These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Deposition of Size-Selected Cu Nanoparticles by Inert Gas Condensation  

PubMed Central

Nanometer size-selected Cu clusters in the size range of 1–5 nm have been produced by a plasma-gas-condensation-type cluster deposition apparatus, which combines a grow-discharge sputtering with an inert gas condensation technique. With this method, by controlling the experimental conditions, it was possible to produce nanoparticles with a strict control in size. The structure and size of Cu nanoparticles were determined by mass spectroscopy and confirmed by atomic force microscopy (AFM) and scanning electron transmission microscopy (STEM) measurements. In order to preserve the structural and morphological properties, the energy of cluster impact was controlled; the energy of acceleration of the nanoparticles was in near values at 0.1 ev/atom for being in soft landing regime. From SEM measurements developed in STEM-HAADF mode, we found that nanoparticles are near sized to those values fixed experimentally also confirmed by AFM observations. The results are relevant, since it demonstrates that proper optimization of operation conditions can lead to desired cluster sizes as well as desired cluster size distributions. It was also demonstrated the efficiency of the method to obtain size-selected Cu clusters films, as a random stacking of nanometer-size crystallites assembly. The deposition of size-selected metal clusters represents a novel method of preparing Cu nanostructures, with high potential in optical and catalytic applications. PMID:20652132

2010-01-01

2

Evaporation and Condensation of Large Droplets in the Presence of Inert Admixtures Containing Soluble Gas  

E-print Network

effect of the greenhouse gases (Krämer et al. 2000). All these phenomena involve evaporation of droplets the mutual influence of heat and mass transfer during gas absorption and evaporation or condensation. The system of transient conjugate nonlinear energy and mass conservation equa- tions was solved using

Elperin, Tov

3

Inert gas thrusters  

NASA Technical Reports Server (NTRS)

Inert gas thrusters considered for space propulsion systems were investigated. Electron diffusion across a magnetic field was examined utilizing a basic model. The production of doubly charged ions was correlated using only overall performance parameters. The use of this correlation is therefore possible in the design stage of large gas thrusters, where detailed plasma properties are not available. Argon hollow cathode performance was investigated over a range of emission currents, with the positions of the inert, keeper, and anode varied. A general trend observed was that the maximum ratio of emission to flow rate increased at higher propellant flow rates. It was also found that an enclosed keeper enhances maximum cathode emission at high flow rates. The maximum cathode emission at a given flow rate was associated with a noisy high voltage mode. Although this mode has some similarities to the plume mode found at low flows and emissions, it is encountered by being initially in the spot mode and increasing emission. A detailed analysis of large, inert-gas thruster performance was carried out. For maximum thruster efficiency, the optimum beam diameter increases from less than a meter at under 2000 sec specific impulse to several meters at 10,000 sec. The corresponding range in input power ranges from several kilowatts to megawatts.

Kaufman, H. R.; Robinson, R. S.

1979-01-01

4

Inert gas ion thruster  

NASA Technical Reports Server (NTRS)

Inert gas performance with three types of 12 cm diameter magnetoelectrostatic containment (MESC) ion thrusters was tested. The types tested included: (1) a hemispherical shaped discharge chamber with platinum cobalt magnets; (2) three different lengths of the hemispherical chambers with samarium cobalt magnets; and (3) three lengths of the conical shaped chambers with aluminum nickel cobalt magnets. The best argon performance was produced by a 8.0 cm long conical chamber with alnico magnets. The best xenon high mass utilization performance was obtained with the same 8.0 cm long conical thruster. The hemispherical thruster obtained 75 to 87% mass utilization at 185 to 205 eV/ion of singly charged ion equivalent beam.

Ramsey, W. D.

1980-01-01

5

Inert gas thrusters  

NASA Technical Reports Server (NTRS)

Inert gas thrusters have continued to be of interest for space propulsion applications. Xenon is of interest in that its physical characteristics are well suited to propulsion. High atomic weight and low tankage fraction were major factors in this choice. If a large amount of propellant was required, so that cryogenic storage was practical, argon is a more economical alternative. Argon was also the preferred propellant for ground applications of thruster technology, such as sputter etching and deposition. Additional magnetic field measurements are reported. These measurements should be of use in magnetic field design. The diffusion of electrons through the magnetic field above multipole anodes was studied in detail. The data were consistent with Bohm diffusion across a magnetic field. The theory based on Bohm diffusion was simple and easily used for diffusion calculations. Limited startup data were obtained for multipole discharge chambers. These data were obtained with refractory cathodes, but should be useful in predicting the upper limits for starting with hollow cathodes.

Kaufman, H. R.

1978-01-01

6

Enhanced-recovery inert gas processes compared  

Microsoft Academic Search

The rising value of natural gas has caused producers to consider inert gas substitutes for gas injection projects. Three processes are currently in use for inert gas generation: boiler flue gas, gas engine exhaust, and nitrogen from cryogenic air separation. In choosing between combustion-based inert gas and cryogenic nitrogen, 3 important factors need to be considered, in addition to cost:

1978-01-01

7

Inert gas thrusters  

NASA Technical Reports Server (NTRS)

Inert gases are of interest as possible alternatives to the usual electric thruster propellants of mercury and cesium. The multipole discharge chamber investigated was shown capable of low discharge chamber losses and flat ion beam profiles with a minimum of optimization. Minimum discharge losses were 200 to 250 eV/ion for xenon and 300 to 350 eV/ion for argon, while flatness parameters in the plane of the accelerator grid were 0.85 to 0.95. The design used employs low magnetic field strengths, which permits the use of sheet-metal parts. The corner problem of the discharge chamber was resolved with recessed corner anodes, which approximately equalized both the magnetic field above the anodes and the electron currents to these anodes. Argon hollow cathodes were investigated at currents up to about 5 amperes using internal thermionic emitters. Cathode chamber diameter optimized in the 1.0 to 2.5 cm range, while orifices diameter optimized in the 0.5 to 5 mm range. The use of a bias voltage for the internal emitter extended the operating range and facilitated starting. The masses of 15 and 30 cm flight type thrusters were estimated at about 4.2 and 10.8 kg.

Kaufman, H. R.

1976-01-01

8

Mechanisms of inert gas narcosis  

NASA Technical Reports Server (NTRS)

Experiments describing the mechanism of inert gas narcosis are reported. A strain of mice, genetically altered to increase susceptibility to botulin poisoning (synaptic response) appears to increase metabolic rates while breathing argon; this infers a genetically altered synaptic response to both botulin toxin and narcotic gases. Studies of metabolic depression in human subjects breathing either air or a 30% mixture of nitrous oxide indicate that nitrous oxide narcosis does not produce pronounced metabolic depression. Tests on mice for relative susceptibilities to narcosis and oxygen poisoning as a function of fatty membrane composition show that alteration of the fatty acid composition of phospholipids increases resistance to metabolically depressant effects of argon but bas no effect on nitrous oxide narcosis. Another study suggests that acclimatization to low tension prior to high pressure oxygen treatment enhances susceptibility of mice to convulsions and death; developing biochemical lesions cause CNS metabolite reductions and pulmonary damage.

1973-01-01

9

46 CFR 147.66 - Inert gas fire extinguishing systems.  

Code of Federal Regulations, 2014 CFR

...extinguishing systems. (a) Inert gas cylinders forming part of...209(b). (b) An inert gas cylinder must be removed from...connections between cylinders and discharge piping for fixed inert gas fire extinguishing systems...

2014-10-01

10

46 CFR 147.66 - Inert gas fire extinguishing systems.  

Code of Federal Regulations, 2012 CFR

...extinguishing systems. (a) Inert gas cylinders forming part of...209(b). (b) An inert gas cylinder must be removed from...connections between cylinders and discharge piping for fixed inert gas fire extinguishing systems...

2012-10-01

11

46 CFR 147.66 - Inert gas fire extinguishing systems.  

Code of Federal Regulations, 2013 CFR

...extinguishing systems. (a) Inert gas cylinders forming part of...209(b). (b) An inert gas cylinder must be removed from...connections between cylinders and discharge piping for fixed inert gas fire extinguishing systems...

2013-10-01

12

46 CFR 154.906 - Inert gas generators.  

Code of Federal Regulations, 2014 CFR

...gas generators. The inert gas generator must: (a) Produce an inert gas containing less than 5% oxygen...device to continuously sample the discharge of the generator for oxygen...station that alarms when the inert gas contains 5% or more...

2014-10-01

13

46 CFR 154.906 - Inert gas generators.  

Code of Federal Regulations, 2013 CFR

...gas generators. The inert gas generator must: (a) Produce an inert gas containing less than 5% oxygen...device to continuously sample the discharge of the generator for oxygen...station that alarms when the inert gas contains 5% or more...

2013-10-01

14

46 CFR 154.906 - Inert gas generators.  

Code of Federal Regulations, 2012 CFR

...gas generators. The inert gas generator must: (a) Produce an inert gas containing less than 5% oxygen...device to continuously sample the discharge of the generator for oxygen...station that alarms when the inert gas contains 5% or more...

2012-10-01

15

46 CFR 154.903 - Inert gas systems: General.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Inert gas systems: General. 154.903 Section...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment...Containment Systems § 154.903 Inert gas systems: General. (a)...

2014-10-01

16

46 CFR 154.903 - Inert gas systems: General.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Inert gas systems: General. 154.903 Section...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment...Containment Systems § 154.903 Inert gas systems: General. (a)...

2010-10-01

17

46 CFR 154.903 - Inert gas systems: General.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Inert gas systems: General. 154.903 Section...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment...Containment Systems § 154.903 Inert gas systems: General. (a)...

2012-10-01

18

46 CFR 154.903 - Inert gas systems: General.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Inert gas systems: General. 154.903 Section...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment...Containment Systems § 154.903 Inert gas systems: General. (a)...

2011-10-01

19

46 CFR 154.908 - Inert gas generator: Location.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Inert gas generator: Location. 154.908 Section 154...Containment Systems § 154.908 Inert gas generator: Location. (a) Except as allowed...paragraph (b) of this section, an inert gas generator must be located in the main...

2012-10-01

20

46 CFR 154.908 - Inert gas generator: Location.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Inert gas generator: Location. 154.908 Section 154...Containment Systems § 154.908 Inert gas generator: Location. (a) Except as allowed...paragraph (b) of this section, an inert gas generator must be located in the main...

2011-10-01

21

46 CFR 154.908 - Inert gas generator: Location.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Inert gas generator: Location. 154.908 Section 154...Containment Systems § 154.908 Inert gas generator: Location. (a) Except as allowed...paragraph (b) of this section, an inert gas generator must be located in the main...

2013-10-01

22

46 CFR 154.908 - Inert gas generator: Location.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 false Inert gas generator: Location. 154.908 Section 154...Containment Systems § 154.908 Inert gas generator: Location. (a) Except as allowed...paragraph (b) of this section, an inert gas generator must be located in the main...

2014-10-01

23

46 CFR 154.904 - Inert gas system: Controls.  

Code of Federal Regulations, 2010 CFR

...valve in the cargo area to prevent the back...vapor into the inert gas system, or another...b) If the inert gas system is in the...outside the cargo area, a second check valve in the cargo area meeting paragraph...Automatic and manual inert gas pressure...

2010-10-01

24

46 CFR 154.906 - Inert gas generators.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Inert gas generators. 154.906 Section 154...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment...Containment Systems § 154.906 Inert gas generators. The inert gas...

2011-10-01

25

46 CFR 154.904 - Inert gas system: Controls.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Inert gas system: Controls. 154.904 Section...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment...Containment Systems § 154.904 Inert gas system: Controls. The inert gas...

2011-10-01

26

46 CFR 154.906 - Inert gas generators.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Inert gas generators. 154.906 Section 154...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment...Containment Systems § 154.906 Inert gas generators. The inert gas...

2010-10-01

27

46 CFR 154.904 - Inert gas system: Controls.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Inert gas system: Controls. 154.904 Section...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment...Containment Systems § 154.904 Inert gas system: Controls. The inert gas...

2012-10-01

28

Positron-inert gas differential elastic scattering  

NASA Technical Reports Server (NTRS)

Measurements are being made in a crossed beam experiment of the relative elastic differential cross section (DCS) for 5 to 300 eV positrons scattering from inert gas atoms (He, Ne, Ar, Kr, and Xe) in the angular range from 30 to 134 deg. Results obtained at energies around the positronium (Ps) formation threshold provide evidence that Ps formation and possibly other inelastic channels have an effect on the elastic scattering channel.

Kauppila, W. E.; Smith, Steven J.; Kwan, C. K.; Stein, T. S.

1990-01-01

29

Crystallization of silicon nanoclusters with inert gas temperature control  

NASA Astrophysics Data System (ADS)

We analyze the fundamental process of crystallization of silicon nanoclusters by means of molecular dynamics simulations, complemented by magnetron-sputter inert gas condensation, which was used to synthesize polycrystalline silicon nanoclusters with good size control. We utilize two well-established Si interatomic potentials: the Stillinger-Weber and the Tersoff III. Both the simulations and experiments show that upon cooling down by an Ar gas thermal bath, initially liquid, free-standing Si nanocluster can grow multiple crystal nuclei, which drive their transition into polycrystalline solid nanoclusters. The simulations allow detailed analysis of the mechanism, and show that the crystallization temperature is size-dependent and that the probability of crystalline phase nucleation depends on the highest temperature the cluster reaches during the initial condensation and the cooling rate after it.

Zhao, Junlei; Singh, Vidyadhar; Grammatikopoulos, Panagiotis; Cassidy, Cathal; Aranishi, Kengo; Sowwan, Mukhles; Nordlund, Kai; Djurabekova, Flyura

2015-01-01

30

46 CFR 153.501 - Requirement for dry inert gas.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 false Requirement for dry inert gas. 153.501 Section 153.501 Shipping COAST...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2010-10-01

31

46 CFR 153.501 - Requirement for dry inert gas.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Requirement for dry inert gas. 153.501 Section 153.501 Shipping COAST...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2011-10-01

32

46 CFR 153.500 - Inert gas systems.  

Code of Federal Regulations, 2011 CFR

... 5 2011-10-01 2011-10-01 false Inert gas systems. 153.500 Section 153.500 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2011-10-01

33

46 CFR 153.501 - Requirement for dry inert gas.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Requirement for dry inert gas. 153.501 Section 153.501 Shipping COAST...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2012-10-01

34

46 CFR 153.500 - Inert gas systems.  

Code of Federal Regulations, 2012 CFR

... 5 2012-10-01 2012-10-01 false Inert gas systems. 153.500 Section 153.500 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2012-10-01

35

46 CFR 153.500 - Inert gas systems.  

Code of Federal Regulations, 2010 CFR

... 5 2010-10-01 2010-10-01 false Inert gas systems. 153.500 Section 153.500 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2010-10-01

36

46 CFR 153.500 - Inert gas systems.  

Code of Federal Regulations, 2013 CFR

... 5 2013-10-01 2013-10-01 false Inert gas systems. 153.500 Section 153.500 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2013-10-01

37

46 CFR 153.500 - Inert gas systems.  

Code of Federal Regulations, 2014 CFR

... 5 2014-10-01 2014-10-01 false Inert gas systems. 153.500 Section 153.500 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2014-10-01

38

Inert Gas Generation Utilizing Diesel Exhaust  

SciTech Connect

The generation of inert gas from 60 KW diesel engine exhaust by catalytic reduction of O{sub 2} and NO{sub x} has been demonstrated. Measured O{sub 2} levels were < 10 V{sub ppm} and NO{sub x} levels were {approx} 0.1 V{sub ppm} over a wide range of equivalence ratios. Durability of the catalytic converter was demonstrated up to 200 hours operating time at two diesel engine load conditions. Effective catalyst operating range was stoichiometric to rich fuel/air ratios. Optimum operation is at stoichiometric fuel/air ratios to minimize CO emissions. Alternative converter designs are proposed to allow operation over the full diesel engine load range with essentially zero emissions of O{sub 2}, NO{sub x} and CO.

