton conductor impregnation into electrodes, localization of Pt near front surface; (2) a novel microelectrode technique which yields electrode kinetic parameters for oxygen reduction and mass transport parameters; (3) demonstration of lack of water transport from anode to cathode; (4) modeling analysis of PEM fuel cell for comparison with experimental results and predicting further improvements in performance; and (5) recommendations of needed research and development for achieving the above goals.

  17. Using hydrogen/deuterium exchange mass spectrometry to define the specific interactions of the phospholipase A2 superfamily with lipid substrates, inhibitors, and membranes.

    Science.gov (United States)

    Cao, Jian; Burke, John E; Dennis, Edward A

    2013-01-18

    The phospholipase A(2) (PLA(2)) superfamily consists of 16 groups and many subgroups and constitutes a diverse set of enzymes that have a common catalytic activity due to convergent evolution. However, different PLA(2) types have unique three-dimensional structures and catalytic residues as well as specific tissue localization and distinct biological functions. Understanding how the different PLA(2) enzymes associate with phospholipid membranes, specific phospholipid substrate molecules, and inhibitors on a molecular basis has advanced in recent years due to the introduction of hydrogen/deuterium exchange mass spectrometry. Its theory, practical considerations, and application to understanding PLA(2)/membrane interactions are addressed.

  18. Using Hydrogen/Deuterium Exchange Mass Spectrometry to Define the Specific Interactions of the Phospholipase A2 Superfamily with Lipid Substrates, Inhibitors, and Membranes*

    Science.gov (United States)

    Cao, Jian; Burke, John E.; Dennis, Edward A.

    2013-01-01

    The phospholipase A2 (PLA2) superfamily consists of 16 groups and many subgroups and constitutes a diverse set of enzymes that have a common catalytic activity due to convergent evolution. However, different PLA2 types have unique three-dimensional structures and catalytic residues as well as specific tissue localization and distinct biological functions. Understanding how the different PLA2 enzymes associate with phospholipid membranes, specific phospholipid substrate molecules, and inhibitors on a molecular basis has advanced in recent years due to the introduction of hydrogen/deuterium exchange mass spectrometry. Its theory, practical considerations, and application to understanding PLA2/membrane interactions are addressed. PMID:23209293

  19. High-throughput analysis of drugs in biological fluids by desorption electrospray ionization mass spectrometry coupled with thin liquid membrane extraction

    DEFF Research Database (Denmark)

    Rosting, Cecilie; Pedersen-Bjergaard, Stig; Hansen, Steen Honore'

    2013-01-01

    Biological fluids such as urine, saliva and whole blood were analyzed for contents of drugs by a new combination of desorption electrospray ionization mass spectrometry (DESI-MS) and thin liquid membrane extraction (TLME). Analytes from the sample were extracted into a thin liquid membrane...... into the method, methadone was detected in urine in full-scan mode with an LOD of 4 ng mL(-1), while amitriptyline, nortriptyline and pethidine showed LODs of 17 ng mL(-1). Quantification was possible for several basic drugs using one common internal standard, providing relative accuracies in the range of 10...

  20. A numerical study on the effects of temperature and mass transfer in high temperature PEM fuel cells with ab-PBI membrane

    International Nuclear Information System (INIS)

    Sun, Hong; Xie, Chen; Chen, Hao; Almheiri, Saif

    2015-01-01

    Highlights: • A two-dimensional model is developed to study the HT-PEMFC with ab-PBI membrane. • The temperature distribution in the ab-PBI membrane is uneven. • With the increase of temperature, the resistance in ab-PBI membrane decreases. • Porosity has the most significant effect on the performance of HT-PEMFC. - Abstract: A two-dimensional, single-phase model is developed to study high temperature proton exchange membrane (HT-PEM) fuel cell with poly(2,5-benzimidazole) (ab-PBI) membrane. In this model, simulation region not only includes the cathode and anode, but also includes ab-PBI membrane; the continuity boundary condition at the interface between the catalyst layer (CL) and the gas diffusion layer (GDL) at each side of the cell is omitted by including the catalyst layers in the respective unified domains for the cathode and the anode. The flows, species, energy, current density are all coupled in the model. Experiments have been conducted to validate the proposed numerical simulations, and it is found that there is a good agreement between the modeling results and those obtained experimentally. By this simulation, not only the oxygen and water fraction distribution in the cathode, but also the temperature distribution and resistance distribution in the ab-PBI membrane are obtained, and the effects of the cell temperature, the porosity in the diffusion layer and its thickness on the current density are analyzed. The innovative researching results are that the temperature distribution is uneven in the ab-PBI membrane and its resistance is greatly affected by the operating temperature. Other results show that the increase of the cell temperature and the porosity in the diffusion layer, and the decrease of the diffusion layer thickness all improve the performance of HT-PEM fuel cells by promoting its internal mass transfer.

  1. Interactive calculation procedures for mixed compression inlets

    Science.gov (United States)

    Reshotko, Eli

    1983-01-01

    The proper design of engine nacelle installations for supersonic aircraft depends on a sophisticated understanding of the interactions between the boundary layers and the bounding external flows. The successful operation of mixed external-internal compression inlets depends significantly on the ability to closely control the operation of the internal compression portion of the inlet. This portion of the inlet is one where compression is achieved by multiple reflection of oblique shock waves and weak compression waves in a converging internal flow passage. However weak these shocks and waves may seem gas-dynamically, they are of sufficient strength to separate a laminar boundary layer and generally even strong enough for separation or incipient separation of the turbulent boundary layers. An understanding was developed of the viscous-inviscid interactions and of the shock wave boundary layer interactions and reflections.

  2. Effect of Mass-Transport Limitations on the Performance of a Packed Bed Membrane Reactor for Partial Oxidations. Transport from the Membrane to the Packed Bed

    NARCIS (Netherlands)

    van Sint Annaland, M.; Kurten, U.; Kuipers, J.A.M.

    2007-01-01

    With a packed bed membrane reactor, the product yield can be significantly enhanced for partial oxidation systems, via distributive addition of oxygen to the reaction mixture along the axial coordinate of the reactor, provided that the reaction order in oxygen of the formation rate of the target

  3. Influences of flow loss and inlet distortions from radial inlets on the performances of centrifugal compressor stages

    Energy Technology Data Exchange (ETDEWEB)

    Han, Feng Hui; Mao, Yi Jun [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an (China); Tan, Ji Jian [Dept. of Research and Development, Shenyang Blower Works Group Co., Ltd., Shenyang (China)

    2016-11-15

    Radial inlets are typical upstream components of multistage centrifugal compressors. Unlike axial inlets, radial inlets generate additional flow loss and introduce flow distortions at impeller inlets. Such distortions negatively affect the aerodynamic performance of compressor stages. In this study, industrial centrifugal compressor stages with different radial inlets are investigated via numerical simulations. Two reference models were built, simulated, and compared with each original compressor stage to analyze the respective and coupling influences of flow loss and inlet distortions caused by radial inlets on the performances of the compressor stage and downstream components. Flow loss and inlet distortions are validated as the main factors through which radial inlets negatively affect compressor performance. Results indicate that flow loss inside radial inlets decreases the performance of the whole compressor stage but exerts minimal effect on downstream components. By contrast, inlet distortions induced by radial inlets negatively influence the performance of the whole compressor stage and exert significant effects on downstream components. Therefore, when optimizing radial inlets, the reduction of inlet distortions might be more effective than the reduction of flow loss. This research provides references and suggestions for the design and improvement of radial inlets.

  4. Effects of inlet conditions on dynamics of a thermal pulse combustor

    Science.gov (United States)

    Mondal, Sirshendu; Mukhopadhyay, Achintya; Sen, Swarnendu

    2012-02-01

    To increase the pulse combustor load, a higher amount of fuel-air mixture has to be supplied. This increases the flow rate or equivalently, the flow time is reduced. However, an increase in flow rate leads to an early extinction. This implies that obtaining pulsating combustion is difficult at higher loads. The objective of the present work is to explore the possibility of extending the regime of pulsating combustion at higher flow rates by preheating and diluting the reactants. In this work, the effects of preheating and dilution are examined by varying the inlet temperature and inlet fuel mass fraction. Varying these parameters, a map, presenting regime of pulsating combustion from steady combustion to extinction for each value of flow time considered, has been made. Lastly, Hopf bifurcation points of the system have been investigated by determining the eigenvalues of Jacobian matrix of the coupled non-linear system at the fixed point using a specialised package for bifurcation analysis, MATCONT. It has been found that at higher load, pulsating combustion can be achieved at higher inlet temperature and lower inlet fuel mass fraction. Comparing the Hopf points with mapping, it is found that existence of Hopf bifurcation agrees with the birth and death of pulsating combustion. The results indicate that altering the mixture condition at the inlet can be used for controlling chaos and stabilising periodic solutions in thermal pulse combustors and thus increase the range of pulsating combustion to higher power regimes.

  5. Membrane assisted solvent extraction coupled with liquid chromatography tandem mass spectrometry applied to the analysis of alkylphenols in water samples.

    Science.gov (United States)

    Salgueiro-González, N; Turnes-Carou, I; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D

    2013-03-15

    This work describes the development and validation of a novel, simple, sensitive and environmental friendly analytical method for the determination of alkylphenols in different types of water samples. The methodology was based on a membrane assisted solvent extraction of only 15 mL of water sample with 500 μL of hexane in combination with liquid chromatography-electrospray ionization tandem mass spectrometry in negative mode (LC-ESI-MS/MS). Acquisition was performed in the multiple reaction monitoring (MRM) mode recording two transitions for the identification of the target compounds. Quantitation is based on the use of deuterated labelled standards as surrogate standards. The figures of merit were satisfactory in all cases: absolute recoveries were close to 50% for most investigated compounds and relative recoveries varied between 81 and 108%. Repeatability and intermediate precision were MQL) were lower than 0.04 μg L(-1) in all cases, which allow the achievement of the limits established by the Directive 2008/105/EC for surface and seawater samples and by the new proposal COM (2011) 876 final. The feasibility of the proposed method was demonstrated analyzing seawater, surface water and drinking water samples from different areas of A Coruña (Northwest of Spain). The analyses evidenced the presence of nonylphenol in seawater (MQL-0.13 μg L(-1)) and surface water samples (0.12-0.19 μg L(-1)). The highest concentration was observed in drinking water (0.25 μg L(-1)). Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Proteomic screen for multiprotein complexes in synaptic plasma membrane from rat hippocampus by blue native gel electrophoresis and tandem mass spectrometry.

    Science.gov (United States)

    Li, Xuanwen; Xie, Chunliang; Jin, Qihui; Liu, Mingjun; He, Quanyuan; Cao, Rui; Lin, Yong; Li, Jianglin; Li, Yan; Chen, Ping; Liang, Songping

    2009-07-01

    Neuronal synapses are specialized sites for information exchange between neurons. Many diseases, such as addiction and mood disorders, likely result from altered expression of synaptic proteins, or altered formation of synaptic complexes involved in neurotransmission or neuroplasticity. A detailed description of native multiprotein complexes in synaptic plasma membranes (PM) is therefore essential for understanding biological mechanisms and disease processes. For the first time in this study, two-dimensional Blue Native/SDS-PAGE electrophoresis, combined with tandem mass spectrometry, was used to screen multiprotein complexes in synaptic plasma membranes from rat hippocampus. As a result, 514 unique proteins were identified, of which 36% were integral membrane proteins. In addition, 19 potentially novel and known heterooligomeric multiprotein complexes were found, such as the SNARE and ATPase complexes. A potentially novel protein complex, involving syntaxin, synapsin I and Na+/K+ ATPase alpha-1, was further confirmed by co-immunoprecipitation and immunofluorescence staining. As demonstrated here, Blue Native-PAGE is a powerful tool for the separation of hydrophobic membrane proteins. The combination of Blue Native-PAGE and mass spectrometry could systematically identify multiprotein complexes.

  7. Diode Laser Sensor for Scramjet Inlets

    Science.gov (United States)

    2011-06-03

    configuration The FLUENT solver was set to implicitly solve the density-based form of the compressible Navier - Stokes equations, assuming perfect gas...Report Stock Number 003-017-00323-0, US Government Printing Office, Washington DC, USA. Smart, M. (2001), ‘Experimental testing of a hypersonic inlet

  8. Improvement of a sample preparation method assisted by sodium deoxycholate for mass-spectrometry-based shotgun membrane proteomics.

    Science.gov (United States)

    Lin, Yong; Lin, Haiyan; Liu, Zhonghua; Wang, Kunbo; Yan, Yujun

    2014-11-01

    In current shotgun-proteomics-based biological discovery, the identification of membrane proteins is a challenge. This is especially true for integral membrane proteins due to their highly hydrophobic nature and low abundance. Thus, much effort has been directed at sample preparation strategies such as use of detergents, chaotropes, and organic solvents. We previously described a sample preparation method for shotgun membrane proteomics, the sodium deoxycholate assisted method, which cleverly circumvents many of the challenges associated with traditional sample preparation methods. However, the method is associated with significant sample loss due to the slightly weaker extraction/solubilization ability of sodium deoxycholate when it is used at relatively low concentrations such as 1%. Hence, we present an enhanced sodium deoxycholate sample preparation strategy that first uses a high concentration of sodium deoxycholate (5%) to lyse membranes and extract/solubilize hydrophobic membrane proteins, and then dilutes the detergent to 1% for a more efficient digestion. We then applied the improved method to shotgun analysis of proteins from rat liver membrane enriched fraction. Compared with other representative sample preparation strategies including our previous sodium deoxycholate assisted method, the enhanced sodium deoxycholate method exhibited superior sensitivity, coverage, and reliability for the identification of membrane proteins particularly those with high hydrophobicity and/or multiple transmembrane domains. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Enhanced SDC-assisted digestion coupled with lipid chromatography-tandem mass spectrometry for shotgun analysis of membrane proteome.

    Science.gov (United States)

    Lin, Yong; Wang, Kunbo; Liu, Zhonghua; Lin, Haiyan; Yu, Lijun

    2015-10-01

    Despite the biological importance of membrane proteins, their analysis has lagged behind that of soluble proteins and still presents a great challenge mainly because of their highly hydrophobic nature and low abundance. Sodium deoxycholate (SDC)-assisted digestion strategy has been introduced in our previous papers, which cleverly circumvents many of the challenges in shotgun membrane proteomics. However, it is associated with significant sample loss due to the slightly weaker extraction/solubilization ability of 1% SDC. In this study, an enhanced SDC-assisted digestion method (ESDC method) was developed that incorporates the almost strongest ability of SDC with a high concentration (5%) to lyse membrane and extract/solubilize hydrophobic membrane proteins, and then dilution to 1% for more efficient digestion. The comparative study using rat liver membrane-enriched sample showed that, compared with previous SDC-assisted method and the "universal" filter-aided sample preparation (FASP) method, the ESDC method not only increased the identified number of total proteins, membrane proteins, hydrophobic proteins, integral membrane proteins (IMPs) and IMPs with more than 5 transmembrane domains (TMDs) by an average of 10.8%, 13.2%, 17.8%, 17.9% and 52.9%, respectively, but also enhanced the identified number of total peptides and hydrophobic peptides by averagely 12.5% and 14.2%. These results demonstrated that the ESDC method provides a substantial improvement in the recovery and identification of membrane proteins, especially those with high hydrophobicity and multiple TMDs, and thereby displaying more potential for shotgun membrane proteomics. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Development of a laser ionization mass spectrometer for the rapid detection of aromatic hydrocarbons in aqueous samples

    Energy Technology Data Exchange (ETDEWEB)

    Oser, H.; Young, S.E.; Coggiola, J. [SRI International, Menlo Park, CA (United States). Molecular Physics Lab.; Hafer, V. [Wellesley Coll., MA (United States); Grist, G. [San Francisco State Univ., CA (United States)

    2004-09-15

    The detection of BTEX compounds in the gas phase has been examined in our laboratory through the use of jet-Resonantly Enhanced Multi-Photon Ionization Time-of-Flight Mass Spectrometry (jet-REMPI-ToF MS). These BTEX compounds, as well as chlorobenzene, are well suited for detection via this method due to spectroscopic absorption properties of the aromatic ring. However, this method utilizes a supersonic jet expansion, which is not applicable to the direct detection of BTEX compounds in water. In order to extend the REMPI-ToF approach to the detection of organics in water, a new type of inlet system must be coupled to the REMPI apparatus. By combining a membrane-based inlet system with a REMPI apparatus, the volatile organic compounds (VOCs) can be successfully introduced into the vacuum chamber without interference from the water solvent. Membrane Introduction Mass Spectrometry (MIMS) has been utilized for over 40 years, but the coupling of a membrane inlet to REMPI ToF mass spectrometry is new. A combination of MIMS and REMPI with time-of flight mass spectrometry, which allows for the direct analysis of water samples, has been developed in our laboratory. The application of ToF MS offers some advantages such as high ion transmission, robustness, and the ability to record a full mass spectrum for each laser shot. The objective of this research was the detection of trace amounts of aromatic contaminants, particularly BETX and chlorobenzene, in aqueous solutions without interference or clogging of the inlet due to the vastly greater amount of water.

  11. Experimental Investigation of a Hypersonic Inlet with Variable Sidewall for Flow Control

    Science.gov (United States)

    Rolim, T. C.; Lu, F. K.

    The main function of a scramjet inlet is to decelerate and compress the air for subsequent reaction with the fuel inside the combustor and, of course, contribute toward meeting the thrust requirement for the entire mission by providing adequate mass flow. It is desirable that the inlet be lightweight and that its geometry be capable of producing a uniform flow in an appropriate state to permit efficient mixing and subsequent combustion. Engine cycle analysis indicates that high contraction ratios CR are desirable for achieving high overall engine efficiency.

  12. Ion transport membrane module and vessel system

    Energy Technology Data Exchange (ETDEWEB)

    Stein, VanEric Edward; Carolan, Michael Francis; Chen, Christopher M.; Armstrong, Phillip Andrew; Wahle, Harold W.; Ohrn, Theodore R.; Kneidel, Kurt E.; Rackers, Keith Gerard; Blake, James Erik; Nataraj, Shankar; van Doorn, Rene Hendrik Elias; Wilson, Merrill Anderson

    2007-02-20

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel. The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

  13. Ion transport membrane module and vessel system

    Energy Technology Data Exchange (ETDEWEB)

    Stein, VanEric Edward [Allentown, PA; Carolan, Michael Francis [Allentown, PA; Chen, Christopher M [Allentown, PA; Armstrong, Phillip Andrew [Orefield, PA; Wahle, Harold W [North Canton, OH; Ohrn, Theodore R [Alliance, OH; Kneidel, Kurt E [Alliance, OH; Rackers, Keith Gerard [Louisville, OH; Blake, James Erik [Uniontown, OH; Nataraj, Shankar [Allentown, PA; Van Doorn, Rene Hendrik Elias (Obersulm-Willsbach, DE); Wilson, Merrill Anderson [West Jordan, UT

    2012-02-14

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel. The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

  14. Ion transport membrane module and vessel system

    Energy Technology Data Exchange (ETDEWEB)

    Stein, VanEric Edward [Allentown, PA; Carolan, Michael Francis [Allentown, PA; Chen, Christopher M [Allentown, PA; Armstrong, Phillip Andrew [Orefield, PA; Wahle, Harold W [North Canton, OH; Ohrn, Theodore R [Alliance, OH; Kneidel, Kurt E [Alliance, OH; Rackers, Keith Gerard [Louisville, OH; Blake, James Erik [Uniontown, OH; Nataraj, Shankar [Allentown, PA; van Doorn, Rene Hendrik Elias (Obersulm-Willsbach, DE); Wilson, Merrill Anderson [West Jordan, UT

    2008-02-26

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel.The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

  15. Numerical study on thermal energy storage performance of phase change material under non-steady-state inlet boundary

    International Nuclear Information System (INIS)

    Tao, Y.B.; He, Y.L.

    2011-01-01

    Highlights: → Based on the unstable solar radiation, a model was established for phase change process under unsteady boundary. → The PCM melting time decreases with the initial inlet temperature increase under the same average inlet temperature. → The melting time reduces about 51.9% with the initial inlet temperature increase from 30 o C to 90 o C. → The melting time decreases with the initial inlet mass flow rate increase under the same average inlet mass flow rate. → The melting time reduces about 36.5% with the initial inlet mass flow rate increase from 2.0 x 10 -4 kg/s to 8.0 x 10 -4 kg/s. -- Abstract: Due to the solar radiation intensity variation over time, the outlet temperature or mass flow rate of heat transfer fluid (HTF) presents non-steady-state characteristics for solar collector. So, in the phase change thermal energy storage (PCTES) unit which is connected to solar collector, the phase change process occurs under the non-steady-state inlet boundary condition. In present paper, regarding the non-steady-state boundary, based on enthalpy method, a two dimensional physical and mathematical model for a shell-and-tube PCTES unit was established and the simulation code was self-developed. The effects of the non-steady-state inlet condition of HTF on the thermal performance of the PCTES unit were numerically analyzed. The results show that when the average HTF inlet temperature in an hour is fixed at a constant value, the melting time (time required for PCM completely melting) decreases with the increase of initial inlet temperature. When the initial inlet temperature increases from 30 o C to 90 o C, the melting time will decrease from 42.75 min to 20.58 min. However, the total TES capacity in an hour reduces from 338.9 kJ/kg to 211.5 kJ/kg. When the average inlet mass flow rate in an hour is fixed at a constant value, with the initial HTF inlet mass flow rate increasing, the melting time of PCM decreases. The initial inlet mass flow rate

  16. Effect of Mass-Transport Limitations on the Performance of a Packed Bed Membrane Reactor for Partial Oxidations. Intraparticle Mass Transport

    NARCIS (Netherlands)

    van Sint Annaland, M.; Kurten, U.; Kuipers, J.A.M.

    2007-01-01

    For partial oxidation systems, where the reaction order in oxygen of the formation rate of the target product is smaller than the reaction order in oxygen of the consecutive reaction rate toward the waste product, a packed bed membrane reactor can be applied to distributively dose oxygen along the

  17. Low speed performance of a supersonic axisymmetric mixed compression inlet with auxiliary inlets. [Lewis 9x15-ft anechoic wind tunnel tests

    Science.gov (United States)

    Wasserbauer, J. F.; Cubbison, R. W.; Trefny, C. J.

    1983-01-01

    The aerodynamic performance of a representative supersonic cruise inlet was investigated using a fan simulator coupled to the inlet to provide characteristic noise signatures and to pump the inlet flow. Data were obtained at Mach numbers from 0 to 0.2 for the inlet equipped with an auxiliary inlet system that provided 20 to 40 percent of the fan flow. Results show that inlet performance improved when the inlet bleed systems were sealed; when the freestream Mach number was increased; and when the auxiliary inlets were opened. The inlet flow could not be choked by either centerbody translation or by increasing the fan speed when the 40 percent auxiliary inlet was incorporated.

  18. 76 FR 63840 - Drawbridge Operation Regulation; Corson Inlet, Strathmere, NJ

    Science.gov (United States)

    2011-10-14

    ... Operation Regulation; Corson Inlet, Strathmere, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... mile 0.9, across Corson Inlet, in Strathmere, NJ. The deviation is necessary to facilitate the..., across Corson Inlet in Strathmere, NJ has a vertical clearance in the closed position to vessels of 15...

  19. High-expression EGFR/cell membrane chromatography-online-high-performance liquid chromatography/mass spectrometry: rapid screening of EGFR antagonists from Semen Strychni.

    Science.gov (United States)

    Sun, Meng; Guo, Ying; Dai, Bingling; Wang, Chen; He, Langchong

    2012-09-15

    Traditional methods for screening active compounds from complex system such as traditional Chinese medicines are relatively cumbersome and time-consuming. In order to improve this situation, we established an online analytical method for screening, separation and identification EGFR antagonists from traditional Chinese medicines, which is described in this study. Cells with high EGFR expression levels were used to prepare the cell membrane stationary phase for the EGFR cell membrane chromatography model with the purpose of screening active compounds. Separation of the retention fractions was achieved by the high-performance liquid chromatography, and identification was conducted via electrospray ionization quadrupole mass spectrometry. The inhibitory effects of active compounds on EGFR cell growth were also demonstrated in vitro. The screening results showed that vauquline and strychnine from Semen Strychni could be active components acting on EGFR similarly to gefitinib as a control drug. Results from biological trials showed that vauquline and strychnine inhibited cell proliferation of HEK293/EGFR cells, and inhibited Erk phosphorylation, and can effectively reduce expression of downstream signaling molecules. This EGFR cell membrane chromatography-online-high-performance liquid chromatography/tandem mass spectrometry method can be applied for rapid screening, separation and identification of EGFR antagonists from traditional Chinese medicines and should be useful for drug discovery with natural medicinal herbs. Copyright © 2012 John Wiley & Sons, Ltd.

  20. Brazos Santiago Inlet, Texas, Shoaling Study

    Science.gov (United States)

    2018-02-01

    Field data collection and numerical modeling using the Coastal Modeling System were performed to gain insight into the complex circulation, wave action ...and sediment deposition patterns. Structural changes to the system as well as dredging modifications are presented as potential alternative...solutions to reduce inlet shoaling. Results show the potential benefits of an in-channel sediment trap and alterations to the structure of the jetty

  1. Identification of ftalates used as additives in the geo membrane of a la Florida reservoir through gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Blanco, M.; Rico, G.; Pargada, L.; Aguiar, E.; Castillo, F.

    2009-01-01

    This article studies the behaviour of the plastified poly (vinyl chloride) (PVC-P) applied as synthetic geo membrane for the waterproofing of the La Florida reservoir. We show the results of the initial examen of its properties and its most significant characteristics eighteen years after being applied. Furthermore we isolate and identify the quantitative and qualitative aspects of the plasticizers used in its formula through infrared spectroscopy, gas chromatography and mass spectrometry technic. We have identified as the said plasticizers di-n-octyl phthalate, di-n-decyl phthalate and n-decyl n-octyl phthalate, and we calculate the joint average molecular weight using Wilsons equation. The results found that the geo membranes we have studied has shown an excellent behaviour along through time. (Author) 53 refs

  2. The lipidomes of vesicular stomatitis virus, semliki forest virus, and the host plasma membrane analyzed by quantitative shotgun mass spectrometry

    DEFF Research Database (Denmark)

    Kalvodova, Lucie; Sampaio, Julio L; Cordo, Sandra

    2009-01-01

    Although enveloped virus assembly in the host cell is a crucial step in the virus life cycle, it remains poorly understood. One issue is how viruses include lipids in their membranes during budding from infected host cells. To analyze this issue, we took advantage of the fact that baby hamster...... kidney cells can be infected by two different viruses, namely, vesicular stomatitis virus and Semliki Forest virus, from the Rhabdoviridae and Togaviridae families, respectively. We purified the host plasma membrane and the two different viruses after exit from the host cells and analyzed the lipid...

  3. C18-attached membrane funnel-based spray ionization mass spectrometry for quantification of anti-diabetic drug from human plasma

    International Nuclear Information System (INIS)

    Li, Wan; Chen, Xiangfeng; Wong, Y.-L. Elaine; Hung, Y.-L. Winnie; Wang, Ze; Deng, Liulin; Dominic Chan, T.-W.

    2016-01-01

    In this work, sorbent-attached membrane funnel-based spray ionization mass spectrometry was explored for quantitative analysis of anti-diabetic drugs spiked in human plasma. C 18 -attached membrane funnel was fabricated for in situ extraction and clean-up to alleviate matrix suppression effect in the ionization process. Repaglinide was used as a target analyte of anti-diabetic drugs. Under optimal working conditions, good linearity (R 2  > 0.99) was obtained in the concentration range of 1–100 ng mL −1 . The method detection limit of target drugs spiked in the human plasma was around 0.30 ng mL −1 . Through the application of an isotope-labeled internal standard, the signal fluctuation caused by residual background matrices was largely alleviated and the precision of measurement (RSD) was below 15%. The recovery of repaglinide for 5, 25, and 100 ng mL −1 of spiked human plasma matrixes ranged from 87% to 112%. The developed method was successfully applied to determine repaglinide in plasma volunteers who orally received a dose of drug association. Our results demonstrated that membrane funnel-based spray is a simple and sensitive method for rapid screening analysis of complex biological samples. - Highlights: • Sorbent attached membrane funnel based spray platform was used for drug determination in human plasma. • The matrix suppression effect of human plasma was largely eliminated. • The method was applied to determine repaglinide in plasma volunteers. • Membrane funnel-based spray is promising for analysis of biological samples.

  4. Unstart coupling mechanism analysis of multiple-modules hypersonic inlet.

    Science.gov (United States)

    Hu, Jichao; Chang, Juntao; Wang, Lei; Cao, Shibin; Bao, Wen

    2013-01-01

    The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted.

  5. Analysis by Mass Spectrometry of the Polar Lipids from the Cellular Membrane of Thermophilic Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    A. M. Seldes

    2000-03-01

    Full Text Available Fast atom bombardment (FAB technique was employed to determine the structure of polar lipids from the cellular membrane of Lactobacillus delbruekii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus. Analysis of spectra provided useful information about the molecular species and aminoacids constituents of the samples.

  6. Large Mass Flux Differences for Opposite Flow Directions of a Condensable Gas through an Asymmetric Porous Membrane

    Czech Academy of Sciences Publication Activity Database

    Uchytil, Petr; Loimer, T.

    2014-01-01

    Roč. 470, NOV 15 (2014), s. 451-457 ISSN 0376-7388 R&D Projects: GA MŠk 7AMB12AT010; GA MŠk(CZ) 7AMB14AT011 Institutional support: RVO:67985858 Keywords : condensation * vapor permeation * asymmetric membranes Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 5.056, year: 2014

  7. Accessibility Changes within Diphtheria Toxin T Domain upon Membrane Penetration Probed by Hydrogen Exchange and Mass Spectrometry

    Czech Academy of Sciences Publication Activity Database

    Man, Petr; Montagner, C.; Vitrac, H.; Kavan, Daniel; Pichard, S.; Gillet, D.; Forest, E.; Forge, V.

    2011-01-01

    Roč. 414, č. 1 (2011), s. 123-134 ISSN 0022-2836 Institutional research plan: CEZ:AV0Z50200510 Keywords : diphtheria toxin * translocation domain * protein/membrane interactions Subject RIV: CE - Biochemistry Impact factor: 4.001, year: 2011

  8. Economical analysis of the spray drying process by pre-dehumidification of the inlet air

    Energy Technology Data Exchange (ETDEWEB)

    Madeira, A.N.; Camargo, J.R. [University of Taubate (UNITAU), SP (Brazil). Mechanical Engineering Dept.

    2009-07-01

    Spray drying is a dehumidification process by atomization in a closed chamber that aims to remove moisture of a product by heat and mass transfer from the product's contained water to the air that, in this process is previously heated. This paper presents a case study for an industry that produces food ingredients. The current process applied in the product to heat the air can uses one of these two systems: a direct heating process that burns liquid petroleum gas in contact with the inlet air or indirect heating that uses a heat exchanger which heat the air. This heating system consumes 90% of the total process energy. However, this inlet air can reach the dehumidifier with high moisture from the atmosphere condition requesting, in this case, more energy consumption according to the year's seasons. This paper promotes a utilization study of the current process through the installation of a pre-dehumidification device of the inlet air and shows a study to three different dehumidification systems that means by refrigeration, adsorption and actual comparing their performance in an energetic and economical point of view. The goals of this study are to analyze the capacity of moisture removing of each removing device, the influence of moisture variation of the inlet air in the process as well as the economic impact of each device in the global system. It concludes that the utilization of dehumidification devices can eliminate the heating system reducing this way the energy consumption. Moreover it promotes the increasing of moisture gradient between the inlet air and the product optimizing the drying process and increasing the global energy efficiency in the global system. Choosing the most appropriate system for the pre-dehumidification device depends on the desired initial and final moisture content of the product, but applying pre-dehumidifiers at the inlet air promotes an energetic optimization in the spray drying process. (author)

  9. Metastasis-related plasma membrane proteins of human breast cancer cells identified by comparative quantitative mass spectrometry

    DEFF Research Database (Denmark)

    Leth-Larsen, Rikke; Lund, Rikke; Hansen, Helle V

    2009-01-01

    The spread of cancer cells from a primary tumor to form metastasis at distant sites is a complex multi-step process. The cancer cell proteins, and plasma membrane proteins in particular, involved in this process are poorly defined and a study of the very early events of the metastatic process using...... clinical samples or in vitro assays is not feasible. We have used a unique model system consisting of two isogenic human breast cancer cell lines that are equally tumorigenic in mice, but while one gives rise to metastasis, the other disseminates single cells that remain dormant at distant organs. Membrane......'-nucleotidase (ecto-5'-NT, CD73), Ndrg1, integrin beta1, CD44, CD74 and MHC class II proteins. The altered expression levels of proteins identified by LC-MS/MS were validated using flow cytometry, Western blotting, immunocyto- and immunohisto-chemistry. Analysis of clinical breast cancer biopsies demonstrated...

  10. C18-attached membrane funnel-based spray ionization mass spectrometry for quantification of anti-diabetic drug from human plasma.

    Science.gov (United States)

    Li, Wan; Chen, Xiangfeng; Wong, Y-L Elaine; Hung, Y-L Winnie; Wang, Ze; Deng, Liulin; Dominic Chan, T-W

    2016-08-24

    In this work, sorbent-attached membrane funnel-based spray ionization mass spectrometry was explored for quantitative analysis of anti-diabetic drugs spiked in human plasma. C18-attached membrane funnel was fabricated for in situ extraction and clean-up to alleviate matrix suppression effect in the ionization process. Repaglinide was used as a target analyte of anti-diabetic drugs. Under optimal working conditions, good linearity (R(2) > 0.99) was obtained in the concentration range of 1-100 ng mL(-1). The method detection limit of target drugs spiked in the human plasma was around 0.30 ng mL(-1). Through the application of an isotope-labeled internal standard, the signal fluctuation caused by residual background matrices was largely alleviated and the precision of measurement (RSD) was below 15%. The recovery of repaglinide for 5, 25, and 100 ng mL(-1) of spiked human plasma matrixes ranged from 87% to 112%. The developed method was successfully applied to determine repaglinide in plasma volunteers who orally received a dose of drug association. Our results demonstrated that membrane funnel-based spray is a simple and sensitive method for rapid screening analysis of complex biological samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Cold water inlet in solar tanks - valuation

    DEFF Research Database (Denmark)

    Andersen, Elsa

    1999-01-01

    The aim of the project is to make a proposal for how to value a storage tank with a poor design of the cold water inlet. Based on measurements and calculations a number of curves, which are valid for this valuation, are worked out. Based on a simple test with a uniform heated storage tank the ratio...... between the energy tapped in one storage volume and the energy content in the tank before the tapping is measured. Afterwards the mixing factor, corresponding to the measured ratio, can be determined. It is proposed that the mixing factor is taken into consideration when the governmental subsidy for SDHW...

  12. A membrane introduction mass spectrometer utilizing ion-molecule reactions for the on-line speciation and quantitation of volatile organic molecules.

    Science.gov (United States)

    Davey, Nicholas G; Bell, Ryan J; Krogh, Erik T; Gill, Chris G

    2015-12-15

    The ability of membrane introduction mass spectrometry to quantitatively resolve low molecular weight volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene and xylene (BTEX) using electron ionization (EI) can be compromised by isobaric interferences. This work focuses on reducing isobaric interferences with ion-molecule reactions in a portable quadrupole ion trap mass spectrometer for the analysis of VOCs. EI was used to produce reagent ions from precursors (chloroform, methyl iodide, trichloroethylene or chlorobenzene) that were continually infused into the helium acceptor phase upstream of the membrane introduction mass spectrometry (MIMS) sampling interface. The reagent ions were selectively stored in the ion trap, and then allowed to react with target VOC analytes in air samples via ion-molecule reactions within the trap storage volume. A variety of reaction times were examined (50-5000 ms), and the resulting product ions were analyzed in positive ion mode. The detection limits achieved were comparable with those obtained using EI (low ppbv), and in some cases better than for EI coupled with tandem mass spectrometry (MS/MS). For the VOCs studied, isobaric interferences were greatly reduced or eliminated using chloroform as a reagent gas. The predominant ionization mechanism was via adduct formation, although charge transfer and hydride abstractions were also observed. An internal standard was shown to be effective at correcting for signal changes due to consumption of reagent ions when complex mixtures were sampled. Ion-molecule reactions were exploited to eliminate isobaric interferences that are often encountered in direct, real-time analysis strategies for atmospheric VOC mixtures. The use of a continuously infused internal standard will improve quantitative results in field applications where analyte concentration and sample complexity may be wide ranging. Copyright © 2015 John Wiley & Sons, Ltd.

  13. A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for direct and on-line measurements of pharmaceuticals and contaminants in small, complex samples.

    Science.gov (United States)

    Duncan, Kyle D; Willis, Megan D; Krogh, Erik T; Gill, Christopher G

    2013-06-15

    High-throughput, automated analytical measurements are desirable in many analytical scenarios, as are rapid sample pre-screening techniques to identify 'positive' samples for subsequent measurements using more time-consuming conventional methodologies (e.g., liquid chromatography/mass spectrometry (LC/MS)). A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for the direct and continuous, on-line measurement of pharmaceuticals and environmental contaminants in small, complex samples is presented. A miniature polydimethylsiloxane hollow fibre membrane (PDMS-HFM) probe is coupled with an electrospray ionization (ESI) triple quadrupole mass spectrometer. Analytes are transported from the probe to the ESI source by a methanol acceptor phase. The probe can be autosampler mounted and directly inserted in small samples (≥400 μL) allowing continuous and simultaneous pptr-ppb level detection of target analytes (chlorophenols, triclosan, gemfibrozil, nonylphenol) in complex samples (artificial urine, beer, natural water, waste water, plant tissue). The probe has been characterized and optimized for acceptor phase flow rate, sample mixing and probe washing. Signal response times, detection limits and calibration data are given for selected ion monitoring (SIM) and tandem mass spectrometry (MS/MS) measurements of target analytes at trace levels. Comparisons with flow cell type CP-MIMS systems are given. Analyte depletion effects are evaluated for small samples (≥400 μL). On-line measurements in small volumes of complex samples, temporally resolved reaction monitoring and in situ/in vivo demonstrations are presented. The miniature CP-MIMS probe developed was successfully used for the direct, on-line detection of target analytes in small volumes (40 mL to 400 μL) of complex samples at pptr to low ppb levels. The probe can be readily automated as well as deployed for in situ/in vivo monitoring, including reaction monitoring, small sample

  14. Effects on inlet technology on cruise speed selection

    Science.gov (United States)

    Bangert, L. H.; Santman, D. M.; Horie, G.; Miller, L. D.

    1980-01-01

    The impact of cruise speed on technology level for certain aircraft components is examined. External-compression inlets were compared with mixed compression, self starting inlets at cruise Mach numbers of 2.0 and 2.3. Inlet engine combinations that provided the greatest aircraft range were identified. Results show that increased transonic to cruise corrected air flow ratio gives decreased range for missions dominated by supersonic cruise. It is also found important that inlets be designed to minimize spillage drag at subsonic cruise, because of the need for efficient performance for overland operations. The external compression inlet emerged as the probable first choice at Mach 2.0, while the self starting inlet was the probable first choice at Mach 2.3. Airframe propulsion system interference effects were significant, and further study is needed to assess the existing design methods and to develop improvements.

  15. Feed gas contaminant control in ion transport membrane systems

    Science.gov (United States)

    Carolan, Michael Francis [Allentown, PA; Minford, Eric [Laurys Station, PA; Waldron, William Emil [Whitehall, PA

    2009-07-07

    Ion transport membrane oxidation system comprising an enclosure having an interior and an interior surface, inlet piping having an internal surface and adapted to introduce a heated feed gas into the interior of the enclosure, and outlet piping adapted to withdraw a product gas from the interior of the enclosure; one or more planar ion transport membrane modules disposed in the interior of the enclosure, each membrane module comprising mixed metal oxide material; and a preheater adapted to heat a feed gas to provide the heated feed gas to the inlet piping, wherein the preheater comprises an interior surface. Any of the interior surfaces of the enclosure, the inlet piping, and the preheater may be lined with a copper-containing metal lining. Alternatively, any of the interior surfaces of the inlet piping and the preheater may be lined with a copper-containing metal lining and the enclosure may comprise copper.

  16. A field-portable membrane introduction mass spectrometer for real-time quantitation and spatial mapping of atmospheric and aqueous contaminants.