Osgerby, I. T.; Durilla, M.

1981-01-01

39

46 CFR 154.908 - Inert gas generator: Location.  

Code of Federal Regulations, 2010 CFR

...b) of this section, an inert gas generator must be located in...space that is not in the cargo area and does not have direct access...control space. (b) An inert gas generator that does not use...equipment may be located in the cargo area if specially approved by...

2010-10-01

40

46 CFR 153.462 - Static discharges from inert gas systems.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Static discharges from inert gas systems. 153.462 Section...LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design...Cargoes § 153.462 Static discharges from inert gas systems. An inert...

2013-10-01

41

Hyperpolarized and Inert Gas MRI: The Future.  

PubMed

Magnetic resonance imaging (MRI) is a potentially ideal imaging modality for noninvasive, nonionizing, and longitudinal assessment of disease. Hyperpolarized (HP) agents have been developed in the past 20 years for MR imaging, and they have the potential to vastly improve MRI sensitivity for the diagnosis and management of various diseases. The polarization of nuclear magnetic resonance (NMR)-sensitive nuclei other than (1)H (e.g., (3)He, (129)Xe) can be enhanced by a factor of up to 100,000 times above thermal equilibrium levels, which enables direct detection of the HP agent with no background signal. In this review, a number of HP media applications in MR imaging are discussed, including HP (3)He and (129)Xe lung imaging, HP (129)Xe brain imaging, and HP (129)Xe biosensors. Inert fluorinated gas MRI, which is a new lung imaging technique that does not require hyperpolarization, is also briefly discussed. This technique will likely be an important future direction for the HP gas lung imaging community. PMID:25228404

Couch, Marcus J; Blasiak, Barbara; Tomanek, Boguslaw; Ouriadov, Alexei V; Fox, Matthew S; Dowhos, Krista M; Albert, Mitchell S

2015-04-01

42

46 CFR 154.903 - Inert gas systems: General.  

Code of Federal Regulations, 2013 CFR

...Construction and Equipment Atmospheric Control in Cargo Containment...boiling point and dewpoint at atmospheric pressure of the inert gas must be below the...c) For the temperatures and pressures at which the gas is stored...

2013-10-01

43

MUNICIPAL LANDFILL GAS CONDENSATE  

EPA Science Inventory

New regulations relative to air emissions from municipal landfills may require the installation of gas collection systems at landfills. As landfill gas (LFG) is collected, water and other vapors in the gas condense in the system or are purposely removed in the normal treatment of...

44

Inert-Gas Diffuser For Plasma Or Arc Welding  

NASA Technical Reports Server (NTRS)

Inert-gas diffuser provides protective gas cover for weld bead as it cools. Follows welding torch, maintaining continuous flow of argon over newly formed joint and prevents it from oxidizing. Helps to ensure welds of consistently high quality. Devised for plasma arc keyhole welding of plates of 0.25-in. or greater thickness, also used in tungsten/inert-gas and other plasma or arc welding processes.

Gilbert, Jeffrey L.; Spencer, Carl N.; Hosking, Timothy J.

1994-01-01

45

Apparatus For Metal/Inert-Gas Welding In Vacuum  

NASA Technical Reports Server (NTRS)

Metal/inert-gas welding-torch assembly operates in vacuum. Plasma generated in interior chamber and focused onto workpiece in vacuum. Pinch rollers feed wire to weld puddle. Controlled flow of plasma reduces dispersal in vacuum, preventing extinction.

Stocks, C. O.

1994-01-01

46

UV emission from excited inert-gas molecules  

Microsoft Academic Search

Continuous vacuum ultraviolet (VUV) spectra of diatomic inert-gas molecules are ideal objects of investigation when solving many fundamental and applied problems. Problems in plasma physics, molecular spectroscopy, development of sources of VUV radiation, and formation of inverted media in gas lasers (including those in the VUV range) are some of the principal ones. This review covering the last two decades

Gennadii N Gerasimov; B E Krylov; A V Loginov; S A Shchukin

1992-01-01

47

Heaterless ignition of inert gas ion thruster hollow cathodes  

NASA Technical Reports Server (NTRS)

Heaterless inert gas ion thruster hollow cathodes were investigated with the aim of reducing ion thruster complexity and increasing ion thruster reliability. Cathodes heated by glow discharges are evaluated for power requirements, flowrate requirements, and life limiting mechanisms. An accelerated cyclic life test is presented.

Schatz, M. F.

1985-01-01

48

Inert fluorinated gas MRI: a new pulmonary imaging modality.  

PubMed

Fluorine-19 ((19)F) MRI of the lungs using inhaled inert fluorinated gases can potentially provide high quality images of the lungs that are similar in quality to those from hyperpolarized (HP) noble gas MRI. Inert fluorinated gases have the advantages of being nontoxic, abundant, and inexpensive compared with HP gases. Due to the high gyromagnetic ratio of (19)F, there is sufficient thermally polarized signal for imaging, and averaging within a single breath-hold is possible due to short longitudinal relaxation times. Therefore, the gases do not need to be hyperpolarized prior to their use in MRI. This eliminates the need for an expensive polarizer and expensive isotopes. Inert fluorinated gas MRI of the lungs has been previously demonstrated in animals, and more recently in healthy volunteers and patients with lung diseases. The ongoing improvements in image quality demonstrate the potential of (19)F MRI for visualizing the distribution of ventilation in human lungs and detecting functional biomarkers. In this brief review, the development of inert fluorinated gas MRI, current progress, and future prospects are discussed. The current state of HP noble gas MRI is also briefly discussed in order to provide context to the development of this new imaging modality. Overall, this may be a viable clinical imaging modality that can provide useful information for the diagnosis and management of chronic respiratory diseases. PMID:25066661

Couch, Marcus J; Ball, Iain K; Li, Tao; Fox, Matthew S; Ouriadov, Alexei V; Biman, Birubi; Albert, Mitchell S

2014-12-01

49

Inert gas accumulation in sonoluminescing bubbles  

Microsoft Academic Search

In this paper we elaborate on the idea [Lohse et al., Phys. Rev. Lett. 78, 1359-1362 (1997)] that (single) sonoluminescing air bubbles rectify argon. The reason for the rectification is that nitrogen and oxygen dissociate and their reaction products dissolve in water. We give further experimental and theoretical evidence and extend the theory to other gas mixtures. We show that

Detlef Lohse; Sascha Hilgenfeldt

1997-01-01

50

Lattice Dynamics of Inert Gas Monolayers  

NASA Astrophysics Data System (ADS)

Lattice dynamics of rare gas monolayers is discussed over a range of nearest-neighbor separations and temperatures. The self-consistent phonon method is used in its harmonic and cubic approximations. The floating phase, in which the atoms occupy sites of a two-dimensional triangular lattice is considered first. The quantum effects are seen to be large in neon at all temperatures, while rather insignificant in xenon at low temperatures. The phonon energies in the transverse and longitudinal modes are calculated. They are found to be more sensitive to temperature and lattice parameter than in three dimensions. Sound velocities and elastic constants are evaluated for the monolayers, as well as several dynamical quantities, zero-point energies, Debye frequencies and mean vibrational amplitudes. Thermodynamic quantities including pressure isotherms, specific heats, lattice compressibility constants and free energies are also presented. The monolayer is next pinned down by a graphite substrate to form a registered structure. In addition to the adatom-adatom interaction, the effect of the graphite surface is now included through a single particle potential, and a dispersive screening force. In this phase, owing to the lack of translational invariance, a band gap is established at the center of the Brillouin zone and the system displays no acoustic phonons. The band gaps are detected and the temperature at which they vanish, known as the floating transition temperature, is calculated for xenon and krypton. The krypton adsorbed monolayer presents a different behavior from its floating counterpart; the substrate increases its anharmonicity. The xenon monolayer, on the other hand, is seen to preserve its floating properties. The cubic theory is applied next to add the appropriate correction to the phonon spectrum, and the final energies turn out to be smaller than the ones predicted by the self -consistent harmonic approximation. The self-energy of the phonons and the dynamic structure factors result naturally from the theory.

Hakim, Toufic Maurice

51

Experimental study of steam condensation on water in countercurrent flow in presence of inert gases  

NASA Astrophysics Data System (ADS)

Experimental results of investigating steam condensation on water in the presence of (noncondensable) inert gases at low temperatures and pressures relevant to open-cycle ocean thermal energy conversion (OTEC) systems are reported. Seven different condenser configurations were tested. The experimental data are correlated using a liquid flow fraction and a vent fraction to yield simple relationships of condenser performance over a wide range of test conditions. Performance maps and envelopes are provided for evaluating the relative merits of tested configurations. The height of transfer unit (HTU) for condensation ranges from 0.2 to 0.3 m among the various condenser geometries. Also reported are the pressure-loss coefficients for all the tested geometries.

Bharathan, D.; Althof, J.

1984-08-01

52

Evacuation of a Residual Oil Pipeline by Inert Gas Displacement  

Microsoft Academic Search

This paper describes an analysis developed to model the inert gas displacement process for evacuating a high-pour-point oil from a long pipeline. The governing equations were derived from the basic conservation equations for mass, momentum, and energy. The resultant computer program accounts for such effects as pipeline elevation changes, laminar and turbulent oil flow, temperature-dependent oil viscosity, and heat loss

S. Webb; E. Bogucz; E. Levy; M. L. Barrett; C. Snyder; C. Waters

1987-01-01

53

Moving in extreme environments: inert gas narcosis and underwater activities.  

PubMed

Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwater breathing apparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body. One of the common consequences of hyperbaric gas is the narcotic effect of inert gas. Nitrogen (a major component of air) under pressure can impede mental function and physical performance at depths of as little as 10 m underwater. With increased depth, symptoms can worsen to include confusion, disturbed coordination, lack of concentration, hallucinations and unconsciousness. Narcosis has been shown to contribute directly to up to 6% of deaths in divers and is likely to be indirectly associated with other diving incidents at depth. This article explores inert gas narcosis, the effect on divers' movement and function underwater and the proposed physiological mechanisms. Also discussed are some of the factors that affect the susceptibility of divers to the condition. In conclusion, understanding the cause of this potentially debilitating problem is important to ensure that safe diving practices continue. PMID:25713701

Clark, James E

2015-01-01

54

Nuclear Technology. Course 28: Welding Inspection. Module 28-3, Tungsten Inert Gas (TIG), Metal Inert Gas (MIG) and Submerged Arc Welding.  

ERIC Educational Resources Information Center

This third in a series of ten modules for a course titled Welding Inspection presents the apparatus, process techniques, procedures, applications, associated defects, and inspection for the tungsten inert gas, metal inert gas, and submerged arc welding processes. The module follows a typical format that includes the following sections: (1)…

Espy, John

55

Synthesis and deposition of metal nanoparticles by gas condensation process  

SciTech Connect

In this work, the synthesis of Pt and Ag nanoparticles by means of the inert gas phase condensation of sputtered atomic vapor is presented. The process parameters (power, sputtering time, and gas flow) were varied in order to study the relationship between deposition conditions and properties of the nanoparticles such as their quantity, size, and size distribution. Moreover, the gas phase condensation process can be combined with a plasma enhanced chemical vapor deposition procedure in order to deposit nanocomposite coatings consisting of metallic nanoparticles embedded in a thin film matrix material. Selected examples of application of the generated nanoparticles and nanocomposites are discussed.

Maicu, Marina, E-mail: marina.maicu@fep.fraunhofer.de; Glöß, Daniel; Frach, Peter [Fraunhofer Institut für Elektronenstrahl und Plasmatechnik, FEP, Winterbergstraße 28, 01277 Dresden (Germany); Schmittgens, Ralph; Gerlach, Gerald [Institut für Festkörperelektronik, IFE, TU Dresden, Helmholtz Straße 18, 01069 Dresden (Germany); Hecker, Dominic [Fraunhofer Institut für Elektronenstrahl und Plasmatechnik, FEP, Winterbergstraße 28, 01277 Dresden, Germany and Institut für Festkörperelektronik, IFE, TU Dresden, Helmholtz Straße 18, 01069 Dresden (Germany)

2014-03-15

56

Closed-Loop System Removes Contaminants From Inert Gas  

NASA Technical Reports Server (NTRS)

Concentration of oxygen in this closed-loop system kept low by use of heated catalytic sorbent bed in cartridge. Proposed to keep concentration of water vapor low by use of predried zeolite sorbent bed in another cartridge, and to remove particles smaller than 0.1 micrometer by use of porous metal filters. In specific application, chamber is one in which semiconducting materials processed. By virtue of closed-loop operation, limited supply of inert gas adequate to provide atmosphere for industrial processing of semiconductors.

Sharma, Pramod K.

1995-01-01

57

A scintillation detector for measuring inert gas beta rays  

NASA Astrophysics Data System (ADS)

The inert gas beta ray scintillation detector, which is made of organic high polymers as the base and coated with compact fluorescence materials, is a lower energy scintillation detector. It can be used in the nuclear power plant and radioactive fields as a lower energy monitor to detect inert gas beta rays. Under the conditions of time constant 10 minutes, confidence level is 99.7 percent (3 sigma), the intensity of gamma rays 2.6 x 10(sup -7) C/kg (Co-60), and the minimum detectable concentration (MDC) of this detector for Xe-133 1.2 Bq/L. The measuring range for Xe-133 is 11.1 (similar to) 3.7 x 10(exp 4) Bq/L. After a special measure is taken, the device is able to withstand 3 x 10(exp 5) Pa gauge pressure. In the loss-of-cooolant-accident, it can prevent the radioactive gas of the detector from leaking. This detector is easier to be manufactured and decontaminated.

Shi, Hengchang; Yu, Yunchang

1989-10-01

58

46 CFR 153.462 - Static discharges from inert gas systems.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Static discharges from inert gas systems. 153.462 Section 153.462 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2011-10-01

59

46 CFR 153.462 - Static discharges from inert gas systems.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Static discharges from inert gas systems. 153.462 Section 153.462 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2012-10-01

60

46 CFR 153.462 - Static discharges from inert gas systems.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Static discharges from inert gas systems. 153.462 Section 153.462 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2014-10-01

61

46 CFR 153.462 - Static discharges from inert gas systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Static discharges from inert gas systems. 153.462 Section 153.462 Shipping...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment...

2010-10-01

62

Development of advanced inert-gas ion thrusters  

NASA Technical Reports Server (NTRS)

Inert gas ion thruster technology offers the greatest potential for providing high specific impulse, low thrust, electric propulsion on large, Earth orbital spacecraft. The development of a thruster module that can be operated on xenon or argon propellant to produce 0.2 N of thrust at a specific impulse of 3000 sec with xenon propellant and at 6000 sec with argon propellant is described. The 30 cm diameter, laboratory model thruster is considered to be scalable to produce 0.5 N thrust. A high efficiency ring cusp discharge chamber was used to achieve an overall thruster efficiency of 77% with xenon propellant and 66% with argon propellant. Measurements were performed to identify ion production and loss processes and to define critical design criteria (at least on a preliminary basis).

Poeschel, R. L.

1983-01-01

63

Doped inert gas crystalline media for cryogenic lasers  

NASA Astrophysics Data System (ADS)

Emissions from charge transfer states of rare gas halide RgX molecules (XeF, KrF), alkali halide ions AX (CsF, CsCl, RbF), from vibrational states of CO and NO, and also from CO2 molecules doped into rare gas and N2 solids combine the known properties of gas phase lasers transitions with high densities of excited states attainable in the condensed phase. Cryogenic solids prepared by direct condensation of gas mixtures are grown routinely and allow for solid state laser experiments and also observation of strong luminescence bands in the VUV (B-X excimer transition of RbF at 136 nm), UV (B-X transition of CsF and CsCl at 196 and 210 nm; CsF(C-A) at 211 nm; XeF(D-X) at 269; 286 and 301 nm in Ne, Ar and Kr hosts, respectively), visible (XeF(B-X) and (C-A) at 411;541 nm) and infrared wavelength region (4.96; 5.4 and 16 micrometers bands of CO, NO and CO2).

Frankowski, M.; Sliwinski, Gerard; Schwentner, Nikolaus

1999-03-01

64

Inert-gas welding and brazing enclosure fabricated from sheet plastic  

NASA Technical Reports Server (NTRS)

Custom-fabricated plastic bag maintains an inert-gas atmosphere for welding and brazing certain metals. The bag fits over part of the workpieces and the welding and brazing tools. It is also used for metal brazing and fusion plating which require an inert-gas atmosphere.

Wisner, J. P.

1965-01-01

65

Relationships among ventilation-perfusion distribution, multiple inert gas methodology and metabolic blood-gas tensions.  

PubMed

The retention equations upon which the Multiple Inert Gas Method is based are derived from basic principles using elementary algebra. It is shown that widely disparate distributions produce indistinguishable sets of retentions. The limits of resolution of perfused compartments in the VA/Q distribution obtainable by the use of the multiple inert gas method are explored mathematically, and determined to be at most shunt and two alveolar compartments ("tripartite" distribution). Every continuous distribution studied produced retentions indistinguishable from those of its unique "matching" tripartite distribution. When a distribution is minimally specified, it is unique. Any additional specification (increased resolution--more compartments) of the distribution results in the existence of an infinitude of possible distributions characterized by indistinguishable sets of retention values. No further increase in resolution results from the use of more tracers. When sets of retention values were extracted from published multiple inert gas method continuous distributions, and compared with the published "measured" retention sets, substantial differences were found. This illustrates the potential errors incurred in the practical, in vivo application of the multiple inert gas method. In preliminary studies, the tripartite distribution could be determined with at least comparable accuracy by blood-gas (oxygen, carbon dioxide) measurements. PMID:2827715

Lee, A S; Patterson, R W; Kaufman, R D

1987-12-01

66

Automated measurement of respiratory gas exchange by an inert gas dilution technique  

NASA Technical Reports Server (NTRS)

A respiratory gas analyzer (RGA) has been developed wherein a mass spectrometer is the sole transducer required for measurement of respiratory gas exchange. The mass spectrometer maintains all signals in absolute phase relationships, precluding the need to synchronize flow and gas composition as required in other systems. The RGA system was evaluated by comparison with the Douglas bag technique. The RGA system established the feasibility of the inert gas dilution method for measuring breath-by-breath respiratory gas exchange. This breath-by-breath analytical capability permits detailed study of transient respiratory responses to exercise.

Sawin, C. F.; Rummel, J. A.; Michel, E. L.

1974-01-01

67

THE SECRETION OF INERT GAS INTO THE SWIM-BLADDER OF FISH  

PubMed Central

The composition of the gas mixture secreted into the swim-bladders of several species of fish has been determined in the mass spectrometer. The secreted gas differed greatly from the gas mixture breathed by the fish in the relative proportions of the chemically inert gases, argon, neon, helium, and nitrogen. Relative to nitrogen the proportion of the very soluble argon was increased and the proportions of the much less soluble neon and helium decreased. The composition of the secreted gas approaches the composition of the gas mixture dissolved in the tissue fluid. A theory of inert gas secretion is proposed. It is suggested that oxygen gas is actively secreted and evolved in the form of minute bubbles, that inert gases diffuse into these bubbles, and that the bubbles are passed into the swim-bladder carrying with them inert gases. Coupled to a preferential reabsorption of oxygen from the swim-bladder this mechanism can achieve high tensions of inert gas in the swim-bladder. The accumulation of nearly pure nitrogen in the swim-bladder of goldfish (Carassius auratus) is accomplished by the secretion of an oxygen-rich gas mixture followed by the reabsorption of oxygen. PMID:13514011

Wittenberg, Jonathan B.

1958-01-01

68

Operation of the J-series thruster using inert gas  

NASA Technical Reports Server (NTRS)

Electron bombardment ion thrusters using inert gases are candidates for large space systems. The J-Series 30 cm diameter thruster, designed for operation up to 3 k-W with mercury, is at a state of technology readiness. The characteristics of operation with xenon, krypton, and argon propellants in a J-Series thruster with that obtained with mercury are compared. The performance of the discharge chamber, ion optics, and neutralizer and the overall efficiency as functions of input power and specific impulse and thruster lifetime were evaluated. As expected, the discharge chamber performance with inert gases decreased with decreasing atomic mass. Aspects of the J-Series thruster design which would require modification to provide operation at high power with insert gases were identified.

Rawlin, V. K.

1982-01-01

69

Continuous injection of an inert gas through a drill rig for drilling into potentially hazardous areas  

DOEpatents

A drill rig for drilling in potentially hazardous areas includes a drill having conventional features such as a frame, a gear motor, gear box, and a drive. A hollow rotating shaft projects through the drive and frame. An auger, connected to the shaft is provided with a multiplicity of holes. An inert gas is supplied to the hollow shaft and directed from the rotating shaft to the holes in the auger. The inert gas flows down the hollow shaft, and then down the hollow auger and out through the holes in the bottom of the auger into the potentially hazardous area. 3 figs.

McCormick, S.H.; Pigott, W.R.

1997-12-30

70

Continuous injection of an inert gas through a drill rig for drilling into potentially hazardous areas  

DOEpatents

A drill rig for drilling in potentially hazardous areas includes a drill having conventional features such as a frame, a gear motor, gear box, and a drive. A hollow rotating shaft projects through the drive and frame. An auger, connected to the shaft is provided with a multiplicity of holes. An inert gas is supplied to the hollow shaft and directed from the rotating shaft to the holes in the auger. The inert gas flows down the hollow shaft, and then down the hollow auger and out through the holes in the bottom of the auger into the potentially hazardous area.

McCormick, Steve H. (Idaho Falls, ID); Pigott, William R. (Idaho Falls, ID)

1997-01-01

71

Continuous injection of an inert gas through a drill rig for drilling into potentially hazardous areas  

SciTech Connect

A drill rig for drilling in potentially hazardous areas includes a drill having conventional features such as a frame, a gear motor, gear box, and a drive. A hollow rotating shaft projects through the drive and frame. An auger, connected to the shaft is provided with a multiplicity of holes. An inert gas is supplied to the hollow shaft and directed from the rotating shaft to the holes in the auger. The inert gas flows down the hollow shaft, and then down the hollow auger, and out through the holes in the bottom of the auger into the potentially hazardous area.

McCormick, S.H.; Pigott, W.R.

1998-04-01

72

Thermodynamics and transport properties of metal\\/inert-gas mixtures used for arc welding  

Microsoft Academic Search

The knowledge of thermodynamics and transport properties of gas mixtures at high temperature is important for many industrial applications. Spark ignition, re-entry problems of space-vehicles, gas dischargers, arc welding, and circuit breakers can be mentioned as examples. This paper focuses on metal\\/inert-gas mixtures in the temperature range from 300 to 30,000K, which are important for arc welding processes. As metals

T. Hoffmann; G. Baldea; U. Riedel

2009-01-01

73

Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D  

E-print Network

Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D W. Zhou*, T. Z. Long and C. K ductility, and the HAZ was found to be the `weakest link'. Keywords: Magnesium alloy, AZ91D, TIG welding, Hot cracking, Liquation, Fracture Introduction Magnesium alloys have high strength/weight ratio

Zhou, Wei

74

Highly sensitive solids mass spectrometer uses inert-gas ion source  

NASA Technical Reports Server (NTRS)

Mass spectrometer provides a recorded analysis of solid material surfaces and bulk. A beam of high-energy inert-gas ions bombards the surface atoms of a sample and converts a percentage into an ionized vapor. The mass spectrum analyzer separates the vapor ionic constituents by mass-to-charge ratio.

1966-01-01

75

Comments on ``Behaviour of inert gas bubbles under chemical concentration gradients'' by G.P. Tiwari  

NASA Astrophysics Data System (ADS)

The motion of inert gas bubbles induced by thermal vacancy gradients has previously been used by the present authors to understand gas bubble release in UO 2 and metals. This approach has been recently questioned by Tiwari. In the present letter, a critical discussion of his viewpoint is presented, together with an analysis of the important experimental results of Marachov et al. There appears to be good evidence for the disputed effect.

Evans, J. H.; van Veen, A.

1998-01-01

76

Optimization of condensing gas drive  

E-print Network

injection pressure was increased. The validity of the model was established by accurately simulating several low pressure gas drives conducted in the laboratory. Oil recoveries at gas breakthrough using the model compared closely with those recoveries... Properties Used to Simulate Lean Gas In3ection. 22 Physical Properties of Reservoir Fluid A. Physical Properties of Reservoir Fluid B. 23 24 Fractional Oil Recovery at Gas Breakthrough Using Freon-Decane, 26 Fractional Oil Recovery at Gas Breakthrough...

Lofton, Larry Keith

1977-01-01

77

Onboard Inert Gas Generation System/Onboard Oxygen Gas Generation System (OBIGGS/OBOGS) Study. Part 1; Aircraft System Requirements  

NASA Technical Reports Server (NTRS)

The purpose of this technology assessment is to define a multiphase research study program investigating Onboard Inert Gas Generation Systems (OBIGGS) and Onboard Oxygen Generation Systems (OBOGS) that would identify current airplane systems design and certification requirements (Subtask 1); explore state-of-the-art technology (Subtask 2); develop systems specifications (Subtask 3); and develop an initial system design (Subtask 4). If feasible, consideration may be given to the development of a prototype laboratory test system that could potentially be used in commercial transport aircraft (Subtask 5). These systems should be capable of providing inert nitrogen gas for improved fire cargo compartment fire suppression and fuel tank inerting and emergency oxygen for crew and passenger use. Subtask I of this research study, presented herein, defines current production aircraft certification requirements and design objectives necessary to meet mandatory FAA certification requirements and Boeing design and performance specifications. These requirements will be utilized for baseline comparisons for subsequent OBIGGS/OBOGS application evaluations and assessments.

Reynolds, Thomas L.; Bailey, Delbert B.; Lewinski, Daniel F.; Roseburg, Conrad M.; Palaszewski, Bryan (Technical Monitor)

2001-01-01

78

Research on inert gas narcosis and air velocity effects on metabolic performance  

NASA Technical Reports Server (NTRS)

The effects of air velocity on metabolic performance are studied by using high forced airflow in a closed environment as a mechanism to control the concentration of volatile animal wastes. Air velocities between 100 and 200 ft/min are without significant effects on the metabolism of rats. At velocities of 200 ft/min and above, oxygen consumption and CO2 production as well as food consumption increase. In most instances, the changes are on the order of 5-10%. At the same time, the RQ for the animals increases slightly and generally correlates well with oxygen consumption and CO2 production. Experiments on the nature of inert gas narcosis show that halothane and methoxyflurane are rather potent inhibitors of the NADH:O2 oxidoreductase system in rats. These experiments suggest that the mechanism of inert gas narcosis is not mandatorily related to a membrane surface phenomenon.

1974-01-01

79

Can pyrophoric materials form in oil tankers with inert gas fire protection systems. Final report  

Microsoft Academic Search

A literature study and analysis was made concerning the potential hazard of pyrophoric ignition of flammable vapors in oil tankers with inert gas systems (IGS). Only two pyrophor possibilities seem to be likely: Formation of ferrous sulfide (FeS) and\\/or ferrous oxide (FeO). Both FeS and FeO may be formed in an oxygen limited atmosphere, such as would be the case

Affens

1977-01-01

80

A voltammetric sensor on the basis of bismuth nanoparticles prepared by the method of gas condensation  

Microsoft Academic Search

A procedure is developed for the immobilization of bismuth nanoparticles prepared by the method of gas condensation on inert\\u000a supports manufactured by the screen printing method using carbon-containing inks. The electrochemical behavior of the immobilized\\u000a bismuth nanoparticles is investigated, and the conditions of their electrochemical activation are found. The composition of\\u000a the modifying suspension “bismuth nanoparticles-liquid” is optimized. The elaborated

N. A. Malakhova; A. A. Mysik; S. Yu. Saraeva; N. Yu. Stozhko; M. A. Uimin; A. E. Ermakov; Kh. Z. Brainina

2010-01-01

81

Gas condensate damage in hydraulically fractured wells  

E-print Network

This project is a research into the effect of gas condensate damage in hydraulically fractured wells. It is the result of a problem encountered in producing a low permeability formation from a well in South Texas owned by the El Paso Production...

Adeyeye, Adedeji Ayoola

2004-09-30

82

Gas condensate damage in hydraulically fractured wells  

E-print Network

This project is a research into the effect of gas condensate damage in hydraulically fractured wells. It is the result of a problem encountered in producing a low permeability formation from a well in South Texas owned by the El Paso Production...

Reza, Rostami Ravari

2004-11-15

83

Substitution-inert trinuclear platinum complexes efficiently condense/aggregate nucleic acids and inhibit enzymatic activity.  