    Science.gov (United States)

    Bell, Ryan J; Davey, Nicholas G; Martinsen, Morten; Collin-Hansen, Christian; Krogh, Erik T; Gill, Christopher G

    2015-02-01

    Environmental concentrations of volatile and semivolatile organic compounds (VOC/SVOCs) can vary dramatically in time and space under the influence of environmental conditions. In an industrial setting, multiple point and diffuse sources can contribute to fugitive emissions. Assessments and monitoring programs using periodic grab sampling provide limited information, often with delay times of days or weeks. We report the development and use of a novel, portable membrane introduction mass spectrometry (MIMS) system capable of resolving and quantifying VOC and SVOCs with high spatial and temporal resolution, in the field, in real-time. An electron impact ionization cylindrical ion trap mass spectrometer modified with a capillary hollow fiber polydimethylsiloxane membrane interface was used for continuous air and water sampling. Tandem mass spectrometry and selected ion monitoring scans performed in series allowed for the quantitation of target analytes, and full scan mode was used to survey for unexpected analytes. Predeployment and in-field external calibrations were combined with a continuously infused internal standard to enable real-time quantitation and monitor instrument performance. The system was operated in a moving vehicle with internet-linked data processing and storage. Software development to integrate MIMS and relevant meta-data for visualization and geospatial presentation in Google Earth is presented. Continuous quantitation enables the capture of transient events that may be missed or under-represented by traditional grab sampling strategies. Real-time geospatial maps of chemical concentration enable adaptive sampling and in-field decision support. Sample datasets presented in this work were collected in Northern Alberta in 2010-2012.

  17. A Field-Portable Membrane Introduction Mass Spectrometer for Real-time Quantitation and Spatial Mapping of Atmospheric and Aqueous Contaminants

    Science.gov (United States)

    Bell, Ryan J.; Davey, Nicholas G.; Martinsen, Morten; Collin-Hansen, Christian; Krogh, Erik T.; Gill, Christopher G.

    2015-02-01

    Environmental concentrations of volatile and semivolatile organic compounds (VOC/SVOCs) can vary dramatically in time and space under the influence of environmental conditions. In an industrial setting, multiple point and diffuse sources can contribute to fugitive emissions. Assessments and monitoring programs using periodic grab sampling provide limited information, often with delay times of days or weeks. We report the development and use of a novel, portable membrane introduction mass spectrometry (MIMS) system capable of resolving and quantifying VOC and SVOCs with high spatial and temporal resolution, in the field, in real-time. An electron impact ionization cylindrical ion trap mass spectrometer modified with a capillary hollow fiber polydimethylsiloxane membrane interface was used for continuous air and water sampling. Tandem mass spectrometry and selected ion monitoring scans performed in series allowed for the quantitation of target analytes, and full scan mode was used to survey for unexpected analytes. Predeployment and in-field external calibrations were combined with a continuously infused internal standard to enable real-time quantitation and monitor instrument performance. The system was operated in a moving vehicle with internet-linked data processing and storage. Software development to integrate MIMS and relevant meta-data for visualization and geospatial presentation in Google Earth is presented. Continuous quantitation enables the capture of transient events that may be missed or under-represented by traditional grab sampling strategies. Real-time geospatial maps of chemical concentration enable adaptive sampling and in-field decision support. Sample datasets presented in this work were collected in Northern Alberta in 2010-2012.

  18. PVDF hollow fiber and nanofiber membranes for fresh water reclamation using membrane distillation

    KAUST Repository

    Francis, Lijo

    2013-11-26

    Polyvinylidene fluoride hollow fiber and nanofibrous membranes are engineered and successfully fabricated using dry-jet wet spinning and electrospinning techniques, respectively. Fabricated membranes are characterized for their morphology, average pore size, pore size distribution, nanofiber diameter distribution, thickness, and water contact angle. Direct contact membrane distillation (DCMD) performances of the fabricated membranes have been investigated using a locally designed and fabricated, fully automated MD bench scale unit and DCMD module. Electrospun nanofibrous membranes showed a water flux as high as 36 L m-2 h-1 whereas hollow fiber membranes showed a water flux of 31.6 L m-2 h-1, at a feed inlet temperature of 80 °C and at a permeate inlet temperature of 20 °C.

  19. Inlet and Outlet Casings of the Turbojet Engines – Design and Experiment

    Directory of Open Access Journals (Sweden)

    D. Hanus

    2000-01-01

    Full Text Available The paper presents special design method for three-dimensional design of the inlet and outlet channels of the turboprop engines. The method is based on the solution of indirect problem in internal aerodynamics, which is realised by mechanical construction of the flow field between inlet and outlet sections of the designed channel. The flow field is represented by number of flow tubes made of special plastic material, of optimised geometrical shape and their course in the space. The method was applied on the design of inlet channel of the three-shaft turboprop engine Walter M 602 and the aircraft L 610 and on the outlet channel of the two-shaft turboprop engine Walter M 601. Both channels have been manufactured and proved excellent aerodynamic properties. The channels have satisfied the airworthiness requirements and have been certified by the Czech Aviation Administration and by Federal Aviation Administration of the U.S.A. as well. The application of the new outlet channel have contributed to considerable improvement of the performance of the engine of more than 3 % at the same absolute fuel consumption and at 5 °C lower temperature of the gases at the inlet section of the turbine. The mass of the new channel is of 1 kg lower than the original one.

  20. Luminescent Measurement Systems for the Investigation of a Scramjet Inlet-Isolator

    Directory of Open Access Journals (Sweden)

    Azam Che Idris

    2014-04-01

    Full Text Available Scramjets have become a main focus of study for many researchers, due to their application as propulsive devices in hypersonic flight. This entails a detailed understanding of the fluid mechanics involved to be able to design and operate these engines with maximum efficiency even at their off-design conditions. It is the objective of the present cold-flow investigation to study and analyse experimentally the mechanics of the fluid structures encountered within a generic scramjet inlet at M = 5. Traditionally, researchers have to rely on stream-thrust analysis, which requires the complex setup of a mass flow meter, a force balance and a heat transducer in order to measure inlet-isolator performance. Alternatively, the pitot rake could be positioned at inlet-isolator exit plane, but this method is intrusive to the flow, and the number of pitot tubes is limited by the model size constraint. Thus, this urgent need for a better flow diagnostics method is addressed in this paper. Pressure-sensitive paint (PSP has been applied to investigate the flow characteristics on the compression ramp, isolator surface and isolator sidewall. Numerous shock-shock interactions, corner and shoulder separation regions, as well as shock trains were captured by the luminescent system. The performance of the scramjet inlet-isolator has been shown to improve when operated in a modest angle of attack.

  1. Formation of membranes by means of immersion precipitation : Part I. A model to describe mass transfer during immersion precipitation

    NARCIS (Netherlands)

    Reuvers, A.J.; van den Berg, J.W.A.; Smolders, C.A.

    1987-01-01

    Equations and boundary conditions are derived for the isothermal diffusion processes in the coagulation bath and in the polymer solution after immersion of a cast (ternary) polymer solution into a (binary) coagulation bath. The mass transfer is expressed in terms of thermodynamic driving forces and

  2. Improved Inlet Conditions for Terrain CFD

    DEFF Research Database (Denmark)

    Pedersen, Jesper Grønnegaard

    The atmospheric boundary layer flow over different types of terrain is studied through simulations made with the finite volume CFD code of Ellipsys 2D and 3D. The simulations are compared to measurements made at the Høvsøre test site and over the hill of Askervein.The primary objective...... for describing the flow after a change in the surface roughness. The derivation of these expressions is based on a range of simulations of flows over flat terrain with different types of roughness changes.The derived expressions show good agreement with simulations and could, as intended, be used to define inlet...... conditions for flow simulations over terrain, where an upstream roughness change is thought to have an influence. More thorough experimental verification is however, thought necessary to make the expressions sufficiently reliable. The same goes for the simulations-based conclusions regarding the flow over...

  3. Numerical Investigation of unsteady inlet flow fields

    Science.gov (United States)

    Hsieh, T.; Wardlaw, A. B., Jr.; Collins, P.; Coakley, T.

    1984-01-01

    The flow field within an unsteady, two-dimensional inlet is studied numerically, using a two dimensional Navier Stokes and a one-dimensional inviscid model. Unsteadiness is introduced by varying the outflow pressure boundary condition. The cases considered include outflow pressure variations which were a single pressure pulse, a rapid increase and a sine function. The amplitude of the imposed exit plane pressure disturbance varied between 1 percent and 20 percent of the mean exit pressure. At the higher levels of pressure fluctuation, the viscous flow field results bore little resemblance to the inviscid ones. The viscous solution included such phenomena as shock trains and bifurcating separation pockets. The induced velocity at the outflow plane predicted by the viscous model differs significantly from accoustical theory or small perturbation results.

  4. Determination of polybrominated diphenyl ethers at trace levels in environmental waters using hollow-fiber microporous membrane liquid-liquid extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Fontanals, Núria; Barri, Thaer; Bergström, Staffan; Jönsson, Jan-Ake

    2006-11-10

    In this study, we present a simple and easy-to-use extraction method that is based on a hollow-fiber microporous membrane liquid-liquid extraction (HF-MMLLE), as an extraction technique, followed by gas chromatography-mass spectrometry (GC-MS) to determine a group of brominated flame retardants (BFRs), polybrominated diphenyl ethers (PBDEs), at trace levels in aqueous samples. The hollow-fiber membrane (HF) filled with organic solvent was immersed into the aqueous sample, spiked with the analytes at ng l(-1) level, and stirred for 60 min. The proposed method could attain enrichment factors (E(e)) up to 5200 times, after optimising parameters, such as organic solvent, stirring speed and extraction time, that affect the extraction. The HF-MMLLE-GC-MS method was successfully applied to the extraction of PBDEs from tap, river and leachate water samples with spike recoveries ranging from 85% to 110%. The method validation with reagent and leachate water samples provided good linearity, detection limits of 1.1 ng l(-1) or lower, both in reagent and leachate water, as well as satisfactory precision in terms of repeatability and reproducibility with values of % relative standard deviation (%RSD) lower than 8.6 and 16.9, respectively.

  5. A new A431/cell membrane chromatography and online high performance liquid chromatography/mass spectrometry method for screening epidermal growth factor receptor antagonists from Radix sophorae flavescentis.

    Science.gov (United States)

    Wang, Sicen; Sun, Meng; Zhang, Yanmin; Du, Hui; He, Langchong

    2010-08-06

    The intracellular kinase domains of epidermal growth factor receptor (EGFR) in some tumor cells such as human epidermal squamous cells (A(431) cells) are an important target for drug discovery. We have developed a new A(431)/cell membrane chromatography (A(431)/CMC)-online-high performance liquid chromatography/mass spectrometry (HPLC/MS) method for screening EGFR antagonists from medicinal herbs such as traditional Chinese medicines (TCMs). In this study, A(431) cells with high EGFR expression levels were used to prepare cell membrane stationary phase (CMSP) in an A(431)/CMC model. The retention fractions eluted from the CMSP column were enriched onto an ODS pre-column and then switched into an HPLC/MS system by combining a 10 port columns switching valve. The screening results found that oxymatrine and matrine from Radix sophorae flavescentis (RSF) were the targeted components which could act on EGFR in similar manner of gefitinib as a control drug. There was a good relationship of their inhibiting effects on EGFR secretion and A(431) cell growth in vitro. This new A(431)/CMC-online-HPLC/MS method can be applied for screening EGFR antagonists from TCMs such as RSF. It will be a useful method for drug discovery with natural medicinal herbs as a leading compound resource. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Efficacy and compatibility with mass spectrometry of methods for elution of proteins from sodium dodecyl sulfate-polyacrylamide gels and polyvinyldifluoride membranes

    DEFF Research Database (Denmark)

    Jørgensen, C.S.; Jagd, M.; Sørensen, B.K.

    2004-01-01

    The resolving power of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) combined with isoelectric focusing in two-dimensional gel electrophoresis has made it one of the most important techniques for resolving complex mixtures, and it is of great importance for proteome mapping...... for recovering intact proteins from polyacrylamide gels and electroblotting membranes to define efficient methods compatible with MS. These methods complement in situ digestion protocols and allow determination of the molecular mass of whole proteins separated by SDS-PAGE. Passive elution of proteins from SDS......-PAGE gels was efficient only in the presence of SDS, whereas electroelution was achieved using butTers without SDS. Surface-enhanced laser desorption/ionization MS (SELDI-MS) analysis of proteins eluted in the presence of SIDS was possible using ion exchange ProteinChip arrays for concentration of sample...

  7. Gas-Phase Mass-Transfer Resistances at Polymeric Electrolyte Membrane Fuel Cells Electrodes: Theoretical Analysis on the Effectiveness of Interdigitated and Serpentine Flow Arrangements

    Directory of Open Access Journals (Sweden)

    Elisabetta Arato

    2016-03-01

    Full Text Available Mass transfer phenomena in polymeric electrolyte membrane fuel cells (PEMFC electrodes has already been analyzed in terms of the interactions between diffusive and forced flows. It was demonstrated that the whole phenomenon could be summarized by expressing the Sherwood number as a function of the Peclet number. The dependence of Sherwood number on Peclet one Sh(Pe function, which was initially deduced by determining three different flow regimes, has now been given a more accurate description. A comparison between the approximate and the accurate results for a reference condition of diluted reactant and limit current has shown that the former are useful for rapid, preliminary calculations. However, a more precise and reliable estimation of the Sherwood number is worth attention, as it provides a detailed description of the electrochemical kinetics and allows a reliable comparison of the various geometrical arrangements used for the distribution of the reactants.

  8. A pilot marine monitoring program in Cook Inlet, Alaska 1993--1994

    International Nuclear Information System (INIS)

    Brown, J.S.; Boehm, P.D.; Hyland, J.L.; Prest, H.F.

    1995-01-01

    Under the mandate of the Oil Pollution Act of 1990 (OPA'90) the Cook Inlet Regional Citizens Advisory Council (CIRCAC) sponsored the initiation of a pilot monitoring program in Cook Inlet, Alaska, The objectives of the pilot monitoring program were to provide baseline data on petroleum hydrocarbon concentrations in sediments and biota of Cook Inlet, and to evaluate the effectiveness of selected monitoring techniques in detecting petroleum hydrocarbon inputs from industry based sources. A sampling program was initiated in 1993 that included petroleum industry, specific sites and reference sites. Sample measurements included polynuclear aromatic hydrocarbons (PAH) in sediments, caged mussels, and semipermeable membrane devices (SPMDs), sediment toxicity using the amphipod, Ampelisca abdita, and estimates of population size and physiological condition of indigenous bivalves. Results of the 1993 sampling program indicated that (1) background levels of petrogenic, pyrogenic, and diagenetic hydrocarbons were present in sediments and indigenous bivalves, and (2) that limited amphipod toxicity and variations in bivalve measurements did not correlate with the hydrocarbons in the sediments. Modifications to the 1993 program were instituted for the 1994 sampling and included, the selection of new industry specific sites, discontinued use of caged bivalves, and design changes to SPMDs to enhance sensitivity. The results of the 1994 sampling program, and comparisons with the 1993 data are presented

  9. Mobile membrane introduction tandem mass spectrometry for on-the-fly measurements and adaptive sampling of VOCs around oil and gas projects in Alberta, Canada

    Science.gov (United States)

    Krogh, E.; Gill, C.; Bell, R.; Davey, N.; Martinsen, M.; Thompson, A.; Simpson, I. J.; Blake, D. R.

    2012-12-01

    The release of hydrocarbons into the environment can have significant environmental and economic consequences. The evolution of smaller, more portable mass spectrometers to the field can provide spatially and temporally resolved information for rapid detection, adaptive sampling and decision support. We have deployed a mobile platform membrane introduction mass spectrometer (MIMS) for the in-field simultaneous measurement of volatile and semi-volatile organic compounds. In this work, we report instrument and data handling advances that produce geographically referenced data in real-time and preliminary data where these improvements have been combined with high precision ultra-trace VOCs analysis to adaptively sample air plumes near oil and gas operations in Alberta, Canada. We have modified a commercially available ion-trap mass spectrometer (Griffin ICX 400) with an in-house temperature controlled capillary hollow fibre polydimethylsiloxane (PDMS) polymer membrane interface and in-line permeation tube flow cell for a continuously infused internal standard. The system is powered by 24 VDC for remote operations in a moving vehicle. Software modifications include the ability to run continuous, interlaced tandem mass spectrometry (MS/MS) experiments for multiple contaminants/internal standards. All data are time and location stamped with on-board GPS and meteorological data to facilitate spatial and temporal data mapping. Tandem MS/MS scans were employed to simultaneously monitor ten volatile and semi-volatile analytes, including benzene, toluene, ethylbenzene and xylene (BTEX), reduced sulfur compounds, halogenated organics and naphthalene. Quantification was achieved by calibrating against a continuously infused deuterated internal standard (toluene-d8). Time referenced MS/MS data were correlated with positional data and processed using Labview and Matlab to produce calibrated, geographical Google Earth data-visualizations that enable adaptive sampling protocols

  10. Application of USP inlet extensions to the TSI impactor system 3306/3320 using HFA 227 based solution metered dose inhalers.

    Science.gov (United States)

    Mogalian, Erik; Myrdal, Paul Brian

    2005-12-01

    The objective of this study was to further evaluate the need for a vertical inlet extension when testing solution metered dose inhalers using the TSI Model 3306 Impactor Inlet in conjunction with the TSI Model 3320 Aerodynamic Particle Sizer (APS). The configurations tested using the TSI system were compared to baseline measurements that were performed using the Andersen Mark II 8-stage cascade impactor (ACI). Seven pressurized solution metered dose inhalers were tested using varied concentrations of beclomethasone dipropionate (BDP), ethanol, and HFA 227 propellant. The inhalers were tested with the cascade impactor, and with the TSI system. The TSI system had three different configurations as the manufacturer provided (0 cm) or with inlet extensions of 20 and 40 cm. The extensions were located between the USP inlet and the Model 3306 Impactor Inlet. There were no practical differences between each system for the stem, actuator, or USP inlet. The fine particle mass (aerodynamic mass TSI system in order to give mass results that correlate to the ACI, especially for formulations having significant concentrations of low volatility excipients. Additionally, the results generated from this study were used to evaluate the product performance of HFA 227 based solution formulations that contain varying concentrations of ethanol as a cosolvent.

  11. Control of distributed heat transfer mechanisms in membrane distillation plants

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2017-01-05

    Various examples are provided that are related to boundary control in membrane distillation (MD) processes. In one example, a system includes a membrane distillation (MD) process comprising a feed side and a permeate side separated by a membrane boundary layer; and processing circuitry configured to control a water production rate of the MD process based at least in part upon a distributed heat transfer across the membrane boundary layer. In another example, a method includes determining a plurality of estimated temperature states of a membrane boundary layer separating a feed side and a permeate side of a membrane distillation (MD) process; and adjusting inlet flow rate or inlet temperature of at least one of the feed side or the permeate side to maintain a difference temperature along the membrane boundary layer about a defined reference temperature based at least in part upon the plurality of estimated temperature states.

  12. Identification of biotransformation products of macrolide and fluoroquinolone antimicrobials in membrane bioreactor treatment by ultrahigh-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Terzic, Senka; Senta, Ivan; Matosic, Marin; Ahel, Marijan

    2011-07-01

    Ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was applied for the identification of transformation products (TPs) of fluoroquinolone (norfloxacin and ciprofloxacin) and macrolide (azithromycin, erythromycin, and roxitromycin) antimicrobials in wastewater effluents from a Zenon hollow-fiber membrane bioreactor (MBR). The detected TPs were thoroughly characterized using the accurate mass feature for the determination of the tentative molecular formulae and MS-MS experiments for the structural elucidation of unknowns. Several novel TPs, which have not been previously reported in the literature, were identified. The TPs of azithromycin and roxithromycin, identified in MBR effluent, were conjugate compounds, which were formed by phosphorylation of desosamine moiety. Transformation of fluoroquinolones yielded two types of products: conjugates, formed by succinylation of the piperazine ring, and smaller metabolites, formed by an oxidative break-up of piperazine moiety to form the 7-[(2-carboxymethyl)amino] group. A semi-quantitative assessment of these TPs suggested that they might have contributed significantly to the overall balance of antimicrobial residues in MBR effluents and thus to the overall removal efficiency. Determination of TPs during a period of 2 months indicated a conspicuous dynamics, which warrants further research to identify microorganisms involved and treatment conditions leading to their formation.

  13. Osteoblast cell membrane chromatography coupled with liquid chromatography and time-of-flight mass spectrometry for screening specific active components from traditional Chinese medicines.

    Science.gov (United States)

    Wang, Nani; Zhang, Qiaoyan; Xin, Hailiang; Shou, Dan; Qin, Luping

    2017-11-01

    A method using osteoblast membrane chromatography coupled with liquid chromatography and time-of-flight mass spectrometry was developed to recognize and identify the specific active components from traditional Chinese medicines. Primary rat osteoblasts were used for the preparation of the stationary phase in the cell chromatography method. Retention components from the cell chromatography were collected and analyzed by liquid chromatography with time-of-flight mass spectrometry. This method was applied in screening active components from extracts of four traditional Chinese medicines. In total, 24 potentially active components with different structures were retained by osteoblast cell chromatography. There were five phenolic glucosides and one triterpenoid saponin from Curculigo orchioides Gaertn, two organic acids and ten flavonoids from Epimedium sagittatum Maxim, one phthalide compound and one organic acid from Angelica sinensis Diels, and two flavonoids and two saponins from Anemarrhena asphodeloides Bunge. Among those, four components (icariin, curculigoside, ferulaic acid, and timosaponin BII) were used for in vitro pharmacodynamics validation. They significantly increased the osteoblast proliferation, alkaline phosphatase activity, levels of bone gla protein and collagen type 1, and promoted mineralized nodule formation. The developed method was an effective screening method for finding active components from complex medicines that act on bone diseases. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Leading edge sweep effects in generic three-dimensional sidewall compression scramjet inlets

    Science.gov (United States)

    Cozart, Aaron B.; Holland, Scott D.; Trexler, Carl A.; Perkins, John N.

    1992-01-01

    A computational and experimental study of generic 3D sidewall compression inlets is conducted to examine the effects of fore and aft leading edge sweep on the internal shock structure. Inlets with leading edge sweeps of +30 deg and -30 deg with sidewall compression angles of 6 deg were tested in the NASA Langley Mach 4 air tunnel at a geometric contraction ratio of 1.87. The principal difference in performance was determined to be in the mass capture. Spillage was identified as having two components: a pressure induced component and a sweep induced component. It was found that while the direction of the leading edge sweep had a large influence on the spillage, the pressure effects were more important.

  15. Improvement of the inlet system for the spray-jet technique for use in spectroscopic studies and molecular deposition

    International Nuclear Information System (INIS)

    Yamada, Toshiki; Shinohara, Hidenori; Mashiko, Shinro

    2006-01-01

    We previously developed a molecular beam apparatus with a spray-jet technique in order to produce a molecular beam of non-volatile molecules in vacuum from the sprayed mist of a sample solution. The apparatus is for use in spectroscopic studies or a means of molecular deposition. The spray-jet inlet system consisted of an ultrasonic nebulizer, an inlet chamber and a pulsed nozzle. In the present paper, further improvements to the spray-jet inlet system are reported. The main improvement is the introduction of a pneumatic nebulizer to replace the previous ultrasonic nebulizer. The efficiency of molecular beam generation was evaluated on the basis of the signal intensity of the resonantly enhanced multiphoton ionization time-of-flight mass (REMPI-TOFMS) spectra for a Rhodamine B/methanol solution and the amount of sample consumed. The introduction of the pneumatic nebulizer increased the efficiency by a factor of 20

  16. Inlet Trade Study for a Low-Boom Aircraft Demonstrator

    Science.gov (United States)

    Heath, Christopher M.; Slater, John W.; Rallabhandi, Sriram K.

    2016-01-01

    Propulsion integration for low-boom supersonic aircraft requires careful inlet selection, placement, and tailoring to achieve acceptable propulsive and aerodynamic performance, without compromising vehicle sonic boom loudness levels. In this investigation, an inward-turning streamline-traced and axisymmetric spike inlet are designed and independently installed on a conceptual low-boom supersonic demonstrator aircraft. The airframe was pre-shaped to achieve a target ground under-track loudness of 76.4 PLdB at cruise using an adjoint-based design optimization process. Aircraft and inlet performance characteristics were obtained by solution of the steady-state Reynolds-averaged Navier-Stokes equations. Isolated cruise inlet performance including total pressure recovery and distortion were computed and compared against installed inlet performance metrics. Evaluation of vehicle near-field pressure signatures, along with under- and off-track propagated loudness levels is also reported. Results indicate the integrated axisymmetric spike design offers higher inlet pressure recovery, lower fan distortion, and reduced sonic boom. The vehicle with streamline-traced inlet exhibits lower external wave drag, which translates to a higher lift-to-drag ratio and increased range capability.

  17. Unstart Coupling Mechanism Analysis of Multiple-Modules Hypersonic Inlet

    Directory of Open Access Journals (Sweden)

    Jichao Hu

    2013-01-01

    Full Text Available The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted.

  18. Sediment Connectivity and Transport Pathways in Tidal Inlets: a Conceptual Framework with Application to Ameland Inlet

    Science.gov (United States)

    Pearson, S.; van Prooijen, B. C.; Zheng Bing, W.; Bak, J.

    2017-12-01

    Predicting the response of tidal inlets and adjacent coastlines to sea level rise and anthropogenic interventions (e.g. sand nourishments) requires understanding of sediment transport pathways. These pathways are strongly dependent on hydrodynamic forcing, grain size, underlying morphology, and the timescale considered. To map and describe these pathways, we considered the concept of sediment connectivity, which quantifies the degree to which sediment transport pathways link sources to receptors. In this study we established a framework for understanding sediment transport pathways in coastal environments, using Ameland Inlet in the Dutch Wadden Sea as a basis. We used the Delft3D morphodynamic model to assess the fate of sediment as it moved between specific morphological units defined in the model domain. Simulation data was synthesized in a graphical network and then graph theory used to analyze connectivity at different space and time scales. At decadal time scales, fine and very fine sand (250μm) shows lower connectivity, even in more energetic areas. Greater sediment connectivity was found under the influence of wind and waves when compared to purely tidal forcing. Connectivity shows considerable spatial variation in cross shore and alongshore directions, depending on proximity to the inlet and dominant wave direction. Furthermore, connectivity generally increases at longer timescales. Asymmetries in connectivity (i.e. unidirectional transport) can be used to explain long-term erosional or depositional trends. As such, an understanding of sediment connectivity as a function of grain size could yield useful insights for resolving sediment transport pathways and the fate of a nourishment in coastal environments.

  19. A coaxially heated membrane introduction mass spectrometry interface for the rapid and sensitive on-line measurement of volatile and semi-volatile organic contaminants in air and water at parts-per-trillion levels.

    Science.gov (United States)

    Thompson, Alexander J; Creba, A Skye; Ferguson, Robyn M; Krogh, Erik T; Gill, Christopher G

    2006-01-01

    A coaxially heated membrane introduction mass spectrometry (MIMS) sampling interface is presented that demonstrates improved on-line performance for the direct measurement of semi-volatile organic compounds (SVOCs) in air and water samples at parts-per-trillion levels. The device is based on a polydimethylsiloxane (PDMS) capillary hollow fibre membrane (HFM) in a pneumatically assisted "flow-over" configuration that is resistively heated on the membrane interior via a coaxial nichrome wire, establishing a thermal gradient counter to the analyte concentration gradient. This arrangement allows for continuous and/or pulsed heating modes, affording excellent sensitivity for the on-line measurement of SVOCs while retaining sensitivity for volatile organic compounds (VOCs). In addition, the signal response time for SVOCs is reduced substantially over conventional "flow-over" MIMS interfaces. Separation and quantitation of analytes are achieved using quadrupole ion trap tandem mass spectrometry. Copyright (c) 2006 John Wiley & Sons, Ltd.

  20. Performance of a Supersonic Over-Wing Inlet with Application to a Low-Sonic-Boom Aircraft

    Science.gov (United States)

    Trefny, Charles J.; Hirt, Stefanie M.; Anderson, Bernhard H.; Fink, Lawrence E.; Magee, Todd E.

    2014-01-01

    Development of commercial supersonic aircraft has been hindered by many related factors including fuel-efficiency, economics, and sonic-boom signatures that have prevented over-land flight. Materials, propulsion, and flight control technologies have developed to the point where, if over-land flight were made possible, a commercial supersonic transport could be economically viable. Computational fluid dynamics, and modern optimization techniques enable designers to reduce the boom signature of candidate aircraft configurations to acceptable levels. However, propulsion systems must be carefully integrated with these low-boom configurations in order that the signatures remain acceptable. One technique to minimize the downward propagation of waves is to mount the propulsion systems above the wing, such that the wing provides shielding from shock waves generated by the inlet and nacelle. This topmounted approach introduces a number of issues with inlet design and performance especially with the highly-swept wing configurations common to low-boom designs. A 1.79%-scale aircraft model was built and tested at the NASA Glenn Research Center's 8-by 6-Foot Supersonic Wind Tunnel (8x6 SWT) to validate the configuration's sonic boom signature. In order to evaluate performance of the top-mounted inlets, the starboard flow-through nacelle on the aerodynamic model was replaced by a 2.3%-scale operational inlet model. This integrated configuration was tested at the 8x6 SWT from Mach 0.25 to 1.8 over a wide range of angles-of-attack and yaw. The inlet was also tested in an isolated configuration over a smaller range of angles-of-attack and yaw. A number of boundary-layer bleed configurations were investigated and found to provide a substantial positive impact on pressure recovery and distortion. Installed inlet performance in terms of mass capture, pressure recovery, and distortion over the Mach number range at the design angle-of-attack of 4-degrees is presented herein and compared

  1. A study on flow development in an APU-style inlet and its effect on centrifugal compressor performance

    Science.gov (United States)

    Lou, Fangyuan

    The objectives of this research were to investigate the flow development inside an APU-style inlet and its effect on centrifugal compressor performance. The motivation arises from the increased applications of gas turbine engines installed with APU-style inlets such as unmanned aerial vehicles, auxiliary power units, and helicopters. The inlet swirl distortion created from these complicated inlet systems has become a major performance and operability concern. To improve the integration between the APU-style inlet and gas turbine engines, better understanding of the flow field in the APU-style inlet and its effect on gas turbine is necessary. A research facility for the purpose of performing an experimental investigation of the flow field inside an APU-style inlet was developed. A subcritical air ejector is used to continuously flow the inlet at desired corrected mass flow rates. The facility is capable of flowing the APU inlet over a wide range of corrected mass flow rate that matches the same Mach numbers as engine operating conditions. Additionally, improvement in the system operational steadiness was achieved by tuning the pressure controller using a PID control method and utilizing multi-layer screens downstream of the APU inlet. Less than 1% relative unsteadiness was achieved for full range operation. The flow field inside the rectangular-sectioned 90? bend of the APU-style inlet was measured using a 3-Component LDV system. The structures for both primary flow and the secondary flow inside the bend were resolved. Additionally, the effect of upstream geometry on the flow development in the downstream bend was also investigated. Furthermore, a Single Stage Centrifugal Compressor research facility was developed at Purdue University in collaboration with Honeywell to operate the APU-style inlet at engine conditions with a compressor. To operate the facility, extensive infrastructure for facility health monitoring and performance control (including lubrication

  2. Development of a membrane-assisted fluidized bed reactor - 1 - Gas phase back-mixing and bubble-to-emulsion phase mass transfer using tracer injection and ultrasound experiments

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.; Laverman, J.A.; Cents, A.H.G.; van Sint Annaland, M.; Kuipers, J.A.M.

    2005-01-01

    A small laboratory-scale membrane-assisted fluidized bed reactor (MAFBR) was constructed in order to experimentally demonstrate the benefits of this reactor concept, especially the enhanced bubble-to-emulsion phase mass transfer and the reduced overall axial gas phase back-mixing, due to the

  3. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    Yunguang Huang

    2015-01-01

    Full Text Available A vacuum ultraviolet lamp based single photon ionization- (SPI- photoelectron ionization (PEI portable reflecting time-of-flight mass spectrometer (TOFMS was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX, SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1 with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear.

  4. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    Science.gov (United States)

    Huang, Yunguang; Li, Jinxu; Tang, Bin; Zhu, Liping; Hou, Keyong; Li, Haiyang

    2015-01-01

    A vacuum ultraviolet lamp based single photon ionization- (SPI-) photoelectron ionization (PEI) portable reflecting time-of-flight mass spectrometer (TOFMS) was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE) below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX), SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1) with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear. PMID:26587023

  5. Numerical and experimental investigation on effects of inlet humidity and fuel flow rate and oxidant on the performance on polymer fuel cell

    International Nuclear Information System (INIS)

    Takalloo, Pourya Karimi; Nia, Ehsan Shabahang; Ghazikhani, Mohsen

    2016-01-01

    Highlights: • The impact of alteration in humidification on performance of fuel cell. • The impact of variation of temperature on performance of fuel cell. • The effects of using pure oxygen on the polarity curve are studied. • Fuel cell has been investigated both experimentally and numerically. - Abstract: Considering the importance of water management in a fuel cell and in order to increase the rate of the electro-chemical process in fuel cells with polymer membrane, it is required to optimize the humidity and inlet flow rates on anode and cathode sides. In this study, the impact of alteration in humidification and inlet flow rates on performance improvements for polymer membrane fuel cells is investigated both experimentally and numerically. To obtain the objective, employing the results from experiments and simulations, polarity curve and power density are produced and further used to conduct the desired investigations. In addition, through the conducted simulations the effects of using pure oxygen in the cathode side and inlet gas temperatures on the polarity curve is studied. The results demonstrate that an increase in humidity of the inlet gases will lead to performance amelioration in the cell, due to reduction in ionic resistance at the membrane. Furthermore, with the aforementioned increment; molar fractions of hydrogen and oxygen are decreased through the channel which results in produced water increment. Amplification in inlet flow rates to a certain level will improve the penetration possibility for gaseous forms leading to betterment of the cell performance in this specified range. Performance improvements with inlet gases temperature increment conclude other results of this study.

  6. Cook Inlet and Kenai Peninsula, Alaska ESI: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the locations of volcanos in Cook Inlet and Kenai Peninsula, Alaska. Vector points in the data set represent the location of the volcanos....

  7. Cook Inlet and Kenai Peninsula, Alaska ESI: INDEX (Index Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries used in the creation of the Environmental Sensitivity Index (ESI) for Cook Inlet and Kenai...

  8. Cook Inlet and Kenai Peninsula, Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  9. AFSC/REFM: Cook Inlet Beluga Whale Economic Survey 2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project was to collect data to understand the publics preferences for protecting the Cook Inlet beluga whale (CIBW), a distinct population...

  10. PIE Nacelle Flow Analysis and TCA Inlet Flow Quality Assessment

    Science.gov (United States)

    Shieh, C. F.; Arslan, Alan; Sundaran, P.; Kim, Suk; Won, Mark J.

    1999-01-01

    This presentation includes three topics: (1) Analysis of isolated boattail drag; (2) Computation of Technology Concept Airplane (TCA)-installed nacelle effects on aerodynamic performance; and (3) Assessment of TCA inlet flow quality.

  11. Cook Inlet and Kenai Peninsula, Alaska ESI: FISHL (Fish Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for anadromous fish streams in Cook Inlet and Kenai Peninsula, Alaska. Vector lines in this data set represent...

  12. Engineering Study of Inlet Entrance Hydrodynamics: Grays Harbor, Washington, USA

    National Research Council Canada - National Science Library

    Cialone, Mary A; Kraus, Nicholas C

    2001-01-01

    .... The influence of the tidal current and water level on wave transformation was also examined. Ebb current produces the greatest change at the inlet entrance, increasing wave heights by as much as 0.5-1.5 m...

  13. Cook Inlet and Kenai Peninsula, Alaska ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for razor clams in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent locations of...

  14. Three dimensional viscous analysis of a hypersonic inlet

    Science.gov (United States)

    Reddy, D. R.; Smith, G. E.; Liou, M.-F.; Benson, Thomas J.

    1989-01-01

    The flow fields in supersonic/hypersonic inlets are currently being studied at NASA Lewis Research Center using 2- and 3-D full Navier-Stokes and Parabolized Navier-Stokes solvers. These tools have been used to analyze the flow through the McDonnell Douglas Option 2 inlet which has been tested at Calspan in support of the National Aerospace Plane Program. Comparisons between the computational and experimental results are presented. These comparisons lead to better overall understanding of the complex flows present in this class of inlets. The aspects of the flow field emphasized in this work are the 3-D effects, the transition from laminar to turbulent flow, and the strong nonuniformities generated within the inlet.

  15. Cook Inlet and Kenai Peninsula, Alaska ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for herring spawning areas in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent...

  16. Development of an Experimental Data Base to Validate Compressor-Face Boundary Conditions Used in Unsteady Inlet Flow Computations

    Science.gov (United States)

    Sajben, Miklos; Freund, Donald D.

    1998-01-01

    The ability to predict the dynamics of integrated inlet/compressor systems is an important part of designing high-speed propulsion systems. The boundaries of the performance envelope are often defined by undesirable transient phenomena in the inlet (unstart, buzz, etc.) in response to disturbances originated either in the engine or in the atmosphere. Stability margins used to compensate for the inability to accurately predict such processes lead to weight and performance penalties, which translate into a reduction in vehicle range. The prediction of transients in an inlet/compressor system requires either the coupling of two complex, unsteady codes (one for the inlet and one for the engine) or else a reliable characterization of the inlet/compressor interface, by specifying a boundary condition. In the context of engineering development programs, only the second option is viable economically. Computations of unsteady inlet flows invariably rely on simple compressor-face boundary conditions (CFBC's). Currently, customary conditions include choked flow, constant static pressure, constant axial velocity, constant Mach number or constant mass flow per unit area. These conditions are straightforward extensions of practices that are valid for and work well with steady inlet flows. Unfortunately, it is not at all likely that any flow property would stay constant during a complex system transient. At the start of this effort, no experimental observation existed that could be used to formulate of verify any of the CFBC'S. This lack of hard information represented a risk for a development program that has been recognized to be unacceptably large. The goal of the present effort was to generate such data. Disturbances reaching the compressor face in flight may have complex spatial structures and temporal histories. Small amplitude disturbances may be decomposed into acoustic, vorticity and entropy contributions that are uncoupled if the undisturbed flow is uniform. This study

  17. Energy efficient air inlet humidity control; Energiezuinige inblaasvochtregeling

    Energy Technology Data Exchange (ETDEWEB)

    Gielen, J.H. [C Point, DLV Plant, Horst (Netherlands)

    2005-03-15

    This project report describes the results of research conducted on the control of the inlet, humidification and dehumidification, based on the air inlet humidity rate. The project was carried out at a mushroom cultivation business in Heijen, the Netherlands [Dutch] Deze projectrapportage geeft de resultaten van het onderzoek naar het regelen van de luchtklep, bevochtiging en ontvochtiging, op basis van het inblaasvochtgehalte. Het project werd uitgevoerd op een champignonkwekerij in Heijen.

  18. Zero voltage mass spectrometry probes and systems

    Science.gov (United States)

    Cooks, Robert Graham; Wleklinski, Michael Stanley; Bag, Soumabha; Li, Yafeng

    2017-10-10

    The invention generally relates to zero volt mass spectrometry probes and systems. In certain embodiments, the invention provides a system including a mass spectrometry probe including a porous material, and a mass spectrometer (bench-top or miniature mass spectrometer). The system operates without an application of voltage to the probe. In certain embodiments, the probe is oriented such that a distal end faces an inlet of the mass spectrometer. In other embodiments, the distal end of the probe is 5 mm or less from an inlet of the mass spectrometer.

  19. Temperature and velocity field of coolant at inlet to WWER-440 core - evaluation of experimental data

    International Nuclear Information System (INIS)

    Jirous, F.; Klik, F.; Janeba, B.; Daliba, J.; Delis, J.