PubMed

The trinuclear platinum complexes (TriplatinNC-A [{Pt(NH3 )3 }2 -?-{trans-Pt(NH3 )2 (NH2 (CH2 )6 NH2 )2 }](6+) , and TriplatinNC [{trans-Pt(NH3 )2 (NH2 (CH2 )6 NH3 (+) )}2 -?-{trans-Pt(NH3 )2 (NH2 (CH2 )6 NH2 )2 }](8+) ) are biologically active agents that bind to DNA through noncovalent (hydrogen bonding, electrostatic) interactions. Herein, we show that TriplatinNC condenses DNA with a much higher potency than conventional DNA condensing agents. Both complexes induce aggregation of small transfer RNA molecules, and TriplatinNC in particular completely inhibits DNA transcription at lower concentrations than naturally occurring spermine. Topoisomerase?I-mediated relaxation of supercoiled DNA was inhibited by TriplatinNC-A and TriplatinNC at concentrations which were 60?times and 250?times lower than that of spermine. The mechanisms for the biological activity of TriplatinNC-A and TriplatinNC may be associated with their ability to condense/aggregate nucleic acids with consequent inhibitory effects on crucial enzymatic activities. PMID:25256921

Malina, Jaroslav; Farrell, Nicholas P; Brabec, Viktor

2014-11-17

84

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

PubMed

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. PMID:23869066

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

2013-10-15

85

Inert Gas Dilution Effect on the Flammability Limits of Hydrocarbon Mixtures  

E-print Network

, in which the inert gas agents, mostly including nitrogen, carbon dioxide, and argon, are of interest, because they are not only non-ozone-depleting but also non-toxic and non-pyrolytic gases. 1.2 Objectives In this research, nitrogen dilution effect... with additional nitrogen using CAFT modeling?????...125 6.7 Methane LFL with additional carbon dioxide using CAFT modeling???...127 6.8 Propylene LFL with additional carbon dioxide using CAFT modeling???.128 6.9 Methane and propane LFL with additional nitrogen...

Zhao, Fuman

2012-02-14

86

Pion condensation in a dense neutrino gas  

E-print Network

We argue that using an equilibrated gas of neutrinos it is possible to probe the phase diagram of QCD for finite isospin and small baryon chemical potentials. We discuss this region of the phase diagram in detail and demonstrate that for large enough neutrino densities a Bose-Einstein condensate of positively charged pions arises. Moreover, we show that for nonzero neutrino density the degeneracy in the lifetimes and masses of the charged pions is lifted.

Hiroaki Abuki; Tomas Brauner; Harmen J. Warringa

2009-08-26

87

Experimental observations of effects of inert gas on cavity formation during irradiation  

SciTech Connect

Cavity (void) formation and swelling in non-fissile materials during neutron irradiation and charged particle bombardments are reviewed. Helium is the most important inert gas and is primarily active as a cavity nucleant. It also enhances formation of dislocation structure. Preimplantation of helium overstimulates cavity nucleation and gives a different temperature response of swelling than when helium is coimplanted during the damage process. Helium affects, and is affected by, radiation-induced phase instability. Many of these effects are explainable in terms of cavity nucleation on submicroscopic critical size gas bubbles, and on the influence of the neutral sink strength of such bubbles. Titanium and zirconium resist cavity formation when vacancy loops are present.

Farrell, K.

1980-04-01

88

Analysis of condensate banking dynamics in a gas condensate reservoir under different injection schemes  

E-print Network

ANALYSIS OF CONDENSATE BANKING DYNAMICS IN A GAS CONDENSATE RESERVOIR UNDER DIFFERENT INJECTION SCHEMES A Thesis by ANGELICA PATRICIA SANDOVAL RODRIGUEZ Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE August 2002 Major Subject: Petroleum Engineering ANALYSIS OF CONDENSATE BANKING DYNAMICS IN A GAS CONDENSATE RESERVOIR UNDER DIFFERENT INJECTION SCHEMES A Thesis by ANGELICA PATRICIA...

Sandoval Rodriguez, Angelica Patricia

2002-01-01

89

Comparison of inert-gas-fusion and modified Kjeldahl techniques for determination of nitrogen in niobium alloys  

NASA Technical Reports Server (NTRS)

This report compares results obtained for the determination of nitrogen in a selected group of niobium-base alloys by the inert-gas-fusion and the Kjeldahl procedures. In the inert-gas-fusion procedure the sample is heated to approximately 2700 C in a helium atmosphere in a single-use graphite crucible. A platinum flux is used to facilitate melting of the sample. The Kjeldahl method consisted of a rapid decomposition with a mixture of hydrofluoric acid, phosphoric acid, and potassium chromate; distillation in the presence of sodium hydroxide; and highly sensitive spectrophotometry with nitroprusside-catalyzed indophenol. In the 30- to 80-ppm range, the relative standard deviation was 5 to 7 percent for the inert-gas-fusion procedure and 2 to 8 percent for the Kjeldahl procedure. The agreement of the nitrogen results obtained by the two techniques is considered satisfactory.

Merkle, E. J.; Graab, J. W.; Davis, W. F.

1974-01-01

90

GAS CONDENSATION IN THE GALACTIC HALO  

SciTech Connect

Using adaptive mesh refinement (AMR) hydrodynamic simulations of vertically stratified hot halo gas, we examine the conditions under which clouds can form and condense out of the hot halo medium to potentially fuel star formation in the gaseous disk. We find that halo clouds do not develop from linear isobaric perturbations. This is a regime where the cooling time is longer than the Brunt-Vaeisaelae time, confirming previous linear analysis. We extend the analysis into the nonlinear regime by considering mildly or strongly nonlinear perturbations with overdensities up to 100, also varying the initial height, the cloud size, and the metallicity of the gas. Here, the result depends on the ratio of cooling time to the time required to accelerate the cloud to the sound speed (similar to the dynamical time). If the ratio exceeds a critical value near unity, the cloud is accelerated without further cooling and gets disrupted by Kelvin-Helmholtz and/or Rayleigh-Taylor instabilities. If it is less than the critical value, the cloud cools and condenses before disruption. Accreting gas with overdensities of 10-20 is expected to be marginally unstable; the cooling fraction will depend on the metallicity, the size of the incoming cloud, and the distance to the galaxy. Locally enhanced overdensities within cold streams have a higher likelihood of cooling out. Our results have implications on the evolution of clouds seeded by cold accretion that are barely resolved in current cosmological hydrodynamic simulations and absorption line systems detected in galaxy halos.

Joung, M. Ryan; Bryan, Greg L.; Putman, Mary E., E-mail: moo@astro.columbia.edu [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

2012-02-01

91

Effect of the Inert Gas Adsorption on the Bilayer Graphene to the Localized Electron Magnetotransport  

NASA Astrophysics Data System (ADS)

Graphene has a fascinating property that the two-dimensional electron gas is easily accessible externally and it is challenging to investigate the effects of the adsorption of inert gases on graphene, which may be the least effective chemically and physically. We carry out the magnetotransport measurements of 4He-adsorbed bilayer graphene at low temperatures and the magnetic field B ranging from 0 to 4 T. The magnetoresistance ?Rxx change from the pristine graphene is measured as a function of gate voltage Vg and B for partial coverage of 1/10 (= 0.1) layers and one layer 4He-adsorbed graphene. The overall magnitudes of ?Rxx for one layer are larger than the one for 1/10 layers. Signs of ?Rxx depend on the Vg for the entire range of B, associated with the magnetoresistance oscillation owing to the weak localization in the pristine graphene.

Fukuda, A.; Terasawa, D.; Ohno, Y.; Matsumoto, K.

2014-12-01

92

Argon: Systematic Review on Neuro- and Organoprotective Properties of an “Inert” Gas  

PubMed Central

Argon belongs to the group of noble gases, which are regarded as chemically inert. Astonishingly some of these gases exert biological properties and during the last decades more and more reports demonstrated neuroprotective and organoprotective effects. Recent studies predominately use in vivo or in vitro models for ischemic pathologies to investigate the effect of argon treatment. Promising data has been published concerning pathologies like cerebral ischemia, traumatic brain injury and hypoxic ischemic encephalopathy. However, models applied and administration of the therapeutic gas vary. Here we provide a systematic review to summarize the available data on argon’s neuro- and organoprotective effects and discuss its possible mechanism of action. We aim to provide a summary to allow further studies with a more homogeneous setting to investigate possible clinical applications of argon. PMID:25310646

Höllig, Anke; Schug, Anita; Fahlenkamp, Astrid V.; Rossaint, Rolf; Coburn, Mark

2014-01-01

93

Electroluminescence of monodispersed silicon nanocrystallites synthesized by pulsed laser ablation in inert background gas  

NASA Astrophysics Data System (ADS)

We have characterized dc-excited light-emitting properties of monodispersed silicon (Si) nanocrystallites (nc-Si) synthesized by pulsed laser ablation in inert background gas. In a case where the monodispersed nc-Si were passivated by an indium oxide (In 2O 3) layer without breaking the vacuum, the electroluminescence (EL) spectrum had a narrow bandwidth of 0.15 eV peaked at slightly higher energy region (1.17 eV) than the bulk Si energy gap (1.11 eV), at room temperature. On the other hand, broad visible EL (peak: 1.7 eV, bandwidth: 0.46 eV) appeared when the monodispersed nc-Si were exposed to air before In 2O 3 passivation. These light-emitting mechanisms are discussed in relation to quantum confinement effects and oxide-related emission centers.

Makino, Toshiharu; Yamada, Yuka; Suzuki, Nobuyasu; Yoshida, Takehito; Onari, Seinosuke

2002-09-01

94

Electron temperature and density measurement of tungsten inert gas arcs with Ar-He shielding gas mixture  

NASA Astrophysics Data System (ADS)

The diagnostics of atmospheric welding plasma is a well-established technology. In most cases the measurements are limited to processes using pure shielding gas. However in many applications shielding gas is a mixture of various components including metal vapor in gas metal arc welding (GMAW). Shielding gas mixtures are intentionally used for tungsten inert gas (TIG) welding in order to improve the welding performance. For example adding Helium to Argon shielding gas allows the weld geometry and porosity to be influenced. Yet thermal plasmas produced with gas mixtures or metal vapor still require further experimental investigation. In this work coherent Thomson scattering is used to measure electron temperature and density in these plasmas, since this technique allows independent measurements of electron and ion temperature. Here thermal plasmas generated by a TIG process with 50% Argon and 50% Helium shielding gas mixture have been investigated. Electron temperature and density measured by coherent Thomson scattering have been compared to the results of spectroscopic measurements of the plasma density using Stark broadening of the 696.5 nm Argon spectral line. Further investigations of MIG processes using Thomson scattering technique are planned.

Kühn-Kauffeldt, M.; Marques, J.-L.; Forster, G.; Schein, J.

2013-10-01

95

Spark gap switch system with condensable dielectric gas  

DOEpatents

A spark gap switch system is disclosed which is capable of operating at a high pulse rate comprising an insulated switch housing having a purging gas entrance port and a gas exit port, a pair of spaced apart electrodes each having one end thereof within the housing and defining a spark gap therebetween, an easily condensable and preferably low molecular weight insulating gas flowing through the switch housing from the housing, a heat exchanger/condenser for condensing the insulating gas after it exits from the housing, a pump for recirculating the condensed insulating gas as a liquid back to the housing, and a heater exchanger/evaporator to vaporize at least a portion of the condensed insulating gas back into a vapor prior to flowing the insulating gas back into the housing.

Thayer, III, William J. (Kent, WA)

1991-01-01

96

Process parameter selection for optimizing the weld pool geometry in the tungsten inert gas welding of stainless steel  

Microsoft Academic Search

In this paper, the selection of process parameters for obtaining an optimal weld pool geometry in the tungsten inert gas (TIG) welding of stainless steel is presented. Basically, the geometry of the weld pool has several quality characteristics, for example, the front height, front width, back height and back width of the weld pool. To consider these quality characteristics together

S. C Juang; Y. S Tarng

2002-01-01

97

Emission lines from condensing intracluster gas  

NASA Technical Reports Server (NTRS)

We present computations of the emission-line spectra produced when hot gas cools nonuniformly. During inhomogeneous cooling, soft X-ray/extreme ultraviolet radiation from 10(exp 5) to 10(exp 7) K gas photoionizes coexisting clouds that have already cooled to 10(exp 4) K. Thus, strong emission lines emerge from both the high-ionization cooling gas and embedded low-ionization knots. This mechanism, which ought to operate naturally within the sonic radii of cooling flows, can generate optical emission-line spectra similar to those observed at the centers of many clusters of galaxies thought to contain such flows. We have computed the X-ray, ultraviolet (UV), optical, and infrared (IR) emission-line fluxes expected under a variety of intracluster conditions so that the self-irradiation hypothesis can be compared thoroughly with observations. If this picture is found to be adequate, the models can also be used to measure mass flow rates and inflow velocities in the vicinities of cooling-flow nebulae and to constrain the column densities and covering factors of condensed material at the centers of these clusters.

Voit, G. Mark; Donahue, Megan; Slavin, Jonathan D.

1994-01-01

98

Characterization of uranium carbide microspheres in an inert zirconium carbide matrix for gas fast reactors  

NASA Astrophysics Data System (ADS)

The characterization of an advanced nuclear fuel for Gas Fast reactors has been studied. Portions of a dispersion/composite fuel involving Uranium Carbide (UC) and Zirconium Carbide (ZrC) have been characterized and studied. Uranium carbide (UC) microspheres produced in the USC-Nuclear Materials Laboratory were subjected to metallographic techniques, and then characterized by analytical methods. A method for separation of spherical and non-spherical microspheres was developed involving an inclined plane. Metallography was done using the LECO SS-1000 grinder/polisher system. Quantitative analysis and imagery were gathered using scanning electron microscopy (SEM), back scattering electron microscopy (BSE), electron microprobe for quantitative analysis (EPMA), and x-ray photoelectron spectroscopy (XPS). X-ray diffraction (XRD) was also used to find the crystal structure of the microspheres. The UC microspheres were further investigated by annealing. The annealing process was completed using a CM Furnace in an inert argon gas. The results of the experiment were analyzed using the same methods mentioned above. Uranium diffusion was found in the ZrC matrix and was confirmed to be possible through diffusion calculations.

Geathers, Jerome J.

99

Requirements for long-life operation of inert gas hollow cathodes: Preliminary report  

NASA Technical Reports Server (NTRS)

An experimental investigation was initiated to establish conditioning procedures for reliable hollow cathode operation via the characterization of critical parameters in a representative cathode test facility. From vacuum pumpdown rates, it was found that approximately 1.5 hours were required to achieve pressure levels within 5 percent of the lowest attainable pressure for this facility, depending on the purge conditions. The facility atmosphere was determined by a residual gas analyzer to be composed of primarily air and water vapor. The effects of vacuum pumping and inert gas purging were evaluated. A maximum effective leakage rate of 2.0 x 10(exp -3)sccm was observed and its probable causes were examined. An extended test of a 0.64 cm diameter Mo-Re hollow cathode was successfully completed. This test ran for 504 hours at an emission current of 23.0 amperes and a xenon flow rate of 6.1 sccm. Discharge voltage rose continuously from 15 to 21 volts over the course of the test. The temperature of the cathode body during the test was relatively stable at 1160 C. Post-test examination revealed ion-bombardment texturing of the orifice plate to be the only detectable sign of wear on the hollow cathode.