    1989-01-01

    Experimentally determined were coolant temperature and velocity fields at the inlet of the WWER-440 reactor core. The accuracy estimate is presented of temperature measurements and the relation is given for determining the resulting measurement error. An estimate is also made of the accuracy of solution of the system of equations for determining coefficients B kn using the method of the least square fit. Coefficients B kn represent the relative contribution of the mass flow of the k-th fuel assembly from the n-th loop and allow the calculation of coolant temperatures at the inlet of the k-th fuel assembly, when coolant temperatures in loops at reactor inlet are known. A comparison is made of the results of measurements on a hydrodynamic model of a WWER-440 reactor with results of measurements made at unit 4 of the Dukovany nuclear power plant. Full agreement was found for 32 model measurements and 6 reactor measurements. It may be assumed that the results of other model measurements obtained for other operating variants will also apply for an actual reactor. Their applicability may, however, only be confirmed by repeating the experiment on other WWER-440 reactors. (Z.M.). 5 figs., 7 refs

  20. Performance modeling of industrial gas turbines with inlet air filtration system

    Directory of Open Access Journals (Sweden)

    Samuel O. Effiom

    2015-03-01

    Full Text Available The effect of inlet air filtration on the performance of two industrial gas turbines (GT is presented. Two GTs were modeled similar to GE LM2500+ and Alstom GT13 E2-2012, using TURBOMATCH and chosen to operate at environmental conditions of Usan offshore oilfield and Maiduguri dessert in Nigeria. The inlet pressure recovered (Precov from the selected filters used in Usan offshore, and Maiduguri ranged between 98.36≤Precov≤99.51% and 98.67≤Precov≤99.56% respectively. At reduced inlet Precov by 98.36% (1.66 kPa and, at a temperature above 15 °C (ISA, a reduction of 16.9%, and 7.3% of power output and efficiency was obtained using GT13 E2-2012, while a decrease of 14.8% and 4.7% exist for power output and efficiency with GE LM2500+. In addition, a reduction in mass flow rate of air and fuel under the same condition was between 4.3≤mair≤10.6% and 10.4≤mfuel≤11.5% for GT13 E2-2012 and GE LM2500+, correspondingly. However, the GE LM2500+ was more predisposed to intake pressure drops since it functioned at a higher overall pressure ratio. The results obtained were found worthwhile and could be the basis for filter selection and efficient compressor housing design in the locations concerned.

  1. Characteristics of a disk MHD generator with inlet swirl

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Nob [Nagaoka University of Technology (Japan)

    1999-10-01

    Two kinds of experimental studies have been performed to know the effect of inlet swirl in a disk-type MHD generator. Firstly, we decreased stagnation temperature in order to simulate a poor inlet plasma condition. Inlet swirl provided relatively higher radial Hall voltage and much better performance even for lower stagnation temperatures compared with those for the simple radial flow case, mainly due to the contribution of Faraday e.m.f. U{sub {theta}}B. High enthalpy extraction level near 30% could be kept even for lower stagnation temperatures in the range of 1600-1700 K. Secondly, we decreased stagnation pressure to know generator performance under smaller pressure ratio inlet to exit. Decrease of stagnation pressure improved enthalpy extraction very much unless the increase of static pressure and decrease of Hall field became significant. Highest enthalpy extraction ratio of 38.2% was successfully achieved. From considerations of momentum balance along the radial direction, positive inlet swirl has an important effect to reduce static pressure and also to reduce the unfavorable effect of Lorentz force. This suggests that introduction of inlet swirl is an influential way to reach high isentropic efficiency. (author)

  2. Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems

    Science.gov (United States)

    McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.

    2011-01-01

    Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.

  3. Competing intermolecular interactions of artemisinin-type agents and aspirin with membrane phospholipids: Combined model mass spectrometry and quantum-chemical study

    International Nuclear Information System (INIS)

    Pashynska, Vlada; Stepanian, Stepan; Gömöry, Agnes; Vekey, Karoly; Adamowicz, Ludwik

    2015-01-01

    Highlights: • Competitive binding of artemisinin agents and aspirin with phospholipids is shown. • Complexation between the antimalarial drugs and aspirin molecules is also found. • Energetically favorable structures of the model complexes are identified by DFT. • Membranotropic activity of the studied drugs can be modified under joint usage. - Abstract: Study of intermolecular interactions of antimalarial artemisinin-type drugs and aspirin with membrane phospholipids is important in term of elucidation of the drugs activity modification under their joint usage. Combined experimental and computational study of the interaction of dihydroartemisinin, α-artemether, and artesunate with aspirin (ASP) and dipalmitoylphosphatidylcholine (DPPC) is performed by electrospray ionization (ESI) mass spectrometry and by DFT B3LYP/aug-cc-pVDZ methods. The results of the ESI investigation of systems containing artemisinin-type agent, ASP and DPPC, reveal a competition between the antimalarial agents and ASP for binding with DPPC molecules. The complexation between the antimalarial drugs and ASP is also found. Observed phenomena suggest that membranotropic activity of artemisin-type agents and aspirin is modified under their combined usage. To elucidate structure-energy characteristics of the non-covalent complexes studied the model DFT calculations are performed for dihydroartemisinin · ASP complex and complexes of the each drug with phosphatidylcholine head of DPPC in neutral and cationized forms

  4. Competing intermolecular interactions of artemisinin-type agents and aspirin with membrane phospholipids: Combined model mass spectrometry and quantum-chemical study

    Energy Technology Data Exchange (ETDEWEB)

    Pashynska, Vlada, E-mail: vlada@vl.kharkov.ua [B.Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine, Lenin Ave., 47, 61103 Kharkov (Ukraine); Stepanian, Stepan [B.Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine, Lenin Ave., 47, 61103 Kharkov (Ukraine); Gömöry, Agnes; Vekey, Karoly [Institute of Organic Chemistry of Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Magyar tudosok korutja, 2, Budapest H-1117 (Hungary); Adamowicz, Ludwik [University of Arizona, Department of Chemistry and Biochemistry, Tucson, AZ 85721 (United States)

    2015-07-09

    Highlights: • Competitive binding of artemisinin agents and aspirin with phospholipids is shown. • Complexation between the antimalarial drugs and aspirin molecules is also found. • Energetically favorable structures of the model complexes are identified by DFT. • Membranotropic activity of the studied drugs can be modified under joint usage. - Abstract: Study of intermolecular interactions of antimalarial artemisinin-type drugs and aspirin with membrane phospholipids is important in term of elucidation of the drugs activity modification under their joint usage. Combined experimental and computational study of the interaction of dihydroartemisinin, α-artemether, and artesunate with aspirin (ASP) and dipalmitoylphosphatidylcholine (DPPC) is performed by electrospray ionization (ESI) mass spectrometry and by DFT B3LYP/aug-cc-pVDZ methods. The results of the ESI investigation of systems containing artemisinin-type agent, ASP and DPPC, reveal a competition between the antimalarial agents and ASP for binding with DPPC molecules. The complexation between the antimalarial drugs and ASP is also found. Observed phenomena suggest that membranotropic activity of artemisin-type agents and aspirin is modified under their combined usage. To elucidate structure-energy characteristics of the non-covalent complexes studied the model DFT calculations are performed for dihydroartemisinin · ASP complex and complexes of the each drug with phosphatidylcholine head of DPPC in neutral and cationized forms.

  5. A Review of the Emerging Field of Underwater Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Emily Chua

    2016-11-01

    Full Text Available Mass spectrometers are versatile sensor systems, owing to their high sensitivity and ability to simultaneously measure multiple chemical species. Over the last two decades, traditional laboratory-based membrane inlet mass spectrometers have been adapted for underwater use. Underwater mass spectrometry has drastically improved our capability to monitor a broad suite of gaseous compounds (e.g., dissolved atmospheric gases, light hydrocarbons, and volatile organic compounds in the aquatic environment. Here we provide an overview of the progress made in the field of underwater mass spectrometry since its inception in the 1990s to the present. In particular, we discuss the approaches undertaken by various research groups in developing in situ mass spectrometers. We also provide examples to illustrate how underwater mass spectrometers have been used in the field. Finally, we present future trends in the field of in situ mass spectrometry. Most of these efforts are aimed at improving the quality and spatial and temporal scales of chemical measurements in the ocean. By providing up-to-date information on underwater mass spectrometry, this review offers guidance for researchers interested in adapting this technology as well as goals for future progress in the field.

  6. Organics Verification Study for Sinclair and Dyes Inlets, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, Nancy P.; Brandenberger, Jill M.; Niewolny, Laurie A.; Johnston, Robert K.

    2006-09-28

    Sinclair and Dyes Inlets near Bremerton, Washington, are on the State of Washington 1998 303(d) list of impaired waters because of fecal coliform contamination in marine water, metals in sediment and fish tissue, and organics in sediment and fish tissue. Because significant cleanup and source control activities have been conducted in the inlets since the data supporting the 1998 303(d) listings were collected, two verification studies were performed to address the 303(d) segments that were listed for metal and organic contaminants in marine sediment. The Metals Verification Study (MVS) was conducted in 2003; the final report, Metals Verification Study for Sinclair and Dyes Inlets, Washington, was published in March 2004 (Kohn et al. 2004). This report describes the Organics Verification Study that was conducted in 2005. The study approach was similar to the MVS in that many surface sediment samples were screened for the major classes of organic contaminants, and then the screening results and other available data were used to select a subset of samples for quantitative chemical analysis. Because the MVS was designed to obtain representative data on concentrations of contaminants in surface sediment throughout Sinclair Inlet, Dyes Inlet, Port Orchard Passage, and Rich Passage, aliquots of the 160 MVS sediment samples were used in the analysis for the Organics Verification Study. However, unlike metals screening methods, organics screening methods are not specific to individual organic compounds, and are not available for some target organics. Therefore, only the quantitative analytical results were used in the organics verification evaluation. The results of the Organics Verification Study showed that sediment quality outside of Sinclair Inlet is unlikely to be impaired because of organic contaminants. Similar to the results for metals, in Sinclair Inlet, the distribution of residual organic contaminants is generally limited to nearshore areas already within the

  7. Shotgun analysis of membrane proteomes by an improved SDS-assisted sample preparation method coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lin, Yong; Jiang, Huajun; Yan, Yujun; Peng, Bin; Chen, Jinhua; Lin, Haiyan; Liu, Zhonghua

    2012-12-12

    Analysis of the membrane proteins, particularly the integral membrane proteins, is limited by the inherent membrane hydrophobicity. Sodium dodecyl sulfate (SDS) is one of the most efficient reagents used for the extraction of membrane proteins, but its presence in samples interferes with LC-MS-based proteomic analyses because it affects RP-LC separations and electrospray ionization. In this paper, we present an improved sample preparation strategy based on SDS-assisted digestion and peptide-level SDS-removal using an optimized potassium dodecyl sulfate (KDS) precipitation method (SSDP method) for shotgun analysis of the membrane proteome. This method utilizes a high concentration of SDS (1.0%) to lyse the membranes and to solubilize the hydrophobic membrane proteins, resulting in a more complete protein digestion in the diluted SDS buffer (0.1% SDS), and a high efficiency of SDS removal and peptide recovery by the optimized KDS precipitation for protein identification. The SSDP method provides evidence that proteins can be efficiently digested, and the SDS can be decreased to 95% peptide recovery. Compared to other sample preparation methods commonly used in shotgun membrane proteomics, the newly developed method not only increased the identified number of the total proteins, membrane proteins and integral membrane proteins by an average of 33.1%, 37.2% and 40.5%, respectively, but also leading to the identification of highest number of matching peptides. All the results showed that the method yielded better recovery and reliability in the identification of the proteins especially the highly hydrophobic integral membrane proteins, and thus providing a promising tool for the shotgun analysis of membrane proteome. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Flow dynamical behavior and performance of a micro viscous pump with unequal inlet and outlet areas

    Directory of Open Access Journals (Sweden)

    Chenhui Hu

    2016-01-01

    Full Text Available The micro viscous pump is an important type of fluidic device. Optimizing the working performance of the pump is crucial for its wider application. A micro viscous pump design with unequal inlet and outlet areas is proposed in this paper. The flow field of the viscous pump is investigated using 2D laminar simulations. The mass flow rate and driving power are studied with different opening angles. The effects of the Reynolds number and the pressure load on the working performance are discussed in detail. Flow structures and vortex evolution are analyzed. With larger inlet and outlet areas, a higher mass flow rate is obtained and less driving power is achieved. A high pressure load results in a reduction in mass flow rate and an increase in driving power. Pumps with large opening angles are more susceptive to the Reynolds number and the pressure load. The adverse impact of the pressure load can be reduced by increasing the rotor speed. The vortex structure is affected by the geometric and operating parameters in the flow field. The flow dynamical behavior of the viscous pump exerts significant influence on its pumping ability. The present work gives rise to performance improvements for the micro viscous pump.

  9. Substernal Thyroid Masses

    Directory of Open Access Journals (Sweden)

    Mohamed A.H. Regal

    2010-10-01

    Full Text Available A thyroid mass, most often a non toxic colloid goiter or occasionally an adenoma, is not an unusual finding below the level of the thoracic inlet.1 In 1992 Creswell and Wells estimated that these tumors comprise 5.8% of all mediastinal lesions.1 There is no standard definition for thyroid glands extending below the thoracic inlet, but such masses descend from their original cervical location for more than 2 or 3 cm below the thoracic inlet, and are not truly primary tumors of the mediastinum. They preserve the connection between the thoracic and cervical portion and receive their blood supply from the neck.2,3 In 1940, the seminal report of Wakeley and Mulvany divided intrathoracic thyroid masses into 3 types; (1”Small substernal extension” of a mainly cervical mass, (2 “Partial” intrathoracic, in which the major portion of the mass is situated within the thorax, and (3”Complete” in which all of the mass lies within the thoracic cavity.

  10. Design and qualification of ITER CS and TF cooling inlets

    International Nuclear Information System (INIS)

    Decool, P.; Cloez, H.; Nicollet, S.; Serries, J.P.

    2005-01-01

    In the ITER superconducting magnets, the CIC (cable-in-conduit) conductors cooling is insured by supercritical helium forced flow in the central and annular parallel channels. In the Central Solenoid (CS), with a thick square jacket conductor, the helium inlet is in the highest field region at the inner bore pancake joggle, and it has to support the high hoop force stress level with a very low stress concentration factor. In the TF (toroidal field) magnets, a thin jacket circular conductor is wound in double pancakes, inserted into radial plates, stacked and embedded into a steel case. The helium inlets are located at the inner bore, in the limited space between the radial plates and the coil casing. The PF coils helium inlets, not studied here, are similar to the CS ones, but with a lower stress level. A complete qualification work on the CS and TF helium inlets is presented. A design optimisation was performed, by FEM analysis, resulting in acceptable stress level in both helium inlets. The welding procedure was qualified and specific fatigue life mock-ups were designed, analysed and manufactured using representative jacket materials. Fatigue life qualification at 4 K was performed in the German test facility applying the relevant loading and number of cycles. Hydraulic mock-ups were manufactured and qualified in the CEA test facility using GN2 at relevant Reynolds number. Pressure drop as well as flow distribution inside conductors' petals were measured. The mechanical and hydraulic results are presented. (authors)

  11. Design and qualification of ITER CS and TF cooling inlets

    Energy Technology Data Exchange (ETDEWEB)

    Decool, P.; Cloez, H.; Nicollet, S.; Serries, J.P. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Nyilas, A. [Forschungszentrum Karlsruhe GmbH (FZK) Institut fur Technische Physik (ITP), Karlsruhe (Germany)

    2005-07-01

    In the ITER superconducting magnets, the CIC (cable-in-conduit) conductors cooling is insured by supercritical helium forced flow in the central and annular parallel channels. In the Central Solenoid (CS), with a thick square jacket conductor, the helium inlet is in the highest field region at the inner bore pancake joggle, and it has to support the high hoop force stress level with a very low stress concentration factor. In the TF (toroidal field) magnets, a thin jacket circular conductor is wound in double pancakes, inserted into radial plates, stacked and embedded into a steel case. The helium inlets are located at the inner bore, in the limited space between the radial plates and the coil casing. The PF coils helium inlets, not studied here, are similar to the CS ones, but with a lower stress level. A complete qualification work on the CS and TF helium inlets is presented. A design optimisation was performed, by FEM analysis, resulting in acceptable stress level in both helium inlets. The welding procedure was qualified and specific fatigue life mock-ups were designed, analysed and manufactured using representative jacket materials. Fatigue life qualification at 4 K was performed in the German test facility applying the relevant loading and number of cycles. Hydraulic mock-ups were manufactured and qualified in the CEA test facility using GN2 at relevant Reynolds number. Pressure drop as well as flow distribution inside conductors' petals were measured. The mechanical and hydraulic results are presented. (authors)

  12. Combined in-gel tryptic digestion and CNBr cleavage for the generation of peptide maps of an integral membrane protein with MALDI-TOF mass spectrometry

    NARCIS (Netherlands)

    Montfort, Bart A. van; Doeven, Mark K.; Canas, Benito; Veenhoff, Liesbeth M.; Poolman, Bert; Robillard, George T.

    2002-01-01

    A limitation of the in-gel approaches for the generation of peptides of membrane proteins is the size and hydrophobicity of the fragments generated. For membrane proteins like the lactose transporter (LacS) of Streptococcus thermophilus, tryptic digestion or CNBr cleavage yields several hydrophobic

  13. Flow control in axial fan inlet guide vanes by synthetic jets

    Directory of Open Access Journals (Sweden)

    Wurst P.

    2013-04-01

    Full Text Available Tested high pressure axial flow fan with hub/tip ratio of 0.70 and external diameter of 600 mm consisted of inlet guide vanes (IGV, rotor and stator blade rows. Fan peripheral velocity was 47 m/s. Air volume flow rate was changed by turning of rear part of the inlet guide vanes. At turning of 20 deg the flow was separated on the IGV profiles. The synthetic jets were introduced through radial holes in machine casing in the location before flow separation origin. Synthetic jet actuator was designed with the use of a speaker by UT AVCR. Its membrane had diameter of 63 mm. Excitation frequency was chosen in the range of 500 Hz – 700 Hz. Synthetic jets favourably influenced separated flow on the vane profiles in the distance of (5 – 12 mm from the casing surface. The reduction of flow separation area caused in the region near the casing the decrease of the profile loss coefficient approximately by 20%.

  14. Gas separation with membranes

    International Nuclear Information System (INIS)

    Schulz, G.; Michele, H.; Werner, U.

    1982-01-01

    Gas separation with membranes has already been tested in numerous fields of application, e.g. uranium enrichment of H 2 separation. In many of these processes the mass transfer units, so-called permeators, have to be connected in tandem in order to achieve high concentrations. A most economical operating method provides for each case an optimization of the cascades with regard to the membrane materials, construction and design of module. By utilization of the concentration gradient along the membrane a new process development has been accomplished - the continuously operating membrane rectification unit. Investment and operating costs can be reduced considerably for a number of separating processes by combining a membrane rectification unit with a conventional recycling cascade. However, the new procedure requires that the specifications for the module construction, flow design, and membrane properties be reconsidered. (orig.) [de

  15. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...

  16. Effect of inlet cone pipe angle in catalytic converter

    Science.gov (United States)

    Amira Zainal, Nurul; Farhain Azmi, Ezzatul; Arifin Samad, Mohd

    2018-03-01

    The catalytic converter shows significant consequence to improve the performance of the vehicle start from it launched into production. Nowadays, the geometric design of the catalytic converter has become critical to avoid the behavior of backpressure in the exhaust system. The backpressure essentially reduced the performance of vehicles and increased the fuel consumption gradually. Consequently, this study aims to design various models of catalytic converter and optimize the volume of fluid flow inside the catalytic converter by changing the inlet cone pipe angles. Three different geometry angles of the inlet cone pipe of the catalytic converter were assessed. The model is simulated in Solidworks software to determine the optimum geometric design of the catalytic converter. The result showed that by decreasing the divergence angle of inlet cone pipe will upsurge the performance of the catalytic converter.

  17. Boundary conditions for free surface inlet and outlet problems

    KAUST Repository

    Taroni, M.

    2012-08-10

    We investigate and compare the boundary conditions that are to be applied to free-surface problems involving inlet and outlets of Newtonian fluid, typically found in coating processes. The flux of fluid is a priori known at an inlet, but unknown at an outlet, where it is governed by the local behaviour near the film-forming meniscus. In the limit of vanishing capillary number Ca it is well known that the flux scales with Ca 2/3, but this classical result is non-uniform as the contact angle approaches π. By examining this limit we find a solution that is uniformly valid for all contact angles. Furthermore, by considering the far-field behaviour of the free surface we show that there exists a critical capillary number above which the problem at an inlet becomes over-determined. The implications of this result for the modelling of coating flows are discussed. © 2012 Cambridge University Press.

  18. Microencapsulation within crosslinked polyethyleneimine membranes.

    Science.gov (United States)

    Poncelet, D; Alexakis, T; Poncelet de Smet, B; Neufeld, R J

    1994-01-01

    A microencapsulation technique is proposed involving the formation of a polyethyleneimine (PEI) membrane crosslinked by an acid dichloride. The membranes were formed at pH 8 in a non-polar solvent, conditions which are better suited for the encapsulation of biocatalysts or fragile biochemicals than those using polyamide membranes. The mean diameter and size distribution of the PEI microcapsules were similar to that observed with nylon membranes. The resultant microcapsules were spherical, free-flowing with a strong membrane. The mass of membrane was seen to be independent of the reaction time (1-4 min), insensitive to the PEI concentration and proportional to the concentration of crosslinking agent.

  19. Bedform evolution in a tidal inlet referred from wavelet analysis

    DEFF Research Database (Denmark)

    Fraccascia, Serena; Winter, Christian; Ernstsen, Verner Brandbyge

    2011-01-01

    Bedforms are common morphological features in subaqueous and aeolian environments and their characterization is commonly the first step to better understand forcing factors acting in the system. The aim of this study was to investigate the spectral characteristics of compound bedforms in a tidal...... inlet and evaluate how they changed over consecutive years, when morphology was modified and bedforms migrated. High resolution bathymetric data from the Grådyb tidal inlet channel (Danish Wadden Sea) from seven years from 2002 to 2009 (not in 2004) were analyzed. Continuous wavelet transform of bed...

  20. The effect of inclusion of inlets in dual drainage modelling

    Science.gov (United States)

    Chang, Tsang-Jung; Wang, Chia-Ho; Chen, Albert S.; Djordjević, Slobodan

    2018-04-01

    In coupled sewer and surface flood modelling approaches, the flow process in gullies is often ignored although the overland flow is drained to sewer network via inlets and gullies. Therefore, the flow entering inlets is transferred to the sewer network immediately, which may lead to a different flood estimation than the reality. In this paper, we compared two modelling approach with and without considering the flow processes in gullies in the coupled sewer and surface modelling. Three historical flood events were adopted for model calibration and validation. The results showed that the inclusion of flow process in gullies can further improve the accuracy of urban flood modelling.

  1. Tangential inlet supersonic separators: a novel apparatus for gas purification

    DEFF Research Database (Denmark)

    Wen, Chuang; Walther, Jens Honore; Yang, Yan

    2016-01-01

    A novel supersonic separator with a tangential inlet is designed to remove the condensable components from gas mixtures. The dynamic parameters of natural gas in the supersonic separation process are numerically calculated using the Reynolds stress turbulence model with the Peng-Robinson real gas...... be generated by the tangential inlet, and it increases to the maximum of 200 m/s at the nozzle throat due to decrease of the nozzle area of the converging part. The tangential velocity can maintain the value of about 160 m/s at the nozzle exit, and correspondingly generates the centrifugal acceleration of 3...

  2. The Effect of Platinum Electrocatalyst on Membrane Degradation in Polymer Electrolyte Fuel Cells.

    Science.gov (United States)

    Bodner, Merit; Cermenek, Bernd; Rami, Mija; Hacker, Viktor

    2015-12-08

    Membrane degradation is a severe factor limiting the lifetime of polymer electrolyte fuel cells. Therefore, obtaining a deeper knowledge is fundamental in order to establish fuel cells as competitive product. A segmented single cell was operated under open circuit voltage with alternating relative humidity. The influence of the catalyst layer on membrane degradation was evaluated by measuring a membrane without electrodes and a membrane-electrode-assembly under identical conditions. After 100 h of accelerated stress testing the proton conductivity of membrane samples near the anode and cathode was investigated by means of ex situ electrochemical impedance spectroscopy. The membrane sample near the cathode inlet exhibited twofold lower membrane resistance and a resulting twofold higher proton conductivity than the membrane sample near the anode inlet. The results from the fluoride ion analysis have shown that the presence of platinum reduces the fluoride emission rate; which supports conclusions drawn from the literature.

  3. The Effect of Platinum Electrocatalyst on Membrane Degradation in Polymer Electrolyte Fuel Cells

    Science.gov (United States)

    Bodner, Merit; Cermenek, Bernd; Rami, Mija; Hacker, Viktor

    2015-01-01

    Membrane degradation is a severe factor limiting the lifetime of polymer electrolyte fuel cells. Therefore, obtaining a deeper knowledge is fundamental in order to establish fuel cells as competitive product. A segmented single cell was operated under open circuit voltage with alternating relative humidity. The influence of the catalyst layer on membrane degradation was evaluated by measuring a membrane without electrodes and a membrane-electrode-assembly under identical conditions. After 100 h of accelerated stress testing the proton conductivity of membrane samples near the anode and cathode was investigated by means of ex situ electrochemical impedance spectroscopy. The membrane sample near the cathode inlet exhibited twofold lower membrane resistance and a resulting twofold higher proton conductivity than the membrane sample near the anode inlet. The results from the fluoride ion analysis have shown that the presence of platinum reduces the fluoride emission rate; which supports conclusions drawn from the literature. PMID:26670258

  4. Unstart phenomena induced by flow choking in scramjet inlet-isolators

    Science.gov (United States)

    Im, Seong-kyun; Do, Hyungrok

    2018-02-01

    A review of recent research outcomes in downstream flow choking-driven unstart is presented. Unstart is a flow phenomenon at the inlet that severely reduces the air mass flow rate through the engine, causing a loss of thrust and considerable transient mechanical loading. Therefore, unstart in a scramjet engine crucially affects the design and the operation range of hypersonic vehicles. Downstream flow choking is known to be one of the major mechanisms inducing inlet unstart, as confirmed by recent scramjet-powered flight tests. The current paper examines recent research progress in identifying flow choking mechanisms that trigger unstart. Three different flow choking mechanisms are discussed: flow blockage, mass addition, and heat release from combustion reactions. Current research outcomes on the characteristic of unstarting flows, such as transient and quasi-steady motions, are reviewed for each flow choking mechanism. The characteristics of unstarted flows are described including Buzzing phenomena and oscillatory motions of unstarted shockwaves. Then, the state-of-the-art methods to predict, detect, and control unstart are presented. The review suggests that further investigations with high-enthalpy ground facilities will aid understanding of heat release-driven unstart.

  5. Inlet design studies for a Mach 2.2 advanced supersonic cruise vehicle

    Science.gov (United States)

    Shimabukuro, K. M.; Welge, H. R.; Lee, A. C.

    1979-01-01

    Various inlet-engine combinations have been studied to find a preferred inlet concept for integration with an advanced technology Mach 2.2 cruise vehicle having a cruise lift-to-drag ratio of 9.6. For the purposes of this study, the range capability for a fixed takeoff gross weight was used to assess the various inlet-engine combinations. Inlet concept selection studies are described which indicated that an axisymmetric, mixed compression inlet was preferred. This study considered four inlet and three engine cycle combinations where the engine airflow was tailored to the inlet airflow delivery capability. Detailed design studies of two mixed compression inlet types are discussed. These were a translating centerbody inlet and a collapsing centerbody bicone inlet. The aerodynamic and mechanical design of each inlet is described. These inlets were also matched to different engine cycles tailored to the inlet airflow capability. The range increments favored the bicone inlet concept primarily because of lighter weight, reduced bleed air, and greater transonic airflow/thrust capability.

  6. Improved Hypersonic Inlet Performance Using Validated Strut Compression Designs

    Science.gov (United States)

    Bulman, M. J.; Stout, P. W.; Fernandez, R.

    1997-01-01

    Aerojet is currently executing two Strutjet propulsion contracts: one a Rocket Based Combined Cycle (RBCC) engine for a NASA-Marshall Space Flight Center (MSFC) Advanced Reusable Transportation Technology (ARTT) program, the second a Dual Mode Ram/Scramjet engine for a USAF Wright Laboratories Storable Fuel Scramjet Flow Path Concepts program. The engines employed in both programs operate at supersonic and low hypersonic speeds and use inlets employing forebody external and sidewall compression. Aerojet has developed and validated a successful design methodology applicable to these inlet types. Design features include an integrated vehicle forebody, external side compression struts, strut sidewall and throat bleed, a throat shock trap, and variable geometry internal contraction. Computation Fluid Dynamic (CFD) predictions and test data show these inlets allow substantially increased flow turning angles over other designs. These increased flow turning angles allow shorter and lighter engines than current designs, which in turn enables higher performing vehicles with broad operating characteristics. This paper describes the designs of two different inlets evaluated by the NASA-MSFC and USAF programs, discusses the results of wind tunnel tests performed by NASA-Lewis Research Center, and provides correlations of test data with CFD predictions. Parameters of interest include low Mach number starting capability, start sensitivity as a function of back pressure at various contraction ratios, flow turning angles, strut and throat bleed effects, and pressure recovery at various Mach numbers.

  7. Physics of Acoustic Radiation from Jet Engine Inlets

    Science.gov (United States)

    Tam, Christopher K. W.; Parrish, Sarah A.; Envia, Edmane; Chien, Eugene W.

    2012-01-01

    Numerical simulations of acoustic radiation from a jet engine inlet are performed using advanced computational aeroacoustics (CAA) algorithms and high-quality numerical boundary treatments. As a model of modern commercial jet engine inlets, the inlet geometry of the NASA Source Diagnostic Test (SDT) is used. Fan noise consists of tones and broadband sound. This investigation considers the radiation of tones associated with upstream propagating duct modes. The primary objective is to identify the dominant physical processes that determine the directivity of the radiated sound. Two such processes have been identified. They are acoustic diffraction and refraction. Diffraction is the natural tendency for an acoustic wave to follow a curved solid surface as it propagates. Refraction is the turning of the direction of propagation of sound waves by mean flow gradients. Parametric studies on the changes in the directivity of radiated sound due to variations in forward flight Mach number and duct mode frequency, azimuthal mode number, and radial mode number are carried out. It is found there is a significant difference in directivity for the radiation of the same duct mode from an engine inlet when operating in static condition and in forward flight. It will be shown that the large change in directivity is the result of the combined effects of diffraction and refraction.

  8. Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Wang, Z.B.; Verhagen, H.J.; Thuy, V.T.T.

    2008-01-01

    Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system are investigated using numerical models. The ocean forcing including tidal and wave actions and sediment transport is simulated using Delft3D model. Fluvial processes in Delft3D are taken into account as results from SOBEK

  9. Micro-Ramps for External Compression Low-Boom Inlets

    Science.gov (United States)

    Rybalko, Michael; Loth, Eric; Chima, Rodrick V.; Hirt, Stefanie M.; DeBonis, James R.

    2010-01-01

    The application of vortex generators for flow control in an external compression, axisymmetric, low-boom concept inlet was investigated using RANS simulations with three-dimensional (3-D), structured, chimera (overset) grids and the WIND-US code. The low-boom inlet design is based on previous scale model 1- by 1-ft wind tunnel tests and features a zero-angle cowl and relaxed isentropic compression centerbody spike, resulting in defocused oblique shocks and a weak terminating normal shock. Validation of the methodology was first performed for micro-ramps in supersonic flow on a flat plate with and without oblique shocks. For the inlet configuration, simulations with several types of vortex generators were conducted for positions both upstream and downstream of the terminating normal shock. The performance parameters included incompressible axisymmetric shape factor, separation area, inlet pressure recovery, and massflow ratio. The design of experiments (DOE) methodology was used to select device size and location, analyze the resulting data, and determine the optimal choice of device geometry. The optimum upstream configuration was found to substantially reduce the post-shock separation area but did not significantly impact recovery at the aerodynamic interface plane (AIP). Downstream device placement allowed for fuller boundary layer velocity profiles and reduced distortion. This resulted in an improved pressure recovery and massflow ratio at the AIP compared to the baseline solid-wall configuration.

  10. 14 CFR 25.941 - Inlet, engine, and exhaust compatibility.

    Science.gov (United States)

    2010-01-01

    ... malfunctions) upon the aerodynamic control of the airplane may not result in any condition that would require..., engine, and exhaust compatibility. For airplanes using variable inlet or exhaust system geometry, or both...), and exhaust must be shown to function properly under all operating conditions for which approval is...

  11. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Indian Academy of Sciences (India)

    This paper presents fundamental outcomes from an experimental study on the hydrodynamic performance near inlet key of Piano Key Weir (PKW). Hydrodynamic performance was tested in a circulated open channel that comprised of PKW and sand bed (d50 = 0.25 mm). Instantaneous velocities were measured at 20 cross ...

  12. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Indian Academy of Sciences (India)

    smoothly bifurcate the flow. 3. Experimental setup. The experiments were conducted in River Engineering Laboratory, Water Resources Devel- opment and Management Department, Indian Institute of Technology Roorkee, India. An experimental program was established to quantify the flow behavior at crest level inlet key ...

  13. Diffuse Ceiling Inlet Systems and the Room Air Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jensen, Rasmus Lund; Rong, Li

    2010-01-01

    A diffuse ceiling inlet system is an air distribution system which is supplying the air through the whole ceiling. The system can remove a large heat load without creating draught in the room. The paper describes measurements in the case of both cooling and heating, and CFD predictions are given ...

  14. Max Data Report Jet Stability versus Inlet Geometry

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Bremer, N. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    This document describes experiments investigating the effect of inlet geometry on the flow field within a glass tank where two jets mix and impinge upon the lid. The setup mimics the outlet plenum of a fast reactor where core exit flows of different temperatures can mix in ways that induce thermal cycling in neighboring structures.

  15. Diffuse Ceiling Inlet Systems and the Room Air Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jensen, Rasmus Lund; Rong, Li

    2010-01-01

    A diffuse ceiling inlet system is an air distribution system which is supplying the air through the whole ceiling. The system can remove a large heat load without creating draught in the room. The paper describes measurements in the case of both cooling and heating, and CFD predictions are given...

  16. Validation of Helium Inlet Design for ITER Toroidal Field Coil

    CERN Document Server

    Boyer, C; Hamada, K; Foussat, A; Le Rest, M; Mitchell, N; Decool, P; Savary, F; Sgobba, S; Weiss, K-P

    2014-01-01

    The ITER organization has performed design and its validation tests on a helium inlet structure for the ITER Toroidal Field (TF) coil under collaboration with CERN, KIT, and CEA-Cadarache. Detailed structural analysis was performed in order to optimize the weld shape. A fatigue resistant design on the fillet weld between the shell covers and the jacket is an important point on the helium inlet structure. A weld filler material was selected based on tensile test at liquid helium temperature after Nb3Sn reaction heat treatment. To validate the design of the weld joint, fatigue tests at 7 K were performed using heat-treated butt weld samples. A pressure drop measurement of a helium inlet mock-up was performed by using nitrogen gas at room temperature in order to confirm uniform flow distribution and pressure drop characteristic. These tests have validated the helium inlet design. Based on the validation, Japanese and European Union domestic agencies, which have responsibilities of the TF coil procurement, are pr...

  17. Improving dynamic performance of proton-exchange membrane fuel cell system using time delay control

    Science.gov (United States)

    Kim, Young-Bae

    Transient behaviour is a key parameter for the vehicular application of proton-exchange membrane (PEM) fuel cell. The goal of this presentation is to construct better control technology to increase the dynamic performance of a PEM fuel cell. The PEM fuel cell model comprises a compressor, an injection pump, a humidifier, a cooler, inlet and outlet manifolds, and a membrane-electrode assembly. The model includes the dynamic states of current, voltage, relative humidity, stoichiometry of air and hydrogen, cathode and anode pressures, cathode and anode mass flow rates, and power. Anode recirculation is also included with the injection pump, as well as anode purging, for preventing anode flooding. A steady-state, isothermal analytical fuel cell model is constructed to analyze the mass transfer and water transportation in the membrane. In order to prevent the starvation of air and flooding in a PEM fuel cell, time delay control is suggested to regulate the optimum stoichiometry of oxygen and hydrogen, even when there are dynamical fluctuations of the required PEM fuel cell power. To prove the dynamical performance improvement of the present method, feed-forward control and Linear Quadratic Gaussian (LQG) control with a state estimator are compared. Matlab/Simulink simulation is performed to validate the proposed methodology to increase the dynamic performance of a PEM fuel cell system.

  18. Vacuum membrane distillation of liquid desiccants Utilizing Hollow Fiber Membranes

    KAUST Repository

    Lefers, Ryan

    2018-01-31

    This paper documents the testing of a vacuum membrane distillation system intended for use with liquid desiccants. Liquid desiccants offer the possibility for low-energy, ambient temperature dehumidification. Effective desalination and purification of diluted desiccants outputs two important products: a concentrated desiccant for reuse in dehumidification and fresh water. In this study, vacuum membrane distillation was used in the laboratory to purify diluted liquid desiccants. Calcium chloride and magnesium chloride were the desiccants selected for testing. Desiccant solutions were pumped through the lumens of poly(vinylidene fluoride) (PVDF) hollow fiber membranes at varying feed inlet temperatures, solution velocity rates and vacuum set points during membrane distillation. An average flux of 8 kg m-2 h-1 was obtained using 30 wt% magnesium chloride solution at a temperature of 50 °C while applying vacuum to achieve 25 mbar absolute pressure on the air side of the membrane. The results are promising for the development of a full-scale vacuum membrane distillation process for desiccant solution regeneration and fresh water recovery. In addition, the recovered condensate was of sufficient quality for use in agricultural irrigation or drinking water.

  19. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  20. Biobased Membrane

    NARCIS (Netherlands)

    Koenders, E.A.B.; Zlopasa, J.; Picken, S.J.

    2015-01-01

    The present invention is in the field of a composition for forming a bio-compatible membrane applicable to building material, such as concrete, cement, etc., to a meth od of applying said composition for forming a bio-compatible membrane, a biocompatible membrane, use of said membrane for various

  1. Combining blue native polyacrylamide gel electrophoresis with liquid chromatography tandem mass spectrometry as an effective strategy for analyzing potential membrane protein complexes of Mycobacterium bovis bacillus Calmette-Guérin

    Directory of Open Access Journals (Sweden)

    Li Weijun

    2011-01-01

    Full Text Available Abstract Background Tuberculosis is an infectious bacterial disease in humans caused primarily by Mycobacterium tuberculosis, and infects one-third of the world's total population. Mycobacterium bovis bacillus Calmette-Guérin (BCG vaccine has been widely used to prevent tuberculosis worldwide since 1921. Membrane proteins play important roles in various cellular processes, and the protein-protein interactions involved in these processes may provide further information about molecular organization and cellular pathways. However, membrane proteins are notoriously under-represented by traditional two-dimensional polyacrylamide gel electrophoresis (2-D PAGE and little is known about mycobacterial membrane and membrane-associated protein complexes. Here we investigated M. bovis BCG by an alternative proteomic strategy coupling blue native PAGE to liquid chromatography tandem mass spectrometry (LC-MS/MS to characterize potential protein-protein interactions in membrane fractions. Results Using this approach, we analyzed native molecular composition of protein complexes in BCG membrane fractions. As a result, 40 proteins (including 12 integral membrane proteins, which were organized in 9 different gel bands, were unambiguous identified. The proteins identified have been experimentally confirmed using 2-D SDS PAGE. We identified MmpL8 and four neighboring proteins that were involved in lipid transport complexes, and all subunits of ATP synthase complex in their monomeric states. Two phenolpthiocerol synthases and three arabinosyltransferases belonging to individual operons were obtained in different gel bands. Furthermore, two giant multifunctional enzymes, Pks7 and Pks8, and four mycobacterial Hsp family members were determined. Additionally, seven ribosomal proteins involved in polyribosome complex and two subunits of the succinate dehydrogenase complex were also found. Notablely, some proteins with high hydrophobicity or multiple transmembrane

  2. Combining blue native polyacrylamide gel electrophoresis with liquid chromatography tandem mass spectrometry as an effective strategy for analyzing potential membrane protein complexes of Mycobacterium bovis bacillus Calmette-Guérin.