Verhey, Timothy R.; Macrae, Gregory S.

1990-01-01

100

Modeling In-Flight Inert Gas Distribution in a 747 Center Wing Fuel Tank  

Microsoft Academic Search

Extensive development and analysis has illustrated that fuel tank inerting, using air separation modules, is a reasonably cost-effective approach to preventing fuel tank explosions. To support the development of the Federal Aviation Administration inerting system, analytical and scale replica models of a Boeing 747 center wing fuel tank were developed and used to gage the ability of these relatively simple

William M. Cavage; Timothy Bowman

101

CFD simulation of water vapour condensation in the presence of non-condensable gas in vertical cylindrical condensers  

PubMed Central

This paper presents the simulation of the condensation of water vapour in the presence of non-condensable gas using computational fluid dynamics (CFD) for turbulent flows in a vertical cylindrical condenser tube. The simulation accounts for the turbulent flow of the gas mixture, the condenser wall and the turbulent flow of the coolant in the annular channel with no assumptions of constant wall temperature or heat flux. The condensate film is assumed to occupy a negligible volume and its effect on the condensation of the water vapour has been taken into account by imposing a set of boundary conditions. A new strategy is used to overcome the limitation of the currently available commercial CFD package to solve the simultaneous simulation of flows involving multispecies and fluids of gas and liquid in separate channels. The results from the CFD simulations are compared with the experimental results from the literature for the condensation of water vapour with air as the non-condensable gas and for inlet mass fraction of the water vapour from 0.66 to 0.98. The CFD simulation results in general agree well with the directly measured quantities and it is found that the variation of heat flux in the condenser tube is more complex than a simple polynomial curve fit. The CFD results also show that, at least for flows involving high water vapour content, the axial velocity of the gas mixture at the interface between the gas mixture and the condensate film is in general not small and cannot be neglected. PMID:24850953

Li, Jun-De

2013-01-01

102

MOX and MOX with 237Np/241Am Inert Fission Gas Generation Comparison in ATR  

SciTech Connect

The treatment of spent fuel produced in nuclear power generation is one of the most important issues to both the nuclear community and the general public. One of the viable options to long-term geological disposal of spent fuel is to extract plutonium, minor actinides (MA), and potentially long-lived fission products from the spent fuel and transmute them into short-lived or stable radionuclides in currently operating light-water reactors (LWR), thus reducing the radiological toxicity of the nuclear waste stream. One of the challenges is to demonstrate that the burnup-dependent characteristic differences between Reactor-Grade Mixed Oxide (RG-MOX) fuel and RG-MOX fuel with MA Np-237 and Am 241 are minimal, particularly, the inert gas generation rate, such that the commercial MOX fuel experience base is applicable. Under the Advanced Fuel Cycle Initiative (AFCI), developmental fuel specimens in experimental assembly LWR-2 are being tested in the northwest (NW) I-24 irradiation position of the Advanced Test Reactor (ATR). The experiment uses MOX fuel test hardware, and contains capsules with MOX fuel consisting of mixed oxide manufactured fuel using reactor grade plutonium (RG-Pu) and mixed oxide manufactured fuel using RG-Pu with added Np/Am. This study will compare the fuel neutronics depletion characteristics of Case-1 RG-MOX and Case-2 RG-MOX with Np/Am.

G. S. Chang; M. Robel; W. J. Carmack; D. J. Utterbeck

2006-06-01

103

Effect of Inert Cover Gas on Performance of Radioisotope Stirling Space Power System  

SciTech Connect

This paper describes an updated Orbital design of a radioisotope Stirling power system and its predicted performance at the beginning and end of a six-year mission to the Jovian moon Europa. The design is based on General Purpose Heat Source (GPHS) modules identical to those previously developed and safety-qualified by the Department of Energy (DOE) which were successfully launched to Jupiter and Saturn by the Jet Propulsion Laboratory (JPL). In each generator, the heat produced by the decay of the Pu-238 isotope is converted to electric power by two free-piston Stirling engines and linear alternators developed by Stirling Technology Company (STC), and their rejected waste heat is transported to radiators by heat pipes. The principal difference between the proposed system design and previous Orbital designs (Or et al. 2000) is the thermal insulation between the heat source and the generator's housing. Previous designs had employed multifoil insulation, whereas the design described here employs Min-K-1800 thermal insulation. Such insulation had been successfully used by Teledyne and GE in earlier RTGs (Radioisotope Thermoelectric Generators). Although Min-K is a much poorer insulator than multifoil in vacuum and requires a substantially greater thickness for equivalent performance, it offers compensating advantages. Specifically it makes it possible to adjust the generator's BOM temperatures by filling its interior volume with inert cover gas. This makes it possible to meet the generator's BOM and EOM performance goals without exceeding its allowable temperature at the beginning of the mission.

Carpenter, Robert; Kumar, V; Ore, C; Schock, Alfred

2001-01-01

104

Joining titanium materials with tungsten inert gas welding, laser welding, and infrared brazing.  

PubMed

Titanium has a number of desirable properties for dental applications that include low density, excellent biocompatibility, and corrosion resistance. However, joining titanium is one of the practical problems with the use of titanium prostheses. Dissolved oxygen and hydrogen may cause severe embrittlement in titanium materials. Therefore the conventional dental soldering methods that use oxygen flame or air torch are not indicated for joining titanium materials. This study compared laser, tungsten inert gas, and infrared radiation heating methods for joining both pure titanium and Ti-6Al-4V alloy. Original rods that were not subjected to joining procedures were used as a control method. Mechanical tests and microstructure analysis were used to evaluate joined samples. Mechanical tests included Vickers microhardness and uniaxial tensile testing of the strength of the joints and percentage elongation. Two-way analysis of variance and Duncan's multiple range test were used to compare mean values of tensile strength and elongation for significant differences (p < or = 0.05). Tensile rupture occurred in the joint region of all specimens by cohesive failure. Ti-6Al-4V samples exhibited significantly greater tensile strength than pure titanium samples. Samples prepared by the three joining methods had markedly lower tensile elongation than the control titanium and Ti-6Al-4V rods. The changes in microstructure and microhardness were studied in the heat-affected and unaffected zones. Microhardness values increased in the heat-affected zone for all the specimens tested. PMID:8809260

Wang, R R; Welsch, G E

1995-11-01

105

Effect of inert cover gas on performance of radioisotope Stirling space power system  

NASA Astrophysics Data System (ADS)

This paper describes an updated Orbital design of a radioisotope Stirling power system and its predicted performance at the beginning and end of a six-year mission to the Jovian moon Europa. The design is based on General Purpose Heat Source (GPHS) modules identical to those previously developed and safety-qualified by the Department of Energy (DOE) which were successfully launched on missions to Jupiter and Saturn by the Jet Propulsion Laboratory (JPL). In each generator, the heat produced by the decay of the Pu-238 isotope is converted to electric power by two free-piston Stirling engines and linear alternators developed by Stirling Technology Company (STC), and their rejected waste heat is transported to radiators by heat pipes. The principal difference between the proposed system design and previous Orbital designs (Or et al., 2000) is the thermal insulation between the heat source and the generator's housing. Previous designs had employed multifoil insulation, whereas the design described here employs Min-K-1800 thermal insulation. Such insulation had been successfully used by Teledyne and GE in earlier RTGs (Radioisotope Thermoelectric Generators). Although Min-K is a much poorer insulator than multifoil in vacuum and requires a substantially greater thickness for equivalent performance, it offers compensating advantages. Specifically it makes it possible to adjust the generator's BOM temperatures by filling its interior volume with inert cover gas. This makes it possible to meet the generator's BOM and EOM performance goals without exceeding its allowable temperature at the beginning of the mission. .

Carpenter, R.; Kumar, V.; Or, C.; Schock, A.

2001-02-01

106

Formation of inorganic electride thin films via site-selective extrusion by energetic inert gas ions  

NASA Astrophysics Data System (ADS)

Inert gas ion implantation (acceleration voltage 300kV) into polycrystalline 12CaO.7Al2O3 (C12A7) films was investigated with fluences from 1×1016 to 1×1017cm-2 at elevated temperatures. Upon hot implantation at 600°C with fluences greater than 1×1017cm-2, the obtained films were colored and exhibited high electrical conductivity in the as-implanted state. The extrusion of O2- ions encaged in the crystallographic cages of C12A7 crystal, which leaves electrons in the cages at concentrations up to ˜1.4×1021cm-3, may cause the high electrical conductivity. On the other hand, when the fluence is less than 1×1017cm-2, the as-implanted films are optically transparent and electrically insulating. The conductivity is enhanced and the films become colored by irradiating with ultraviolet light due to the formation of F +-like centers. The electrons forming the F+-like centers are photo released from the encaged H- ions, which are presumably derived from the preexisting OH- groups. The induced electron concentration is proportional to the calculated displacements per atom, which suggests that nuclear collision effects of the implanted ions play a dominant role in forming the electron and H- ion in the films. The hot ion implantation technique provides a nonchemical process for preparing electronic conductive C12A7 films.

Miyakawa, Masashi; Toda, Yoshitake; Hayashi, Katsuro; Hirano, Masahiro; Kamiya, Toshio; Matsunami, Noriaki; Hosono, Hideo

2005-01-01

107

On the Gas Dynamics of Inert-Gas-Assisted Laser Cutting of Steel Plate  

NASA Astrophysics Data System (ADS)

Laser beam cutting of sheet metal requires an assist gas to blow away the molten material. Since the assist-gas dynamics influences the quality and speed of the cut, the orientation of the gas nozzle with respect to the kerf is also expected to be important. A 1 kW cw CO2 laser with nitrogen assist gas was used to cut mild steel sheet of 1 to 4 mm thickness, using a sonic coaxial nozzle as a baseline. Off-axis nozzles were oriented from 20 deg to 60 deg from normal with exit Mach numbers from 1 to 2.4. Results showed maximum cutting speed at a 40 deg nozzle orientation. Shadowgrams of a geometrically-similar model kerf then revealed a separated shock wave-boundary layer interaction within the kerf for the (untilted) coaxial nozzle case. This was alleviated, resulting in a uniform supersonic flow throughout the kerf and consequent higher cutting speeds, by tilting the nozzle between 20 deg and 45 deg from the normal. This result did not depend upon the exit Mach number of the nozzle. (Research supported by NSF Grant DMI-9400119.)

Brandt, A. D.; Settles, G. S.; Scroggs, S. D.

1996-11-01

108

A comparative evaluation of electrical velocimetry and inert gas rebreathing for the non-invasive assessment of cardiac output  

Microsoft Academic Search

Background  When assessing the function of the cardiovascular system, cardiac output (CO) is a substantial parameter. For its determination,\\u000a numerous non-invasive techniques have been proposed in the recent years including inert gas rebreathing (IGR) and impedance\\u000a cardiography (ICG). The aim of our study was to evaluate whether a novel ICG algorithm (electrical velocimetry) and IGR can\\u000a be used interchangeably in the

Frederik Trinkmann; Manuel Berger; Ursula Hoffmann; Martin Borggrefe; Jens J. Kaden; Joachim Saur

109

Mathematical simulation of the process of condensing natural gas  

NASA Astrophysics Data System (ADS)

Presents a two-dimensional unsteady model of heat transfer in terms of condensation of natural gas at low temperatures. Performed calculations of the process heat and mass transfer of liquefied natural gas (LNG) storage tanks of cylindrical shape. The influence of model parameters on the nature of heat transfer. Defined temperature regimes eliminate evaporation by cooling liquefied natural gas. The obtained dependence of the mass flow rate of vapor condensation gas temperature. Identified the possibility of regulating the process of "cooling down" liquefied natural gas in terms of its partial evaporation with low cost energy.

Tastandieva, G. M.

2015-01-01

110

Mobility of Supercooled liquid Toluene, Ethylbenzene, and Benzene near their Glass Transition Temperatures Investigated using Inert Gas Permeation  

SciTech Connect

We investigate the mobility of supercooled liquid toluene, ethylbenzene, and benzene near their respective glass transition temperatures (Tg). The permeation rate of Ar, Kr, and Xe through the supercooled liquid created when initially amorphous overlayers heated above their glass transition temperature is used to determine the diffusivity. Amorphous benzene crystallizes at temperatures well below its Tg and as a result the inert gas underlayer remains trapped until the onset of benzene desorption. In contrast, for toluene and ethylbenzene the onset of inert gas permeation is observed at temperatues near Tg. The inert gas desorption peak temperature as a function of the heating rate and overlayer thickness is used to quantify the diffusivity of supercooled liquid toluene and ethylbenzene from 115 K to 135 K. In this temperature range, diffusivities are found to vary across five orders of magnitude (~10-14 to 10-9 cm2/s). These data are compared to viscosity measurements and used to determine the low temperature fractional Stokes-Einstein exponent. Efforts to determine the diffusivity of a mixture of benzene and ethylbenzene are detailed, and the effect of mixing these materials on benzene crystallization is explored using infrared spectroscopy.

May, Robert A.; Smith, R. Scott; Kay, Bruce D.

2013-11-21

111

Determination of gas-condensate relative permeability on whole cores under reservoir conditions. [Middle East  

Microsoft Academic Search

The work reported here was undertaken on rock samples from a Middle-East carbonate retrograde condensate gas field, in order to determine relative permeability to gas and condensate curves. Special attention was given to determination of condensate minimum flowing saturation (or critical condensate saturation) and to reduction of permeability to gas in the presence of immobile condensate saturation. The originality of

J. F. Gravier; A. F. Abed; C. Barroux; P. Lemouzy

1983-01-01

112

Formation of inorganic electride thin films via site-selective extrusion by energetic inert gas ions  

SciTech Connect

Inert gas ion implantation (acceleration voltage 300 kV) into polycrystalline 12CaO{center_dot}7Al{sub 2}O{sub 3} (C12A7) films was investigated with fluences from 1x10{sup 16} to 1x10{sup 17} cm{sup -2} at elevated temperatures. Upon hot implantation at 600 deg. C with fluences greater than 1x10{sup 17} cm{sup -2}, the obtained films were colored and exhibited high electrical conductivity in the as-implanted state. The extrusion of O{sup 2-} ions encaged in the crystallographic cages of C12A7 crystal, which leaves electrons in the cages at concentrations up to {approx}1.4x10{sup 21} cm{sup -3}, may cause the high electrical conductivity. On the other hand, when the fluence is less than 1x10{sup 17} cm{sup -2}, the as-implanted films are optically transparent and electrically insulating. The conductivity is enhanced and the films become colored by irradiating with ultraviolet light due to the formation of F{sup +}-like centers. The electrons forming the F{sup +}-like centers are photo released from the encaged H{sup -} ions, which are presumably derived from the preexisting OH{sup -} groups. The induced electron concentration is proportional to the calculated displacements per atom, which suggests that nuclear collision effects of the implanted ions play a dominant role in forming the electron and H{sup -} ion in the films. The hot ion implantation technique provides a nonchemical process for preparing electronic conductive C12A7 films.

Miyakawa, Masashi; Toda, Yoshitake; Hayashi, Katsuro; Hirano, Masahiro; Kamiya, Toshio; Matsunami, Noriaki; Hosono, Hideo [Frontier Collaborative Research Center, P.O. Box S2-13, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan); Hosono Transparent Electro-Active Materials, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency, KSP C-1232, 3-2-1 Sakado, Takatsu-ku, Kawasaki 213-0012 (Japan); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan); Center for Integrated Research in Science and Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Frontier Collaborative Research Center and Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)

2005-01-15

113

A study of thorium exposure during tungsten inert gas welding in an airline engineering population.  

PubMed

To investigate the theoretic possibility of excessive exposure to thorium during the process of tungsten inert gas (TIG) welding using thoriated rods we carried out a cross-sectional study of TIG welders and an age- and skill-matched group. We measured the radiation doses from inhaled thorium that was retained in the body and investigated whether any differences in health or biologic indices could have been attributable to the welding and tip-grinding process. Sixty-four TIG welders, 11 non-TIG welders, and 61 control subjects from an airline engineering population participated. All of the subjects were interviewed for biographic, occupational history and morbidity details. All of the welders and eight control subjects carried out large-volume urine sampling to recover thorium 232 and thorium 228; this group also had chest radiographs. All of the subjects had a blood sample taken to estimate liver enzymes, and they provided small-volume urine samples for the estimation of retinol-binding protein and beta 2-microglobulin. We found no excess of morbidity among the TIG or non-TIG welding groups, and the levels of retinol-binding protein and beta 2-microglobulin were the same for both groups. There was a higher aspartate aminotransferase level in the control group. The internal radiation doses were estimated at less than an annual level of intake in all cases, and considerably less if the exposure (as was the case) was assumed to be chronic over many years. Some additional precautionary measures are suggested to reduce further any potential hazard from this process. PMID:8396174

McElearney, N; Irvine, D

1993-07-01

114

Condensation heat transfer in rotating heat pipes in the presence of a non-condensable gas  

NASA Technical Reports Server (NTRS)

An analysis of condensation problems in rotating heat pipes containing vapors with different concentrations of non-condensable gases is given. In situations such as this, temperature and concentration gradients are set up in the vapor-gas mixture. There is a transport of mass due to temperature gradients accompanied by an energy transport phenomena due to a concentration gradient. A Nusselt type analysis is not suited to this type of problem; however, a boundary layer type approach has successfully been used to analyze stationary condensation systems with non-condensable gases present. The present boundary layer analysis is presented for condensation processes on the inside of a rotating heat pipe in the presence of non-condensable gases.

Daniels, T. C.; Medwell, J. O.; Williams, R. J.

1977-01-01

115

Condensation of natural gas or methane into gasoline range hydrocarbons  

SciTech Connect

This invention relates to a new process for the direct conversion of natural gas or methane into gasoline-range hydrocarbons (i.e., synthetic transportation fuels or lower olefins) via catalytic condensation using superacid catalysts.

Olah, G. A.

1985-04-23

116

Condensation of natural gas or methane into gasoline range hydrocarbons  

SciTech Connect

This invention relates to a new process for the direct conversion of natural gas or methane into gasoline-range hydrocarbons (i.e., synthetic transportation fuels or lower olefins) via catalytic condensation using superacid catalysts.

Olah, G.A.

1984-02-21

117

Compatibility of Space Nuclear Power Plant Materials in an Inert He/Xe Working Gas Containing Reactive Impurities  

SciTech Connect

A major materials selection and qualification issue identified in the Space Materials Plan is the potential for creating materials compatibility problems by combining dissimilar reactor core, Brayton Unit and other power conversion plant materials in a recirculating, inert He/Xe gas loop containing reactive impurity gases. Reported here are results of equilibrium thermochemical analyses that address the compatibility of space nuclear power plant (SNPP) materials in high temperature impure He gas environments. These studies provide early information regarding the constraints that exist for SNPP materials selection and provide guidance for establishing test objectives and environments for SNPP materials qualification testing.

MM Hall

2006-01-31

118

Noninvasive cardiac output measurement by inert gas rebreathing in suspected pulmonary hypertension.  

PubMed

The objective of this study was to evaluate inert gas rebreathing (IGR) reliability in cardiac output (CO) measurement compared with Fick method and thermodilution. IGR is a noninvasive method for CO measurement; CO by IGR is calculated as pulmonary blood flow plus intrapulmonary shunt. IGR may be ideal for follow-up of patients with pulmonary hypertension (PH), sparing the need of repeated invasive right-sided cardiac catheterization. Right-sided cardiac catheterization with CO measurement by thermodilution, Fick method, and IGR was performed in 125 patients with possible PH by echocardiography. Patients were grouped according to right-sided cardiac catheterization-measured mean pulmonary and wedge pressures: normal pulmonary arterial pressure (n = 20, mean pulmonary arterial pressure = 18 ± 3 mm Hg, pulmonary capillary wedge pressure = 11 ± 5 mm Hg), PH and normal pulmonary capillary wedge pressure (PH-NW, n = 37 mean pulmonary arterial pressure = 42 ± 13 mm Hg, pulmonary capillary wedge pressure = 11 ± 6 mm Hg), and PH and high pulmonary capillary wedge pressure (PH-HW, n = 68, mean pulmonary arterial pressure = 37 ± 9 mm Hg, pulmonary capillary wedge pressure = 24 ± 6 mm Hg). Thermodilution and Fick measurements were comparable. Fick and IGR agreement was observed in normal pulmonary arterial pressure (CO = 4.10 ± 1.14 and 4.08 ± 0.97 L/min, respectively), whereas IGR overestimated Fick in patients with PH-NW and those with PH-HW because of intrapulmonary shunting overestimation in hypoxemic patients. When patients with arterial oxygen saturation (SO2) ?90% were excluded, IGR and Fick agreement improved in PH-NW (CO = 4.90 ± 1.70 and 4.76 ± 1.35 L/min, respectively) and PH-HW (CO = 4.05 ± 1.04 and 4.10 ± 1.17 L/min, respectively). In hypoxemic patients, we estimated pulmonary shunt as Fick - pulmonary blood flow and calculated shunt as: -0.2423 × arterial SO2 + 21.373 L/min. In conclusion, IGR is reliable for CO measurement in patients with PH with arterial SO2 >90%. For patients with arterial SO2 ?90%, a new formula for shunt calculation is proposed. PMID:24315114

Farina, Stefania; Teruzzi, Giovanni; Cattadori, Gaia; Ferrari, Cristina; De Martini, Stefano; Bussotti, Maurizio; Calligaris, Giuseppe; Bartorelli, Antonio; Agostoni, Piergiuseppe

2014-02-01

119

Onboard Inert Gas Generation System/Onboard Oxygen Gas Generation System (OBIGGS/OBOGS) Study. Part 2; Gas Separation Technology--State of the Art  

NASA Technical Reports Server (NTRS)

This purpose of this contract study task was to investigate the State of the Art in Gas Separation Technologies utilized for separating air into both nitrogen and oxygen gases for potential applications on commercial aircraft. The intended applications included: nitrogen gas for fuel tank inerting, cargo compartment fire protection, and emergency oxygen for passenger and crew use in the event of loss of cabin pressure. The approach was to investigate three principle methods of gas separation: Hollow Fiber Membrane (HFM), Ceramic Membrane (CM), and liquefaction: Total Atmospheric Liquefaction of Oxygen and Nitrogen (TALON). Additional data on the performance of molecular sieve pressure swing adsorption (PSA) systems was also collected and discussed. Performance comparisons of these technologies are contained in the body of the report.

Reynolds, Thomas L.; Eklund, Thor I.; Haack, Gregory A.

2001-01-01

120

A Variable Cell Model for Simulating Gas Condensate Reservoir Performance  

E-print Network

are eubject to publication review by Editorial Committee of the Society ofPetroleum Engineers. Permieaionto for simulating gas relatively high, near-constant, oil saturation in condensate reeervoir performance has been maturation profiles, which ie exhibitpd when gas pressure. Between this region near tha wellbore

Al-Majed, Abdulaziz Abdullah

121

Method for extending the useful shelf-life of refrigerated red blood cells by flushing with inert gas  

DOEpatents

Method using oxygen removal for extending the useful shelf-life of refrigerated red blood cells. A cost-effective, 4.degree. C. storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. Preservation of adenosine triphosphate levels and reduction in hemolysis and in membrane vesicle production of red blood cells stored at 4.degree. C. for prolonged periods of time is achieved by removing oxygen therefrom at the time of storage; in particular, by flushing with an inert gas. Adenosine triphosphate levels of the stored red blood cells are boosted in some samples by addition of ammonium phosphate.

Bitensky, Mark W. (Los Alamos, NM); Yoshida, Tatsuro (Los Alamos, NM)

1997-01-01

122

Method for extending the useful shelf-life of refrigerated red blood cells by flushing with inert gas  

DOEpatents

A method is disclosed using oxygen removal for extending the useful shelf-life of refrigerated red blood cells. A cost-effective, 4 C storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. Preservation of adenosine triphosphate levels and reduction in hemolysis and in membrane vesicle production of red blood cells stored at 4 C for prolonged periods of time is achieved by removing oxygen from the red blood cells at the time of storage; in particular, by flushing with an inert gas. Adenosine triphosphate levels of the stored red blood cells are boosted in some samples by addition of ammonium phosphate. 4 figs.

Bitensky, M.W.; Yoshida, Tatsuro

1997-04-29

123

CLOUDS TOWARD THE VIRGO CLUSTER PERIPHERY: GAS-RICH OPTICALLY INERT GALAXIES  

SciTech Connect

Aperture synthesis observations of two H I cloud complexes located in the periphery of the Virgo galaxy cluster are presented. These low H I-mass clouds (M{sub H{sub I}}< 10{sup 9} M{sub sun}) are seen projected on the M region of the western Virgo cluster, where the galaxy population is thought to lie behind the main A cluster surrounding M87. The kinematic measurements of both unresolved Arecibo and resolved Very Large Array (VLA)-C observations are in good agreement. The H I detections cannot be identified with any optical, IR, or UV emission from available archival imaging. They are inert at these wavelengths. The H I masses of the individual VLA detections range from 7.28 {<=} log(M{sub H{sub I}}/M{sub sun}){<=} 7.85. The total dynamical mass estimates are several times their H I content, ranging from 7.00 {<=} log(M{sub dyn}/M{sub sun}){<=} 9.07, with the assumption that the clouds are self-gravitating and in dynamical equilibrium. We report the observed parameters derived from the VLA observations. One of these H I clouds appears to be the most isolated optically inert detection observed in the outer reaches of Virgo.

Kent, Brian R., E-mail: bkent@nrao.ed [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)

2010-12-20

124

Reactive Transport Modeling of Acid Gas Generation and Condensation  

SciTech Connect

Pulvirenti et al. (2004) recently conducted a laboratory evaporation/condensation experiment on a synthetic solution of primarily calcium chloride. This solution represents one potential type of evaporated pore water at Yucca Mountain, Nevada, a site proposed for geologic storage of high-level nuclear waste. These authors reported that boiling this solution to near dryness (a concentration factor >75,000 relative to actual pore waters) leads to the generation of acid condensate (pH 4.5) presumably due to volatilization of HCl (and minor HF and/or HNO{sub 3}). To investigate the various processes taking place, including boiling, gas transport, and condensation, their experiment was simulated by modifying an existing multicomponent and multiphase reactive transport code (TOUGHREACT). This code was extended with a Pitzer ion-interaction model to deal with high ionic strength. The model of the experiment was set-up to capture the observed increase in boiling temperature (143 C at {approx}1 bar) resulting from high concentrations of dissolved salts (up to 8 m CaCl{sub 2}). The computed HCI fugacity ({approx} 10{sup -4} bars) generated by boiling under these conditions is not sufficient to lower the pH of the condensate (cooled to 80 and 25 C) down to observed values unless the H{sub 2}O mass fraction in gas is reduced below {approx}10%. This is because the condensate becomes progressively diluted by H{sub 2}O gas condensation. However, when the system is modeled to remove water vapor, the computed pH of instantaneous condensates decreases to {approx}1.7, consistent with the experiment (Figure 1). The results also show that the HCl fugacity increases, and calcite, gypsum, sylvite, halite, MgCl{sub 2}4H{sub 2}O and CaCl{sub 2} precipitate sequentially with increasing concentration factors.

G. Zhahg; N. Spycher; E. Sonnenthal; C. Steefel

2005-01-25

125

Gas condensate reservoir characterisation for CO2 geological storage  

NASA Astrophysics Data System (ADS)

During oil and gas production hydrocarbon recovery efficiency is significantly increased by injecting miscible CO2 gas in order to displace hydrocarbons towards producing wells. This process of enhanced oil recovery (EOR) might be used for the total CO2 storage after complete hydrocarbon reservoir depletion. This kind of potential storage sites was selected for detailed studies, including generalised development study to investigate the applicability of CO2 for storages. The study is focused on compositional modelling to predict the miscibility pressures. We consider depleted gas condensate field in Kazakhstan as important target for CO2 storage and EOR. This reservoir being depleted below the dew point leads to retrograde condensate formed in the pore system. CO2 injection in the depleted gas condensate reservoirs may allow enhanced gas recovery by reservoir pressurisation and liquid re-vaporisation. In addition a number of geological and petrophysical parameters should satisfy storage requirements. Studied carbonate gas condensate and oil field has strong seal, good petrophysical parameters and already proven successful containment CO2 and sour gas in high pressure and high temperature (HPHT) conditions. The reservoir is isolated Lower Permian and Carboniferous carbonate platform covering an area of about 30 km. The reservoir contains a gas column about 1.5 km thick. Importantly, the strong massive sealing consists of the salt and shale seal. Sour gas that filled in the oil-saturated shale had an active role to form strong sealing. Two-stage hydrocarbon saturation of oil and later gas within the seal frame were accompanied by bitumen precipitation in shales forming a perfect additional seal. Field hydrocarbon production began three decades ago maintaining a strategy in full replacement of gas in order to maintain pressure of the reservoir above the dew point. This was partially due to the sour nature of the gas with CO2 content over 5%. Our models and calculations demonstrate that injection of produced and additional gas (CO2 and sour gases) is economically viable and ecologically safe. Gas injection monitoring using surface injection well head pressures and measured injected volumes demonstrates a highly effective gas injection process. Injection well head pressure response shows no increase, indicating absence of compartmentalization close to the near well bore gas injection region in reservoir. And injector pulse study shows interconnectivity across the injection region highlighting good quality reservoir across the potential CO2 injection zones. Preliminary CO2 storage potential was also estimated for this type of geological site.

Ivakhnenko, A. P.