    Science.gov (United States)

    Zheng, Jianhua; Wei, Candong; Zhao, Lina; Liu, Liguo; Leng, Wenchuan; Li, Weijun; Jin, Qi

    2011-01-18

    Tuberculosis is an infectious bacterial disease in humans caused primarily by Mycobacterium tuberculosis, and infects one-third of the world's total population. Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccine has been widely used to prevent tuberculosis worldwide since 1921. Membrane proteins play important roles in various cellular processes, and the protein-protein interactions involved in these processes may provide further information about molecular organization and cellular pathways. However, membrane proteins are notoriously under-represented by traditional two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and little is known about mycobacterial membrane and membrane-associated protein complexes. Here we investigated M. bovis BCG by an alternative proteomic strategy coupling blue native PAGE to liquid chromatography tandem mass spectrometry (LC-MS/MS) to characterize potential protein-protein interactions in membrane fractions. Using this approach, we analyzed native molecular composition of protein complexes in BCG membrane fractions. As a result, 40 proteins (including 12 integral membrane proteins), which were organized in 9 different gel bands, were unambiguous identified. The proteins identified have been experimentally confirmed using 2-D SDS PAGE. We identified MmpL8 and four neighboring proteins that were involved in lipid transport complexes, and all subunits of ATP synthase complex in their monomeric states. Two phenolpthiocerol synthases and three arabinosyltransferases belonging to individual operons were obtained in different gel bands. Furthermore, two giant multifunctional enzymes, Pks7 and Pks8, and four mycobacterial Hsp family members were determined. Additionally, seven ribosomal proteins involved in polyribosome complex and two subunits of the succinate dehydrogenase complex were also found. Notablely, some proteins with high hydrophobicity or multiple transmembrane helixes were identified well in our work. In this

  3. Improvement of methane content in a hydrogenotrophic anaerobic digester via the proper operation of membrane module integrated into an external-loop.

    Science.gov (United States)

    Ojeda, Felipe; Bakonyi, Péter; Buitrón, Germán

    2017-12-01

    This work assessed the feasibility of a hydrogenotrophic biogas process integrated with a membrane module in the external-loop design. The major scope was to conduct the investigation from the perspective of the membrane unit and reveal how the operating strategy influences the efficiency of biogas formation. It was observed that the fermenter worked with an improved efficacy, indicated by the higher concentration of methane in the headspace (80-90%) when the gas loading intensity, defined as the ratio of inlet gas permeation rate and the circulation rate of the liquid phase, was adjusted to lower values (3-5.3×10 -3 ). Such results are implying that the mass transfer of H 2 into the reactor is dependent on this critical parameter. Moreover, attention should be paid to the fouling of the module under longer-term experiments to keep its performance at a sufficient level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Review of Singular Cooling Inlet and Linear Pressure Drop for ITER Coils Cable in Conduit Conductor

    Science.gov (United States)

    Nicollet, S.; Bessette, D.; Cloez, H.; Decool, P.; Lacroix, B.; Lebailly, C. A.; Serries, J. P.

    2006-04-01

    New tests and measurements performed (Othello Facility, EFDA Task) on TF mock up cooling inlet and different central spirals (characteristics: hydraulic outer diameter and perforation ratio) are presented, as well as the new model of singular and linear friction factor. The ITER Coils CICC hydraulic length pressure drop is determined in operating conditions (m=8 g/s, P=0.6 MPa and T=5 K): the important result is an increase in linear pressure drop for the TF (290 Pa/m) and CS (430 Pa/m), in comparison with prototype model coils TFMC (100 Pa/m) and CSMC (180 Pa/m). The main reason is the reduction of the central spiral diameter and associated increase of friction factor and bundle to total mass flow ratio α (from 1/3 up to 2/3 typically). The ratio of singular cooling inlet to CICC linear pressure drop is estimated: TF mock up ratio (3 m) is lower than previous CS mock up tested (12 m), due to design changes. The cryogenic power necessary to compensate the CICC pressure drop is calculated for the 4 primary loop circuits: typically 2.3 kW at 5 K for TF winding system represents 40% of the whole average TF winding magnet heat loads during operation.

  5. Inlet and outlet boundary conditions for the discrete velocity direction model

    Science.gov (United States)

    Zhang, Zhenyu; Zhao, Wei; Zhao, Qingjun; Lu, Guojing; Xu, Jianzhong

    2018-02-01

    The discrete velocity direction model is an approximate method to the Boltzmann equation, which is an optional kinetic method to microgas flow and heat transfer. In this paper, the treatment of the inlet and outlet boundary conditions for the model is proposed. In the computation strategy, the microscopic molecular speed distribution functions at inlet and outlet are indirectly determined by the macroscopic gas pressure, mass flux and temperature, which are all measurable parameters in microgas flow and heat transfer. The discrete velocity direction model with the pressure correction boundary conditions was applied into the plane Poiseuille flow in microscales and the calculations cover all flow regimes. The numerical results agree well with the data of the NS equation near the continuum regime and the date of linearized Boltzmann equation and the DSMC method in the transition regime and free molecular flow. The Knudsen paradox and the nonlinear pressure distributions have been accurately captured by the discrete velocity direction model with the present boundary conditions.

  6. Dimensional analysis of membrane distillation flux through fibrous membranes

    Science.gov (United States)

    Mauter, Meagan

    We developed a dimensional-analysis-based empirical modeling method for membrane distillation (MD) flux that is adaptable for novel membrane structures. The method makes fewer simplifying assumptions about membrane pore geometry than existing theoretical (i.e. mechanistic) models, and allows selection of simple, easily-measureable membrane characteristics as structural parameters. Furthermore, the model does not require estimation of membrane surface temperatures; it accounts for convective heat transfer to the membrane surface without iterative fitting of mass and heat transfer equations. The Buckingham-Pi dimensional analysis method is tested for direct contact membrane distillation (DCMD) using non-woven/fibrous structures as the model membrane material. Twelve easily-measured variables to describe DCMD operating conditions, fluid properties, membrane structures, and flux were identified and combined into eight dimensionless parameters. These parameters were regressed using experimentally-collected data for multiple electrospun membrane types and DCMD system conditions, achieving R2 values >95%. We found that vapor flux through isotropic fibrous membranes can be estimated using only membrane thickness, solid fraction, and fiber diameter as structural parameters. Buckingham-Pi model DCMD flux predictions compare favorably with previously-developed empirical and theoretical models, and suggest this simple yet theoretically-grounded empirical modeling method can be used practically for predicting MD vapor flux from membrane structural parameters.

  7. Predicting optimal back-shock times in ultrafiltration hollow fiber modules II: Effect of inlet flow and concentration dependent viscosity

    DEFF Research Database (Denmark)

    Vinther, Frank; Pinelo, Manuel; Brøns, Morten

    2015-01-01

    This paper concerns mathematical modeling and computational fluid dynamics of back-shocking during hollow fibre ultrafiltration of dextran T500. In this paper we present a mathematical model based on first Principles, i.e., solving the Navier-Stokes equation along with the continuity equation...... fibre membranes, J. Membr. Sci. 470 (2014) 275-293 [33]).Furthermore, the simulations have been performed with two different inlet velocities, i.e., crossflow velocities and are clone with and without a concentration dependent viscosity. This enables us, for the first time, to investigate the effect...... in this paper.Furthermore, it is found that the optimal back-shock time increases when the viscosity is allowed to depend on the concentration It is found that this can be explained by a decrease in the velocity tangential to the membrane due to the increase in viscosity where the concentration is high...

  8. 78 FR 54668 - Cook Inlet Regional Citizens' Advisory Council (CIRCAC) Charter Renewal

    Science.gov (United States)

    2013-09-05

    ... Inlet Regional Citizens' Advisory Council (CIRCAC) as an alternative voluntary advisory group for Cook... Coast Guard recertified the Cook Inlet Regional Citizen's Advisory Council through August 31, 2013... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2013-0720] Cook Inlet Regional Citizens...

  9. 76 FR 42134 - Application for Recertification of Cook Inlet Regional Citizens' Advisory Council

    Science.gov (United States)

    2011-07-18

    ... Cook Inlet Regional Citizens' Advisory Council AGENCY: Coast Guard, DHS. ACTION: Notice of availability... application for recertification submitted by the Cook Inlet Regional Citizen's Advisory Council (CIRCAC) for... of a Regional Citizens' Advisory Council for Cook Inlet, Alaska. This advisory group monitors the...

  10. 76 FR 24513 - Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida

    Science.gov (United States)

    2011-05-02

    ...] Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida AGENCY... as part of the Jupiter Inlet Lighthouse Outstanding Natural Area. DATES: Effective Date: May 2, 2011... U.S.C. 1787), which created the Jupiter Inlet Lighthouse Outstanding Natural Area, and which...

  11. 40 CFR 81.54 - Cook Inlet Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Regions § 81.54 Cook Inlet Intrastate Air Quality Control Region. The Cook Inlet Intrastate Air Quality Control Region (Alaska) consists of the territorial area encompassed by the boundaries... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Cook Inlet Intrastate Air Quality...

  12. Classification of tidal inlets along the Central east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, N.A.; Vikas, M.; Rao, S.; JayaKumar S.

    ) as long as the alongshore sediment bypasses the tidal inlet. Classification of coastal systems in a broader view is necessary for the management of tidal inlets. There are several methods to classify tidal inlets based on different perspectives namely geo-morphological...

  13. 36 CFR 13.320 - Preference to Cook Inlet Region, Incorporated.

    Science.gov (United States)

    2010-07-01

    ... Region, Incorporated. 13.320 Section 13.320 Parks, Forests, and Public Property NATIONAL PARK SERVICE... to Cook Inlet Region, Incorporated. (a) The Cook Inlet Region, Incorporated (CIRI), in cooperation with village corporations within the Cook Inlet region when appropriate, will have a right of first...

  14. 78 FR 11094 - Safety Zone; Lake Worth Dredge Operations, Lake Worth Inlet; West Palm Beach, FL

    Science.gov (United States)

    2013-02-15

    ... 1625-AA00 Safety Zone; Lake Worth Dredge Operations, Lake Worth Inlet; West Palm Beach, FL AGENCY... safety zone on Lake Worth Inlet, West Palm Beach, Florida, to provide for the safety of life and vessels..., dredging operations will be conducted on Lake Worth Inlet in West Palm Beach, Florida. These operations...

  15. Numerical and experimental investigation of VG flow control for a low-boom inlet

    Science.gov (United States)

    Rybalko, Michael

    The application of vortex generators (VGs) for shock/boundary layer interaction flow control in a novel external compression, axisymmetric, low-boom concept inlet was studied using numerical and experimental methods. The low-boom inlet design features a zero-angle cowl and relaxed isentropic compression centerbody spike, resulting in defocused oblique shocks and a weak terminating normal shock. This allows reduced external gas dynamic waves at high mass flow rates but suffers from flow separation near the throat and a large hub-side boundary layer at the Aerodynamic Interface Plane (AIP), which marks the inflow to the jet engine turbo-machinery. Supersonic VGs were investigated to reduce the shock-induced flow separation near the throat while subsonic VGs were investigated to reduce boundary layer radial distortion at the AIP. To guide large-scale inlet experiments, Reynolds-Averaged Navier-Stokes (RANS) simulations using three-dimensional, structured, chimera (overset) grids and the WIND-US code were conducted. Flow control cases included conventional and novel types of vortex generators at positions both upstream of the terminating normal shock (supersonic VGs) and downstream (subsonic VGs). The performance parameters included incompressible axisymmetric shape factor, post-shock separation area, inlet pressure recovery, and mass flow ratio. The design of experiments (DOE) methodology was used to select device size and location, analyze the resulting data, and determine the optimal choice of device geometry. Based on the above studies, a test matrix of supersonic and subsonic VGs was adapted for a large-scale inlet test to be conducted at the 8'x6' supersonic wind tunnel at NASA Glenn Research Center (GRC). Comparisons of RANS simulations with data from the Fall 2010 8'x6' inlet test showed that predicted VG performance trends and case rankings for both supersonic and subsonic devices were consistent with experimental results. For example, experimental surface oil

  16. A conformational investigation of propeptide binding to the integral membrane protein γ-glutamyl carboxylase using nanodisc hydrogen exchange mass spectrometry

    DEFF Research Database (Denmark)

    Parker, Christine H; Morgan, Christopher R; Rand, Kasper Dyrberg

    2014-01-01

    Gamma (γ)-glutamyl carboxylase (GGCX) is an integral membrane protein responsible for the post-translational catalytic conversion of select glutamic acid (Glu) residues to γ-carboxy glutamic acid (Gla) in vitamin K-dependent (VKD) proteins. Understanding the mechanism of carboxylation and the rol...

  17. ARSENIC DETERMINATION IN SALINE WATERS UTILIZING A TUBULAR MEMBRANE AS A GAS-LIQUID SEPATRATOR FOR HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    Science.gov (United States)

    A tubular silicone rubber membrane is evaluated as a gas-liquid separator for the determination of arsenic in saline waters via HG-ICP-MS. The system was optimized in terms of NaBH and HCI concentrations. The intermediate gas and carrier gas were optimized in terms of sensitiity ...

  18. Novel diglycolamide functionalized calix[4]arenes for actinide extraction and supported liquid membrane studies: Part II. Role of substituents in the pendent arms and mass transfer modeling I

    NARCIS (Netherlands)

    Ansari, S.A.; Mohapatra, P.K.; Iqbal, M.; Kandwal, P.; Huskens, Jurriaan; Verboom, Willem

    2013-01-01

    Several calix[4]arene-functionalized diglycolamide (C4DGA) ligands were evaluated for the extraction as well as supported liquid membrane (SLM) transport of actinides and fission product elements from nitric acid feed solutions. The extraction efficiency of the C4DGA ligands for Am(III) was orders

  19. Mesoporous Silica Gel–Based Mixed Matrix Membranes for Improving Mass Transfer in Forward Osmosis: Effect of Pore Size of Filler

    Science.gov (United States)

    Lee, Jian-Yuan; Wang, Yining; Tang, Chuyang Y.; Huo, Fengwei

    2015-01-01

    The efficiency of forward osmosis (FO) process is generally limited by the internal concentration polarization (ICP) of solutes inside its porous substrate. In this study, mesoporous silica gel (SG) with nominal pore size ranging from 4–30 nm was used as fillers to prepare SG-based mixed matrix substrates. The resulting mixed matrix membranes had significantly reduced structural parameter and enhanced membrane water permeability as a result of the improved surface porosity of the substrates. An optimal filler pore size of ~9 nm was observed. This is in direct contrast to the case of thin film nanocomposite membranes, where microporous nanoparticle fillers are loaded to the membrane rejection layer and are designed in such a way that these fillers are able to retain solutes while allowing water to permeate through them. In the current study, the mesoporous fillers are designed as channels to both water and solute molecules. FO performance was enhanced at increasing filler pore size up to 9 nm due to the lower hydraulic resistance of the fillers. Nevertheless, further increasing filler pore size to 30 nm was accompanied with reduced FO efficiency, which can be attributed to the intrusion of polymer dope into the filler pores. PMID:26592565

  20. Bedload transport in an inlet channel during a tidal cycle

    DEFF Research Database (Denmark)

    Ernstsen, V. B.; Becker, M.; Winter, C.

    2007-01-01

      Based on high-resolution swath bathymetry measurements at centimetre-scale precision conducted during a tidal cycle in a dune field in the Grådyb tidal inlet channel in the DanishWadden Sea, a simple tool to calculate bedload transport is presented. Bedload transport was related to simultaneous...... variations in grain-size composition of the mobilised sediment should be taken into account by sediment transport formulae....

  1. 2239 EFFECT OF INLET-AIR TEMPERATURE ON PHYSICO ...

    African Journals Online (AJOL)

    Mimi

    divided into two portions (samples A and B) and spray-dried using co-current spray dryer at a constant feed rate (20.5 ml/sec) but at air-inlet temperatures of 204oC and. 260oC, respectively ... serve as cheap but nutritious infant formula ingredients. Breakfast cereals, macaroni, spaghetti, noodles flakes and sausage binders ...

  2. Reconstruction of paleo-inlet dynamics using sedimentologic analyses, geomorphic features, and benthic foraminiferal assemblages: former ephemeral inlets of Cedar Island, Virginia, USA

    Science.gov (United States)

    McBride, R.; Wood, E. T.

    2017-12-01

    Cedar Island, VA is a low-profile, washover-dominated barrier island that has breached at least three times in the past sixty years. Cedar Island Inlet, a former wave-dominated tidal inlet, was open for the following time periods: 1) 1956-1962, 2) 1992-1997, and 3) 1998-2007. Air photos, satellite imagery, and geomorphic features (i.e., relict flood tidal deltas, recurved-spit ridges) record the spatial and temporal extent of the three ephemeral inlets. Based on three sediment vibracores, benthic foraminiferal and sedimentologic analyses offer high resolution insights of inlet dynamics and lifecycle evolution. Four foraminiferal biofacies are completely dominated by Elphidium excavatum (54-100%) and contain unique assemblages of accessory species based on cluster analyses: tidal inlet floor (low abundance estuarine and shelf species; 23% Haynesina germanica); flood tidal delta/inlet fill (high abundance estuarine and shelf species; 2% Buccella frigida, 2% Ammonia parkinsoniana, and 2% Haynesina germanica); high-energy inlet fill (low abundance, low diversity shelf species; 9% Elphidium gunteri); and washover/beach/aeolian (low abundance, predominantly shelf species; 3% Buccella frigida and 3% Ammonia parkinsoniana). The estuarine biofacies is barren of all foraminifera. Grain size trends indicate a first order coarsening-upward succession with second order coarsening- and fining-upwards packages in inlet throat deposits, while a first order fining-upward succession is observed in flood tidal delta deposits with two second order coarsening-upward packages in the proximal flood tidal delta. Contrary to typical wave-dominated tidal inlets that open, migrate laterally in the direction of net longshore transport, and close, the 1998-2007 tidal inlet, and possibly the 1956-1962 inlet, migrated laterally and rotated, whereas the 1992-1997 inlet remained stationary and did not rotate. In the vicinity of the vibracores, preserved deposits are attributed to the 1956-1962 and

  3. Impact of inlet coherent motions on compressor performance

    Science.gov (United States)

    Forlese, Jacopo; Spoleti, Giovanni

    2017-08-01

    Automotive engine induction systems may be characterized by significant flow angularity and total pressure distortion at the compressor inlet. The impact of the swirl on compressor performance should be quantified to guide the design of the induction systems. In diesel engines, the presence of a valve for flow reduction and control of low pressure EGR recirculation could generate coherent motion and influence the performance of the compressor. Starting from experimental map, the compressor speed-lines have been simulated using a 3D CFD commercial code imposing different concept motion at the inlet. The swirl intensity, the direction and the number of vortices have been imposed in order to taking into account some combinations. Finally, a merit function has been defined to evaluate the performance of the compressor with the defined swirl concepts. The aim of the current work is to obtain an indication on the effect of a swirling motion at the compressor inlet on the engine performance and provide a guideline to the induction system design.

  4. Shock Positioning Controls Designs for a Supersonic Inlet

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.

    2010-01-01

    Under the NASA Fundamental Aeronautics Program, the Supersonics Project is working to overcome the obstacles to supersonic commercial flight. The supersonic inlet design that is utilized to efficiently compress the incoming air and deliver it to the engine has many design challenges. Among those challenges is the shock positioning of internal compression inlets, which requires active control in order to maintain performance and to prevent inlet unstarts due to upstream (freestream) and downstream (engine) disturbances. In this paper a novel feedback control technique is presented, which emphasizes disturbance attenuation among other control performance criteria, while it ties the speed of the actuation system(s) to the design of the controller. In this design, the desired performance specifications for the overall control system are used to design the closed loop gain of the feedback controller and then, knowing the transfer function of the plant, the controller is calculated to achieve this performance. The innovation is that this design procedure is methodical and allows maximization of the performance of the designed control system with respect to actuator rates, while the stability of the calculated controller is guaranteed.

  5. Characterizing Interferences in an NOy Thermal Dissociation Inlet

    Science.gov (United States)

    Womack, C.; Veres, P. R.; Brock, C. A.; Neuman, J. A.; Eilerman, S. J.; Zarzana, K. J.; Dube, W. P.; Wild, R. J.; Wooldridge, P. J.; Cohen, R. C.; Brown, S. S.

    2016-12-01

    Nitrogen oxides (NOx = NO and NO2) are emitted into the troposphere by various anthropogenic and natural sources, and contribute to increased levels of ambient ozone. Reactive nitrogen species (NOy), which include nitric acid, peroxy acetyl and organic nitrates, and other species, serve as reservoirs and sinks for NOx, thus influencing O3 production. Their detection is therefore critical to understanding ozone chemistry. However, accurate measurements of NOy have proven to be difficult to obtain, and measurements of total NOy sometimes do not agree with the sum of measurements of its individual components. In recent years, quartz thermal dissociation (TD) inlets have been used to thermally convert all NOy species to NO2, followed by detection by techniques such as laser induced fluorescence (LIF) or cavity ringdown spectroscopy (CRDS). Here we discuss recent work in characterizing the NOy channel of our four-channel TD-CRDS instrument. In particular, we have examined the thermal conversion efficiency of several representative NOy species under a range of experimental conditions. We find that under certain conditions, the conversion efficiency is sensitive to inlet residence time and to the concentration of other trace gases found in ambient sampling, such as ozone. We also report the thermal dissociation curves of N2O5 and ammonium nitrate aerosol, and discuss the interferences observed when ammonia and ozone are co-sampled in the inlet.

  6. Exchange inlet optimization by genetic algorithm for improved RBCC performance

    Science.gov (United States)

    Chorkawy, G.; Etele, J.

    2017-09-01

    A genetic algorithm based on real parameter representation using a variable selection pressure and variable probability of mutation is used to optimize an annular air breathing rocket inlet called the Exchange Inlet. A rapid and accurate design method which provides estimates for air breathing, mixing, and isentropic flow performance is used as the engine of the optimization routine. Comparison to detailed numerical simulations show that the design method yields desired exit Mach numbers to within approximately 1% over 75% of the annular exit area and predicts entrained air massflows to between 1% and 9% of numerically simulated values depending on the flight condition. Optimum designs are shown to be obtained within approximately 8000 fitness function evaluations in a search space on the order of 106. The method is also shown to be able to identify beneficial values for particular alleles when they exist while showing the ability to handle cases where physical and aphysical designs co-exist at particular values of a subset of alleles within a gene. For an air breathing engine based on a hydrogen fuelled rocket an exchange inlet is designed which yields a predicted air entrainment ratio within 95% of the theoretical maximum.

  7. Thermography of the New River Inlet plume and nearshore currents

    Science.gov (United States)

    Chickadel, C.; Jessup, A.

    2012-12-01

    As part of the DARLA and RIVET experiments, thermal imaging systems mounted on a tower and in an airplane captured water flow in the New River Inlet, NC, USA. Kilometer-scale, airborne thermal imagery of the inlet details the ebb flow of the estuarine plume water mixing with ocean water. Multiple fronts, corresponding to the preferred channels through the ebb tidal delta, are imaged in the aerial data. A series of internal fronts suggest discreet sources of the tidal plume that vary with time. Focused thermal measurements made from a tower on the south side of the inlet viewed an area within a radius of a few hundred meters. Sub-meter resolution video from the tower revealed fine-scale flow features and the interaction of tidal exchange and wave-forced surfzone currents. Using the tower and airborne thermal image data we plan to provide geophysical information to compare with numerical models and in situ measurements made by other investigators. From the overflights, we will map the spatial and temporal extent of the estuarine plume to correlate with tidal phase and local wind conditions. From the tower data, we will investigate the structure of the nearshore flow using a thermal particle image velocimetry (PIV) technique, which is based on tracking motion of the surface temperature patterns. Long term variability of the mean and turbulent two-dimensional PIV currents will be correlated to local wave, tidal, and wind forcing parameters.

  8. Dynamic modeling and experimental validation for direct contact membrane distillation (DCMD) process

    KAUST Repository

    Eleiwi, Fadi

    2016-02-01

    This work proposes a mathematical dynamic model for the direct contact membrane distillation (DCMD) process. The model is based on a 2D Advection–Diffusion Equation (ADE), which describes the heat and mass transfer mechanisms that take place inside the DCMD module. The model studies the behavior of the process in the time varying and the steady state phases, contributing to understanding the process performance, especially when it is driven by intermittent energy supply, such as the solar energy. The model is experimentally validated in the steady state phase, where the permeate flux is measured for different feed inlet temperatures and the maximum absolute error recorded is 2.78 °C. Moreover, experimental validation includes the time variation phase, where the feed inlet temperature ranges from 30 °C to 75 °C with 0.1 °C increment every 2min. The validation marks relative error to be less than 5%, which leads to a strong correlation between the model predictions and the experiments.

  9. Membranous nephropathy

    Science.gov (United States)

    ... check for hepatitis B, hepatitis C, and syphilis Complement levels Cryoglobulin test Treatment The goal of treatment ... not as helpful for people with membranous nephropathy. Medicines used treat membranous nephropathy include: Angiotensin-converting enzyme ( ...

  10. Effect of the inlet throttling on the thermal-hydraulic instability of the natural circulation BWR

    International Nuclear Information System (INIS)

    Furuya, Masahiro; Inada, Fumio; Yoneda, Kimitoshi

    1997-01-01

    Although it is well-established that inlet restriction has a stabilizing for forced circulation BWR, the effect of inlet on the thermal-hydraulic stability of natural circulation BWR remains unknown since increasing inlet restriction affect thermal-hydraulic stability due to reduction of the recirculation flow rate. Therefore experiments have been conducted to investigate the effect of inlet restriction on the thermal-hydraulic stability. A test facility used in this experiments was designed and constructed to have non-dimensional values which are nearly equal to those of natural circulation BWR. Experimental results showed that driving force of the natural circulation was described as a function of heat flux and inlet subcooling independent of inlet restriction. Stability maps in reference to the channel inlet subcooling, heat flux were presented for various inlet restriction which were carried out by an analysis based on the homogeneous flow various using this function. Instability region during the inlet subcooling shifted to the higher inlet subcooling with increasing inlet restriction and became larger with increasing heat flux. (author)

  11. Otolith microchemistry: Insights into bioavailable pollutants in a man-made, urban inlet.

    Science.gov (United States)

    Andronis, Christina; Evans, Noreen J; McDonald, Bradley J; Nice, Helen E; Gagnon, Marthe Monique

    2017-05-15

    Black bream (Acanthopagrus butcheri) were collected from an artificial inlet, Claisebrook Cove, Western Australia. Claisebrook Cove is adjacent to an historic contaminated site that was remediated during the 1990s. It was later identified as a priority area due to elevated levels of sediment contaminants including Zn, Cu, and Pb. Black bream were collected from this cove in 2005 and 2012 and their otoliths were analysed by laser ablation inductively coupled plasma mass spectrometry of the most recent growth zone. Levels of Zn and Mn, which are metabolically regulated, did not correlate with sediment contamination. However, reduction in sediment Cu levels over time coincided with reduced Cu otolith levels from 2005 to 2012. Results indicate that the elemental composition of the marginal edge of Black bream otoliths can identify bioavailable contaminants in an urban estuary and, with monitoring, can be utilized to establish long-term trends. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. The effect of inlet flow oscillations on reflooding of a tubular test section

    International Nuclear Information System (INIS)

    Oh, S.; Banerjee, S.; Yadigaroglu, G.

    1983-01-01

    The reflooding of a vertical channel under oscillatory inlet flow conditions has been investigated experimentally. Compared to constant injection, oscillations always increase the liquid carryover in the early stages of reflooding. As reflooding progresses, the enhancement diminishes. The crossover point roughly coincides with saturation of the liquid at the quench front (QF). The higher liquid carryover at the beginning increases downstream heat transfer and speeds up QF propagation. But this higher liquid carryover, in turn, reduces the test section mass accumulation rate and delays QF propagation at later stages. The enhancement of liquid carryover, and the early increase and subsequent decrease in quench velocity are all accentuated as the oscillation amplitude and frequency increase. Large amplitude oscillations change the characteristics of QF propagation and the heat transfer immediately downstream of QF substantially. Correlations based on constant-injection reflooding data are not adequate, even if they are applied on an average local-conditions basis

  13. The Effects of Air Preheating and Fuel/Air Inlet Diameter on the Characteristics of Vortex Flame

    Directory of Open Access Journals (Sweden)

    Mostafa Khaleghi

    2015-01-01

    Full Text Available The effects of fuel/air inlet diameter as well as air preheating on the flame stability, temperature distribution, pollutant formation, and combustion characteristics of a lab-scaled asymmetric vortex flame have been investigated. A three-dimensional steady-state finite volume solver has been used to solve the governing and energy equations. The solver uses a first-order upwind scheme to discretize the governing equations in the space. The semi-implicit method for pressure linked equations has been applied to couple the pressure to the velocity terms. Several turbulence models were applied to predict the flame temperature and it was found that k-ε RNG has given the best results in accordance with the experimental results. The results reveal that the inlet air diameter can enhance the thermal properties and reduce the NOx emission while the inlet fuel diameter has less significant impact. Increasing diameters are accompanied with a pressure drop. It was found that preheating the air and fuel would significantly affect the flame temperature and NOx emission with constant mass flow rate.

  14. Methodology for the Design of Streamline-Traced External-Compression Supersonic Inlets

    Science.gov (United States)

    Slater, John W.

    2014-01-01

    A design methodology based on streamline-tracing is discussed for the design of external-compression, supersonic inlets for flight below Mach 2.0. The methodology establishes a supersonic compression surface and capture cross-section by tracing streamlines through an axisymmetric Busemann flowfield. The compression system of shock and Mach waves is altered through modifications to the leading edge and shoulder of the compression surface. An external terminal shock is established to create subsonic flow which is diffused in the subsonic diffuser. The design methodology was implemented into the SUPIN inlet design tool. SUPIN uses specified design factors to design the inlets and computes the inlet performance, which includes the flow rates, total pressure recovery, and wave drag. A design study was conducted using SUPIN and the Wind-US computational fluid dynamics code to design and analyze the properties of two streamline-traced, external-compression (STEX) supersonic inlets for Mach 1.6 freestream conditions. The STEX inlets were compared to axisymmetric pitot, two-dimensional, and axisymmetric spike inlets. The STEX inlets had slightly lower total pressure recovery and higher levels of total pressure distortion than the axisymmetric spike inlet. The cowl wave drag coefficients of the STEX inlets were 20% of those for the axisymmetric spike inlet. The STEX inlets had external sound pressures that were 37% of those of the axisymmetric spike inlet, which may result in lower adverse sonic boom characteristics. The flexibility of the shape of the capture cross-section may result in benefits for the integration of STEX inlets with aircraft.

  15. Membrane Biophysics

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2013-01-01

    Physics, mathematics and chemistry all play a vital role in understanding the true nature and functioning of biological membranes, key elements of living processes. Besides simple spectroscopic observations and electrical measurements of membranes we address in this book the phenomena of coexistence and independent existence of different membrane components using various theoretical approaches. This treatment will be helpful for readers who want to understand biological processes by applying both simple observations and fundamental scientific analysis. It provides a deep understanding of the causes and effects of processes inside membranes, and will thus eventually open new doors for high-level pharmaceutical approaches towards fighting membrane- and cell-related diseases.

  16. Performance of a Cross-Flow Humidifier with a High Flux Water Vapor Transport Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ahluwalia, R. K.; Wang, X.; Johnson, W. B.; Berg, F.; Kadylak, D.

    2015-09-30

    Water vapor transport (WVT) flux across a composite membrane that consists of a very thin perfluorosulfonic acid (PFSA) ionomer layer sandwiched between two expanded polytetrafluoroethylene (PTFE) microporous layers is investigated. Static and dynamic tests are conducted to measure WVT flux for different composite structures; a transport model shows that the underlying individual resistances for water diffusion in the gas phase and microporous and ionomer layers and for interfacial kinetics of water uptake at the ionomer surface are equally important under different conditions. A finite-difference model is formulated to determine water transport in a full-scale (2-m2 active membrane area) planar cross-flow humidifier module assembled using pleats of the optimized composite membrane. In agreement with the experimental data, the modeled WVT flux in the module increases at higher inlet relative humidity (RH) of the wet stream and at lower pressures, but the mass transfer effectiveness is higher at higher pressures. The model indicates that the WVT flux is highest under conditions that maintain the wet stream at close to 100% RH while preventing the dry stream from becoming saturated. The overall water transport is determined by the gradient in RH of the wet and dry streams but is also affected by vapor diffusion in the gas layer and the microporous layer.

  17. Real Time Extraction Kinetics of Electro Membrane Extraction Verified by Comparing Drug Metabolism Profiles Obtained from a Flow-Flow Electro Membrane Extraction-Mass Spectrometry System with LC-MS

    DEFF Research Database (Denmark)

    Fuchs, David; Jensen, Henrik; Pedersen-Bjergaard, Stig

    2015-01-01

    A simple to construct and operate, "dip-in" electromembrane extraction (EME) probe directly coupled to electrospray ionization-mass spectrometry (ESI-MS) for rapid extraction and real time analysis of various analytes was developed. The setup demonstrated that EME-MS can be used as a viable...... alternative to conventional protein precipitation followed by liquid chromatography-mass spectrometry (LC-MS) for studying drug metabolism. Comparison of EME-MS with LC-MS for drug metabolism analysis demonstrated for the first time that real time extraction of analytes by EME is possible. Metabolism kinetics...... were investigated for three different drugs: amitriptyline, promethazine, and methadone. By comparing the EME-MS extraction profiles of the drug substances and formed drug metabolites with the metabolism profiles obtained by conventional protein precipitation followed by LC-MS good correlation...

  18. Interlaminated ice-proximal glacimarine sediments in Muir Inlet, Alaska

    Science.gov (United States)

    Mackiewicz, N.E.; Powell, R.D.; Carlson, P.R.; Molnia, B.F.

    1984-01-01

    Muir Inlet in Glacier Bay, Alaska, is a glacial fjord receiving a tremendous volume of sediment annually. The rate of sediment accumulation is greatest proximal to Muir Glacier (about 9 m yr-1) and decreases away from the glacier. The primary sediment sources are meltwater streams discharging at subglacial and ice-marginal positions to form overflows, interflows, and underflows (continuous turbidity currents). Overflows and interflows interact with diurnal tidal currents and their volume and sediment concentration varies diurnally and annually with meltwater discharge. These effects produce cyclic deposits of a thin fine-grained sand or silt lamina that grades normally to a thicker poorly to very poorly sorted mud lamina. This lamina couplet is termed a cyclopel. Underflows are suggested to occur in this glacimarine environment because of conditions unique to subglacial fluvial systems. Underflow deposits occur only in proximal positions (177 ??m) is ubiquitous, though low (Muir Inlet produce interlaminated sand/silt/clay that characterizes sediment proximal to a glacier and fines seaward to mud. Sediment is classified into one of three sediment types: 1. (1) Type I sediment is very fine grained (mean 8.65-7.17 ??), low in sand (0.1-11.2%), and very poorly to poorly sorted. It is the dominant sediment type in Muir Inlet, and is transported by plumes and deposited by suspension settling. 2. (2) Type II sediment is fine- to coarse-grained (mean 6.70-3.12 ??), low to high in sand (5.1-86.6%), and very poorly to moderately sorted. It represents reworked sediment, proximal plume deposits, or coarse-grained laminae of cyclopels. 3. (3) Type III sediment is coarse-grained (mean 3.89-2.38 ??), high in sand (58.0-100.0%), and poorly to well sorted. It is deposited by sediment gravity flows or underflows. ?? 1984.

  19. Bedload transport in an inlet channel during a tidal cycle

    DEFF Research Database (Denmark)

    Ernstsen, V. B.; Becker, M.; Winter, C.

    2007-01-01

      Based on high-resolution swath bathymetry measurements at centimetre-scale precision conducted during a tidal cycle in a dune field in the Grådyb tidal inlet channel in the DanishWadden Sea, a simple tool to calculate bedload transport is presented. Bedload transport was related to simultaneous...... dunes being active during the ebb tide, but negligible during the flood tide. Bedload transport was also predicted using five classical and widely used formulae. These predictors were all unable to depict the temporal variation in bedload transport during the tidal cycle. It is suggested that temporal...

  20. Superhydrophobic Membrane Contactor for Acid Gas Removal

    Science.gov (United States)

    Faiqotul Himma, Nurul; Gede Wenten, I.

    2017-07-01

    Gas-liquid membrane contactor has gained a great attention as an alternative to conventional absorption columns in acid gas removal from natural gas or post-combustion. The membrane contactor offers high mass transfer area and excellent operational flexibility. However, hydrophobic microporous membranes commonly used are still susceptible to wetting by liquid absorbents, leading to the deterioration of absorption performance in long-term operation. Therefore, many studies were recently directed to improve the membrane wetting resistant by endowing superhydrophobicity. This article then presents a review on superhydrophobic membrane development and its application for acid gas removal using membrane contactor. An overview of gas-liquid membrane contactor is firstly presented, followed by the preparation of superhydrophobic membranes. The performances of superhydrophobic membranes in acid gas absorption are then discussed, and the recommendation for future research is finally outlined. This review may provide an insight into the further development of superhydrophobic membrane contactor.

  1. Impact of inlet fogging and fuels on power and efficiency of gas turbine plants

    Directory of Open Access Journals (Sweden)

    Basha Mehaboob

    2013-01-01

    Full Text Available A computational study to assess the performance of different gas turbine power plant configurations is presented in this paper. The work includes the effect of humidity, ambient inlet air temperature and types of fuels on gas turbine plant configurations with and without fogger unit. Investigation also covers economic analysis and effect of fuels on emissions. GT frames of various sizes/ratings are being used in gas turbine power plants in Saudi Arabia. 20 MWe GE 5271RA, 40 MWe GE-6561B and 70 MWe GE-6101FA frames are selected for the present study. Fogger units with maximum mass flow rate of 2 kg/s are considered for the present analysis. Reverse Osmosis unit of capacity 4 kg/s supplies required water to the fogger units. GT PRO software has been used for carrying out the analysis including; net plant output and net efficiency, break even electricity price and break even fuel LHV price etc., for a given location of Saudi Arabia. The relative humidity and temperature have been varied from 30 to 45 % and from 80 to 100° F, respectively. Fuels considered in the study are natural gas, diesel and heavy bunker oil. Simulated gas turbine plant output from GT PRO has been validated against an existing gas turbine plant output. It has been observed that the simulated plant output is less than the existing gas turbine plant output by 5%. Results show that variation of humidity does not affect the gas turbine performance appreciably for all types of fuels. For a decrease of inlet air temperature by 10 °F, net plant output and efficiency have been found to increase by 5 and 2 %, respectively for all fuels, for GT only situation. However, for GT with Fogger scenario, for a decrease of inlet air temperature by 10 °F, net plant output and efficiency have been found to further increase by 3.2 and 1.2 %, respectively for all fuels. For all GT frames with fogger, the net plant output and efficiency are relatively higher as compared to GT only case for all

  2. Experimental and numerical investigations of BWR fuel bundle inlet flow

    International Nuclear Information System (INIS)

    Hoashi, E; Morooka, S; Ishitori, T; Komita, H; Endo, T; Honda, H; Yamamoto, T; Kato, T; Kawamura, S

    2009-01-01

    We have been studying the mechanism of the flow pattern near the fuel bundle inlet of BWR using both flow visualization test and computational fluid dynamics (CFD) simulation. In the visualization test, both single- and multi-bundle test sections were used. The former test section includes only a corner orifice facing two support beams and the latter simulates 16 bundles surrounded by four beams. An observation window is set on the side of the walls imitating the support beams upstream of the orifices in both test sections. In the CFD simulation, as well as the visualization test, the single-bundle model is composed of one bundle with a corner orifice and the multi-bundle model is a 1/4 cut of the test section that includes 4 bundles with the following four orifices: a corner orifice facing the corner of the two neighboring support beams, a center orifice at the opposite side from the corner orifice, and two side orifices. Twin-vortices were observed just upstream of the corner orifice in the multi-bundle test as well as the single-bundle test. A single-vortex and a vortex filament were observed at the side orifice inlet and no vortex was observed at the center orifice. These flow patterns were also predicted in the CFD simulation using Reynolds Stress Model as a turbulent model and the results were in good agreement with the test results mentioned above. (author)

  3. [Ebstein's "like" anomaly ventricular double inlet. A rare association].

    Science.gov (United States)

    Muñoz Castellanos, Luis; Kuri Nivon, Magdalena

    The association of univentricular heart with double inlet and Ebstein's "like" anomaly of the common atrioventricular valve is extremely rare. Two hearts with this association are described with the segmental sequential system which determine the atrial situs, the types of atrioventricular and ventriculoarterial connections and associated anomalies. Both hearts had atrial situs solitus, and a univentricular heart with common atrioventricular valve, a foramen primum and double outlet ventricle with normal crossed great arteries. In the fiefirst heart the four leaflets of the atrioventricular valve were displaced and fused to the ventricular walls, from the atrioventricular union roward the apex with atrialization of the inlet and trabecular zones and there was stenosis in the infundibulum and in the pulmonary valve. In the second heart the proximal segment of the atrioventricular valve was displaced and fused to the ventricular whith shot atrialization and the distal segment was dysplastic with fibromixoid nodules and tendinous cords short and thick; the pulmonary artery was dilate. Both hearts are grouped in the atrioventricular univentricular connection in the segmental sequential system. The application of this method in the diagnosis of congenital heart disease demonstrates its usefulness. The associations of complex anomalies in these hearts show us the infinite spectrum of presentation of congenital heart disease which expands our knowledge of pediatric cardiology. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  4. Flow distribution in the inlet plenum of steam generator

    International Nuclear Information System (INIS)

    Khadamakar, H.P.; Patwardhan, A.W.; Padmakumar, G.; Vaidyanathan, G.

    2011-01-01

    Highlights: → Various flow distribution devices have been studied to make the flow distribution uniform in axial as well as tangential direction. → Experiments were performed using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV). → CFD modeling has been carried out to give more insights. → Various flow distribution devices have been compared. - Abstract: The flow distribution in a 1/5th and 1/8th scale models of inlet plenum of steam generator (SG) has been studied by a combination of experiments and Computational Fluid Dynamics (CFD) simulations. The distribution of liquid sodium in the inlet plenum of the SG strongly affects the thermal as well as mechanical performance of the steam generator. Various flow distribution devices have been used to make the flow distribution uniform in axial as well as tangential direction in the window region. Experiments have been conducted to measure the radial velocity distribution using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV) under a variety of conditions. CFD modeling has been carried out for various configurations to give more insight into the flow distribution phenomena. The various flow distribution devices have been compared on the basis of a non-uniformity index parameter.

  5. Real Time Extraction Kinetics of Electro Membrane Extraction Verified by Comparing Drug Metabolism Profiles Obtained from a Flow-Flow Electro Membrane Extraction-Mass Spectrometry System with LC-MS.

    Science.gov (United States)

    Fuchs, David; Jensen, Henrik; Pedersen-Bjergaard, Stig; Gabel-Jensen, Charlotte; Hansen, Steen Honoré; Petersen, Nickolaj Jacob

    2015-06-02

    A simple to construct and operate, "dip-in" electromembrane extraction (EME) probe directly coupled to electrospray ionization-mass spectrometry (ESI-MS) for rapid extraction and real time analysis of various analytes was developed. The setup demonstrated that EME-MS can be used as a viable alternative to conventional protein precipitation followed by liquid chromatography-mass spectrometry (LC-MS) for studying drug metabolism. Comparison of EME-MS with LC-MS for drug metabolism analysis demonstrated for the first time that real time extraction of analytes by EME is possible. Metabolism kinetics were investigated for three different drugs: amitriptyline, promethazine, and methadone. By comparing the EME-MS extraction profiles of the drug substances and formed drug metabolites with the metabolism profiles obtained by conventional protein precipitation followed by LC-MS good correlation was obtained with only very limited time delay in the extraction. The results indicate that, by tuning the electromembrane properties, for example, by optimizing the extraction voltage, extremely fast extraction kinetics can be obtained. A metabolic profile could be generated while the drug was metabolized offering a significant time saving as compared to conventional LC-MS where laborious protein precipitation or other sample pretreatments are required before analysis. This makes the developed EME-MS setup a highly promising sample preparation method for various kinds of applications where fast and real-time analysis of analytes is of interest.

  6. Gas-dynamic problems in off-design operation of supersonic inlets ( review)

    Science.gov (United States)

    Zvegintsev, V. I.

    2017-11-01

    Modern concepts of operation of supersonic inlets of high-velocity air-breathing engines are analyzed. It is demonstrated that the flow in the engine duct becomes extremely complicated in off-design modes of inlet operation, which can lead to unpredictable consequences, in particular, to inlet unstart. The term "inlet unstart" is considered in the present paper as a synonym of the absence of theoretical understanding and prediction of gas-dynamic phenomena. Various approaches are proposed to ensure self-regulation of the inlet-combustor system for air-breathing engines. Possible directions of further research are indicated for the purpose of stable operation of inlets in a wide range of flight conditions.

  7. Effects of inlet treatment location and treatment cavity depth on compressor noise

    Science.gov (United States)

    Clark, L. R.

    1975-01-01

    The ability of acoustic liners to reduce compressor noise inside and in front of an inlet was studied. An axial flow research compressor and a specially designed inlet were used inside an anechoic chamber. Acoustic and performance data were obtained for a range of inlet treatment locations and cavity depths to determine their effects on inlet noise over a range of blade passing frequencies. The greatest noise reductions in front of the inlet were obtained with acoustic treatment located close to the compressor and backed with the deepest cavities tested. Inside the inlet the maximum noise level reductions were obtained in the area of the treatment regardless of treatment location. No appreciable losses in compressor performance were measured.

  8. Performance of different hollow fiber membranes for seawater desalination using membrane distillation

    KAUST Repository

    Francis, Lijo

    2014-08-11

    Membrane distillation requires a highly porous hydrophobic membrane with low surface energy. In this paper, we compare the direct contact membrane distillation (DCMD) performances of four different types of in-house fabricated hollow fiber membranes and two different commercially available hollow fiber membranes. Hollow fiber membranes are fabricated using wet-jet phase inversion technique and the polymeric matrices used for the fabrication are polyvinylidine fluoride (PVDF) and polyvinyl chloride (PVC). Commercial hollow fiber membrane materials are made of polytetrafluoroethylene (PTFE) and polypropylene (PP). PVDF hollow fibers showed a superior performance among all the hollow fibers tested in the DCMD process and gave a water vapor flux of 31 kg m-2h-1 at a feed and coolant inlet temperatures of 80 and 20°C, respectively. Under the same conditions, the water vapor flux observed for PP, PTFE, and PVC hollow fiber membranes are 13, 11, and 6 kg m-2h-1, respectively, with 99.99% salt rejection observed for all membranes used.

  9. Experimental investigation of the effect of inlet particle properties on the capture efficiency in an exhaust particulate filter

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Sandeep; Rothamer, David; Zelenyuk, Alla; Stewart, Mark; Bell, David

    2017-11-01

    The impact of inlet particle properties on the filtration performance of clean and particulate matter (PM) laden cordierite filter samples was evaluated using PM generated by a spark-ignition direct-injection (SIDI) engine fuelled with tier II EEE certification gasoline. Prior to the filtration experiments, a scanning mobility particle spectrometer (SMPS) was used to measure the electrical-mobility based particle size distribution (PSD) in the SIDI exhaust from distinct engine operating conditions. An advanced aerosol characterization system that comprised of a centrifugal particle mass analyser (CPMA), a differential mobility analyser (DMA), and a single particle mass spectrometer (SPLAT II) was used to obtain additional information on the SIDI particulate, including particle composition, mass, and dynamic shape factors (DSFs) in the transition () and free-molecular () flow regimes. During the filtration experiments, real-time measurements of PSDs upstream and downstream of the filter sample were used to estimate the filtration performance and the total trapped mass within the filter using an integrated particle size distribution method. The filter loading process was paused multiple times to evaluate the filtration performance in the partially loaded state. The change in vacuum aerodynamic diameter () distribution of mass-selected particles was examined for flow through the filter to identify whether preferential capture of particles of certain shapes occurred in the filter. The filter was also probed using different inlet PSDs to understand their impact on particle capture within the filter sample. Results from the filtration experiment suggest that pausing the filter loading process and subsequently performing the filter probing experiments did not impact the overall evolution of filtration performance. Within the present distribution of particle sizes, filter efficiency was independent of particle shape potentially due to the diffusion-dominant filtration

  10. Analytical Model of Inlet Growth and Equilibrium Cross-Sectional Area

    Science.gov (United States)

    2016-04-01

    ERDC/CHL CHETN-IV-107 April 2016 Approved for public release; distribution is unlimited. Analytical Model of Inlet Growth and Equilibrium Cross...encompass a broader range of theoretical alternatives to investigate inlet stability. The quadratic formula provides quantitative estimates of equilibrium ...rework sediment. Escoffier (1940) theorized that stable inlets form when the maximum flow equals an equilibrium value based on sediment transport

  11. Investigation of a Half-Conical Scoop Inlet Mounted at Five Alternate Circumferential Locations around a Circular Fuselage Pressure-Recovery Results at a Mach Number 2.01

    Science.gov (United States)

    Hasel, Lowell E.; Lankford, John L.; Robins, A. W.

    1953-01-01

    The effects of inlet circumferential position around the fuselage on the characteristics of a half-conical scoop inlet having a 24.6deg half-angle cone have been investigated in the langley 4- by 4-foot supersonic pressure tunnel. Pressure-recovery results have been obtained at a Mach number of 2.01 for a fixed boundary-layer-bleed height which was 60 percent of the boundary-layer thickness at an angle of attack of 0deg, and for cowling position parameters of 42.4deg and 38.0deg. inlet had a capture area equal to 24.9 percent of the basic-fuselage frontal area. The angle of attack was varied from 0deg to 12deg. The most favorable pressure-recovery characteristics at angles of attack were obtained with the Inlet located on the bottom of the fuselage where the maximum recovery increased from a value of 81 percent at an angle of attack of 0deg to 87 percent at 12deg. In general, the pressure recovery decreased with increasing angle of attack for all other inlet locations. At a given angle of attack the pressure recovery decreased as the inlet location was progressively moved from the bottom to the top of the fuselage. Stable subcritical operation of the inlet with nearly constant pressure recovery was obtained for inlet mass-flow ratios from 1.0 to about 0.76 at an angle of attack of 0deg with the central body in the design position.

  12. Flux Enhancement in Membrane Distillation Using Nanofiber Membranes

    Directory of Open Access Journals (Sweden)

    T. Jiříček

    2016-01-01

    Full Text Available Membrane distillation (MD is an emerging separation technology, whose largest application potential lies in the desalination of highly concentrated solutions, which are out of the scope of reverse osmosis. Despite many attractive features, this technology is still awaiting large industrial application. The main reason is the lack of commercially available membranes with fluxes comparable to reverse osmosis. MD is a thermal separation process driven by a partial vapour pressure difference. Flux, distillate purity, and thermal efficiency are always in conflict, all three being strictly connected with pore size, membrane hydrophobicity, and thickness. The world has not seen the ideal membrane yet, but nanofibers may offer a solution to these contradictory requirements. Membranes of electrospun PVDF were tested under various conditions on a direct contact (DCMD unit, in order to determine the optimum conditions for maximum flux. In addition, their performance was compared to commonly available PTFE, PE, and PES membranes. It was confirmed that thinner membranes have higher fluxes and a lower distillate purity and also higher energy losses via conduction across the membrane. As both mass and heat transfer are connected, it is best to develop new membranes with a target application in mind, for the specific membrane module and operational conditions.

  13. Mass Transfer Method and Apparatus

    DEFF Research Database (Denmark)

    1995-01-01

    .g. polytetrafluoroethylene (PTFE, Teflon $m(3)) membranes, in the form of hollow fibres having gas-containing pores and contacting the second fluid with the inner surface of the membranes. Useful membranes are characterized in that they e.g. have a porosity ($g(e)) of at least 0.50, a mass transfer coefficient of e...

  14. Fundamental Aeronautics Program: Supersonics Project. Channeled Center-Body Inlet Experiment Overview

    Science.gov (United States)

    SaintJohn, Clint; Ratnayake, Nalin; Frederick, Mike

    2012-01-01

    The presentation describes supersonic flight testing accomplished on a novel mixed compression axisymmetric inlet utilizing channels for off design flow matching rather than a translating centerbody concept.

  15. Effects of a shallow flood shoal and friction on hydrodynamics of a multiple-inlet system

    Science.gov (United States)

    Orescanin, Mara M.; Elgar, Steve; Raubenheimer, Britt; Gorrell, Levi

    2017-07-01

    Prior studies have shown that frictional changes owing to evolving geometry of an inlet in a multiple inlet-bay system can affect tidally driven circulation. Here, a step between a relatively deep inlet and a shallow bay also is shown to affect tidal sea-level fluctuations in a bay connected to multiple inlets. To examine the relative importance of friction and a step, a lumped element (parameter) model is used that includes tidal reflection from the step. The model is applied to the two-inlet system of Katama Inlet (which connects Katama Bay on Martha's Vineyard, MA to the Atlantic Ocean) and Edgartown Channel (which connects the bay to Vineyard Sound). Consistent with observations and previous numerical simulations, the lumped element model suggests that the presence of a shallow flood shoal limits the influence of an inlet. In addition, the model suggests an increasing importance of friction relative to the importance of the step as an inlet shallows, narrows, and lengthens, as observed at Katama Inlet from 2011 to 2014.

  16. Turbulence Intensity at Inlet of 80- by 120-Foot Wind Tunnel Caused by Upwind Blockage

    Science.gov (United States)

    Salazar, Denise; Yuricich, Jillian

    2014-01-01

    In order to estimate the magnitude of turbulence in the National Full-Scale Aerodynamics Complex (NFAC) 80- by 120-Foot Wind Tunnel (80 x 120) caused by buildings located upwind from the 80 x 120 inlet, a 150th-scale study was performed that utilized a nominal two-dimensional blockage placed ahead of the inlet. The distance of the blockage ahead of the inlet was varied. This report describes velocity measurements made in the plane of the 80 x 120 model inlet for the case of zero ambient (atmospheric) wind.

  17. Tidal and subtidal exchange flows at an inlet of the Wadden Sea

    Science.gov (United States)

    Valle-Levinson, Arnoldo; Stanev, Emil; Badewien, Thomas H.

    2018-03-01

    Observations of underway velocity profiles during complete spring and neap tidal cycles were used to determine whether the spatial structures of tidal and subtidal flows at a tidal inlet in a multiple-inlet embayment are consistent with those observed at single-inlet embayments. Measurements were obtained at the Otzumer Balje, one of the multiple inlets among the East Frisian Islands of the Wadden Sea. The 1.5 km-wide inlet displayed a bathymetric profile consisting of a channel ∼15 m deep flanked by model for a basin with one inlet. Maximum semidiurnal flows appear at the surface in the channel, furthest away from bottom friction effects. Therefore, Otzumer Balje displays tidal hydrodynamics that are independent of the other inlets of the embayment. Subtidal exchange flows are laterally sheared, with residual inflow in the channel combined with outflow over shoals. The spatial distribution of these residual flows follow theoretical expectations of tidally driven flows interacting with bathymetry. Such distribution is similar to the tidal residual circulation at other inlets with only one communication to the ocean, suggesting that at subtidal scales the Otzumer Balje responds to tidal forcing independently of the other inlets.

  18. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high speed civil aircraft will require breakthrough developments in propulsion design, including novel techniques to optimize inlet...

  19. Performance and Adaptive Surge-Preventing Acceleration Prediction of a Turboshaft Engine under Inlet Flow Distortion

    Directory of Open Access Journals (Sweden)

    Cao Dalu

    2017-01-01

    Full Text Available The intention of this paper is to research the inlet flow distortion influence on overall performance of turboshaft engine and put forward a method called Distortion Factor Item (DFI to improve the fuel supply plan for surge-preventing acceleration when turboshaft engine suddenly encounters inlet flow distortion. Based on the parallel compressor theory, steady-state and transition-state numerical simulation model of turboshaft engine with sub-compressor model were established for researching the influence of inlet flow distortion on turboshaft engine. This paper made a detailed analysis on the compressor operation from the aspects of performance and stability, and then analyzed the overall performance and dynamic response of the whole engine under inlet flow distortion. Improved fuel supply plan with DFI method was applied to control the acceleration process adaptively when encountering different inlet flow distortion. Several simulation examples about extreme natural environments were calculated to testify DFI method’s environmental applicability. The result shows that the inlet flow distortion reduces the air inflow and decreases the surge margin of compressor, and increase the engine exhaust loss. Encountering inlet flow distortion has many adverse influences such as sudden rotor acceleration, turbine inlet temperature rise and power output reduction. By using improved fuel supply plan with DFI, turboshaft engine above-idle acceleration can avoid surge effectively under inlet flow distortion with environmental applicability.

  20. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high speed civil aircraft will require breakthrough developments in propulsion design, including novel techniques to optimize inlet...

  1. Cavitation in centrifugal pump with rotating walls of axial inlet device

    Science.gov (United States)

    Moloshnyi, O.; Sotnyk, M.

    2017-08-01

    The article deals with the analysis of cavitation processes in the flowing part of the double entry centrifugal pump. The analysis is conducted using numerical modeling of the centrifugal pump operating process in the software environment ANSYS CFX. Two models of the axial inlet device is researched. It is shaped by a cylindrical section and diffuser section in front of the impeller, which includes fairing. The walls of the axial inlet device rotate with the same speed as the pump rotor. The numerical experiment is conducted under the condition of the flow rate change and absolute pressure at the inlet. The analysis shows that the pump has the average statistical cavitation performance. The occurrence of the cavitation in the axial inlet device is after narrowing the cross-section of flow channel and at the beginning of the diffuser section. Additional sudden expansion at the outlet of the axial inlet diffuser section does not affect the cavitation characteristics of the impeller, however, improves cavitation characteristics of the axial inlet device. For considered geometric parameters of the axial inlet device the cavitation in the impeller begins earlier than in the axial inlet device. That is, the considered design of the axial inlet device will not be subjected to destruction at the ensuring operation without cavitation in the impeller.

  2. High Pressure Atmospheric Sampling Inlet System for Venus or the Gas Giants, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a miniaturized high pressure atmospheric sampling inlet system for sample acquisition in extreme planetary environments,...

  3. A liquid-phase microextraction method, combining a dual gauge microsyringe with a hollow fiber membrane, for the determination of organochlorine pesticides in aqueous solution by gas chromatography/ion trap mass spectrometry.

    Science.gov (United States)

    Yan, Chih-Hao; Wu, Hui-Fen

    2004-01-01

    A liquid-phase microextraction (LPME) method has been demonstrated for the extraction and determination of organochlorine pesticides (OCPs) in aqueous solution. The method combines a dual gauge microsyringe with a hollow fiber membrane (LPME/DGM-HF) followed by detection by gas chromatography/ion trap mass spectrometry (GC/ITMS). The advantages include speed, low solvent and sample consumption, simplicity and ease of use. The extraction time, solvent selection, salt concentration and sample stirring rate have been investigated in order to optimize extraction efficiency. The viability is evaluated by measuring the linearity and detection limit of the five OCPs in aqueous solution. Detection linearity for the OCPs has been achieved over a range of concentrations between 1 and 500 microg/L (r2 > 0.930), with a detection limit of 0.1 microg/L for each OCP. Copyright 2004 John Wiley & Sons, Ltd.

  4. Membrane paradigm

    International Nuclear Information System (INIS)

    Price, R.H.; Thorne, K.S.

    1986-01-01

    The membrane paradigm is a modified frozen star approach to modeling black holes, with particles and fields assuming a complex, static, boundary-layer type structure (membrane) near the event horizon. The membrane has no effects on the present or future evolution of particles and fields above itself. The mathematical representation is a combination of a formalism containing terms for the shear and bulk viscosity, surface pressure, momentum, temperature, entropy, etc., of the horizon and the 3+1 formalism. The latter model considers a family of three-dimensional spacelike hypersurfaces in one-dimensional time. The membrane model considers a magnetic field threading the hole and undergoing torque from the hole rotation. The field is cleaned by the horizon and distributed over the horizon so that ohmic dissipation is minimized. The membrane paradigm is invalid inside the horizon, but is useful for theoretically probing the properties of slowly evolving black holes

  5. Membrane processes

    Science.gov (United States)

    Staszak, Katarzyna

    2017-11-01

    The membrane processes have played important role in the industrial separation process. These technologies can be found in all industrial areas such as food, beverages, metallurgy, pulp and paper, textile, pharmaceutical, automotive, biotechnology and chemical industry, as well as in water treatment for domestic and industrial application. Although these processes are known since twentieth century, there are still many studies that focus on the testing of new membranes' materials and determining of conditions for optimal selectivity, i. e. the optimum transmembrane pressure (TMP) or permeate flux to minimize fouling. Moreover the researchers proposed some calculation methods to predict the membrane processes properties. In this article, the laboratory scale experiments of membrane separation techniques, as well their validation by calculation methods are presented. Because membrane is the "heart" of the process, experimental and computational methods for its characterization are also described.

  6. Observations of Seafloor Roughness in a Tidally Modulated Inlet

    Science.gov (United States)

    Lippmann, T. C.; Hunt, J.

    2014-12-01

    The vertical structure of shallow water flows are influenced by the presence of a bottom boundary layer, which spans the water column for long period waves or mean flows. The nature of the boundary is determined in part by the roughness elements that make up the seafloor, and includes sometimes complex undulations associated with regular and irregular shaped bedforms whose scales range several orders of magnitude from orbital wave ripples (10-1 m) to mega-ripples (100 m) and even larger features (101-103) such as sand waves, bars, and dunes. Modeling efforts often parameterize the effects of roughness elements on flow fields, depending on the complexity of the boundary layer formulations. The problem is exacerbated by the transient nature of bedforms and their large spatial extent and variability. This is particularly important in high flow areas with large sediment transport, such as tidally dominated sandy inlets like New River Inlet, NC. Quantification of small scale seafloor variability over large spatial areas requires the use of mobile platforms that can measure with fine scale (order cm) accuracy in wide swaths. The problem is difficult in shallow water where waves and currents are large, and water clarity is often limited. In this work, we present results from bathymetric surveys obtained with the Coastal Bathymetry Survey System, a personal watercraft equipped with a Imagenex multibeam acoustic echosounder and Applanix POS-MV 320 GPS-aided inertial measurement unit. This system is able to measure shallow water seafloor bathymetry and backscatter intensity with very fine scale (10-1 m) resolution and over relatively large scales (103 m) in the presence of high waves and currents. Wavenumber spectra show that the noise floor of the resolved multibeam bathymetry is on the order of 2.5 - 5 cm in amplitude, depending on water depths ranging 2 - 6 m, and about 30 cm in wavelength. Seafloor roughness elements are estimated from wavenumber spectra across the inlet

  7. Inlet throttling effect on the boiling two-phase flow stability in a natural circulation loop with a chimney

    International Nuclear Information System (INIS)

    Furuya, M.; Inada, F.; Yasuo, A.

    2001-01-01

    Experiments have been conducted to investigate an effect of inlet restriction on the thermal-hydraulic stability. A Test facility used in this study was designed and constructed to have non-dimensional values that are nearly equal to those of natural circulation BWR. Experimental results showed that driving force of the natural circulation at the stability boundary was described as a function of heat flux and inlet subcooling independent of inlet restriction. In order to extend experimental database regarding thermal-hydraulic stability to different inlet restriction, numerical analysis was carried out based on the homogeneous flow model. Stability maps in reference to the core inlet subcooling and heat flux were presented for various inlet restrictions using the above-mentioned function. Instability region during the inlet subcooling shifted to the higher inlet subcooling with increasing inlet restriction and became larger with increasing heat flux. (orig.)

  8. Moderator inlet line hanger replacement for Pickering nuclear power station

    International Nuclear Information System (INIS)

    Kirkpatrick, R.A.; Bowman, J.M.; Symmons, W.R.; El-Nesr, S.

    1988-01-01

    Ontario Hydro's Pickering Nuclear Generating Station (PNGS), Units 1 and 2 were shutdown for large scale fuel channel replacement. Other nonroutine inspection and maintenance activities were performed to determine the overall condition of the units and it was seen that a moderator inlet line hanger (identified as HR-29) had failed in both units. Subsequent inspections during planned maintenance outages of Pickering NGS Units 3 and 4 revealed that hanger HR-29 had failed and required replacement. A research program was conducted to find a suitable technique. These problems included accessing tooling through small inspection ports, manipulating tooling from a significant distance and the high radiation fields within the vault. This paper describes the program undertaken to replace hanger HR-29. (author)

  9. Mitigation of thermal transients by tube bundle inlet plenum design

    International Nuclear Information System (INIS)

    Oras, J.J.; Kasza, K.E.

    1984-06-01

    A multiphase program aimed at investigating the importance of thermal buoyancy to LMFBR steam-generator and heat-exchanger thermal hydraulics under low-flow transient conditions is being conducted in the Argonne Mixing Components Test Facility (MCTF) on a 60 0 sector shell-side flow model of the Westinghouse straight-tube steam generator being developed under the US/DOE large-component development program. A series of shell-side constant-flow thermal-downramp transient tests have been conducted focusing on the phenomenon of thermal-buoyancy-induced-flow channeling. In addition, it was discovered that a shell-inlet flow-distribution plenum can play a significant role in mitigating the severity of a thermal transient entering a steam generator or heat exchanger

  10. Comparison of Chip Inlet Geometry in Microfluidic Devices for Cell Studies

    Directory of Open Access Journals (Sweden)

    Yung-Shin Sun

    2016-06-01

    Full Text Available Micro-fabricated devices integrated with fluidic components provide an in vitro platform for cell studies best mimicking the in vivo micro-environment. These devices are capable of creating precise and controllable surroundings of pH value, temperature, salt concentration, and other physical or chemical stimuli. Various cell studies such as chemotaxis and electrotaxis can be performed by using such devices. Moreover, microfluidic chips are designed and fabricated for applications in cell separations such as circulating tumor cell (CTC chips. Usually, there are two most commonly used inlets in connecting the microfluidic chip to sample/reagent loading tubes: the vertical (top-loading inlet and the parallel (in-line inlet. Designing this macro-to-micro interface is believed to play an important role in device performance. In this study, by using the commercial COMSOL Multiphysics software, we compared the cell capture behavior in microfluidic devices with different inlet types and sample flow velocities. Three different inlets were constructed: the vertical inlet, the parallel inlet, and the vertically parallel inlet. We investigated the velocity field, the flow streamline, the cell capture rate, and the laminar shear stress in these inlets. It was concluded that the inlet should be designed depending on the experimental purpose, i.e., one wants to maximize or minimize cell capture. Also, although increasing the flow velocity could reduce cell sedimentation, too high shear stresses are thought harmful to cells. Our findings indicate that the inlet design and flow velocity are crucial and should be well considered in fabricating microfluidic devices for cell studies.

  11. Thermodynamic assessment of impact of inlet air cooling techniques on gas turbine and combined cycle performance

    International Nuclear Information System (INIS)

    Mohapatra, Alok Ku; Sanjay

    2014-01-01

    The article is focused on the comparison of impact of two different methods of inlet air cooling (vapor compression and vapor absorption cooling) integrated to a cooled gas turbine based combined cycle plant. Air-film cooling has been adopted as the cooling technique for gas turbine blades. A parametric study of the effect of compressor pressure ratio, compressor inlet temperature (T i , C ), turbine inlet temperature (T i , T ), ambient relative humidity and ambient temperature on performance parameters of plant has been carried out. Optimum T i , T corresponding to maximum plant efficiency of combined cycle increases by 100 °C due to the integration of inlet air cooling. It has been observed that vapor compression cooling improves the efficiency of gas turbine cycle by 4.88% and work output by 14.77%. In case of vapor absorption cooling an improvement of 17.2% in gas cycle work output and 9.47% in gas cycle efficiency has been observed. For combined cycle configuration, however, vapor compression cooling should be preferred over absorption cooling in terms of higher plant performance. The optimum value of compressor inlet temperature has been observed to be 20 °C for the chosen set of conditions for both the inlet air cooling schemes. - Highlights: • Inlet air cooling improves performance of cooled gas turbine based combined cycle. • Vapor compression inlet air cooling is superior to vapor absorption inlet cooling. • For every turbine inlet temperature, there exists an optimum pressure ratio. • The optimum compressor inlet temperature is found to be 293 K

  12. Continuous-output terminal-shock-position sensor for mixed-compression inlets evaluated in wind tunnel tests of YF-12 aircraft inlet

    Science.gov (United States)

    Dustin, M. O.; Cole, G. L.; Neiner, G. H.

    1974-01-01

    An electronic sensor was built to measure the position of the terminal shock in a supersonic inlet. The sensor uses several static-pressure taps in the inlet wall. The sensor output is continuously proportional to shock position. When the sensor was installed in a YF-12 aircraft flight inlet during wind tunnel tests, it indicated shock position within + or - 5 percent of the total distance covered by the static-pressure-tap region. The maximum error caused by an angle of attack change of 4 deg was less than 25 percent. In the region of normal inlet operation, the angle of attack error is negligible. Frequency-response tests show the amplitude ratio is constant out to 60 Hz, and decreases to about 50 percent at 100 Hz, with a phase lag of 50 deg.

  13. North Inlet-Winyah Bay National Estuarine Research Reserve's (NERR) Estuarine Water Quality Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 1993-2002

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of the Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve...

  14. Long-Term Ecological Research (LTER) Climate Data with Water Parameters from North Inlet Meteorological Station, North Inlet Estuary, Georgetown, South Carolina: 1982-1996.

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — Meteorological data with water parameters were collected on an hourly basis from June 3, 1982 through April 29, 1996 in the North Inlet Estuary, Georgetown County,...

  15. North Inlet • Winyah Bay (NIW) National Estuarine Research Reserve Meteorological Data, North Inlet Estuary, Georgetown, South Carolina: 1997 • 1999.

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve System...

  16. Tidally influenced alongshore circulation at an inlet-adjacent shoreline

    Science.gov (United States)

    Hansen, Jeff E.; Elias, Edwin P.L.; List, Jeffrey H.; Erikson, Li H.; Barnard, Patrick L.

    2013-01-01

    The contribution of tidal forcing to alongshore circulation inside the surfzone is investigated at a 7 km long sandy beach adjacent to a large tidal inlet. Ocean Beach in San Francisco, CA (USA) is onshore of a ∼150 km2 ebb-tidal delta and directly south of the Golden Gate, the sole entrance to San Francisco Bay. Using a coupled flow-wave numerical model, we find that the tides modulate, and in some cases can reverse the direction of, surfzone alongshore flows through two separate mechanisms. First, tidal flow through the inlet results in a barotropic tidal pressure gradient that, when integrated across the surfzone, represents an important contribution to the surfzone alongshore force balance. Even during energetic wave conditions, the tidal pressure gradient can account for more than 30% of the total alongshore pressure gradient (wave and tidal components) and up to 55% during small waves. The wave driven component of the alongshore pressure gradient results from alongshore wave height and corresponding setup gradients induced by refraction over the ebb-tidal delta. Second, wave refraction patterns over the inner shelf are tidally modulated as a result of both tidal water depth changes and strong tidal flows (∼1 m/s), with the effect from currents being larger. These tidally induced changes in wave refraction result in corresponding variability of the alongshore radiation stress and pressure gradients within the surfzone. Our results indicate that tidal contributions to the surfzone force balance can be significant and important in determining the direction and magnitude of alongshore flow.

  17. Primordial membranes

    DEFF Research Database (Denmark)

    Hanczyc, Martin M; Monnard, Pierre-Alain

    2017-01-01

    Cellular membranes, which are self-assembled bilayer structures mainly composed of lipids, proteins and conjugated polysaccharides, are the defining feature of cell physiology. It is likely that the complexity of contemporary cells was preceded by simpler chemical systems or protocells during...... the various evolutionary stages that led from inanimate to living matter. It is also likely that primitive membranes played a similar role in protocell 'physiology'. The composition of such ancestral membranes has been proposed as mixtures of single hydrocarbon chain amphiphiles, which are simpler versions...

  18. Performance analysis of a membrane humidifier containing porous metal foam as flow distributor in a PEM fuel cell system

    International Nuclear Information System (INIS)

    Afshari, Ebrahim; Baharlou Houreh, Nasser

    2014-01-01

    Highlights: • Three metal foam configurations for the membrane humidifier are introduced. • The performances of the humidifiers containing metal foam are investigated. • A 3D CFD model is developed to compare the introduced humidifiers with one another. • Using metal foam at dry side has no positive effect on the humidifier performance. - Abstract: Using metal foam as flow distributor in membrane humidifier for proton exchange membrane (PEM) fuel cell system has some unique characteristics like more water transfer, low manufacturing complexity and low cost compared to the conventional flow channel plate. Metal foam can be applied at wet side or dry side or both sides of a humidifier. The three-dimensional CFD models are developed to investigate the performance of the above mentioned meanwhile compare them with the conventional humidifier. This model consists of a set of coupled equations including conservations of mass, momentum, species and energy for all regions of the humidifier. The results indicate that with the metal foam installed at wet side and both sides, water recovery ratio and dew point at dry side outlet are more than that of the conventional humidifier, indicating a better humidifier performance; while using metal foam at dry side has no positive effect on humidifier performance. At dry side mass flow rates higher than 10 mgr/s pressure drop in humidifier containing metal foam at wet side is lower than that of the conventional humidifier. As the mass flow rate increases from 9 to 15 mgr/s humidifier containing metal foam at wet side has better performance, while at mass flow rates lower than 9 mgr/s, the humidifier containing metal foam at both sides has better performance. At dry side inlet temperatures lower than 303 K, humidifier containing metal foam at wet side has better performance and at temperatures higher than 303 K, humidifier containing metal foam at both sides has better performance

  19. CFD modelling of a membrane reactor for hydrogen production from ammonia

    Science.gov (United States)

    Shwe Hla, San; Dolan, Michael D.

    2018-01-01

    Despite the growing use of hydrogen (H2) as a transport fuel, one of the major barriers still remaining is efficient and inexpensive fuel distribution and storage. Current approaches, such as compression, liquefaction or metal hydride formation, incur a significant energy penalty. Ammonia (NH3) has long been considered a prospective H2 medium, exhibiting a higher volumetric H2 density than liquid H2, through liquid-phase storage at mild pressure. Decomposition of NH3 into H2 and N2 can be achieved via use of catalytic reactors and fuel-cell-grade H2 can be produced using metal membranes at H2 distribution sites.In this study, a 3-Dimensional (3D) Computational Fluid Dynamics (CFD) model has been developed to understand the performance of the H2 separation process in gas mixtures derived from an NH3-cracking reaction. The reactor consists of 19 tubular membrane tubes, each 470 mm long, inside a tubular shell with an inner diameter of 130 mm. Standard transport and energy equations governing a 3D, pressure-based, steady-state model were derived from the laws of conservation of mass, momentum and energy. The governing equations were solved using commercial CFD software ANSYS Fluent 18.0. Gas flow and mixing were modelled by the two-equation standard k-epsilon model for closure. Coupled solver was used for pressure-velocity coupling, enabling a pseudo-transient option with pseudo time steps of 0.01 s. To estimate H2 permeation through the metal membrane, a constant H2 permeability of 3.0E-07 mol.m-1 s-1 Pa-0.5 derived from series of experiments tested under a range of industrial conditions, was used. Model simulations were conducted for an adiabatic temperature of 300 °C, a feed-side pressure of 7.8 bara and a permeate side pressure of 0.1 bara. A parametric analysis was carried out to explore the effects of variation in total feed-gas flow and effects of changes in NH3-cracking efficiency on H2 production rates and H2 yields. The model estimated that 4.6-11.6 kg H2

  20. Biochar-amended filter socks reduce herbicide losses via tile line surface inlets

    Science.gov (United States)

    Standing water in depressions and behind terraces in fields with subsurface drainage systems can result in reduced crop yields. This concern can be partially alleviated by installing surface inlets that reduce the duration of ponding. Unfortunately, these inlets provide an open conduit for surface w...

  1. Analytical study of suction boundary layer control for subsonic V/STOL inlets

    Science.gov (United States)

    Boles, M. A.; Ramesh, K.; Hwang, D. P.

    1984-01-01

    Analytical procedures used to evaluate the application of suction boundary-layer control (BLC) to subsonic V/STOL inlets are presented. These procedures have been used to analytically predict the optimum (minimum suction power required) location and extent for a suction slot of two different surface resistances within a subsonic V/STOL inlet. Results of this analytical study are presented.

  2. Vortex Generators in a Two-Dimensional, External-Compression Supersonic Inlet

    Science.gov (United States)

    Baydar, Ezgihan; Lu, Frank K.; Slater, John W.

    2016-01-01

    Computational fluid dynamics simulations are performed as part of a process to design a vortex generator array for a two-dimensional inlet for Mach 1.6. The objective is to improve total pressure recovery a on at the engine face of the inlet. Both vane-type and ramp-type vortex generators are examined.

  3. 76 FR 62428 - Cook Inlet Regional Citizens' Advisory Council (CIRCAC) Charter Renewal

    Science.gov (United States)

    2011-10-07

    ... Inlet Regional Citizens' Advisory Council (CIRCAC) as an alternative voluntary advisory group for Cook... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2011-0852] Cook Inlet Regional Citizens' Advisory Council (CIRCAC) Charter Renewal AGENCY: Coast Guard, DHS. ACTION: Notice of recertification...

  4. 33 CFR 110.170 - Lockwoods Folly Inlet, N.C.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lockwoods Folly Inlet, N.C. 110.170 Section 110.170 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.170 Lockwoods Folly Inlet, N.C. (a) Explosives...

  5. 77 FR 43513 - Olympia Harbor Days Tug Boat Races, Budd Inlet, WA

    Science.gov (United States)

    2012-07-25

    ... Harbor Days Tug Boat Races, Budd Inlet, WA AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of... Races, Budd Inlet, WA from 12 p.m. through 8 p.m. on September 2, 2012. This action is necessary to restrict vessel movement within the specified race area immediately prior to, during, and immediately after...

  6. Blade bowing effects on radial equilibrium of inlet flow in axial compressor cascades

    Directory of Open Access Journals (Sweden)

    Han XU

    2017-10-01

    Full Text Available The circumferentially averaged equation of the inlet flow radial equilibrium in axial compressor was deduced. It indicates that the blade inlet radial pressure gradient is closely related to the radial component of the circumferential fluctuation (CF source item. Several simplified cascades with/without aerodynamic loading were numerically studied to investigate the effects of blade bowing on the inlet flow radial equilibrium. A data reduction program was conducted to obtain the CF source from three-dimensional (3D simulation results. Flow parameters at the passage inlet were focused on and each term in the radial equilibrium equation was discussed quantitatively. Results indicate that the inviscid blade force is the inducement of the inlet CF due to geometrical asymmetry. Blade bowing induces variation of the inlet CF, thus changes the radial pressure gradient and leads to flow migration before leading edge (LE in the cascades. Positive bowing drives the inlet flow to migrate from end walls to mid-span and negative bowing turns it to the reverse direction to build a new equilibrium. In addition, comparative studies indicate that the inlet Mach number and blade loading can efficiently impact the effectiveness of blade bowing on radial equilibrium in compressor design.

  7. The Effect of the Holes Size Change of Lower-Support-Structure-Bottom Plate on the Reactor Core-Inlet Flow-Distribution

    International Nuclear Information System (INIS)

    Lee, Gong Hee; Bang, Young Seok; Cheong, Ae Ju

    2015-01-01

    Complex thermal-hydraulic phenomena exist inside PWR because reactor interiors include a fuel assembly, control rod assembly, ICI (In-Core Instrumentation), and other internal structures. Because changes to reactor design may influence interior, thermal-hydraulic characteristics, licensing applicants commonly conduct a flow-distribution test and use test results (e.g., core-inlet flow-rate distribution) as the input data for a core thermal-margin analysis program. Because the APR+ (Advanced Power Reactor Plus) had more fuel assemblies (241EA → 257EA) and the design of some internal structures was changed (from those of APR1400), the core-inlet flow-rate distribution for a 1/5 scaled-down reactor model was measured and high flow-rates were found especially near the outer region of the reactor core. In this study, to examine the effect of the holes size change (i.e. smaller diameter) in the outer region of the LSSBP, not a 50% blockage of the flow holes, on the reactor core-inlet flow-distribution, simulations were conducted with the commercial CFD (Computational Fluid Dynamics) software, ANSYS CFX R.14. The predicted results were compared with those of the original LSSBP. In this study, to examine the effect of the holes size change (smaller diameter) in the outer region of the LSSBP on the reactor core-inlet flow-distribution, simulations were conducted with the commercial CFD software, ANSYS CFX R.14. The predicted results were compared with those of the original LSSBP. Through these comparisons it was concluded that a more uniform distribution of the mass-flow rate at the core-inlet plane could be obtained by reducing the holes size in the outer region of the LSSBP

  8. Evaluation of clayey masses compositions starting from the residue incorporation of the red ceramic industry to obtain tubular ceramic membranes; Avaliacao das composicoes de massas argilosas a partir da incorporacao de residuo da industria de ceramica vermelha na obtencao de membranas ceramicas tubulares

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adriano Lima da; Chaves, Alexsandra Cristina; Luna, Carlos Bruno Barreto; Neves, Gelmires de Araujo; Lira, Helio de Lucena, E-mail: adrianolimadasilva@hotmail.com, E-mail: alexsandra.chaves@ifap.edu.br, E-mail: brunobarretodemaufcg@hotmail.com, E-mail: gelmires@ufcg.edu.br, E-mail: helio@ufcg.edu.br [Universidade Federal de Campina Grande (UAEMa/CCT/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2017-01-15

    The inappropriate residue disposal of red ceramic industry is very high. Nowadays, one of the major challenges is the investigation of processes to obtain alternative materials, enabling the use of these residues to manufacture new materials. This work's objective is to study clayey masses' compositions starting from the residue incorporation of the red ceramic industry to be used in tubular ceramic membranes. Two compositions of ceramic masses were established, composition A (50% of residue) and composition B (70% of residue). Granulometric analysis of the ceramic masses presented an average size of particles, what indicates membranes in the microfiltration scale. Another observed factor is related to the increase of residue amount, what favored a decrease in the ceramic mass' plasticity. A rise in the apparent porosity was also observed, probably because of a possible growing in the bigger pores numbers, due to the sintering high temperature and the elevation of residue quantity itself. (author)

  9. Jet Engine Fan Response to Inlet Distortions Generated by Ingesting Boundary Layer Flow

    Science.gov (United States)

    Giuliani, James Edward

    Future civil transport designs may incorporate engines integrated into the body of the aircraft to take advantage of efficiency increases due to weight and drag reduction. Additional increases in engine efficiency are predicted if the inlets ingest the lower momentum boundary layer flow that develops along the surface of the aircraft. Previous studies have shown, however, that the efficiency benefits of Boundary Layer Ingesting (BLI) inlets are very sensitive to the magnitude of fan and duct losses, and blade structural response to the non-uniform flow field that results from a BLI inlet has not been studied in-depth. This project represents an effort to extend the modeling capabilities of TURBO, an existing rotating turbomachinery unsteady analysis code, to include the ability to solve the external and internal flow fields of a BLI inlet. The TURBO code has been a successful tool in evaluating fan response to flow distortions for traditional engine/inlet integrations. Extending TURBO to simulate the external and inlet flow field upstream of the fan will allow accurate pressure distortions that result from BLI inlet configurations to be computed and used to analyze fan aerodynamics and structural response. To validate the modifications for the BLI inlet flow field, an experimental NASA project to study flush-mounted S-duct inlets with large amounts of boundary layer ingestion was modeled. Results for the flow upstream and in the inlet are presented and compared to experimental data for several high Reynolds number flows to validate the modifications to the solver. Once the inlet modifications were validated, a hypothetical compressor fan was connected to the inlet, matching the inlet operating conditions so that the effect on the distortion could be evaluated. Although the total pressure distortion upstream of the fan was symmetrical for this geometry, the pressure rise generated by the fan blades was not, because of the velocity non-uniformity of the distortion

  10. Characterization of Polymeric Nanofiltration Membranes

    Directory of Open Access Journals (Sweden)

    Simoncic, B.