2012-04-01

126

Determination of Gas-Condensate Relative Permeability on Whole Cores Under Reservoir Conditions  

Microsoft Academic Search

Rock samples from a Middle East carbonate retrograde condensate gas field were studied to determine their relative permeability to gas and condensate curves. The authors emphasized the determination of condensate minimum flowing saturation-or critical condensate saturation-and the reduction of permeability to gas in the presence of immobile condensate saturation. A ternary pseudoreservoir fluid of methane\\/pentane\\/nonane made it possible to work

J. F. Gravier; P. Lemouzy; C. Barroux; A. F. Abed

1986-01-01

127

Removal of particle matter from dust-vapor-gas mixture in condenser with inclined tubes  

NASA Astrophysics Data System (ADS)

The article presents results of the research of particulate matter and droplets removal on inclined tubes of the flue gas cleaning condenser in the process of vapor condensation of vapor-and-gas emissions from kraft pulp production.

Romanova, L. V.; Gogonin, I. I.

2012-03-01

128

Industrial Research of Condensing Unit for Natural Gas Boiler House  

NASA Astrophysics Data System (ADS)

In the course of work industrial research was carried out at the boiler plant A/S "Imanta" where a 10MW passive condensing economizer working on natural gas was installed after the 116MW water boiler. The work describes the design of the condensing economizer and wiring diagram. During the industrial experiment, the following measurements were made: the temperature of water before and after the economizer; the ambient temperature; the quantity of water passing through the economizer; heat, produced by the economizer and water boilers. The work summarizes the data from 2010-2011.

Ziemele, Jelena; Blumberga, Dagnija; Talcis, Normunds; Laicane, Ilze

2012-12-01

129

Computation of decompression schedules for single inert gas-oxygen dives using a hand-held programmable calculator.  

PubMed

An algorithm for on-site computation with a hand-held programmable calculator (TI-59, Texas Instruments) of single inert-gas decompression schedules is described. This program is based on Workman's 'M-value' method. It can compute decompression schedules with changes in the oxygen content of the breathing mixture and extension of stay at any decompression stop. The features of the program that enable calculation of atypical dive profiles, along with the portability of small calculators, would make such an algorithm suitable for on-site applications. However, since dive profiles generated by the program have not yet been tested, divers are warned not to generate schedules until their safety has been established by field tests. PMID:6257447

Ranade, A; Peterson, R E

1980-08-01

130

Effect of non-condensable gas on vapor flow in the condenser of VCHP  

NASA Astrophysics Data System (ADS)

A fundamental study of the effect of noncondensable gas on a vapor flow in the condenser region of VCHP (variable conductance heat pipe) was conducted experimentally and analytically. In the experiment, a specific thermosyphon or a wickless VCHP model was fabricated which has a condenser of rectangular cross sectional area to realize two-dimensional flow field. Detailed flow field surveys conducted are measurements of temperature distributions by thermocouples, heat transfer rates in the condenser by film gauge and hot-wire, and flow field visualization by laser holographic interferometer. In order to investigate the dominant physical parameters in the flow field observed in the experiment a numerical simulation was performed by adopting a binary mixture model. An important finding in this study is a fact that the gravity force has a strong effect on the location and profile of an interfacial layer between vapor and noncondensable gas. The idea of formation of a clear diffusion front layer in the condenser would mislead to an erroneous interpretation of thermofluid dynamic behavior of VCHPs for terrestrial use.

Kobayashi, Yasunori; Okumura, Akira; Matsue, Toshihisa

1989-06-01

131

Flue gas condensing at biofuel fired district heating plants  

SciTech Connect

Water is introduced into a boiler with fuel moisture, humidity in combustion air and from combustion of fuel hydrogen. In the combustion chamber evaporation of water uses energy and lowers the combustion temperature. It is called the heat of vaporisation. Reverse process, condensation of water vapour gives back the same amount of energy. Water vapour in flue gases begins to condensate when the temperature reaches the dew point. For example in wood and peat combustion the dew point of flue gases is about 60 - 70{degrees}C. Heat of condensation is transfered to the district heating circulation using heat exchangers. An increase of 19 - 21 % to the boiler heat output at Virrat heating plant and 24% at Saarijarvi plant was achieved by flue gas condensation. This resulted in overall efficiency of 106.2 - 108.6 % at Virrat and 107.5 - 107.7% (based on LHV). Flue gas scrubbing and neutralisation resulted in 87 - 94% and 31 - 37 % sulphur reduction respectively. Reduction of particulate emissions at Virrat plant was 89 - 98%. The Saarijarvi plant has ESP, so the emissions are very low (< 6 mg/Nm{sup 3}) already before the scrubber.

Oravainen, K.H. [VTT Energy, Jyvaskyla (Finland)

1996-12-31

132

Spectroscopy of Cosmic Carbon Analogs in Inert-Gas Matrices and in the Gas-Phase: Comparative Results and Perspectives for Astrophysics  

NASA Technical Reports Server (NTRS)

Recent studies of the spectroscopy of large (up to approx. 50 carbon atoms) neutral and Ionized polycyclic aromatic hydrocarbons (PAHs) and Fullerenes isolated in inert gas matrices will be presented. The advantages and the limitations of matrix isolation spectroscopy for the study of the molecular spectroscopy of interstellar dust analogs will be discussed. The laboratory data will be compared to the astronomical spectra (the interstellar extinction, the diffuse interstellar bands). Finally, the spectra of PAH ions isolated in neon/argon matrices will be compared to the spectra obtained for PAH ion seeded in a supersonic expansion. The astrophysical implications and future perspectives will be discussed.

Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

2001-01-01

133

Treatability of oil shale gas condensate waste water  

SciTech Connect

Laboratory-scale experiments were conducted with an actual modified in-situ (MIS) gas condensate to assess the performance of steam stripping, of the activated-sludge process, and of activated-carbon adsorption for upgrading the quality of this waste water. Steam-stripping experiments were carried out with a laboratory-scale, packed tower which contacted preheated, raw-gas condensate with low-pressure steam in a countercurrent manner. At a steam/liquid ratio of 0.24 kg/kg, removals of both ammonia and alkalinity were at least 99%, and an incidental removal of 82% of the raw waste water TOC was also observed. No stripper-feedwater pH adjustment was required. 5 references, 6 figures, 6 tables.

Lewis, R.S.; Rawlings, G.D.; Day, D.R.

1983-02-01

134

Modeled heating and surface erosion comparing motile (gas borne) and stationary (surface coating) inert particle additives  

SciTech Connect

The unsteady, non-similar, chemically reactive, turbulent boundary layer equations are modified for gas plus dispersed solid particle mixtures, for gas phase turbulent combustion reactions and for heterogeneous gas-solid surface erosive reactions. The exterior (ballistic core) edge boundary conditions for the solutions are modified to include dispersed particle influences on core propellant combustion-generated turbulence levels, combustion reactants and products, and reaction-induced, non-isentropic mixture states. The wall surface (in this study it is always steel) is considered either bare or coated with a fixed particle coating which is conceptually non-reactive, insulative, and non-ablative. Two families of solutions are compared. These correspond to: (1) consideration of gas-borne, free-slip, almost spontaneously mobile (motile) solid particle additives which influence the turbulent heat transfer at the uncoated steel surface and, in contrast, (2) consideration of particle-free, gas phase turbulent heat transfer to the insulated surface coated by stationary particles. Significant differences in erosive heat transfer are found in comparing the two families of solutions over a substantial range of interior ballistic flow conditions. The most effective influences on reducing erosive heat transfer appear to favor mobile, gas-borne particle additives.

Buckingham, A.C.; Siekhaus, W.J.

1982-09-27

135

Development of a Market Optimized Condensing Gas Water Heater  

SciTech Connect

This program covered the development of a market optimized condensing gas water heater for residential applications. The intent of the program was to develop a condensing design that minimized the large initial cost premium associated with traditional condensing water heater designs. Equally important was that the considered approach utilizes design and construction methods that deliver the desired efficiency without compromising product reliability. Standard condensing water heater approaches in the marketplace utilize high cost materials such as stainless steel tanks and heat exchangers as well as expensive burner systems to achieve the higher efficiencies. The key in this program was to develop a water heater design that uses low-cost, available components and technologies to achieve higher efficiency at a modest cost premium. By doing this, the design can reduce the payback to a more reasonable length, increasing the appeal of the product to the marketplace. Condensing water heaters have been in existence for years, but have not been able to significantly penetrate the market. The issue has typically been cost. The high purchase price associated with existing condensing water heaters, sometimes as much as $2000, has been a very difficult hurdle to overcome in the marketplace. The design developed under this program has the potential to reduce the purchase price of this condensing design by as much as $1000 as compared to traditional condensing units. The condensing water heater design developed over the course of this program led to an approach that delivered the following performance attributes: 90%+ thermal efficiency; 76,000 Btu/hr input rate in a 50 gallon tank; First hour rating greater than 180 gph; Rapid recovery time; and Overall operating condition well matched to combination heat and hot water applications. Over the final three years of the program, TIAX worked very closely with A.O. Smith Water Products Company as our commercial partner to optimize the design for manufacturing. This work included the initiation of a large field testing program (over 125 units) and an in-depth reliability program intended to minimize the risks associated with a new product introduction. At the time of this report, A.O. Smith plans to introduce this product to the marketplace in the early 2006 time period.

Peter Pescatore

2006-01-11

136

Role of interphase interactions during gas detonation in inert porous medium  

NASA Astrophysics Data System (ADS)

A mathematical model of detonation in a two-phase mixture consisting of a gaseous monofuel and closely packed noninflammable solid particles is proposed. The structure of detonation waves in a pure gas is compared to that in monodisperse mixtures with various diameters of particles. Two special regimes of detonation are separated, in which (i) gas is immediately inflamed due to shock compression and (ii) ignition starts at the surface of particles, upon reflection of the chock wave front. It is shown that inertial effects during the flow past particles can both increase and decrease the detonation velocities. The calculated detonation velocities well agree with experimental data.

Balapanov, D. M.; Urmancheev, S. F.

2010-07-01

137

Molecular dynamics investigations of the coalescence of iron clusters embedded in an inert-gas heat bath  

SciTech Connect

A detailed analysis of the coalescence of iron clusters over the course of their growth in an inert-gas atmosphere is presented. The investigation is performed by molecular dynamics simulations, using a recent version of the embedded atom method for iron. For several coalescence events extracted from realistic particle-growth simulations, the change of temperature, the atomic structure, and the morphology are analyzed. Here, the change in morphology is investigated by the relative number of atoms in the surface related to the driving force of the coalescence, the surface energy. The duration of the coalescence depends on the state of the colliding clusters, which is related to their temperature. At elevated temperatures an exponential decay of the relaxation of the cluster shape is found in case of liquid clusters. Clusters at lower temperatures exhibit a regular atomic structure. The coalescence includes the restructuring of the clusters, leading to deviations from the exponential decay of the cluster properties. Here, a distinct three-step coalescence process has been identified for structured clusters under nonadiabatic conditions. Each of these steps is related to a different extent of heat exchange with the carrier gas.

Luemmen, N.; Kraska, T. [Physical Chemistry, University of Cologne, Luxemburger Strasse 116, D-50939 Cologne (Germany)

2005-05-15

138

EFFECT OF VENTILATION AND PERFUSION IMBALANCE ON INERT GAS REBREATHING VARIABLES  

EPA Science Inventory

The effects of ventilation-to-perfusion (Va/Qc) maldistribution within the lungs on measured multiple gas rebreathing variables were studied in 14 dogs. The rebreathing method (using He, C18C, and C2H2) allows for measurements of pulmonary capillary blood flow (Qc), diffusing cap...

139

Calculation of hydrocarbon-in-place in gas and gas-condensate reservoirs - Carbon dioxide sequestration  

USGS Publications Warehouse

The Energy Independence and Security Act of 2007 (Public Law 110-140) authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for carbon dioxide (CO2), requiring estimation of hydrocarbon-in-place volumes and formation volume factors for all the oil, gas, and gas-condensate reservoirs within the U.S. sedimentary basins. The procedures to calculate in-place volumes for oil and gas reservoirs have already been presented by Verma and Bird (2005) to help with the USGS assessment of the undiscovered resources in the National Petroleum Reserve, Alaska, but there is no straightforward procedure available for calculating in-place volumes for gas-condensate reservoirs for the carbon sequestration project. The objective of the present study is to propose a simple procedure for calculating the hydrocarbon-in-place volume of a condensate reservoir to help estimate the hydrocarbon pore volume for potential CO2 sequestration.

Verma, Mahendra K.

2012-01-01

140

Determination of gas-condensate relative permeability on whole cores under reservoir conditions  

SciTech Connect

Rock samples from a Middle East carbonate retrograde condensate gas field were studied to determine their relative permeability to gas and condensate curves. The authors emphasized the determination of condensate minimum flowing saturation-or critical condensate saturation-and the reduction of permeability to gas in the presence of immobile condensate saturation. A ternary pseudoreservoir fluid of methane/pentane/nonane made it possible to work in simulated reservoir conditions with a greater flexibility for experimental procedures. The initial water saturation equaling that in the reservoir was restored. The results of the gas-condensate indicate that the critical condensate saturations are high (the average value is 36% PV) and that the reduction of permeability to gas is higher than for a standard gas/oil system. Also presented are the details of the experimental procedures, the fluid characteristics, the results, and a discussion.

Gravier, J.F.; Lemouzy, P.; Barroux, C.; Abed, A.F.

1986-02-01

141

Modeling of performance behavior in gas condensate reservoirs using a variable mobility concept  

E-print Network

The proposed work provides a concept for predicting well performance behavior in a gas condensate reservoir using an empirical model for gas mobility. The proposed model predicts the behavior of the gas permeability (or mobility) function...

Wilson, Benton Wade

2004-09-30

142

Bubble columns for condensation at high concentrations of noncondensable gas: Heat-transfer model and experiments  

E-print Network

Carrier gas based thermodynamic cycles are common in water desalination applications. These cycles often require condensation of water vapor out of the carrier gas stream. As the carrier gas is most likely a noncondensable ...

Narayan, G. Prakash

143

Abnormal distribution of microhardness in tungsten inert gas arc butt-welded AZ61 magnesium alloy plates  

SciTech Connect

In this study, the effects of heat input on the distribution of microhardness of tungsten inert gas (TIG) arc welded hot-extruded AZ61 magnesium alloy joints were investigated. The results show that with an increase of heat input, the distributions of microhardness at the top and bottom of the welded joints are different because they are determined by both the effect of grain coarsening and the effect of dispersion strengthening. With an increase of the heat input, the microhardness of the heat-affected zone (HAZ) at the top and bottom of welded joints and the fusion zone (FZ) at the bottom of welded joints decreased gradually, while the microhardness of the FZ at the top of welded joints decreased initially and then increased sharply. The reason for the abnormal distribution of microhardness of the FZ at the top of the welded joints is that this area is close to the heat source during welding and then large numbers of hard {beta}-Mg{sub 17}(Al,Zn){sub 12} particles are precipitated. Hence, in this case, the effect of dispersion strengthening dominated the microhardness.