    2007-11-01

    Full Text Available As membrane processes are increasingly used in industrial applications, there is a growing interest in methods of membrane characterization. Traditional membrane characteristics, such as cut-off value and pore size distribution, are being supplemented by membrane surface characteristics, such as charge density or zeta potential and hydrophobicity. This study, therefore, characterizes the three different polymeric membranes used (NFT-50, DL and DK. The molecular mass cut-off (MMCO value was determined using a set of reference solutes within the molecular range 150-600 Da, whereas streaming potential measurements enabled quantification of the surface charge characteristics. Hydrophobicity was studied using contact angle measurements. The results indicated that even though all three membranes had very similar layer compositions which consisted of poly(piperazneamide, as top layers they showed different values of measured quantitive. The NFT-50 membrane had the lowest MMCO value and the most hydrophilic membrane surface, followed by DK and DL. Membrane fouling as measured by flux reduction was determined by streaming potential measurements and accompanied by a positive change in zeta potential.

  11. Advantages of air conditioning and supercharging an LM6000 gas turbine inlet

    Energy Technology Data Exchange (ETDEWEB)

    Kolp, D.A. [Kolp Engineering, Avon, CT (United States); Flye, W.M. [Stewart and Stevenson, Houston, TX (United States); Guidotti, H.A. [Energy Services, Inc., Framington, CT (United States)

    1995-07-01

    Of all the external factors affecting a gas turbine, inlet pressure and temperature have the greatest impact on performance. The effect of inlet temperature variations is especially pronounced in the new generation of high-efficiency gas turbines typified by the 40 MW GE LM6000. A reduction of 50 F (28 C) in inlet temperature can result in a 30 percent increase in power and a 4.5 percent improvement in heat rate. An elevation increase to 5,000 ft (1,524 m) above sea level decreases turbine output 17 percent; conversely supercharging can increase output more than 20 percent. This paper addresses various means of heating, cooling and supercharging LM6000 inlet air. An economic model is developed and sample cases are cited to illustrate the optimization of gas turbine inlet systems, taking into account site conditions, incremental equipment cost and subsequent performance enhancement.

  12. Design of a reactor inlet temperature controller for EBR-2 using state feedback

    International Nuclear Information System (INIS)

    Vilim, R.B.; Planchon, H.P.

    1990-01-01

    A new reactor inlet temperature controller for pool type liquid-metal reactors has been developed and will be tested in EBR-II. The controller makes use of modern control techniques to take into account stratification and mixing in the cold pool during normal operation. Secondary flowrate is varied so that the reactor inlet temperature tracks a setpoint while reactor outlet temperature, primary flowrate and secondary cold leg temperature are treated as exogenous disturbances and are free to vary. A disturbance rejection technique minimizes the effect of these disturbances on inlet temperature. A linear quadratic regulator improves inlet temperature response. Tests in EBR-II will provide experimental data for assessing the performance improvements that modern control can produce over the existing EBR-II analog inlet temperature controller. 10 refs., 8 figs

  13. Selective catalytic reduction converter design: The effect of ammonia nonuniformity at inlet

    International Nuclear Information System (INIS)

    Paramadayalan, Thiyagarajan; Pant, Atul

    2013-01-01

    A three-dimensional CFD model of SCR converter with detailed chemistry is developed. The model is used to study the effects of radial variation in inlet ammonia profile on SCR emission performance at different temperatures. The model shows that radial variation in inlet ammonia concentration affects the SCR performance in the operating range of 200-400 .deg. C. In automotive SCR systems, ammonia is non-uniformly distributed due to evaporation/reaction of injected urea, and using a 1D model or a 3D model with flat ammonia profile at inlet for these conditions can result in erroneous emission prediction. The 3D SCR model is also used to study the effect of converter design parameters like inlet cone angle and monolith cell density on the SCR performance for a non-uniform ammonia concentration profile at the inlet. The performance of SCR is evaluated using DeNO x efficiency and ammonia slip

  14. An experimental study of high contraction ratio, subsonic wind tunnel inlets

    Science.gov (United States)

    Caylor, M. J.; Batill, S. M.

    1984-01-01

    The inlet or contraction section has significant impact on the performance and operating characteristics of any subsonic wind tunnel. Previous experimental studies have been conducted to examine specific aspects of inlet performance and design. This work builds on this earlier experience by performing a comprehensive experimental analysis of a member of a family of high contraction ratio inlets used on indraft type wind tunnels. Quantitative flow field measurements were made using wall static ports, a five-hole pressure probe, and a hot wire anemometry system. Smoke flow visualization techniques were used to examine the inlet flow in a more qualitative manner and to correlate with quantitative measurements. This experimental investigation has provided insight into some of the many problems associated with inlet flows.

  15. Thermal stratification built up in hot water tank with different inlet stratifiers

    DEFF Research Database (Denmark)

    Dragsted, Janne; Furbo, Simon; Dannemand, Mark

    2017-01-01

    in order to elucidate how well thermal stratification is established in the tank with differently designed inlet stratifiers under different controlled laboratory conditions. The investigated inlet stratifiers are from Solvis GmbH & Co KG and EyeCular Technologies ApS. The inlet stratifier from Solvis Gmb......Thermal stratification in a water storage tank can strongly increase the thermal performance of solar heating systems. Thermal stratification can be built up in a storage tank during charge, if the heated water enters through an inlet stratifier. Experiments with a test tank have been carried out......H is a rigid plastic pipe with holes for each 30 cm. The holes are designed with flaps preventing counter flow into the pipe. The inlet stratifier from EyeCular Technologies ApS is made of a flexible polymer with openings all along the side and in the full length of the stratifier. The flexibility...

  16. A Review of Water Management in Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Zidong Wei

    2009-11-01

    Full Text Available At present, despite the great advances in polymer electrolyte membrane fuel cell (PEMFC technology over the past two decades through intensive research and development activities, their large-scale commercialization is still hampered by their higher materials cost and lower reliability and durability. In this review, water management is given special consideration. Water management is of vital importance to achieve maximum performance and durability from PEMFCs. On the one hand, to maintain good proton conductivity, the relative humidity of inlet gases is typically held at a large value to ensure that the membrane remains fully hydrated. On the other hand, the pores of the catalyst layer (CL and the gas diffusion layer (GDL are frequently flooded by excessive liquid water, resulting in a higher mass transport resistance. Thus, a subtle equilibrium has to be maintained between membrane drying and liquid water flooding to prevent fuel cell degradation and guarantee a high performance level, which is the essential problem of water management. This paper presents a comprehensive review of the state-of-the-art studies of water management, including the experimental methods and modeling and simulation for the characterization of water management and the water management strategies. As one important aspect of water management, water flooding has been extensively studied during the last two decades. Herein, the causes, detection, effects on cell performance and mitigation strategies of water flooding are overviewed in detail. In the end of the paper the emphasis is given to: (i the delicate equilibrium of membrane drying vs. water flooding in water management; (ii determining which phenomenon is principally responsible for the deterioration of the PEMFC performance, the flooding of the porous electrode or the gas channels in the bipolar plate, and (iii what measures should be taken to prevent water flooding from happening in PEMFCs.

  17. Ducted fan inlet/exit and rotor tip flow improvements for vertical lift systems

    Science.gov (United States)

    Akturk, Ali

    The current research utilized experimental and computational techniques in 5" and 22" diameter ducted fan test systems that have been custom designed and manufactured. Qualitative investigation of flow around the ducted fan was also performed using smoke flow visualizations. Quantitative measurements consisted of 2D and 3D velocity measurements using planar and Stereoscopic Particle Image Velocimetry (PIV and SPIV), high resolution total pressure measurements using Kiel total pressure probes and real time six-component force and torque measurements. The computational techniques used in this thesis included a recently developed radial equilibrium based rotor model(REBRM) and a three dimensional Reynolds-Averaged Navier Stokes (RANS) based CFD model. A radial equilibrium based rotor model (REBRM) developed by the author was effectively integrated into a three-dimensional RANS based computational system. The PIV measurements and computational flow predictions using (REBRM) near the fan inlet plane were in a good agreement at hover and forward flight conditions. The aerodynamic modifications resulting from the fan inlet flow distortions in forward flight regime were clearly captured in 2D PIV results. High resolution total pressure measurements at the downstream of the fan rotor showed that tip leakage, rotor hub separation, and passage flow related total pressure losses were dominant in hover condition. However, the losses were dramatically increased in forward flight because of inlet lip separation and distortion. A novel ducted fan inlet flow conditioning concept named "Double Ducted Fan" (DDF) was developed. The (DDF) concept has a potential to significantly improve the performance and controllability of VTOL UAVs and many other ducted fan based vertical lift systems. The new concept that will significantly reduce the inlet lip separation related performance penalties used a secondary stationary duct system to control "inlet lip separation" occurring especially at

  18. Analysis of flow distribution in plate-type core affected by uneven inlet temperature distribution

    International Nuclear Information System (INIS)

    Xia, G.L.; Su, G.H.; Peng, M.J.

    2016-01-01

    Highlights: • Flow and power distribution of plate-type core are studied using RELAP5-3D code. • Effect of uneven inlet temperature on flow distribution can be considered. • Reactor power peaking factor shifts to low inlet temperature region. • Flow peaking factor shifts to high inlet temperature region. • Effect of uneven inlet temperature on flow distribution is much greater than power. - Abstract: The flow and power distribution characteristics of plate-type fuel reactor core have been investigated in the present study. A reactor core thermal-hydraulic and neutronics coupled model was established using RELAP5-3D codes. The coupled modeling method was used to establish the thermo-hydraulic model, and the phenomenon of two-phase flow instability in a parallel two-channel system was used to verify the reliability of the method. Besides, the influence on power and flow distributions of uneven core inlet temperature was also studied by the application of coupled three-dimensional neutron-kinetics and thermal-hydraulics. The results show that, the coupled modeling method is reliable and can be used to establish the thermo-hydraulic model of a reactor core. By this method, both the effects of heating power and inlet temperature on flow distribution have been studied. The flow and power distributions of reactor core are inseparable and have a great effect on each other under the strong coupling of thermal-hydraulic and neutronics, but the non-uniformity of power distribution is greater than flow distribution. When reactor core inlet temperature distribution is uneven, reactor power peaking factor shifts to the low inlet temperature region, and flow peaking factor shifts to the high inlet temperature region. The effect of uneven core inlet temperature on flow distribution has a far greater impact than reactor power.

  19. Combination of liquid-phase hollow fiber membrane microextraction with gas chromatography-negative chemical ionization mass spectrometry for the determination of dichlorophenol isomers in water and urine.

    Science.gov (United States)

    Lai, Bin-Wei; Liu, Bo-Min; Malik, Pradip K; Wu, Hui-Fen

    2006-08-18

    A method for the determination of trace amount of dichlorophenol isomers in urine samples using the combination of liquid-phase hollow fiber microextraction (LPME-HF) with gas chromatography-negative chemical ionization mass spectrometry (GC-NCI-MS) has been demonstrated. The method has been optimized with respect to several parameters including the effects of negative chemical ionization (NCI) reagent pressure, the hollow fiber length, extraction time, stirring rate, sample pH and salt concentration for the determination of dichlorophenol isomers in water. The correlation coefficient (r2) of the calibration curves for 2,5-dichlorophenol, 2,3-dichlorophenol, 2,6-dichlorophenol, 3,5-dichlorophenol and 3,4-dichlorophenol were 0.988, 0.981, 0.985, 0.971 and 0.994, respectively. The average recovery rates for 2,5-dichlorophenol, 2,3-dichlorophenol, 2,6-dichlorophenol, 3,5-dichlorophenol and 3,4-dichlorophenol were 0.97, 0.93, 0.96, 0.95 and 0.95, respectively (n=3 for each dichlorophenol) indicate that the methodology is feasible for the determination of trace amounts of dichlorophenol isomers in water and urine samples. Limits of detection (LOD) have been found to be in the range of 5-20 ng/ml. In addition, differentiation of the five dichlorophenol isomers is an easy task using the current approach of combining LPME-HF with NCI-GC-MS technique since they exhibit different NCI spectra.

  20. New Types of Ionization Sources for Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-12-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle (Contractor) and MDS Sciex (Participant) and ESA, Inc. (Participant) is to research, develop and apply new types of ionization sources and sampling/inlet systems for analytical mass spectrometry making use of the Participants state-of-the-art atmospheric sampling mass spectrometry electrochemical cell technology instrumentation and ancillary equipment. The two overriding goals of this research project are: to understand the relationship among the various instrumental components and operational parameters of the various ion sources and inlet systems under study, the chemical nature of the gases, solvents, and analytes in use, and the nature and abundances of the ions ultimately observed in the mass spectrometer; and to develop new and better analytical and fundamental applications of these ion sources and inlet systems or alternative sources and inlets coupled with mass spectrometry on the basis of the fundamental understanding obtained in Goal 1. The end results of this work are expected to be: (1) an expanded utility for the ion sources and inlet systems under study (such as the analysis of new types of analytes) and the control or alteration of the ionic species observed in the gas-phase; (2) enhanced instrument performance as judged by operational figures-of-merit such as dynamic range, detection limits, susceptibility to matrix signal suppression and sensitivity; and (3) novel applications (such as surface sampling with electrospray) in both applied and fundamental studies. The research projects outlined herein build upon work initiated under the previous CRADA between the Contractor and MDS Sciex on ion sources and inlet systems for mass spectrometry. Specific ion source and inlet systems for exploration of the fundamental properties and practical implementation of these principles are given.

  1. Seasonal dynamics of adjoining tidal coastal inlet on east coast of India ­measurements and modelling

    Digital Repository Service at National Institute of Oceanography (India)

    Jayakumar, S.; Reddy, N.A.; Ramanamurty, M.V.; ManiMurali, R.; ArunaKumar, A.; Rao, S.

    of these two inlets is carried out using satellite images and GIS. Field investigations are carried out on the hydrodynamics inside the inlet comprising of water level variations and flow dynamics. Nearshore wave information is obtained by transforming...

  2. On the question of starting conditions for frontal axisymmetric inlets tested in hot-shot wind tunnels

    Science.gov (United States)

    Gounko, Yu. P.; Mazhul, I. I.

    2017-05-01

    The work presents the results of an analysis of starting conditions for some frontal axisymmetric inlets of internal compression tested at freestream Mach numbers M = 3-8.4 in the hot-shot wind tunnels based at Khristianovich Institute of Theoretical and Applied Mechanics (ITAM). The results of these inlets test are compared with the data of numerical computations of inviscid, laminar, and turbulent flows carried out by the pseudo-unsteady method. There were determined the inlet throat areas limiting either with regard to the inlet starting or with regard to providing the maximally possible degree of geometric compression of the inlet-captured supersonic airstream at its deceleration in the already started inlet. Reshaping of computed flow patterns in the inlets depending on the variation of the minimal cross section of the inlet internal duct is analyzed.

  3. An experimental study of the air humidification process using a membrane contactor

    Directory of Open Access Journals (Sweden)

    Englart Sebastian

    2017-01-01

    Full Text Available The article presents the results of the experimental examination of the effectiveness of air humidification using a membrane module. The construction of the membrane module and the measuring stand is also discussed. In order to assess the effectiveness of air humidification using the membrane module, the measurements of temperature and humidity at the membrane module’s inlet and outlet, air flow rate, water flow rate and water temperature were taken. Based on the measurements, the effectiveness coefficients, E, have been determined. The power demand for the solution under study has also been discussed.

  4. Concentration gradient driven molecular dynamics: a new method for simulations of membrane permeation and separation.

    Science.gov (United States)

    Ozcan, Aydin; Perego, Claudio; Salvalaglio, Matteo; Parrinello, Michele; Yazaydin, Ozgur

    2017-05-01

    In this study, we introduce a new non-equilibrium molecular dynamics simulation method to perform simulations of concentration driven membrane permeation processes. The methodology is based on the application of a non-conservative bias force controlling the concentration of species at the inlet and outlet of a membrane. We demonstrate our method for pure methane, ethane and ethylene permeation and for ethane/ethylene separation through a flexible ZIF-8 membrane. Results show that a stationary concentration gradient is maintained across the membrane, realistically simulating an out-of-equilibrium diffusive process, and the computed permeabilities and selectivity are in good agreement with experimental results.

  5. Low stoichiometry operation of a proton exchange membrane fuel cell employing the interdigitated flow field

    DEFF Research Database (Denmark)

    Berning, Torsten; Kær, Søren Knudsen

    2012-01-01

    A multiphase fuel cell model based on computational fluid dynamics is used to investigate the possibility of operating a proton exchange membrane fuel cell at low stoichiometric flow ratios (ξ < 1.5) employing the interdigitated flow field design and using completely dry inlet gases. A case study...

  6. Southern Salish Sea Habitat Map Series: Admiralty Inlet

    Science.gov (United States)

    Cochrane, Guy R.; Dethier, Megan N.; Hodson, Timothy O.; Kull, Kristine K.; Golden, Nadine E.; Ritchie, Andrew C.; Moegling, Crescent; Pacunski, Robert E.; Cochrane, Guy R.

    2015-01-01

    In 2010 the Environmental Protection Agency, Region 10 initiated the Puget Sound Scientific Studies and Technical Investigations Assistance Program, designed to support research in support of implementing the Puget Sound Action Agenda. The Action Agenda was created in response to Puget Sound having been designated as one of 28 estuaries of national significance under section 320 of the U.S. Clean Water Act, and its overall goal is to restore the Puget Sound Estuary's environment by 2020. The Southern Salish Sea Mapping Project was funded by the Assistance Program request for proposals process, which also supports a large number of coastal-zone- and ocean-management issues. The issues include the recommendations of the Marine Protected Areas Work Group to the Washington State Legislature (Van Cleve and others, 2009), which endorses a Puget Sound and coast-wide marine conservation needs assessment, gap analysis of existing Marine Protected Areas (MPA) and recommendations for action. This publication is the first of four U.S. Geological Survey Scientific Investigation Maps that make up the Southern Salish Sea Mapping Project. The remaining three map blocks to be published in the future, located south of Admiralty Inlet, are shown in figure 1.

  7. Laminar Flow Through Circular Tubes with Side Inlets

    Science.gov (United States)

    Abedian, Behrouz; Muhlanger, Eric

    2004-11-01

    We discuss experimental results on steady axisymmetric flow of a Newtonian incompressible fluid through circular pipes with side inlets. Circular tubes with a set of holes along their sidewalls are used in a number of medical procedures as straight catheters to transfer fluid into or out of the human body. For example, because of the small size of the incision required, they are commonly used in peritoneal dialysis. The internal diameter and the diameter of the side holes are often 1 mm and less, and as a result, the fluid flow is laminar in a typical medical procedure. An understanding of the flow inside the catheter tube in terms of its geometric parameters will be key in designing new catheters with optimal clinical performance for specific applications. In the experiments, water is withdrawn from a smooth tube with side holes and the local axial pressure and flow rates through the side holes are measured for different flow conditions. A nondimensionalization of the data shows a power-law behavior in only some cases. Using numerical simulations, it is shown how the interaction of the axial flow with the impinging jets from the side holes can change the overall behavior of the flow for a given suction pressure.

  8. Thermal response of a turbulent premixed flame to the imposed inlet oscillating velocity

    International Nuclear Information System (INIS)

    Hajialigol, N.; Mazaheri, Kiumars

    2017-01-01

    Thermal response is known as thermal behavior of an unstable combustor. Such investigation, which has not been found in the literature, is important in terms of safety and prevention of the structural failure. In this study, the thermal response of a combustor with an inlet excitation is numerically investigated. Due to the geometry shape, two recirculating zones are found. Any change in the amplitude and frequency can affect these recirculation zones. At low fixed frequencies (below 50 Hz) and with a change in the amplitude, these two recirculation zones have no important influence on the heat release. Thus, at the low frequencies, excitation amplitude has no considerable effect on flame transfer function. For both adiabatic and convective cases, at fixed frequency, when amplitude increases, mass flow rate from cold to hot gases increases and this makes a reduction in the maximum temperature. Further, at a contestant amplitude, with increasing the frequency, the maximum temperature reduces, with a higher reduction for convective case. The physical interpretation of observed changes is sought in the relation between hydrodynamic and thermal field, relative length of combustor respect to the acoustic wavelength and so on. - Highlights: • Flame transfer function value reduces with raising amplitude. • Any change in the exciting acoustic waves can affect recirculation zones. • At low frequencies, raising amplitude has no important effect on thermal response. • Temperature reduction, caused by raising amplitude, is larger in convective cases.

  9. Study on the design of inlet and exhaust system of a stationary internal combustion engine

    International Nuclear Information System (INIS)

    Kesgin, Ugur

    2005-01-01

    The design and operational variables of inlet and exhaust systems are decisive to determine overall engine performance. The best engine overall performance can be obtained by proper design of the engine inlet and exhaust systems and by matching the correct turbocharger to the engine. This paper presents the results of investigations to design the inlet and exhaust systems of a stationary natural gas engine family. To do this, a computational model is verified in which zero dimensional phenomena within the cylinder and one dimensional phenomena in the engine inlet and exhaust systems are used. Using this engine model, the effects of the parameters of the inlet and exhaust systems on the engine performance are obtained. In particular, the following parameters are chosen: valve timing, valve diameter, valve lift profiles, diameter of the exhaust manifold, inlet and exhaust pipe lengths, and geometry of pipe junctions. Proper sizing of the inlet and exhaust pipe systems is achieved very precisely by these investigations. Also, valve timing is tuned by using the results obtained in this study. In general, a very high improvement potential for the engines studied here is presented

  10. Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

    Science.gov (United States)

    Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

    2002-01-01

    A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

  11. Experimental Investigation of a Forward Swept Rotor in a Multistage Fan with Inlet Distortion

    Directory of Open Access Journals (Sweden)

    Aspi R. Wadia

    2011-01-01

    Full Text Available Previous studies of transonic swept rotors in single stage fans have demonstrated the potential of significant improvements in both efficiency and stall margin with forward swept blading. This paper extends the assessment of the payoff derived from forward sweep to multistage configurations. The experimental investigation compare two builds of an advanced two-stage fan configuration tested alternately with a radial and a forward swept stage 1 blade. In the two-stage evaluations, the testing was extended to include the effect on inlet flow distortion. While the common second stage among the two builds prevented the overall fan from showing clean inlet performance and stability benefits with the forward swept rotor 1, this configuration did demonstrate superior front stage efficiency and tolerance to inlet distortion. Having obtained already low distortion sensitivity with the radial rotor 1 configuration relative to current production military fan standards, the sensitivity to inlet distortion was halved with the forward swept rotor 1 configuration. In the case of the 180-degree one-per-rev distortion pattern, the two-stage configuration was evaluated both with and without inlet guide vanes (IGVs. The presence of the inlet guide vanes had a profound impact in lowering the two-stage fan's sensitivity with inlet distortion.

  12. Effect of piano-key shape inlet on critical submergence at a vertical pipe intake

    International Nuclear Information System (INIS)

    Shemshi, R; Kabiri-Samani, A

    2012-01-01

    Intake vortices are the result of angular momentum conservation at the flow constriction, where angular velocity increases with a decrease in the cross sectional area. The common solution for avoiding air-entrainment and swirl is to provide sufficient submergence to the intake. If the required approach flow conditions can not be met to avoid swirl and air entrainment, other approaches for preventing vortices at water intakes are considered. There are several means of avoiding air-entrainment, where the most cost-effective option is often determined by a physical model study. Among the most economical and common measures of reducing the effect of air-entrainment and swirl strength, is the optimized shape of inlet for instance by installing a Piano-Key inlet over the pipe intake. If Piano-Key inlet is used, then, its' optimum geometry should be studied experimentally. Since there is not any realized guidance for the use of Piano-Key inlets in pipe intakes, hence, a comprehensive set of model experiments have been carried out using Piano-Key inlets with different dimensions, with respect to the vertical pipe intakes, and four different pipe diameters of (D=) 75, 100, 125 and 150 mm. Results showed that by employing a Piano-Key inlet over the vertical pipe intake, the critical submergence reduces significantly. Fianally, according to the results, the effect of Piano-Key inlet geometry on critical submergence were evaluated in the form of realized relationships which would be of practical interest for design engineers.

  13. Identification of chemical warfare agents from vapor samples using a field-portable capillary gas chromatography/membrane-interfaced electron ionization quadrupole mass spectrometry instrument with Tri-Bed concentrator.

    Science.gov (United States)

    Nagashima, Hisayuki; Kondo, Tomohide; Nagoya, Tomoki; Ikeda, Toru; Kurimata, Naoko; Unoke, Shohei; Seto, Yasuo

    2015-08-07

    A field-portable gas chromatograph-mass spectrometer (Hapsite ER system) was evaluated for the detection of chemical warfare agents (CWAs) in the vapor phase. The system consisted of Tri-Bed concentrator gas sampler (trapping time: 3s(-1)min), a nonpolar low thermal-mass capillary gas chromatography column capable of raising temperatures up to 200°C, a hydrophobic membrane-interfaced electron ionization quadrupole mass spectrometer evacuated by a non-evaporative getter pump for data acquisition, and a personal computer for data analysis. Sample vapors containing as little as 22μg sarin (GB), 100μg soman (GD), 210μg tabun (GA), 55μg cyclohexylsarin (GF), 4.8μg sulfur mustard, 390μg nitrogen mustard 1, 140μg of nitrogen mustard 2, 130μg nitrogen mustard 3, 120μg of 2-chloroacetophenone and 990μg of chloropicrin per cubic meter could be confirmed after Tri-Bed micro-concentration (for 1min) and automated AMDIS search within 12min. Using manual deconvolution by background subtraction of neighboring regions on the extracted ion chromatograms, the above-mentioned CWAs could be confirmed at lower concentration levels. The memory effects were also examined and we found that blister agents showed significantly more carry-over than nerve agents. Gasoline vapor was found to interfere with the detection of GB and GD, raising the concentration limits for confirmation in the presence of gasoline by both AMDIS search and manual deconvolution; however, GA and GF were not subject to interference by gasoline. Lewisite 1, and o-chlorobenzylidene malononitrile could also be confirmed by gas chromatography, but it was hard to quantify them. Vapors of phosgene, chlorine, and cyanogen chloride could be confirmed by direct mass spectrometric detection at concentration levels higher than 2, 140, and 10mg/m(3) respectively, by bypassing the micro-concentration trap and gas chromatographic separation. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Application of heated inlet extensions to the TSI 3306/3321 system: comparison with the Andersen cascade impactor and next generation impactor.

    Science.gov (United States)

    Myrdal, Paul B; Mogalian, Erik; Mitchell, Jolyon; Nagel, Mark; Wright, Charlie; Kiser, Brent; Prell, Mark; Woessner, Mike; Stein, Stephen W

    2006-01-01

    Pharmaceutical aerosol size distribution analysis based on multi-stage inertial impaction is well accepted, though laborious. The TSI 3306 Impactor Inlet/3321 time-of-flight (TOF) Aerodynamic Particle Size Analyzer (APS) has been evaluated for its ease of use and potential for time savings during product development. However, instrument inlet modifications may be necessary for increased correlation with equivalent measurements obtained by inertial impaction following pharmacopeial methods. A heated inlet extension tube was located between the USP/Ph.Eur. throat and the Single-Stage Impactor (SSI) to promote evaporation of residual ethanol from aerosol droplets, generated from two formulations containing ethanol as semi-volatile solubilizer (8 and 20% w/w) for the active pharmaceutical ingredient. As temperature and extension length increased, the SSI-measured fine particle fraction (aerosol < 4.7 microm aerodynamic diameter) also increased, for the aerosols used in this study. These values correlated quite closely with equivalent measures made by multi-stage cascade impactor equipped with the same throat. Particle size distribution profiles measured with the APS for either formulation did not significantly change utilizing the heated extensions, suggesting that ethanol evaporation was largely complete at any condition by the time the aerosol entered the measurement zone of the TOF analyzer. The addition of a heated inlet extension may be useful to facilitate evaporation of residual semi-volatile species, especially when an agreement of APS-derived particle size mass distribution data from the SSI with multi-stage cascade impactors is desired. However, complete evaporation of the semi-volatile species may not be necessary for SSI-generated mass distribution to match conventionally used cascade impactors.

  15. 49 CFR 195.413 - Underwater inspection and reburial of pipelines in the Gulf of Mexico and its inlets.

    Science.gov (United States)

    2010-10-01

    ... the Gulf of Mexico and its inlets. 195.413 Section 195.413 Transportation Other Regulations Relating... Maintenance § 195.413 Underwater inspection and reburial of pipelines in the Gulf of Mexico and its inlets. (a... shall prepare and follow a procedure to identify its pipelines in the Gulf of Mexico and its inlets in...

  16. 49 CFR 192.612 - Underwater inspection and reburial of pipelines in the Gulf of Mexico and its inlets.

    Science.gov (United States)

    2010-10-01

    ... the Gulf of Mexico and its inlets. 192.612 Section 192.612 Transportation Other Regulations Relating... Mexico and its inlets. (a) Each operator shall prepare and follow a procedure to identify its pipelines in the Gulf of Mexico and its inlets in waters less than 15 feet (4.6 meters) deep as measured from...

  17. Background-Oriented Schlieren used in a hypersonic inlet test at NASA GRC

    Science.gov (United States)

    Clem, Michelle; Woike, Mark; Saunders, John

    2016-01-01

    Background Oriented Schlieren (BOS) is a derivative of the classical schlieren technology, which is used to visualize density gradients, such as shock wave structures in a wind tunnel. Changes in refractive index resulting from density gradients cause light rays to bend, resulting in apparent motion of a random background pattern. The apparent motion of the pattern is determined using cross-correlation algorithms (between no-flow and with-flow image pairs) producing a schlieren-like image. One advantage of BOS is its simplified setup which enables a larger field-of-view (FOV) than traditional schlieren systems. In the present study, BOS was implemented into the Combined Cycle Engine Large-Scale Inlet Mode Transition Experiment (CCE LIMX) in the 10x10 Supersonic Wind Tunnel at NASA Glenn Research Center. The model hardware for the CCE LIMX accommodates a fully integrated turbine based combined cycle propulsion system. To date, inlet mode transition between turbine and ramjet operation has been successfully demonstrated. High-speed BOS was used to visualize the behavior of the flow structures shock waves during unsteady inlet unstarts, a phenomenon known as buzz. Transient video images of inlet buzz were recorded for both the ramjet flow path (high speed inlet) and turbine flow path (low speed inlet). To understand the stability limits of the inlet, operation was pushed to the point of unstart and buzz. BOS was implemented in order to view both inlets simultaneously, since the required FOV was beyond the capability of the current traditional schlieren system. An example of BOS data (Images 1-6) capturing inlet buzz are presented.

  18. Air Motion and Thermal Environment in Pig Housing Facilities with Diffuse Inlet

    DEFF Research Database (Denmark)

    Jacobsen, Lis

    in ambient temperature and air exchange rate. The effect of housing equipment on environmental conditions has been examined both experimental and numerically and it was found that impervious housing equipment has a significant effect on the climatic conditions close to the wall in the occupational zone....... The wind tunnel experiments show that the diffuse material works as a heat exchanger and preheats the inlet air if the temperature in the room is higher than the inlet air. The result of the experiment is that the heat exchanging function of the inlet boundary surface is dependent on flow velocity...

  19. Feasibility Report on Navigation Improvements for Mexico Beach Inlet, Mexico Beach, Florida.

    Science.gov (United States)

    1989-03-01

    Inlet March 1989 Mexico Beach, Florida S. PERFORMING Ono. REPORT NUNSCR 7. AtjTHOR(s) 11- CONTRACT Oft GRANT NUMB5ER(.) Halter W. Burdin Kenneth P...seemed to offer a solution to some of the problems at Mexico Beach inlet. Preliminary design was performed using the principles of good jetty design...COESAM/PDFC-89/02 FEASIBILITY REPORT ON NAVIGATION IMPROVEMENTS 6.4 FOR MEXICO BEACH INLET MEXICO BEACH, FLORIDA %1 4Y 2 1 US Army Corps AMRH18 of

  20. Robotic membranes

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette

    2008-01-01

    , Vivisection and Strange Metabolisms, were developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts in Copenhagen as a means of engaging intangible digital data with tactile physical material. As robotic membranes, they are a dual examination...

  1. Screening therapeutics according to their uptake across the blood-brain barrier: A high throughput method based on immobilized artificial membrane liquid chromatography-diode-array-detection coupled to electrospray-time-of-flight mass spectrometry.

    Science.gov (United States)

    Russo, Giacomo; Grumetto, Lucia; Szucs, Roman; Barbato, Francesco; Lynen, Frederic

    2018-02-07

    The Blood-Brain Barrier (BBB) plays an essential role in protecting the brain tissues against possible injurious substances. In the present work, 79 neutral, basic, acidic and amphoteric structurally unrelated analytes were considered and their chromatographic retention coefficients on immobilized artificial membrane (IAM) stationary phase were determined employing a mass spectrometry (MS) -compatible buffer based on ammonium acetate. Their BBB passage predictive strength was evaluated and the statistical models based on IAM indexes and in silico physico-chemical descriptors showed solid statistics (r 2 (n-1) = 0.78). The predictive strength of the indexes achieved by the MS-compatible method was comparable to that achieved by employing the more "biomimetic" Dulbecco's phosphate buffered saline, even if some differences in the elution order were observed. The method was transferred to the MS, employing a diode-array-detection coupled to an electrospray ionization source and a time-of-flight analyzer. This setup allowed the simultaneous analysis of up to eight analytes, yielding a remarkable acceleration of the analysis time. Copyright © 2018. Published by Elsevier B.V.

  2. Development of an analytical method coupling cell membrane chromatography with gas chromatography-mass spectrometry via microextraction by packed sorbent and its application in the screening of volatile active compounds in natural products.

    Science.gov (United States)

    Li, Miao; Wang, Sicen; He, Langchong

    2015-01-01

    Natural products (NPs) are important sources of lead compounds in modern drug discovery. To facilitate the screening of volatile active compounds in NPs, we have developed a new biochromatography method that uses rat vascular smooth muscle cells (VSMC), which are rich in L-type calcium channels (LCC), to prepare the stationary phase. This integrated method, which couples cell membrane chromatography (CMC) with gas chromatography-mass spectrometry (GC-MS) via microextraction by packed sorbent (MEPS) technology, has been termed VSMC/CMC-MEPS-GC-MS. Methodological validation confirmed its specificity, reliability and convenience. Screening results for Radix Angelicae Dahuricae and Fructus Cnidii obtained using VSMC/CMC-MEPS-GC-MS were consistent with those obtained using VSMC/CMC-offline-GC-MS. MEPS connection plays as simplified solid-phase extraction and replaces the uncontrollable evaporation operation in reported offline connections, so our new method is supposed to be more efficient and reliable than the offline ones, especially for compounds that are volatile, thermally unstable or difficult to purify. In application, senkyunolide A and ligustilide were preliminary identified as the volatile active components in Rhizoma Chuanxiong. We have thus confirmed the suitability of VSMC/CMC-MEPS-GC-MS for volatile active compounds screening in NP. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Membrane Assisted Enzyme Fractionation

    DEFF Research Database (Denmark)

    Yuan, Linfeng

    . In this thesis, separations using crossflow elecro-membrane filtration (EMF) of amino acids, bovine serum albumin (BSA) and industrial enzymes from Novozymes were performed. The main objective of this study was to investigate the technological feasibility of EMF in the application of industrial enzyme...... fractionation, such as removal of a side activity from the main enzyme activity. As a proof-of-concept, amino acids were used as model solution to test the feasibility of EMF in the application of amphoteric molecule separation. A single amino acid was used to illustrate the effect of an electric field...... on the separation performance were very small in the investigated range. The mass transport of each enzyme can be well explained by the Extended-Nernst-Planck equation. Better separation was observed at lower feed concentration, higher solution pH in the investigated range and with a polysulfone (PS) MF membrane...

  4. Cook Inlet and Kenai Peninsula, Alaska ESI: RIPS (Rip Current Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains locations of rip currents in Cook Inlet, Alaska. Vector lines in the data set represent rip zone locations. Location-specific type and source...

  5. Fundamental Aeronautics Program: Supersonics Project - Channeled Center-Body Inlet Experiment Overview

    Science.gov (United States)

    St. John, Clint; Ratnayake, Nalin A.; Frederick, Mike

    2012-01-01

    The presentation describes supersonic flight testing accomplished on a novel mixed-compression axisymmetric inlet utilizing channels for off-design flow matching rather than a translating centerbody concept.

  6. Scramjet Inlet Control by Off-Body Energy Addition and MHD Deceleration

    National Research Council Canada - National Science Library

    Macheret, Sergey O; Shneider, Mikhail N; Miles, Richard B; Van Wie, David

    2003-01-01

    ...; however, interelectrode arcing may limit the performance. The paper also analyzes MHD control of shock incidence, and air capture increase using energy addition (a "virtual cowl") in scramjet inlets...

  7. Miniaturized In Situ Atmospheric Probe Sampling Inlet System for Uranus or Saturn, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a miniaturized in situ atmospheric probe sampling inlet system for measuring chemical and isotopic composition of the...

  8. Environmental Sensitivity Index (ESI) Atlas: Cook Inlet, Alaska, maps and geographic information systems (NODC Accession 0046027)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) data for Cook Inlet and Kenai Peninsula, Alaska. ESI data characterize estuarine environments and...

  9. Cook Inlet and Kenai Peninsula, Alaska ESI: ICE (Ice Extent Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains locations of ice extent in Cook Inlet, Alaska. Vector lines in the data set represent 50 percent ice coverage. Location-specific type and...

  10. Experimental and Computational Investigation of Flow in a Transonic Compressor Inlet

    National Research Council Canada - National Science Library

    Brunner, Matthew D

    2005-01-01

    .... The data for Mach number were compared to data obtained with a three-hole probe. A numerical investigation of the flow in the inlet ducting to the rotor was also initiated using the commercial code CFX marketed by ANSYS...

  11. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high-speed civil aircraft will require breakthrough developments in propulsion systems, including novel techniques to optimize inlet...

  12. Shinnecock Inlet, New York, Site Investigation. Report 2: Evaluation of Sand Bypass Options

    National Research Council Canada - National Science Library

    Williams, Gregory

    1998-01-01

    .... This report discusses the geologic history of the inlet and using the results of a coastal processes study, evaluates ebb shoal morphology and longshore transport processes as they relate to sand management (bypass) options...

  13. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high-speed civil aircraft will require breakthrough developments in propulsion systems, including novel techniques to optimize inlet...

  14. Telemetry data from satellite tags deployed on harbor seals in Cook Inlet, Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Between 2004 and 2006 we conducted four harbor seal tagging trips in Cook Inlet during the months of October and May. In total, we captured and released 93 harbor...

  15. AFSC/NMML: Cook Inlet Beluga Opportunistic Sightings, 1975 to 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — As a part of National Marine Fisheries Service (NMFS) management of the endangered Cook Inlet beluga whale population, a database of opportunistic beluga whale...

  16. Cook Inlet Beluga Opportunistic Sightings, 1975 to 2015 (NCEI Accession 0142326)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — As a part of National Marine Fisheries Service (NMFS) management of the endangered Cook Inlet beluga whale population, a database of opportunistic beluga whale...

  17. CREEK Project's Oyster Biomass Database for Eight Creeks in the North Inlet Estuary, South Carolina

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — A group of eight tidal creeks dominated by oysters, Crassostrea virginica, in North Inlet Estuary, South Carolina, USA were studied using a replicated BACI (Before -...

  18. Miniaturized, Low Power Cryogenic Inlet System with Sampling Probes for Titan, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a miniature, low power cryogenic inlet system with sampling probes for Titan. This addresses a key technology gap for...

  19. Cook Inlet and Kenai Peninsula, Alaska ESI: M_MAMPT (Marine Mammal Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for seals and sea lions in Cook Inlet and Kenai Peninsula, Alaska. Vector points in this data set represent locations...

  20. Empirical method to calculate Clinch River Breeder Reactor (CRBR) inlet plenum transient temperatures

    International Nuclear Information System (INIS)

    Howarth, W.L.

    1976-01-01

    Sodium flow enters the CRBR inlet plenum via three loops or inlets. An empirical equation was developed to calculate transient temperatures in the CRBR inlet plenum from known loop flows and temperatures. The constants in the empirical equation were derived from 1/4 scale Inlet Plenum Model tests using water as the test fluid. The sodium temperature distribution was simulated by an electrolyte. Step electrolyte transients at 100 percent model flow were used to calculate the equation constants. Step electrolyte runs at 50 percent and 10 percent flow confirmed that the constants were independent of flow. Also, a transient was tested which varied simultaneously flow rate and electrolyte. Agreement of the test results with the empirical equation results was good which verifies the empirical equation

  1. Cook Inlet and Kenai Peninsula, Alaska ESI: HYDRO (Hydrography Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing coastal hydrography used in the creation of the Environmental Sensitivity Index (ESI) for Cook Inlet...

  2. AFSC/NMML: Beluga whale aerial survey in Cook Inlet, Alaska, 1993-2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Fisheries Service (NMFS) has conducted aerial counts of Cook Inlet beluga whales (Delphinapterus leucas) from 1993 to 2014 (excluding 2013)....

  3. Classification of tidal inlets along the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Vikas, M.; Reddy, N.A.; Rao, S.; JayaKumar, S.

    considering mean annual significant wave height. The classification is also extended considering significant wave heights obtained for South-West monsoon, North-East monsoon and Fair Weather seasons. It has been observed that 74% of the inlets are tide...

  4. Miniaturized, Low Power Cryogenic Inlet System with Sampling Probes for Titan, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. has demonstrated feasibility in Phase 1 and now proposes a Phase 2 effort to develop a miniature, low power cryogenic inlet system with...

  5. AFSC/NMML: Beluga whale Counts from Aerial Surveys in Cook Inlet, Alaska, 1993-2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Mammal Laboratory conducted aerial surveys to monitor the abundance and distribution of beluga whales in Cook Inlet, Alaska. This database...

  6. Membranes and theoretical modeling of membrane distillation: a review.

    Science.gov (United States)

    Khayet, Mohamed

    2011-05-11

    Membrane distillation (MD) is one of the non-isothermal membrane separation processes used in various applications such desalination, environmental/waste cleanup, food, etc. It is known since 1963 and is still being developed at laboratory stage for different purposes and not fully implemented in industry. An abrupt increase in the number of papers on MD membrane engineering (i.e. design, fabrication and testing in MD) is seen since only 6 years ago. The present paper offers a comprehensive MD state-of-the-art review covering a wide range of commercial membranes, MD membrane engineering, their MD performance, transport mechanisms, experimental and theoretical modeling of different MD configurations as well as recent developments in MD. Improved MD membranes with specific morphology, micro- and nano-structures are highly demanded. Membranes with different pore sizes, porosities, thicknesses and materials as well as novel structures are required in order to carry out systematic MD studies for better understanding mass transport in different MD configurations, thereby improving the MD performance and looking for MD industrialization. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Integral Membrane Proteins and Bilayer Proteomics

    OpenAIRE

    Whitelegge, Julian P.

    2013-01-01

    Integral membrane proteins reside within the bilayer membranes that surround cells and organelles, playing critical roles in movement of molecules across them and the transduction of energy and signals. While their extreme amphipathicity presents technical challenges, biological mass spectrometry has been applied to all aspects of membrane protein chemistry and biology, including analysis of primary, secondary, tertiary and quaternary structure, as well as the dynamics that accompany function...

  8. Integral membrane proteins and bilayer proteomics.

    Science.gov (United States)

    Whitelegge, Julian P

    2013-03-05

    Integral membrane proteins reside within the bilayer membranes that surround cells and organelles, playing critical roles in movement of molecules across them and the transduction of energy and signals. While their extreme amphipathicity presents technical challenges, biological mass spectrometry has been applied to all aspects of membrane protein chemistry and biology, including analysis of primary, secondary, tertiary, and quaternary structures as well as the dynamics that accompany functional cycles and catalysis.

  9. New River Inlet DRI: Observations and Modeling of Flow and Material Exchange

    Science.gov (United States)

    2012-09-30

    Figure 2). NRI is a shallow-water, frictional estuary that connects to the ocean via a 5 km long, narrow channel to the back bay. NRI is considered...Inlet ( NRI ), the technique can be applied to any inlet. Residence time can be thought of as the average time a volume of water will remain entrained...from NRI , this approach will provide a baseline with which to examine the importance of various physical processes on tidal exchange and residence

  10. The concept of double inlet-double outlet right ventricle: a distinct congenital heart disease

    OpenAIRE

    Spadotto, V; Frescura, C; Ho, SY; Thiene, G

    2016-01-01

    The aim of this study was to estimate the incidence and to analyze the anatomy of double inlet-double outlet right ventricle complex and its associated cardiac anomalies in our autopsy series. Among the 1640 hearts with congenital heart disease of our Anatomical Collection, we reviewed the specimens with double inlet-double outlet right ventricle, according to the sequential-segmental analysis, identifying associated cardiac anomalies and examining lung histology to assess the presence of pul...

  11. Flow Visualization of a Scramjet Inlet - Isolator Model in Supersonic Flow

    Science.gov (United States)

    Seckin, S.; Yuceil, K. B.

    2013-04-01

    Understanding the physical mechanisms and having insight to the complex flowfield involving unstart phenomena in supersonic inlets has gained considerable attention especially in the area of scramjet inlet/isolator aerothermodynamics. In this study, Schlieren visualization and computational analysis of shock wave structures in ramjet/scramjet inlet/isolator models in supersonic flow have been performed. Experiments were performed in the supersonic wind tunnel at the Trisonic Research Laboratory in Istanbul Technical University. The test section floor and the existing mechanism underneath have been modified to be able to mount the designed inlet/isolator model on the floor of the test section. The inlet/isolator model with a 12- degree compression ramp is investigated at Mach 2 both computationally and experimentally. Computations were performed using Star-CCM+ software to investigate shock wave structures in and around the three dimensional inlet/isolator model as mounted on the test section floor as a guide for designing the experimental model. In the results, the effects of shock wave - boundary layer interactions with flow separations with were observed. Ensemble average of the density distributions on a series of planes from one side wall to the other from the CFD results agreed well with the Schlieren images obtained experimentally. The structure of the shock waves and angles obtained from the Schlieren images agree quite well with those obtained from the CFD results. The effects of lambda-shock formations which indicate possible boundary layer separations, reflections of shock waves, and shock wave - boundary layer interactions on inlet unstart phenomena have been discussed. In order to investigate inlet unstart mechanism further, different experimental setups have been suggested for future work.

  12. Performance and Adaptive Surge-Preventing Acceleration Prediction of a Turboshaft Engine under Inlet Flow Distortion

    OpenAIRE

    Cao Dalu; Tang Hailong; Chen Min

    2017-01-01

    The intention of this paper is to research the inlet flow distortion influence on overall performance of turboshaft engine and put forward a method called Distortion Factor Item (DFI) to improve the fuel supply plan for surge-preventing acceleration when turboshaft engine suddenly encounters inlet flow distortion. Based on the parallel compressor theory, steady-state and transition-state numerical simulation model of turboshaft engine with sub-compressor model were established for researching...

  13. Flow Visualization of a Scramjet Inlet – Isolator Model in Supersonic Flow

    Directory of Open Access Journals (Sweden)

    Yuceil K.B.

    2013-04-01

    Full Text Available Understanding the physical mechanisms and having insight to the complex flowfield involving unstart phenomena in supersonic inlets has gained considerable attention especially in the area of scramjet inlet/isolator aerothermodynamics. In this study, Schlieren visualization and computational analysis of shock wave structures in ramjet/scramjet inlet/isolator models in supersonic flow have been performed. Experiments were performed in the supersonic wind tunnel at the Trisonic Research Laboratory in Istanbul Technical University. The test section floor and the existing mechanism underneath have been modified to be able to mount the designed inlet/isolator model on the floor of the test section. The inlet/isolator model with a 12- degree compression ramp is investigated at Mach 2 both computationally and experimentally. Computations were performed using Star-CCM+ software to investigate shock wave structures in and around the three dimensional inlet/isolator model as mounted on the test section floor as a guide for designing the experimental model. In the results, the effects of shock wave – boundary layer interactions with flow separations with were observed. Ensemble average of the density distributions on a series of planes from one side wall to the other from the CFD results agreed well with the Schlieren images obtained experimentally. The structure of the shock waves and angles obtained from the Schlieren images agree quite well with those obtained from the CFD results. The effects of lambda-shock formations which indicate possible boundary layer separations, reflections of shock waves, and shock wave – boundary layer interactions on inlet unstart phenomena have been discussed. In order to investigate inlet unstart mechanism further, different experimental setups have been suggested for future work.

  14. The Effect of Inlet Waveforms on Computational Hemodynamics of Patient-Specific Intracranial Aneurysms

    OpenAIRE

    Xiang, J.; Siddiqui, A.H.; Meng, H.

    2014-01-01

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic qu...

  15. Progress Towards Understanding Fan Inlet Implications of Top-Mounted Propulsion

    Science.gov (United States)

    Friedlander, David

    2017-01-01

    Computational fluid dynamic (CFD) simulations were performed on an N+2 commercial supersonic transport aircraft design that featured top-mounted propulsion. The simulations were run at take-off conditions at both 0 degrees and 8 degrees angle of attack. The results showed little separation in around the inlets with inlet performance on par with an under-the-wing configuration. The next step will be to take these results and determine the acoustic impact of the top-mounted propulsion system.

  16. Development of a solenoid actuated planar valveless micropump with single and multiple inlet-outlet arrangements

    Science.gov (United States)

    Kumar, N.; George, D.; Sajeesh, P.; Manivannan, P. V.; Sen, A. K.

    2016-07-01

    We report a planar solenoid actuated valveless micropump with multiple inlet-outlet configurations. The self-priming characteristics of the multiple inlet-multiple outlet micropump are studied. The filling dynamics of the micropump chamber during start-up and the effects of fluid viscosity, voltage and frequency on the dynamics are investigated. Numerical simulations for multiple inlet-multiple outlet micropumps are carried out using fluid structure algorithm. With DI water and at 5.0 Vp-p, 20 Hz frequency, the two inlet-two outlet micropump provides a maximum flow rate of 336 μl min-1 and maximum back pressure of 441 Pa. Performance characteristics of the two inlet-two outlet micropump are studied for aqueous fluids of different viscosity. Transport of biological cell lines and diluted blood samples are demonstrated; the flow rate-frequency characteristics are studied. Viability of cells during pumping with multiple inlet multiple outlet configuration is also studied in this work, which shows 100% of cells are viable. Application of the proposed micropump for simultaneous pumping, mixing and distribution of fluids is demonstrated. The proposed integrated, standalone and portable micropump is suitable for drug delivery, lab-on-chip and micro-total-analysis applications.

  17. CFD simulation of inlet design effect on deoiling hydrocyclone separation efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Noroozi, S.; Hashemabadi, S.H. [Computational Fluid Dynamics Research Laboratory, School of Chemical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2009-12-15

    An Eulerian-Eulerian three-dimensional CFD model was developed to study the effect of different inlet designs on deoiling hydrocyclone separation efficiency. Reynolds averaged Navier Stokes and continuity equations were applied to solve steady turbulent flow through the cyclone with the Reynolds stress model. In addition, the modified drag correlation for liquid-liquid emulsion with respect to the Reynolds number range and viscosity ratio of two phases was used and the simulation results were compared with those predicted by the Schiller-Naumann correlation. Pressure profile, tangential and axial velocities and separation efficiency of the deoiling hydrocyclone were calculated for four different inlet designs and compared with the standard design. The simulation results for the standard design demonstrate an acceptable agreement with reported experimental data. The results show that all new four inlet designs offer higher efficiencies compared to the standard design. The difference between the efficiency of the LLHC, of the new inlets and the standard design can be improved by increasing the inlet velocity. Furthermore, the simulations show that the separation efficiency can be improved by about 10 % when using a helical form of inlet. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  18. Dynamics of the inlet system of a four-stroke engine

    Science.gov (United States)

    Boden, R H; Schecter, Harry

    1944-01-01

    Tests were run on a single-cylinder and a multicylinder four-stroke engine in order to determine the effect of the dynamics of the inlet system upon indicated mean effective pressure. Tests on the single-cylinder engine were made at various speeds, inlet valve timings, and inlet pipe lengths. These tests indicated that the indicated mean effective pressure could be raised considerably at any one speed by the use of a suitably long inlet pipe. Tests at other speeds with this length of pipe showed higher indicated mean effective pressure than with a very short pipe, although not so high as could be obtained with the pipe length adjusted for each speed. A general relation was discovered between optimum time of inlet valve closing and pipe length; namely, that longer pipes require later inlet valve closing in order to be fully effective. Tests were also made on three cylinders connected to a single pipe. With this arrangement, increased volumetric efficiency at low speed was obtainable by using a long pipe, but only with a sacrifice of volumetric efficiency at high speed. Volumetric efficiency at high speed was progressively lower as the pipe length was increased.

  19. Test results of the reactor inlet coolant temperature control system of HTTR

    International Nuclear Information System (INIS)

    Saito, Kenji; Nakagawa, Shigeaki; Hirato, Yoji

    2004-04-01

    The reactor control system of HTTR is composed of the reactor power control system, the reactor inlet coolant temperature control system, the primary coolant flow rate control system and so on. The reactor control system of HTTR achieves reactor power 30 MW, reactor outlet coolant temperature 850degC, reactor inlet coolant temperature 395degC under the condition that primary coolant flow rate is fixed. In the Rise-to-Power Test, the performance test of the reactor inlet coolant temperature control system was carried out in order to confirm the control capability of this control system. This report shows the test results of performance test. As a result, the control parameters, which can control the reactor inlet coolant temperature stably during the reactor operation, were successfully selected. And it was confirmed that the reactor inlet coolant temperature control system has the capability of controlling the reactor inlet coolant temperature stably against any disturbances on the basis of operational condition of HTTR. (author)

  20. Development of a coupled supersonic inlet-fan Navier–Stokes simulation method

    Directory of Open Access Journals (Sweden)

    Qiushi LI

    2018-02-01

    Full Text Available A coupled supersonic inlet-fan Navier–Stokes simulation method was developed by using COMSOL-CFD code. The flow turning, pressure rise and loss effects across blade rows of the fan and the inlet-fan interactions were taken into account as source terms of the governing equations without a blade geometry by a body force model. In this model, viscous effects in blade passages can also be calculated directly, which include the exchange of momentum between fluids and detailed viscous flow close to walls. NASA Rotor 37 compressor test rig was used to validate the ability of the body force model to estimate the real performance of blade rows. Calculated pressure ratio characteristics and the distribution of the total pressure, total temperature, and swirl angle in the span direction agreed well with experimental and numerical data. It is shown that the body force model is a promising approach for predicting the flow field of the turbomachinery. Then, coupled axisymmetric mixed compression supersonic inlet-fan simulations were conducted at Mach number 2.8 operating conditions. The analysis includes coupled steady-state performance, and effects of the fan on the inlet. The results indicate that the coupled simulation method is capable of simulating behavior of the supersonic inlet-fan system. Keywords: Body force model, Coupled simulation, Rapid numerical method, Supersonic inlet-fan, Viscous flow

  1. Phycocyanin stability in microcapsules processed by spray drying method using different inlet temperature

    Science.gov (United States)

    Purnamayati, L.; Dewi, EN; Kurniasih, R. A.

    2018-02-01

    Phycocyanin is natural blue colorant which easily damages by heat. The inlet temperature of spray dryer is an important parameter representing the feature of the microcapsules.The aim of this study was to investigate the phycocyanin stability of microcapsules made from Spirulina sp with maltodextrin and κ-Carrageenan as the coating material, processed by spray drying method in different inlet temperature. Microcapsules were processed in three various inlet temperaturei.e. 90°C, 110°C, and 130°C, respectively. The results indicated that phycocyanin microcapsule with 90°C of inlet temperature produced the highest moisture content, phycocyanin concentration and encapsulation efficiency of 3,5%, 1,729% and 29,623%, respectively. On the other hand, the highest encapsulation yield was produced by 130°C of theinlet temperature of 29,48% and not significantly different with 110°C. The results of Scanning Electron Microscopy (SEM) showed that phycocyanin microcapsules with 110°C of inlet temperature produced the most rounded shape. To sum up, 110°C was the best inlet temperature to phycocyanin microencapsulation by the spray dryer.

  2. A mathematical model for predicting the life of polymer electrolyte fuel cell membranes subjected to hydration cycling

    Science.gov (United States)

    Burlatsky, S. F.; Gummalla, M.; O'Neill, J.; Atrazhev, V. V.; Varyukhin, A. N.; Dmitriev, D. V.; Erikhman, N. S.

    2012-10-01

    Under typical Polymer Electrolyte Membrane Fuel Cell (PEMFC) fuel cell operating conditions, part of the membrane electrode assembly is subjected to humidity cycling due to variation of inlet gas RH and/or flow rate. Cyclic membrane hydration/dehydration would cause cyclic swelling/shrinking of the unconstrained membrane. In a constrained membrane, it causes cyclic stress resulting in mechanical failure in the area adjacent to the gas inlet. A mathematical modeling framework for prediction of the lifetime of a PEMFC membrane subjected to hydration cycling is developed in this paper. The model predicts membrane lifetime as a function of RH cycling amplitude and membrane mechanical properties. The modeling framework consists of three model components: a fuel cell RH distribution model, a hydration/dehydration induced stress model that predicts stress distribution in the membrane, and a damage accrual model that predicts membrane lifetime. Short descriptions of the model components along with overall framework are presented in the paper. The model was used for lifetime prediction of a GORE-SELECT membrane.

  3. Orifice Mass Flow Calculation in NASA's W-8 Single Stage Axial Compressor Facility

    Science.gov (United States)

    Bozak, Richard F.

    2018-01-01

    Updates to the orifice mass flow calculation for the W-8 Single Stage Axial Compressor Facility at NASA Glenn Research Center are provided to include the effect of humidity and incorporate ISO 5167. A methodology for including the effect of humidity into the inlet orifice mass flow calculation is provided. Orifice mass flow calculations provided by ASME PTC-19.5-2004, ASME MFC-3M-2004, ASME Fluid Meters, and ISO 5167 are compared for W-8's atmospheric inlet orifice plate. Differences in expansion factor and discharge coefficient given by these standards give a variation of about +/- 75% mass flow except for a few cases. A comparison of the calculations with an inlet static pressure mass flow correlation and a fan exit mass flow integration using test data from a 2017 turbofan rotor test in W-8 show good agreement between the inlet static pressure mass flow correlation, ISO 5167, and ASME Fluid Meters. While W-8's atmospheric inlet orifice plate violates the pipe diameter limit defined by each of the standards, the ISO 5167 is chosen to be the primary orifice mass flow calculation to use in the W-8 facility.

  4. Submerged membrane distillation for seawater desalination

    KAUST Repository

    Francis, Lijo

    2014-08-11

    A submerged membrane distillation (SMD) process for fresh water production from Red Sea water using commercially available hollow fiber membranes has been successfully employed and compared with the conventional direct contact membrane distillation (DCMD) process. The hollow fiber membranes have been characterized for its morphology using field effect scanning electron microscope. In SMD process, a bunch of hollow fiber membranes are glued together at both ends to get a simplified open membrane module assembly submerged into the coolant tank equipped with a mechanical stirrer. Hot feed stream is allowed to pass through the lumen side of the membrane using a feed pump. Continuous stirring at the coolant side will reduce the temperature and concentration polarization. During the conventional DCMD process, using feed-coolant streams with co-current and counter-current flows has been tested and the results are compared in this study. In SMD process, a water vapor flux of 10.2 kg m-2 h-1 is achieved when using a feed inlet temperature of 80°C and coolant temperature of 20°C. Under the same conditions, during conventional DCMD process, a water vapor flux of 11.6 and 10.1 kg m-2 h-1 were observed during counter-current and co-current flow streams, respectively. Results show that the water production in the SMD process is comparable with the conventional DCMD process, while the feed-coolant flow streams are in the co-current direction. During conventional DCMD operation, a 15% increase in the water production is observed when feed-coolant streams are in the counter-current direction compared to the co-current direction. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  5. A method for screening active components from Chinese herbs by cell membrane chromatography-offline-high performance liquid chromatography/mass spectrometry and an online statistical tool for data processing.

    Science.gov (United States)

    Cao, Yan; Wang, Shaozhan; Li, Yinghua; Chen, Xiaofei; Chen, Langdong; Wang, Dongyao; Zhu, Zhenyu; Yuan, Yongfang; Lv, Diya

    2018-03-09

    Cell membrane chromatography (CMC) has been successfully applied to screen bioactive compounds from Chinese herbs for many years, and some offline and online two-dimensional (2D) CMC-high performance liquid chromatography (HPLC) hyphenated systems have been established to perform screening assays. However, the requirement of sample preparation steps for the second-dimensional analysis in offline systems and the need for an interface device and technical expertise in the online system limit their extensive use. In the present study, an offline 2D CMC-HPLC analysis combined with the XCMS (various forms of chromatography coupled to mass spectrometry) Online statistical tool for data processing was established. First, our previously reported online 2D screening system was used to analyze three Chinese herbs that were reported to have potential anti-inflammatory effects, and two binding components were identified. By contrast, the proposed offline 2D screening method with XCMS Online analysis was applied, and three more ingredients were discovered in addition to the two compounds revealed by the online system. Then, cross-validation of the three compounds was performed, and they were confirmed to be included in the online data as well, but were not identified there because of their low concentrations and lack of credible statistical approaches. Last, pharmacological experiments showed that these five ingredients could inhibit IL-6 release and IL-6 gene expression on LPS-induced RAW cells in a dose-dependent manner. Compared with previous 2D CMC screening systems, this newly developed offline 2D method needs no sample preparation steps for the second-dimensional analysis, and it is sensitive, efficient, and convenient. It will be applicable in identifying active components from Chinese herbs and practical in discovery of lead compounds derived from herbs. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Modeling of a Membrane-Based Absorption Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Woods, J.; Pellegrino, J.; Kozubal, E.; Slayzak, S.; Burch, J.

    2009-01-01

    In this paper, a membrane heat pump is proposed and analyzed. Fundamentally, the proposed heat pump consists of an aqueous CaCl{sub 2} solution flow separated from a water flow by a vapor-permeable membrane. The low activity of the solution results in a net flux of water vapor across the membrane, which heats the solution stream and cools the water stream. This mechanism upgrades water-side low-temperature heat to solution-side high-temperature heat, creating a 'temperature lift.' The modeling results show that using two membranes and an air gap instead of a single membrane increases the temperature lift by 185%. The model predicts temperature lifts for the air-gap design of 24, 16, and 6 C for inlet temperatures of 55, 35, and 15 C, respectively. Membranes with lower thermal conductivities and higher porosities improve the performance of single-membrane designs while thinner membranes improve the performance of air-gap designs. This device can be used with a solar heating system which already uses concentrated salt solutions for liquid-desiccant cooling.

  7. Removal of arsenic from contaminated groundwater by solar-driven membrane distillation using three different commercial membranes.

    Science.gov (United States)

    Pal, Parimal; Manna, Ajay K

    2010-11-01

    Investigations on solar-driven membrane distillation (SDMD) were carried out for removal of arsenic from contaminated groundwater. Three different types of hydrophobic membranes made of polytetrafluoroethylene (PTFE) and polypropylene (PP) with surface area of 120 × 10(-4)m(2) were used as flat sheet in a direct contact membrane distillation (DCMD) set up in a cross flow module. Effects of initial arsenic concentration in the feed, feed velocity, feed temperature and distillate inlet temperature on arsenic removal efficiency and flux were studied where temperatures of feed and distillate were found to have significant effect on the flux. Almost 100% arsenic separation was achieved without wetting membrane pore even after 120 h of operation. The PTFE membrane with a flux of 49.80 kg/m(2)h was found to the best one out of the tested membranes. The study shows that solar-driven DCMD can effectively separate arsenic from groundwater using a cross flow membrane module with PTFE hydrophobic membrane. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Injector Element which Maintains a Constant Mean Spray Angle and Optimum Pressure Drop During Throttling by Varying the Geometry of Tangential Inlets

    Science.gov (United States)

    Trinh, Huu P. (Inventor); Myers, William Neill (Inventor)

    2014-01-01

    A method for determining the optimum inlet geometry of a liquid rocket engine swirl injector includes obtaining a throttleable level phase value, volume flow rate, chamber pressure, liquid propellant density, inlet injector pressure, desired target spray angle and desired target optimum delta pressure value between an inlet and a chamber for a plurality of engine stages. The tangential inlet area for each throttleable stage is calculated. The correlation between the tangential inlet areas and delta pressure values is used to calculate the spring displacement and variable inlet geometry. An injector designed using the method includes a plurality of geometrically calculated tangential inlets in an injection tube; an injection tube cap with a plurality of inlet slots slidably engages the injection tube. A pressure differential across the injector element causes the cap to slide along the injection tube and variably align the inlet slots with the tangential inlets.

  9. Prediction of Mass Flow Rate in Supersonic Natural Gas Processing

    Directory of Open Access Journals (Sweden)

    Wen Chuang

    2015-11-01

    Full Text Available The mass flow rate of natural gas through the supersonic separator was numerically calculated by various cubic equations of state. The numerical results show that the compressibility factor and specific heat ratio for ideal gas law diverge remarkably from real gas models at a high inlet pressure. Simultaneously, the deviation of mass flow calculated by the ideal and real gas models reaches over 10 %. The difference increases with the lower of the inlet temperature regardless of the inlet pressure. A higher back pressure results in an earlier location of the shock wave. The pressure ratio of 0.72 is the first threshold to get the separator work normally. The second threshold is 0.95, in which case the whole flow is subsonic and cannot reach the choked state. The shock position moves upstream with the real gas model compared to the ideal gas law in the cyclonic separation section.

  10. The development of a completely automated oxygen isotope mass spectrometer

    International Nuclear Information System (INIS)

    Ahern, T.K.

    1980-01-01

    A completely automated mass spectrometer system has been developed to measure the oxygen isotope ratio of carbon dioxide samples. The system has an accuracy of 0.03 percent, and is capable of analyzing more than 100 samples a day. The system uses an Interdata minicomputer as the primary controller. The intelligence of the system is contained within hardware circuits, software within the minicomputer, and firmware written for a Motorola 6802 microprocessor. A microprocessor-based inlet system controller maximizes the throughput of carbon dioxide samples within the inlet system. The inlet system normally contains four different aliquots of carbon dioxide and introduces these samples to the mass spectrometer through a single admittance leak. The system has been used in the analysis of 111 samples of ice taken from the Steele glacier

  11. Ion transport membrane module and vessel system with directed internal gas flow

    Science.gov (United States)

    Holmes, Michael Jerome; Ohrn, Theodore R.; Chen, Christopher Ming-Poh

    2010-02-09

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an inlet adapted to introduce gas into the interior of the vessel, an outlet adapted to withdraw gas from the interior of the vessel, and an axis; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region; and (c) one or more gas flow control partitions disposed in the interior of the pressure vessel and adapted to change a direction of gas flow within the vessel.

  12. Augustine Volcano, Cook Inlet, Alaska (January 12, 2006)

    Science.gov (United States)

    2006-01-01

    Since last spring, the U.S. Geological Survey's Alaska Volcano Observatory (AVO) has detected increasing volcanic unrest at Augustine Volcano in Cook Inlet, Alaska near Anchorage. Based on all available monitoring data, AVO regards that an eruption similar to 1976 and 1986 is the most probable outcome. During January, activity has been episodic, and characterized by emission of steam and ash plumes, rising to altitudes in excess of 9,000 m (30,000 ft), and posing hazards to aircraft in the vicinity. An ASTER image was acquired at 12:42 AST on January 12, 2006, during an eruptive phase of Augustine. The perspective rendition shows the eruption plume derived from the ASTER image data. ASTER's stereo viewing capability was used to calculate the 3-dimensional topography of the eruption cloud as it was blown to the south by prevailing winds. From a maximum height of 3060 m (9950 ft), the plume cooled and its top descended to 1900 m (6175 ft). The perspective view shows the ASTER data draped over the plume top topography, combined with a base image acquired in 2000 by the Landsat satellite, that is itself draped over ground elevation data from the Shuttle Radar Topography Mission. The topographic relief has been increased 1.5 times for this illustration. Comparison of the ASTER plume topography data with ash dispersal models and weather radar data will allow the National Weather Service to validate and improve such models. These models are used to forecast volcanic ash plume trajectories and provide hazard alerts and warnings to aircraft in the Alaska region. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with

  13. A life-cycle model for wave-dominated tidal inlets along passive margin coasts of North America

    Science.gov (United States)

    Seminack, Christopher T.; McBride, Randolph A.

    2018-03-01

    A regional overview of 107 wave-dominated tidal inlets along the U.S. Atlantic coast, U.S. Gulf of Mexico coast, and Canadian Gulf of St. Lawrence coast yielded a generalized wave-dominated tidal inlet life-cycle model that recognized the rotational nature of tidal inlets. Tidal inlets are influenced by concurrently acting processes transpiring over two timescales: short-term, event-driven processes and long-term, evolutionary processes. Wave-dominated tidal inlets are classified into three rotational categories based on net longshore sediment transport direction and rotation direction along the landward (back-barrier) portion of the inlet channel: downdrift channel rotation, updrift channel rotation, or little-to-no channel rotation. Lateral shifting of the flood-tidal delta depocenter in response to available estuarine accommodation space appears to control inlet channel rotation. Flood-tidal delta deposits fill accommodation space locally within the estuary (i.e., creating bathymetric highs), causing the tidal-inlet channel to rotate. External influences, such as fluvial discharge, pre-existing back-barrier channels, and impeding salt marsh will also influence inlet-channel rotation. Storm events may rejuvenate the tidal inlet by scouring sediment within the flood-tidal delta, increasing local accommodation space. Wave-dominated tidal inlets are generally unstable and tend to open, concurrently migrate laterally and rotate, infill, and close. Channel rotation is a primary reason for wave-dominated tidal inlet closure. During rotation, the inlet channel lengthens and hydraulic efficiency decreases, thus causing tidal prism to decrease. Tidal prism, estuarine accommodation space, and sediment supply to the flood-tidal delta are the primary variables responsible for tidal inlet rotation. Stability of wave-dominated tidal inlets is further explained by: stability (S) = tidal prism (Ω) + estuarine accommodation space (V) - volume of annual sediment supply (Mt

  14. Spatial heterogeneity of biofouling under different cross-flow velocities in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia

    2016-09-06

    The spatially heterogeneous distribution of biofouling in spiral wound membrane systems restricts (i) the water distribution over the membrane surface and therefore (ii) the membrane-based water treatment. The objective of the study was to assess the spatial heterogeneity of biofilm development over the membrane fouling simulator (MFS) length (inlet and outlet part) at three different cross-flow velocities (0.08, 0.12 and 0.16 m/s). The MFS contained sheets of membrane and feed spacer and simulated the first 0.20 m of spiral-wound membrane modules where biofouling accumulates the most in practice. In-situ non-destructive oxygen imaging using planar optodes was applied to determine the biofilm spatially resolved activity and heterogeneity.

  15. Mercury in Sediment, Water, and Biota of Sinclair Inlet, Puget Sound, Washington, 1989-2007

    Science.gov (United States)

    Paulson, Anthony J.; Keys, Morgan E.; Scholting, Kelly L.

    2010-01-01

    Historical records of mercury contamination in dated sediment cores from Sinclair Inlet are coincidental with activities at the U.S. Navy Puget Sound Naval Shipyard; peak total mercury concentrations occurred around World War II. After World War II, better metallurgical management practices and environmental regulations reduced mercury contamination, but total mercury concentrations in surface sediment of Sinclair Inlet have decreased slowly because of the low rate of sedimentation relative to the vertical mixing within sediment. The slopes of linear regressions between the total mercury and total organic carbon concentrations of sediment offshore of Puget Sound urban areas was the best indicator of general mercury contamination above pre-industrial levels. Prior to the 2000-01 remediation, this indicator placed Sinclair Inlet in the tier of estuaries with the highest level of mercury contamination, along with Bellingham Bay in northern Puget Sound and Elliott Bay near Seattle. This indicator also suggests that the 2000/2001 remediation dredging had significant positive effect on Sinclair Inlet as a whole. In 2007, about 80 percent of the area of the Bremerton naval complex had sediment total mercury concentrations within about 0.5 milligrams per kilogram of the Sinclair Inlet regression. Three areas adjacent to the waterfront of the Bremerton naval complex have total mercury concentrations above this range and indicate a possible terrestrial source from waterfront areas of Bremerton naval complex. Total mercury concentrations in unfiltered Sinclair Inlet marine waters are about three times higher than those of central Puget Sound, but the small numbers of samples and complex physical and geochemical processes make it difficult to interpret the geographical distribution of mercury in marine waters from Sinclair Inlet. Total mercury concentrations in various biota species were compared among geographical locations and included data of composite samples, individual

  16. Tidal hydrodynamics in a two-inlet coastal lagoon in the Gulf of California

    Science.gov (United States)

    Serrano, David; Ramírez-Félix, Evlin; Valle-Levinson, Arnoldo

    2013-07-01

    The aim of this study is to understand the effects of friction and advection in the hydrodynamics of a two-inlet coastal lagoon, Santa María La Reforma, in Northwest Mexico. A vertically integrated numerical model is used to describe sea level variations and tidal currents, and to study the dynamics inside the system. Observed sea level and current measurements were used to calibrate the model. Results show a ˜90 min phase lag of the tidal signal in the center of the system with respect to both inlets. Tidal currents greater than 1.0 m s-1 were recorded and modeled at both inlets. The sea level in the lagoon shows one-quarter of period of M2 out of phase (˜3 h) with respect to the velocity. Bottom friction generated the greatest M4 harmonic and largest tidal asymmetries at the narrowest section of the lagoon, ˜35 km away from the inlets. The tidal momentum balance along the main axis of the lagoon was dominated by pressure gradient and friction, describing a quasi-standing tidal wave in currents and in amplitude. This behavior resulted from waves traveling in opposite directions from the two tidal inlets, causing constructive interference in elevation but destructive interference inflow.

  17. Effect of blade sweep on inlet flow in axial compressor cascades

    Directory of Open Access Journals (Sweden)

    Hao Chang

    2015-02-01

    Full Text Available This paper presents comparative numerical studies to investigate the effects of blade sweep on inlet flow in axial compressor cascades. A series of swept and straight cascades was modeled in order to obtain a general understanding of the inlet flow field that is induced by sweep. A computational fluid dynamics (CFD package was used to simulate the cascades and obtain the required three-dimensional (3D flow parameters. A circumferentially averaged method was introduced which provided the circumferential fluctuation (CF terms in the momentum equation. A program for data reduction was conducted to obtain a circumferentially averaged flow field. The influences of the inlet flow fields of the cascades were studied and spanwise distributions of each term in the momentum equation were analyzed. The results indicate that blade sweep does affect inlet radial equilibrium. The characteristic of radial fluid transfer is changed and thus influencing the axial velocity distributions. The inlet flow field varies mainly due to the combined effect of the radial pressure gradient and the CF component. The axial velocity varies consistently with the incidence variation induced by the sweep, as observed in the previous literature. In addition, factors that might influence the radial equilibrium such as blade camber angles, solidity and the effect of the distance from the leading edge are also taken into consideration and comparatively analyzed.

  18. Advanced Ultrasupercritical (AUSC) Tube Membrane Panel Development

    Energy Technology Data Exchange (ETDEWEB)

    Pschirer, James [Alstom Power Inc., Windsor, CT (United States); Burgess, Joshua [Alstom Power Inc., Windsor, CT (United States); Schrecengost, Robert [Alstom Power Inc., Windsor, CT (United States)

    2017-08-16

    Alstom Power Inc., a wholly owned subsidiary of the General Electric Company (GE), has completed the project “Advanced Ultrasupercritical (AUSC) Tube Membrane Panel Development” under U.S. Department of Energy (DOE) Award Number DE-FE0024076. This project was part of DOE’s Novel Crosscutting Research and Development to Support Advanced Energy Systems program. AUSC Tube Membrane Panel Development was a two and one half year project to develop and verify the manufacturability and serviceability of welded tube membrane panels made from high performance materials suitable for the AUSC steam cycles, defined as high pressure steam turbine inlet conditions of 700-760°C (1292-1400°F) and 24.5-35MPa (3500-5000psi). The difficulty of this challenge lies in the fact that the membrane-welded construction imposes demands on the materials that are unlike any that exist in other parts of the boiler. Tube membrane panels have been designed, fabricated, and installed in boilers for over 50 years with relatively favorable experience when fabricated from carbon and Cr-Mo low alloy steels. The AUSC steam cycle requires membrane tube panels fabricated from materials that have not been used in a weldment with metal temperatures in the range of 582-610°C (1080-1130°F). Fabrication materials chosen for the tubing were Grade 92 and HR6W. Grade 92 is a creep strength enhanced ferritic Cr-Mo alloy and HR6W is a high nickel alloy. Once the materials were chosen, GE performed the engineering design of the panels, prepared shop manufacturing drawings, and developed manufacturing and inspection plans. After the materials were purchased, GE manufactured and inspected the tube membrane panels, determined if post fabrication heat treatment of the tube membrane panels was needed, performed pre- and post-weld heat treatment on the Grade 92 panels, conducted final nondestructive inspection of any heat treated tube membrane panels, conducted destructive inspection of the completed tube

  19. A Computational and Experimental Study of Coflow Laminar Methane/Air Diffusion Flames: Effects of Fuel Dilution, Inlet Velocity, and Gravity

    Science.gov (United States)

    Cao, S.; Ma, B.; Bennett, B. A. V.; Giassi, D.; Stocker, D. P.; Takahashi, F.; Long, M. B.; Smooke, M. D.

    2014-01-01

    The influences of fuel dilution, inlet velocity, and gravity on the shape and structure of laminar coflow CH4-air diffusion flames were investigated computationally and experimentally. A series of nitrogen-diluted flames measured in the Structure and Liftoff in Combustion Experiment (SLICE) on board the International Space Station was assessed numerically under microgravity (mu g) and normal gravity (1g) conditions with CH4 mole fraction ranging from 0.4 to 1.0 and average inlet velocity ranging from 23 to 90 cm/s. Computationally, the MC-Smooth vorticity-velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modeled by sectional aerosol equations. The governing equations and boundary conditions were discretized on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton's method. Experimentally, flame shape and soot temperature were determined by flame emission images recorded by a digital color camera. Very good agreement between computation and measurement was obtained, and the conclusions were as follows. (1) Buoyant and nonbuoyant luminous flame lengths are proportional to the mass flow rate of the fuel mixture; computed and measured nonbuoyant flames are noticeably longer than their 1g counterparts; the effect of fuel dilution on flame shape (i.e., flame length and flame radius) is negligible when the flame shape is normalized by the methane flow rate. (2) Buoyancy-induced reduction of the flame radius through radially inward convection near the flame front is demonstrated. (3) Buoyant and nonbuoyant flame structure is mainly controlled by the fuel mass flow rate, and the effects from fuel dilution and inlet velocity are secondary.

  20. Reaction paths and host phases of uranium isotopes (235U; 238U), Saanich Inlet

    Science.gov (United States)

    Amini, M.; Holmden, C. E.; Francois, R. H.

    2009-12-01

    In recent times, Uranium has become increasingly the focus of stable isotope fractionation studies. Variations in 238U/235U have been reported as a result of redox reactions [1,2] from the nuclear field shift effect [3], and a mass-dependent, microbially-mediated, kinetic isotope effect [4]. The 238U/235U variability caused by changes in environmental redox conditions leads to an increase in the 238U/235U ratios of the reduced U species sequestered into marine sediments. This points to U isotope variability as a new tool to study ancient ocean redox changes. However, the process by which reduced sediments become enriched in the heavy isotopes of U is not yet known, and hence the utility of 238U/235U as a redox tracer remains to be demonstrated. In order to further constrain sedimentary U enrichment and related isotope effect, we are investigating U isotopic compositions of water samples and fresh surface sediment grab samples over a range of redox conditions in the seasonally anoxic Saanich Inlet, on the east coast of Vancouver Island. U was sequentially extracted from sediments in order to characterize specific fractions for their isotopic composition. The measurements were carried out by MC-ICPMS using 233U/236U-double spike technique. The data are reported as δ238U relative to NBL 112a with a 238U/235U ratio of 137.88 (2sd). External precision is better than 0.10‰ (2sd). Fifteeen analyses of seawater yielded δ238U of -0.42±0.08‰ (2sd). The results for the water samples indicate a homogenous δ238U value throughout the Saanich Inlet water column that matches the global seawater signature. All of the water samples from above and below average -0.42±0.05‰ (2sd). In contrast, a plankton net sample yielded a distinctly different, (about 0.5‰ lighter) isotope value. Bacterial reduction experiments [4] have also shown isotope enrichment factors of about -0.3‰. In addition, metal isotope fractionation occurs during adsorption with the light isotope being

  1. The impact of inlet angle and outlet angle of guide vane on pump in reversal based hydraulic turbine performance

    International Nuclear Information System (INIS)

    Shi, F X; Yang, J H; Wang, X H; Zhang, R H; Li, C E

    2012-01-01

    In this paper, in order to research the impact of inlet angle and outlet angle of guide vane on hydraulic turbine performance, a centrifugal pump in reversal is adopted as turbine. A numerical simulation method is adopted for researching outer performance and flow field of turbine. The results show: inlet angle has a crucial role to turbine, to the same flow, there is a noticeable decline for the efficiency and head of turbine with the inlet angle increases. At the best efficiency point(EFP),to a same inlet angle, when the inlet angle greater than inlet angle, velocity circulation in guide vane outlet decreases, which lead the efficiency of turbine to reduce, Contrarily, the efficiency rises. With the increase of inlet angle and outlet angle, the EFP moves to the big flow area and the uniformity of pressure distribution becomes worse. The paper indicates that the inlet angle and outlet angle have great impact on the turbine performance, and the best combination exists for the inlet angle and outlet angle of the guide vane.

  2. Advances in Membrane Distillation for Water Desalination and Purification Applications

    Directory of Open Access Journals (Sweden)

    Juan Gomez

    2013-01-01

    Full Text Available Membrane distillation is a process that utilizes differences in vapor pressure to permeate water through a macro-porous membrane and reject other non-volatile constituents present in the influent water. This review considers the fundamental heat and mass transfer processes in membrane distillation, recent advances in membrane technology, module configurations, and the applications and economics of membrane distillation, and identifies areas that may lead to technological improvements in membrane distillation as well as the application characteristics required for commercial deployment.

  3. A CFD Study on Inlet Plenum Flow Field of Pebble Bed Reactor

    International Nuclear Information System (INIS)

    Kim, Min Hwan; Lee, Won Jae; Chang, Jong Hwa

    2005-01-01

    High temperature gas cooled reactor, largely divided into two types of PBR (Pebble Bed Reactor) and PMR (Prismatic Modular Reactor), has becomes great interest of researchers in connection with the hydrogen production. KAERI has started a project to develop the gas cooled reactor for the hydrogen production and has been doing in-depth study for selecting the reactor type between PBR and PMR. As a part of the study, PBMR (Pebble Bed Modular Reactor) was selected as a reference PBR reactor for the CFD analysis and the flow field of its inlet plenum was simulated with computational fluid dynamics program CFX5. Due to asymmetrical arrangement of pipes to the inlet plenum, non-uniform flow distribution has been expected to occur, giving rise to non-uniform power distribution at the core. Flow fields of different arrangement of inlet pipes were also investigated, as one of measures to reduce the non-uniformity

  4. Effect of diamond trip geometries on boundary layer transition for hypersonic inlet

    Science.gov (United States)

    Zhao, H. Y.; Ni, H. L.; Zhang, Z. M.; Yi, M. R.

    2016-10-01

    In order to grasp the effect of diamond trip geometries on boundary layer transition of hypersonic inlet, an experiment at Mach number 6 in a hypersonic wind tunnel was performed for a hypersonic inlet. The heat transfers at the inlet wall were measured through the infrared thermography. The transition region was judged by the comparison of heat transfer between experiment and computation. Ten diamond forced transition trips were designed according to Modern Design of Experiments. The experimental results shown that the effect order of trip geometries on transition region were the trip height, distance between diamond elements and diagonal length of diamond element from the largest to the smallest. Transition region moved forward to the model tip with increasing trip height or trip length, or with decreasing distance between diamond elements, or with increasing diagonal length of element. The optimized configuration was obtained for diamond forced-transition trip when the optimization object was transition region.

  5. Improving the performance of a compression ignition engine by directing flow of inlet air

    Science.gov (United States)

    Kemper, Carlton

    1946-01-01

    The object of this report is to present the results of tests performed by the National Advisory Committee for Aeronautics to determine the effect on engine performance of directing the flow of the inlet air to a 5-inch by 7-inch cylinder, solid injection, compression ignition engine, After a few preliminary tests, comparative runs were made at a speed of 1500 r.p.m. with and without directed air flow. It was found that directing the flow of the inlet air toward the fuel injection valve gave steadier engine operation, and an appreciable increase in power, and decreased fuel consumption. The results indicate the possibility of improving the performance of a given type of combustion chamber without changing its shape and with no change in valve timing. They would also seem to prove that directional turbulence, set up before the inlet valve of a four-stroke cycle engine, continues in the engine cylinder throughout the compression stroke.

  6. Effect of gas inlet angle on the gas-assisted extrusion forming of polymer melt

    Science.gov (United States)

    Ren, Z.; Huang, X. Y.

    2017-06-01

    In this paper, the effect of gas inlet angle on the gas-assisted extrusion (GAE) forming of polymer melt was studied by means of numerical simulation method. The geometric models and the corresponding finite element meshes of four different gas inlet angles (0°, 30°, 60°, and 90°) were established. The computed fluid dynamic software package Polyflow was used. The shear stress, normal stress, and first normal stress difference of melt at the gas/melt interface were obtained. The results show that the influence of gas inlet angle at 30 on the gas-assisted extrusion forming of melt is lest, which can provide the technique guidance for the optimal designing of the gas-assisted die for the polymer melt.

  7. Velocity and Temperature Distribution in Flow from an Inlet Device in Rooms with Displacement Ventilation

    DEFF Research Database (Denmark)

    Jacobsen, T.V.; Nielsen, Peter V.

    Measurements are performed in a full-scale test room with displacement ventilation with focus on the velocity and temperature field in the region close to the inlet device. Investigations based on these detailed measurements have been made in order to see if it is possible to describe the velocit...... decay and the shape of velocity and temperature profiles in front of the inlet device by traditional jet theory, by stratified flow theory or by a combination of the two theories.......Measurements are performed in a full-scale test room with displacement ventilation with focus on the velocity and temperature field in the region close to the inlet device. Investigations based on these detailed measurements have been made in order to see if it is possible to describe the velocity...

  8. The effect of inlet swirl on the rotordynamic shroud forces in a centrifugal pump

    Science.gov (United States)

    Ginzburg, A.; Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1992-01-01

    The role played by fluid forces in determining the rotordynamic stability of a centrifugal pump is gaining increasing attention. The present research investigates the contributions to the rotordynamic forces from the discharge-to-suction leakage flows between the front shroud of the rotating impeller and the stationary pump casing. In particular, the dependency of the rotordynamic characteristics of leakage flows on the swirl at the inlet to the leakage path was examined. An inlet guide vane was designed for the experiment so that swirl could be introduced at the leakage flow inlet. The data demonstrates substantial rotordynamic effects and a destabilizing tangential force for small positive whirl ratios; this force decreased with increasing flow rate. The effect of swirl on the rotordynamic forces was found to be destabilizing.

  9. Analysis of the Scramjet inlet flow field using two-dimensional Navier-Stokes equations

    Science.gov (United States)

    Kumar, A.; Tiwari, S. N.

    1982-01-01

    A computer code was developed to solve the full two dimensional Navier-Stokes equations in a scramjet inlet. The analysis uses a numerical coordinate transformation which generates a set of boundary-fitted curvilinear coordinates. The explicit finite difference algorithm of MacCormack is used to solve the governing equations. A two-layer eddy viscosity model is used for the turbulent flow. The code can analyze both inviscid and viscous flows with multiple struts in the flow field. Detailed results are presented for two model problems and two scramjet inlets with one and two struts. The application of the two dimensional analysis in the preliminary design of the actual scramjet inlet is briefly discussed.

  10. From biological membranes to biomimetic model membranes

    Directory of Open Access Journals (Sweden)

    Eeman, M.

    2010-01-01

    Full Text Available Biological membranes play an essential role in the cellular protection as well as in the control and the transport of nutrients. Many mechanisms such as molecular recognition, enzymatic catalysis, cellular adhesion and membrane fusion take place into the biological membranes. In 1972, Singer et al. provided a membrane model, called fluid mosaic model, in which each leaflet of the bilayer is formed by a homogeneous environment of lipids in a fluid state including globular assembling of proteins and glycoproteins. Since its conception in 1972, many developments were brought to this model in terms of composition and molecular organization. The main development of the fluid mosaic model was made by Simons et al. (1997 and Brown et al. (1997 who suggested that membrane lipids are organized into lateral microdomains (or lipid rafts with a specific composition and a molecular dynamic that are different to the composition and the dynamic of the surrounding liquid crystalline phase. The discovery of a phase separation in the plane of the membrane has induced an explosion in the research efforts related to the biology of cell membranes but also in the development of new technologies for the study of these biological systems. Due to the high complexity of biological membranes and in order to investigate the biological processes that occur on the membrane surface or within the membrane lipid bilayer, a large number of studies are performed using biomimicking model membranes. This paper aims at revisiting the fundamental properties of biological membranes in terms of membrane composition, membrane dynamic and molecular organization, as well as at describing the most common biomimicking models that are frequently used for investigating biological processes such as membrane fusion, membrane trafficking, pore formation as well as membrane interactions at a molecular level.

  11. Effects of inlet/outlet configurations on the electrostatic capture of airborne nanoparticles and viruses

    International Nuclear Information System (INIS)

    Jang, Jaesung; Akin, Demir; Bashir, Rashid

    2008-01-01

    Motivated by capture and detection of airborne biological agents in real time with a cantilever biosensor without introducing the agents into liquids, we present the effects of inlet/outlet configurations of a homemade particle collector on the electrostatic capture of airborne 100 nm diameter nanoparticles under swirling gas flows. This particle collector has three different inlet/outlet configurations: forward inlet/outlet (FO), backward inlet/outlet (BO) and straight inlet/outlet (SO) configurations. We also present the electrostatic capture of Vaccinia viruses using the same particle collector and compare these virus measurements with the nanoparticle cases. The most particles were collected in the FO configuration. The numbers of particles captured in the BO and SO configurations were close within their standard deviations. For all the three configurations tested, the number of particles captured in the center electrode C was much smaller than those captured in the other electrodes at a flow rate of 1.1 l min −1 and an applied potential of 2 kV. Using a commercial CFD code FLUENT, we also simulated the effects of the three inlet/outlet configurations on the particle capture in terms of particle trajectories, velocities and travel times. This simulation was in a good agreement with measurements that the FO configuration is the most favorable to particle capture among the tested configurations at a flow rate of 1.1 l min −1 . The effects of particle diameters on the capture will also be discussed. This collector can be used for real-time monitoring of bioaerosols along with cantilever biosensors

  12. Combined Cycle Engine Large-Scale Inlet for Mode Transition Experiments: System Identification Rack Hardware Design

    Science.gov (United States)

    Thomas, Randy; Stueber, Thomas J.

    2013-01-01

    The System Identification (SysID) Rack is a real-time hardware-in-the-loop data acquisition (DAQ) and control instrument rack that was designed and built to support inlet testing in the NASA Glenn Research Center 10- by 10-Foot Supersonic Wind Tunnel. This instrument rack is used to support experiments on the Combined-Cycle Engine Large-Scale Inlet for Mode Transition Experiment (CCE? LIMX). The CCE?LIMX is a testbed for an integrated dual flow-path inlet configuration with the two flow paths in an over-and-under arrangement such that the high-speed flow path is located below the lowspeed flow path. The CCE?LIMX includes multiple actuators that are designed to redirect airflow from one flow path to the other; this action is referred to as "inlet mode transition." Multiple phases of experiments have been planned to support research that investigates inlet mode transition: inlet characterization (Phase-1) and system identification (Phase-2). The SysID Rack hardware design met the following requirements to support Phase-1 and Phase-2 experiments: safely and effectively move multiple actuators individually or synchronously; sample and save effector control and position sensor feedback signals; automate control of actuator positioning based on a mode transition schedule; sample and save pressure sensor signals; and perform DAQ and control processes operating at 2.5 KHz. This document describes the hardware components used to build the SysID Rack including their function, specifications, and system interface. Furthermore, provided in this document are a SysID Rack effectors signal list (signal flow); system identification experiment setup; illustrations indicating a typical SysID Rack experiment; and a SysID Rack performance overview for Phase-1 and Phase-2 experiments. The SysID Rack described in this document was a useful tool to meet the project objectives.

  13. Experimental determination of the hydraulic resistance coefficient at the microchannel inlet

    Science.gov (United States)

    Aniskin, V. M.

    2017-11-01

    The paper presents the results of the hydraulic resistance coefficient measurements at the inlet of microchannel. The Reynolds number ranged from 900 to 2300. The channel with inlet diameter of 3.5 mm is abruptly narrowed to a diameter of 0.9 mm. We measured the pressure drop in the area of sharp change in diameter. Measured hydraulic resistance coefficient was compared with the previously obtained coefficients for microchannels of the same geometry. It is shown that for the studied interconnected channel geometry no differences were found between micro and minichannels.

  14. Analysis of distortion data from TF30-P-3 mixed compression inlet test

    Science.gov (United States)

    King, R. W.; Schuerman, J. A.; Muller, R. G.

    1976-01-01

    A program was conducted to reduce and analyze inlet and engine data obtained during testing of a TF30-P-3 engine operating behind a mixed compression inlet. Previously developed distortion analysis techniques were applied to the data to assist in the development of a new distortion methodology. Instantaneous distortion techniques were refined as part of the distortion methodology development. A technique for estimating maximum levels of instantaneous distortion from steady state and average turbulence data was also developed as part of the program.

  15. A comparative assessment of alternative combustion turbine inlet air cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.R.; Katipamula, S.; Konynenbelt, J.H.

    1996-02-01

    Interest in combustion turbine inlet air cooling (CTAC) has increased during the last few years as electric utilities face increasing demand for peak power. Inlet air cooling increases the generating capacity and decreases the heat rate of a combustion turbine during hot weather when the demand for electricity is generally the greatest. Several CTAC systems have been installed, but the general applicability of the concept and the preference for specific concepts is still being debated. Concurrently, Rocky Research of Boulder City, Nevada has been funded by the U.S. Department of Energy to conduct research on complex compound (ammoniated salt) chiller systems for low-temperature refrigeration applications.

  16. Numerical simulation of a ramjet inlet flowfield in response to large amplitude combustor pressure oscillation

    Science.gov (United States)

    Hsieh, T.; Wardlaw, A. B., Jr.; Coakley, T.

    1984-01-01

    The unsteady flow of a two-dimensional ramjet inlet is studied numerically by solving the Navier-Stokes equation with a two-equation turbulence model. Unsteadiness is introduced by prescribing the pressure disturbance at the inlet exit plane. The case with a sinusoidal exit plane pressure fluctuation of 20 percent of the steady exit pressure is considered. The resulting flow field exhibits a complicated interaction between the terminal shock, separation pockets and core flow. The exit plane properties feature a non-linear response to the imposed sinusoidal pressure variation.

  17. Migration of Tidal Inlets of Chilika Lagoon, Odisha, India -A Critical Study

    OpenAIRE

    Siba Prasad Mishra; Joygopal Jena

    2014-01-01

    Chilika Lake, Asia’s largest brackish water lagoon situated on the East coast of India is separated from Bay of Bengal by sand bars and connected with the sea by a series of tidal inlets. The inlets are maintained by discharges of inflowing streams during monsoon and by tides and ebb tides during non-monsoon. Imbalance in ingress and egress of sediment due to their continuous exchange between sea and the lagoon causes sedimentation of lagoon. Varying inflow, littoral drift and such other fact...

  18. Comparison of microconcentric and membrane-desolvation sample introduction systems for determination of low rare earth element concentrations in surface and subsurface waters using sector field inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chung, C.-H. [Department of Earth Sciences and Earth Dynamic System Research Center (EDSRC), National Cheng Kung University, Tainan, 70101, Taiwan (China); Brenner, Isaac [Department of Earth Sciences and Earth Dynamic System Research Center (EDSRC), National Cheng Kung University, Tainan, 70101, Taiwan (China)], E-mail: Brenner@cc.huji.ac.il; You, C.-F. [Department of Earth Sciences and Earth Dynamic System Research Center (EDSRC), National Cheng Kung University, Tainan, 70101, Taiwan (China)

    2009-09-15

    Analytical performances of a microconcentric nebulizer (MCN) and a membrane-desolvation sample introduction system (Aridus) were compared for determination of low concentrations of rare earth elements (REEs) in surface and subsurface waters using a double focusing sector field inductively coupled plasma mass spectrometer. Conventional figures of merit were employed, such as sensitivities, limits of detection (LOD), REE-O{sup +} formation, matrix induced interferences, long term signal variations, and recovery from spiked sea water samples and a pristine water CRM. Sensitivity as a function of mass for the MCN was quite flat with the exception of light REE (LREE{sup +}) which was dependent on REE-O{sup +} generation. Signal responses using the Aridus were enhanced by factors of 4-10. Large sensitivity enhancements were observed for {sup 139}La{sup +}, {sup 140}Ce{sup +} and {sup 141}Pr{sup +}, due to the attenuation of their REE-O{sup +} (where the Aridus {sup 140}Ce{sup 16}O{sup +}/{sup 140}Ce{sup +} was three orders of magnitude lower than that determined using the MCN) as a result of water analysis reduction in the plasma. Despite higher sensitivities, Aridus LODs were not significantly different from those obtained using the MCN, and values varied from 0.05 to 0.2 ng L{sup - 1} and 0.1 to 0.2 ng L{sup - 1} for the MCN and Aridus systems, respectively. When using the MCN, LREE{sup +} signals were closely associated with REE-O bond strengths, implying that LREE-O{sup +} production and breakdown are related to the strength of REE-O bonds in REE-O{sup +} ions suggesting that medium REE (MREE)-O{sup +} and heavy REE (HREE)-O{sup +} if formed, were thermally unstable in the plasma. In the presence of conservative Na concentrations, MCN LREE{sup +} signal suppressions varied from about 15 to 25% and about 5 to 10% for MREE{sup +} and HREE{sup +}. In contrast, regular 15% signal suppressions for all REE{sup +} were observed for the Aridus. In the case of the MCN, more

  19. Interactions between oxygen permeation and homogeneous-phase fuel conversion on the sweep side of an ion transport membrane

    KAUST Repository

    Hong, Jongsup

    2013-02-01

    The interactions between oxygen permeation and homogeneous fuel oxidation reactions on the sweep side of an ion transport membrane (ITM) are examined using a comprehensive model, which couples the dependency of the oxygen permeation rate on the membrane surface conditions and detailed chemistry and transport in the vicinity of the membrane. We assume that the membrane surface is not catalytic to hydrocarbon or syngas oxidation. Results show that increasing the sweep gas inlet temperature and fuel concentration enhances oxygen permeation substantially. This is accomplished through promoting oxidation reactions (oxygen consumption) and the transport of the products and reaction heat towards the membrane, which lowers the oxygen concentration and increases the gas temperature near the membrane. Faster reactions at higher fuel concentration and higher inlet gas temperature support substantial fuel conversion and lead to a higher oxygen permeation flux without the contribution of surface catalytic activity. Beyond a certain maximum in the fuel concentration, extensive heat loss to the membrane (and feed side) reduces the oxidation kinetic rates and limits oxygen permeation as the reaction front reaches the membrane. The sweep gas flow rate and channel height have moderate impacts on oxygen permeation and fuel conversion due to the residence time requirements for the chemical reactions and the location of the reaction zone relative to the membrane surface. © 2012 Elsevier B.V.

  20. Gas Chromatographic-Mass Spectrometric Analysis of Essential Oil ...

    African Journals Online (AJOL)

    Purpose: To analyze the essential oil composition of the flower of Jasminum officinale L. var. grandifloroum L. (Jasminum grandiflorum) by gas chromatography-mass spectrometry (GC-MS). Methods: The optimum GC-MS conditions used for the analysis were 250 oC inlet temperature, 150 oC MSD detector temperature, ...

  1. Mass transfer analysis for terephthalic acid biodegradation by ...

    African Journals Online (AJOL)

    Biodegradation of terephthalic acid (TA) by polyvinyl alcohol (PVA)-alginate immobilized Pseudomonas sp. was carried out in a packed-bed reactor. The effect of inlet TA concentration on biodegradation was investigated at 30°C, pH 7 and flow rate of 20 ml/min. The effects of flow rate on mass transfer and biodegradation ...

  2. A thin membrane artificial muscle rotary motor

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain A.; Hale, Thom; Gisby, Todd; Inamura, Tokushu; McKay, Thomas; O' Brien, Benjamin; Walbran, Scott [University of Auckland, The Biomimetics Lab, Auckland Bioengineering Institute, Auckland (New Zealand); Calius, Emilio P. [Industrial Research Ltd., P.O. Box 2225, Auckland (New Zealand)

    2010-01-15

    Desirable rotary motor attributes for robotics include the ability to develop high torque in a low mass body and to generate peak power at low rotational speeds. Electro-active polymer artificial muscles offer promise as actuator elements for robotic motors. A promising artificial muscle technology for use as a driving mechanism for rotary motion is the dielectric elastomer actuator (DEA). We present a membrane DEA motor in which phased actuation of electroded sectors of the motor membrane impart orbital motion to a central drive that turns a rotor. The motor is inherently scalable, flexible, flat, silent in operation, amenable to deposition-based manufacturing approaches, and uses relatively inexpensive materials. As a membrane it can also form part of the skin of a robot. We have investigated the torque and power of stacked membrane layers. Specific power and torque ratios when calculated using active membrane mass only were 20.8 W/kg and 4.1 Nm/kg, respectively. These numbers compare favorably with a commercially available stepper motor. Multi-membrane fabrication substantially boosts torque and power and increases the active mass of membrane relative to supporting framework. Through finite element modeling, we show the mechanisms governing the maximum torque the device can generate and how the motor can be improved. (orig.)

  3. A thin membrane artificial muscle rotary motor

    Science.gov (United States)

    Anderson, Iain A.; Hale, Thom; Gisby, Todd; Inamura, Tokushu; McKay, Thomas; O'Brien, Benjamin; Walbran, Scott; Calius, Emilio P.

    2010-01-01

    Desirable rotary motor attributes for robotics include the ability to develop high torque in a low mass body and to generate peak power at low rotational speeds. Electro-active polymer artificial muscles offer promise as actuator elements for robotic motors. A promising artificial muscle technology for use as a driving mechanism for rotary motion is the dielectric elastomer actuator (DEA). We present a membrane DEA motor in which phased actuation of electroded sectors of the motor membrane impart orbital motion to a central drive that turns a rotor. The motor is inherently scalable, flexible, flat, silent in operation, amenable to deposition-based manufacturing approaches, and uses relatively inexpensive materials. As a membrane it can also form part of the skin of a robot. We have investigated the torque and power of stacked membrane layers. Specific power and torque ratios when calculated using active membrane mass only were 20.8 W/kg and 4.1 Nm/kg, respectively. These numbers compare favorably with a commercially available stepper motor. Multi-membrane fabrication substantially boosts torque and power and increases the active mass of membrane relative to supporting framework. Through finite element modeling, we show the mechanisms governing the maximum torque the device can generate and how the motor can be improved.

  4. The dynamic response of an activated carbon adsorption column for a step change in adsorbate concentration by the column inlet

    International Nuclear Information System (INIS)

    Visser, J.K.

    1989-01-01

    The dynamic response of an adsorption column for a step change in the inlet concentration was investigated for three commercially available activated carbons namely Le Carbone G 210 AS, Norit RB1 and Norit RB3. n-Octane, n-nonane, n-decane, n-undecane, perfluoromethylcyclohexane and toluene were used as adsorbates to analyse breakthrough curves. Results indicate that the adsorption equilibrium of n-alkanes, perfluoromethylcyclohexane and toluene on Le Carbone G 210 AS activated carbon can be adequately described by the Langmuir isotherm. In the velocity region investigated there was a linear relationship between the linear velocity of the inert carrier gas and the mass transfer coefficient. Desorption breakthrough curves were modelled by the Walter desorption equation and good correlation was achieved for the desorption of n-alkanes from Le Carbone and Norit carbons. The constant separation factor obtained for desorption curves confirmed the highly non linear shape of the equilibruim curve for these systems. Results of the investigation indicate that the mass transfer rate is fastest in the case of Norit RB1 activated carbon because the particle size is the smallest and is slowest for Norit RB3. Norit RB1 or Le Carbone G 210 AS activated carbon are recommended as adsorbent for the removal of oil vapour from hydrogen gas. 84 refs., 162 figs., 137 tabs

  5. Direct coupling of polymer-based microchip electrophoresis to online MALDI-MS using a rotating ball inlet.

    Science.gov (United States)

    Musyimi, Harrison K; Guy, Jason; Narcisse, Damien A; Soper, Steven A; Murray, Kermit K

    2005-12-01

    We report on the coupling of a polymer-based microfluidic chip to a MALDI-TOF MS using a rotating ball interface. The microfluidic chips were fabricated by micromilling a mold insert into a brass plate, which was then used for replicating polymer microparts via hot embossing. Assembly of the chip was accomplished by thermally annealing a cover slip to the embossed substrate to enclose the channels. The linear separation channel was 50 microm wide, 100 microm deep, and possessed an 8 cm effective length separation channel with a double-T injector (V(inj) = 10 nL). The exit of the separation channel was machined to allow direct contact deposition of effluent onto a specially constructed rotating ball inlet to the mass spectrometer. Matrix addition was accomplished in-line on the surface of the ball. The coupling utilized the ball as the cathode transfer electrode to transport sample into the vacuum for desorption with a 355 nm Nd:YAG laser and analyzed on a TOF mass spectrometer. The ball was cleaned online after every rotation. The ability to couple poly(methylmethacrylate) microchip electrophoresis devices for the separation of peptides and peptide fragments produced from a protein digest with subsequent online MALDI MS detection was demonstrated.

  6. Conjugate heat and mass transfer in heat mass exchanger ducts

    CERN Document Server

    Zhang, Li-Zhi

    2013-01-01

    Conjugate Heat and Mass Transfer in Heat Mass Exchanger Ducts bridges the gap between fundamentals and recent discoveries, making it a valuable tool for anyone looking to expand their knowledge of heat exchangers. The first book on the market to cover conjugate heat and mass transfer in heat exchangers, author Li-Zhi Zhang goes beyond the basics to cover recent advancements in equipment for energy use and environmental control (such as heat and moisture recovery ventilators, hollow fiber membrane modules for humidification/dehumidification, membrane modules for air purification, desi

  7. Inlet spillage drag tests and numerical flow-field analysis at subsonic and transonic speeds of a 1/8-scale, two-dimensional, external-compression, variable-geometry, supersonic inlet configuration

    Science.gov (United States)

    Hawkins, J. E.; Kirkland, F. P.; Turner, R. L.

    1976-01-01

    Accurate spillage drag and pressure data are presented for a realistic supersonic inlet configuration. Results are compared with predictions from a finite-differencing, inviscid analysis computer procedure. The analytical technique shows good promise for the evaluation of inlet drag, but necessary refinements were identified. A detailed description of the analytical procedure is contained in the Appendix.

  8. Molecular Interactions at Membranes

    DEFF Research Database (Denmark)

    Jagalski, Vivien

    Biological membranes are essential and complex structures in every living cell consisting of a fluid lipid bilayer sheet and membrane proteins. Its significance makes biological membranes not only interesting for medical research, but also has made it a target for toxins in the course of evolution....... Today, we know more than ever before about the properties of biological membranes. Advanced biophysical techniques and sophisticated membrane models allow us to answer specific questions about the structure of the components within membranes and their interactions. However, many detailed structural...... mechanisms of membrane compounds, including compounds associated with membranes, are still unknown due to the challenges that arise when probing the hydrophobic nature of the membrane's interior. For integral membrane proteins that span through the entire membrane, the amphiphilic environment is essential...

  9. Rapid Biogas Production by Compact Multi-Layer Membrane Bioreactor: Efficiency of Synthetic Polymeric Membranes

    Directory of Open Access Journals (Sweden)

    Supansa Youngsukkasem

    2013-11-01

    Full Text Available Entrapment of methane-producing microorganisms between semi-permeable synthetic membranes in a multi-layer membrane bioreactor (MMBR was studied and compared to the digestion capacity of a free-cell digester, using a hydraulic retention time of one day and organic loading rates (OLR of 3.08, 6.16, and 8.16 g COD/L·day. The reactor was designed to retain bacterial cells with uprising plug flow through a narrow tunnel between membrane layers, in order to acquire maximal mass transfer in a compact bioreactor. Membranes of hydrophobic polyamide 46 (PA and hydroxyethylated polyamide 46 (HPA as well as a commercial membrane of polyvinylidene fluoride (PVDF were examined. While the bacteria in the free-cell digester were washed out, the membrane bioreactor succeeded in retaining them. Cross-flow of the liquid through the membrane surface and diffusion of the substrate through the membranes, using no extra driving force, allowed the bacteria to receive nutrients and to produce biogas. However, the choice of membrane type was crucial. Synthesized hydrophobic PA membrane was not effective for this purpose, producing 50–121 mL biogas/day, while developed HPA membrane and the reference PVDF were able to transfer the nutrients and metabolites while retaining the cells, producing 1102–1633 and 1016–1960 mL biogas/day, respectively.

  10. Identification of ftalates used as additives in the geo membrane of a la Florida reservoir through gas chromatography-mass spectrometry; Determinacion de las ftalatos utilizados como aditivos en la geomembrana de la bolsa de la florida mediante cromtografia de gases-espectrometria de masas

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, M.; Rico, G.; Pargada, L.; Aguiar, E.; Castillo, F.

    2009-07-01

    This article studies the behaviour of the plastified poly (vinyl chloride) (PVC-P) applied as synthetic geo membrane for the waterproofing of the La Florida reservoir. We show the results of the initial examen of its properties and its most significant characteristics eighteen years after being applied. Furthermore we isolate and identify the quantitative and qualitative aspects of the plasticizers used in its formula through infrared spectroscopy, gas chromatography and mass spectrometry technic. We have identified as the said plasticizers di-n-octyl phthalate, di-n-decyl phthalate and n-decyl n-octyl phthalate, and we calculate the joint average molecular weight using Wilsons equation. The results found that the geo membranes we have studied has shown an excellent behaviour along through time. (Author) 53 refs.

  11. Unsteady supercritical/critical dual flowpath inlet flow and its control methods

    Directory of Open Access Journals (Sweden)

    Jun LIU

    2017-12-01

    Full Text Available The characteristics of unsteady flow in a dual-flowpath inlet, which was designed for a Turbine Based Combined Cycle (TBCC propulsion system, and the control methods of unsteady flow were investigated experimentally and numerically. It was characterized by large-amplitude pressure oscillations and traveling shock waves. As the inlet operated in supercritical condition, namely the terminal shock located in the throat, the shock oscillated, and the period of oscillation was about 50 ms, while the amplitude was 6 mm. The shock oscillation was caused by separation in the diffuser. This shock oscillation can be controlled by extending the length of diffuser which reduces pressure gradient along the flowpath. As the inlet operated in critical condition, namely the terminal shock located at the shoulder of the third compression ramp, the shock oscillated, and the period of oscillation was about 7.5 ms, while the amplitude was 12 mm. At this condition, the shock oscillation was caused by an incompatible backpressure in the bleed region. It can be controlled by increasing the backpressure of the bleed region. Keywords: Airbreathing hypersonic vehicle, Dual flowpath inlet, Terminal shock oscillation, Turbine based combined cycle, Unsteady flow

  12. Turbulent velocity and concentration measurements in a macro-scale multi-inlet vortex nanoprecipitation reactor

    Science.gov (United States)

    Liu, Zhenping; Fox, Rodney; Hill, James; Olsen, Michael

    2013-11-01

    Flash Nanoprecipitation (FNP) is a technique to produce monodisperse functional nanoparticles. Microscale multi-inlet vortex reactors (MIVR) have been effectively applied to FNP due to their ability to provide rapid mixing and flexibility of inlet flow conditions. A scaled-up MIVR could potentially generate large quantities of functional nanoparticles, giving FNP wider applicability in industry. In the presented research, the turbulent velocity field inside a scaled-up, macroscale MIVR is measured by particle image velocimetry (PIV). Within the reactor, velocity is measured using both two-dimensional and stereoscopic PIV at two Reynolds numbers (3500 and 8750) based on the flow at each inlet. Data have been collected at numerous locations in the inlet channels, the reaction chamber, and the reactor outlet. Mean velocity and Reynolds stresses have been obtained based on 5000 instantaneous velocity realizations at each measurement location. The turbulent mixing process has also been investigated with passive scalar planar laser-induced fluorescence and simultaneous PIV/PLIF. Velocity and concentration results are compared to results from previous experiments in a microscale MIVR. Scaled profiles of turbulent quantities are similar to those previously found in the microscale MIVR.

  13. Assessing climate change impacts on the stability of small tidal inlets : Part 1 - Data poor environments

    NARCIS (Netherlands)

    Duong, Trang Minh; Ranasinghe, Roshanka; Luijendijk, Arjen; Walstra, Dirk-Jan R.; Roelvink, Dano

    2017-01-01

    Bar-built or barrier estuaries (here referred to as Small tidal inlets, or STIs), which are commonly found along wave-dominated, microtidal mainland coasts, are highly likely to be affected by climate change (CC). Due to their pre-dominance in tropical and sub-tropical regions of the world, many

  14. Turning the tide : Growth and dynamics of a tidal basin and inlet in experiments

    NARCIS (Netherlands)

    Kleinhans, Maarten G.; Van Scheltinga, Renske Terwisscha; Van Der Vegt, Maarten; Markies, Henk

    2015-01-01

    Dynamic equilibrium of short tidal systems with ebb deltas, inlets, and basins is poorly understood. Observations suggest the possibility of equilibrium with sediment import balancing export, while individual channels and shoals at the local scale remain dynamic. Our objectives are to ascertain (1)

  15. 78 FR 71546 - Safety Zone; Belt Parkway Bridge Construction, Gerritsen Inlet, Brooklyn, NY

    Science.gov (United States)

    2013-11-29

    ... 1625-AA00 Safety Zone; Belt Parkway Bridge Construction, Gerritsen Inlet, Brooklyn, NY AGENCY: Coast... the construction of the Bridge. DATES: Comments and related material must be received by the Coast... construction and demolition of Belt Parkway Bridge. There is no previous regulatory action for this Bridge. C...

  16. Radar Interferometry Detection of Hinge Line Migration on Rutford Ice Stream and Carlson Inlet, Antarctica

    Science.gov (United States)

    Rignot, Eric

    1997-01-01

    Satellite synthetic-aperture radar (SAR) Interferometry is employed to map the hinge line, or limit of tidal flexing, of Rutford Ice Stream and Carlson Inlet, Antarctica, and detect its migration between 1992 and 1996. The hinge line is mapped using a model fit from an elastic beam theory.

  17. Aerodynamic configuration integration design of hypersonic cruise aircraft with inward-turning inlets

    Directory of Open Access Journals (Sweden)

    Jifei WANG

    2017-08-01

    Full Text Available In this work, a novel airframe/propulsion integration design method of the wing-body configuration for hypersonic cruise aircraft is proposed, where the configuration is integrated with inward-turning inlets. With the help of this method, the major design concern of balancing the aerodynamic performance against the requirements for efficient propulsion can be well addressed. A novel geometric parametrically modelling method based on a combination of patched class and shape transition (CST and COONs surface is proposed to represent the configuration, especially a complex configuration with an irregular inlet lip shape. The modelling method enlarges the design space of components on the premise of guaranteeing the configuration integrity via special constraints imposed on the interface across adjacent surfaces. A basic flow inside a cone shaped by a dual-inflection-point generatrix is optimized to generate the inward-turning inlet with improvements of both compression efficiency and flow uniformity. The performance improvement mechanism of this basic flow is the compression velocity variation induced by the variation of the generatrix slope along the flow path. At the design point, numerical simulation results show that the lift-to-drag ratio of the configuration is as high as 5.2 and the inlet works well with a high level of compression efficiency and flow uniformity. The design result also has a good performance on off-design conditions. The achievement of all the design targets turns out that the integration design method proposed in this paper is efficient and practical.

  18. Residual water transport in the Marsdiep tidal inlet inferred from observations and a numerical model

    NARCIS (Netherlands)

    Sassi, M.G.; Gerkema, T.; Duran-Matute, M.; Nauw, J.J.

    2016-01-01

    At tidal inlets, large amounts of water are exchanged with the adjacent sea during the tidal cycle.The residual flows, the net effect of ebb and flood, are generally small compared with the gross flux;they vary in magnitude and sign from one tidal period to the other; and their long-term mean

  19. Effects of gravity and inlet location on a two-phase countercurrent imbibition in porous media

    KAUST Repository

    El-Amin, Mohamed

    2012-01-01

    We introduce a numerical investigation of the effect of gravity on the problem of two-phase countercurrent imbibition in porous media. We consider three cases of inlet location, namely, from, side, top, and bottom. A 2D rectangular domain is considered for numerical simulation. The results indicate that gravity has a significant effect depending on open-boundary location.

  20. Characteristics of flow distribution in compact parallel flow heat exchangers, part I: Typical inlet header

    International Nuclear Information System (INIS)

    Wang, Chi-Chuan; Yang, Kai-Shing; Tsai, Jhong-Syuan; Chen, Ing Youn

    2011-01-01

    This study experimentally and numerically investigates the single-phase flow into parallel flow heat exchangers with inlet and outlet rectangular headers having square cross section and 9 circular tubes. The effects of inlet flow condition, tube diameter, header size, area ratio, flow directions (Z and U-type), as well as the gravity are investigated. The experimental results indicate that flow distribution for U-type flow is more uniform than Z-type flow. Depending on the inlet volumetric flow rate, the flow ratio at the first several tubes can be lower than 50% of the last tube for Z-type arrangement, and this phenomenon becomes more and more pronounced with the rising velocity at the intake conduit. The mal-distribution can be eased via reducing the branching tube size or increasing the entrance settling distance at the intake conduit. It is found that the influence of gravity on mal-distribution is negligible and the mal-distribution is associated with the jet flow pattern. - Highlights: → The flow distribution into parallel flow heat exchangers with rectangular headers is examined. → The first several tubes may show only 50% flow rate of the last tube. → The mal-distribution becomes more severe with the rising velocity at the intake conduit. → The mal-distribution is mainly associated with the jet flow pattern. → Flow distribution is improved via smaller tubes or increasing the inlet distance at the intake conduit.