Xu Nan [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Shen Jun, E-mail: shenjun2626@163.com [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Xie Weidong; Wang Linzhi; Wang Dan; Min Dong [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

2010-07-15

144

Plasma-weld pool interaction in tungsten inert-gas configuration  

NASA Astrophysics Data System (ADS)

A three-dimensional (3D) transient model of a transferred argon arc in interaction with an anode material is presented and the results discussed. The model based on a finite volume method is developed using the open software @Saturne distributed by Electricité de France. The 3D model includes the characterization of the plasma gas and of the work piece with a current continuity resolution in the whole domain. Transport and thermodynamic properties are dependent on the local temperature and on the vapours emitted by the eroded material due to the heat flux transferred by the plasma. Drag force, Marangoni force, Laplace and gravity forces are taken into account on the weld pool description. The plasma and the weld pool characteristics are presented and compared with experimental and theoretical results from the literature. For a distance between the two electrodes of d = 5 mm and an applied current intensity of I = 200 A, the vapour concentration is weak. The influence of the parameters used in the Marangoni formulation is highlighted. Finally, in agreement with some authors, we show with this global transient 3D model that it is not necessary to include the voltage drop in the energy balance.

Mougenot, J.; Gonzalez, J.-J.; Freton, P.; Masquère, M.

2013-04-01

145

Condensation  

NSDL National Science Digital Library

In this activity, learners explore the process of condensation. After seeing water vapor condense, learners will help design a test to see if cooling water vapor has an effect on the rate of condensation.

James H. Kessler

2007-01-01

146

Process using serpentine heat exchange relationship for condensing substantially single component gas streams  

Microsoft Academic Search

A method is disclosed for cooling, condensing and sub-cooling a substantially single component gas stream by passing the gas stream through a heat exchange relationship with a vaporizing multicomponent stream so that carry-up of the condensed liquid phase is maintained without condensed phase backmixing and pot-boiling of the coolant stream is avoided. The single component gas stream is passed through

J. M. Geist; M. R. Alvarez; H. C. Rowles; H. L. Vines; D. W. Woodward

1985-01-01

147

An inverse approach to estimate bubble-mediated air-sea gas flux from inert gas measurements  

E-print Network

as a function of wind speed. Our results indicate air injection values at high wind speeds (> 10 m s-1-sea interface commonly is parameterized as the product of a gas transfer coefficient, k, and the air-sea concentration gradient of a gas such that, Fas=-kc([C]-cpc) or Fas=-kc([C]-[C] slp eq ) (1) where [C] (mol m3

Khatiwala, Samar

148

Nucleation and growth of Nb nanoclusters during plasma gas condensation  

SciTech Connect

Niobium nanoclusters were produced using a plasma gas condensation process. The influence of gas flow rate, aggregation length, and source current on the nanocluster nucleation and growth were analyzed. Nanoclusters with an average diameter from 4 nm to 10 nm were produced. Cluster size and concentration were tuned by controlling the process inputs. The effects of each parameter on the nucleation zone, growth length, and residence time was examined. The parameters do not affect the cluster formation and growth independently; their influence on cluster formation can be either cumulative or competing. Examining the nucleation and growth over a wide combination of parameters provided insight into their interactions and the impact on the growth process. These results provide the opportunity for a broader understanding into the nucleation and growth of nanoclusters and some insights into how process parameters interact during deposition. This knowledge will enhance the ability to create nanoclusters with desired size dispersions.

Bray, K. R.; Jiao, C. Q. [UES, Inc., 4401 Dayton-Xenia Rd, Dayton, Ohio 45432 (United States)] [UES, Inc., 4401 Dayton-Xenia Rd, Dayton, Ohio 45432 (United States); DeCerbo, J. N. [Air Force Research Laboratory, AFRL/RQQE, 1950 Fifth St., WPAFB, Ohio 45433 (United States)] [Air Force Research Laboratory, AFRL/RQQE, 1950 Fifth St., WPAFB, Ohio 45433 (United States)

2013-06-21

149

Heat transfer performances of a thermosyphon contained non-condensible gas (1)  

NASA Astrophysics Data System (ADS)

The heat transfer performances of the thermosiphon contained non-condensible gas with the working fluid were obtained by an experimental study. The relations among the heat transfer rate, the effectively working length of condenser, the temperature difference between the evaporator and the condenser, and the over-all heat transfer coefficient are described.

Kaneko, K.; Negishi, K.

1985-03-01

150

Effect of nozzle orientation on the gas dynamics of inert-gas laser cutting of mild steel  

SciTech Connect

This investigation applies sonic and supersonic coaxial and off-axis nozzles to the cutting of mild steel sheet of 1 to 4 mm thickness. A 1 kW CW CO{sub 2} laser is used with nitrogen as the assist gas. Sonic coaxial cutting is compared to that of off-axis nozzles which vary in orientation from 20-60{degrees} behind the laser axis, and in exit Mach number from 1 to 2.4. Results show a 50% increase in maximum cutting speed at about a 40{degrees} nozzle angle. In comparison, variations in nozzle exit Mach number have little effect. A scale-model kerf was used to visualize the kerf gas dynamics, revealing that nozzle angles of 0-20{degrees} cause a shock wave/boundary layer interaction with flow separation inside the kerf. Angles of 20-45{degrees} alleviate this interaction, producing a uniform supersonic flow throughout the kerf which yields high cutting speeds due to high shear forces. For nozzle angles greater than 45{degrees} the assist gas is diverted away from the kerf, reducing cutting speed. Compared to nozzle angle, exit Mach number was found to be of secondary importance.

Brandt, A.D.; Scroggs, S.D.; Settles, G.S. [Penn State Univ., University Park, PA (United States)

1996-12-31

151

A Modified Genetic Algorithm Applied to Horizontal Well Placement Optimization in Gas Condensate Reservoirs  

E-print Network

A MODIFIED GENETIC ALGORITHM APPLIED TO HORIZONTAL WELL PLACEMENT OPTIMIZATION IN GAS CONDENSATE RESERVOIRS A Thesis by ADRIAN NICOLAS MORALES Submitted to the Office of Graduate Studies of Texas A&M University in partial... Condensate Reservoirs Copyright 2010 Adrian Nicolas Morales A MODIFIED GENETIC ALGORITHM APPLIED TO HORIZONTAL WELL PLACEMENT OPTIMIZATION IN GAS CONDENSATE RESERVOIRS A Thesis by ADRIAN NICOLAS MORALES Submitted to the Office of Graduate...

Morales, Adrian

2011-02-22

152

Finite-temperature perturbation theory for a spatially inhomogeneous Bose-condensed gas  

Microsoft Academic Search

We develop a finite-temperature perturbation theory (beyond the mean field) for a Bose-condensed gas and calculate temperature-dependent damping rates and energy shifts for Bogolyubov excitations of any energy. The theory is generalized for the case of excitations in a spatially inhomogeneous (trapped) Bose-condensed gas, where we emphasize the principal importance of inhomogeneity of the condensate density profile and develop the

P. O. Fedichev; G. V. Shlyapnikov

1998-01-01

153

Handling two-phase gas condensate flow in offshore pipeline systems  

Microsoft Academic Search

Special flow problems occur in offshore pipelines transmitting gas to processing plants onshore: as the hot, freshly produced gas cools en route, the pipeline pressure falls and the heavier hydrocarbons condense. To aid drilling operators in designing condensate-separation and transport facilities, the following should be considered: (1) temperature behavior and two-phase flow in offshore lines, (2) condensate handling and slug-catcher

Oranje

1983-01-01

154

Handling two-phase gas condensate flow in offshore pipeline systems  

SciTech Connect

Special flow problems occur in offshore pipelines transmitting gas to processing plants onshore: as the hot, freshly produced gas cools en route, the pipeline pressure falls and the heavier hydrocarbons condense. To aid drilling operators in designing condensate-separation and transport facilities, the following should be considered: (1) temperature behavior and two-phase flow in offshore lines, (2) condensate handling and slug-catcher design on booster platforms, (3) onshore separation terminal operation, and (4) the testing of industrial liquid separators.

Oranje, L.

1983-04-18

155

Damping of low-energy excitations of a Bose-condensed gas in the hydrodynamic regime  

E-print Network

We develop a theory to describe the damping of elementary excitations of a Bose-condensed gas in the hydrodynamic regime for the thermal cloud. We discuss second sound in a spatially homogeneous gas and the lowest excitations of a trapped condensate.

P. O. Fedichev; A. E. Muryshev; G. V. Shlyapnikov

2000-01-21

156

Ground-Based Inerting of Commercial Transport Aircraft Fuel Tanks  

Microsoft Academic Search

Extensive research has been performed by the Federal Aviation Administration to help develop practical and cost-effective inerting systems for commercial transport airplane fuel tanks. The concept of ground-based inerting has been studied in the laboratory and on two different aircraft in an attempt to develop a cost- effective methodology for fuel tank inerting. These research projects studied inert gas requirements,

William M. Cavage

157

Fluid-dynamical and poro-elastic coupling of gas permeability of inert and sorbing gases on an Australian sub-bituminous coal  

NASA Astrophysics Data System (ADS)

The interaction and the coupling of slip-flow, a fluid dynamic phenomenon, and the cleat volume compressibility which is a poroelastic phenomenon has been investigated on two samples from the Taroom coal measure, Surat Basin, Queensland Australia. Measurements were performed using inert (helium and argon) and sorbing gases (nitrogen, methane and carbon dioxide) at controlled effective stress. We observed the following regular sequence of permeability coefficients for the different gases: Helium >> argon => nitrogen > methane >> CO2 Even after slip-flow correction, different intrinsic permeability coefficients are obtained for the same sample if different gases are used in the tests. The permeability values determined with helium are largest while those measured with CO2 are lowest. Inert gases like helium and argon show higher apparent- and even slip flow-corrected permeability coefficients than sorbing gases like methane or carbon dioxide. This observation is contrary to the prediction that the slip-flow corrected permeability have to be the same for all gases. The cleat volume compressibility cf was evaluated using the 'matchstick approach' [1, 2]. The cleat volume compressibility coefficients cf are almost identical for the two samples taken from the same well. However, for one sample a strong dependence of the cf with the mean pore pressure was observed. This is attributed to a strong slip-flow effect caused by a narrow cleat system as compared to the sister sample. The cleat volume compressibility coefficient cf is almost the same for inert and sorbing gases. We conclude that the occurrence of slip-flow in coals is able to compensate the permeability reduction resulting from increasing effective stress. This should lead to a much higher productivity of coal bed methane reservoirs in the third production phase (pseudo-steady state phase; [3]). This conclusion appears to be also valid for shale gas and tight gas reservoirs, where the gas transport takes place in meso- and micropores, as well.

Gensterblum, Y.; Krooss, B. M.

2013-12-01

158

Effect of support on the thermal decomposition of (NH 4) 6Mo 7O 24·4H 2O in the inert gas atmosphere  

Microsoft Academic Search

Thermal decomposition of bulk or supported (NH4)6Mo7O24·4H2O (AHM) in the inert gas (Ar) atmosphere was studied. Several solids, including MgO, SiO2, ZrO2, C, Nb2O5 or Al2O3, were used as supports. The AHM decomposition was monitored by the mass-spectrometric analysis of the evolved gases and thermal analysis. Solid products were characterised using X-ray diffraction (XRD), UV–Vis, X-ray photoelectron spectroscopy (XPS), and

C Thomazeau; V Martin; P Afanasiev

2000-01-01

159

The Production of Polycyclic Aromatic Hydrocarbon Anions in Inert Gas Matrices Doped with Alkali Metals. Electronic Absorption Spectra of the Pentacene Anion (C22H14(-))  

NASA Technical Reports Server (NTRS)

The absorption spectra of pentacene (C22H14) and its radical cation (C22H14(+)) and anion (C22H14(-)) isolated in inert-gas matrices of Ne, Ar, and Kr are reported from the ultraviolet to the near-infrared. The associated vibronic band systems and their spectroscopic assignments are discussed together with the physical and chemical conditions governing ion (and counterion) production in the solid matrix. In particular, the formation of isolated pentacene anions is found to be optimized in matrices doped with alkali metal (Na and K).

Halasinski, Thomas M.; Hudgins, Douglas M.; Salama, Farid; Allamandola, Louis J.; Mead, Susan (Technical Monitor)

1999-01-01

160

Free electron in compressed inert gases  

SciTech Connect

The behavior of excess and intrinsic free electrons inside compressed inert gases is described as a function of pressure by using a pairwise approximation for the electron interaction with atomic surroundings. The change of sign from negative to positive for the xenon atom electric potential inside condensed xenon is predicted to occur at a pressure around 3 GPa, preventing slow electron embedding into solid xenon from the gas phase at higher pressure. To overcome this difficulty, the electrons should be injected into a solid sample just before its pulsed shock loading. The ionization of xenon by pressure and its further metallization are described by decreasing the forbidden gap at the expense of increasing the xenon ground electronic term and simultaneous splitting of the upper ionized electronic state. A good coincidence between the calculated and measured pressure of the dielectric-metal transition in xenon is demonstrated.

Gordon, E. B. [Russian Academy of Sciences, Institute of Problems of Chemical Physics (Russian Federation)], E-mail: gordon@ficp.ac.ru; Smirnov, B. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2008-08-15

161

A new approach for biological online testing of stack gas condensate from municipal waste incinerators.  

PubMed

A biological testing system for the monitoring of stack gas condensates of municipal waste incinerators has been developed using Euglena gracilis as a test organism. The motility, velocity and cellular form of the organisms were the endpoints, calculated by an image analysis system. All endpoints showed statistically significant changes in a short time when organisms were exposed to samples collected during combustion situations with increased pollutant concentrations. The velocity of the organisms proved to be the most appropriate endpoint. A semi-continuous system with E. gracilis for monitoring stack gas condensate is proposed, which could result in an online system for testing stack gas condensates in the future. PMID:12214718

Elsner, Dorothea; Fomin, Anette

2002-01-01

162

Determination of gas-condensate relative permeability on whole cores under reservoir conditions. [Middle East  

SciTech Connect

The work reported here was undertaken on rock samples from a Middle-East carbonate retrograde condensate gas field, in order to determine relative permeability to gas and condensate curves. Special attention was given to determination of condensate minimum flowing saturation (or critical condensate saturation) and to reduction of permeability to gas in the presence of immobile condensate saturation. The originality of this work lies in the use of a pseudoreservoir fluid, made up of a methane-pentane-nonane ternary mixture. This choice made it possible to work in conditions representative of reservoir conditions, but with a greater flexibility for experimental procedures. The initial water saturation was restored as in the reservoir. Results indicate two specific behaviours of the gas-condensate system: critical condensate saturations are high (the average value is 36% P.V.), and reduction of permeability to gas is higher than for a standard gas-oil system. Details on experimental procedures, fluid characteristics, results and discussion of these results are reported in this paper.

Gravier, J.F.; Abed, A.F.; Barroux, C.; Lemouzy, P.

1983-03-01

163

Bose-Einstein condensation in a gas of sodium atoms  

Microsoft Academic Search

We have observed Bose-Einstein condensation of sodium atoms. The atoms were trapped in a novel trap that employed both magnetic and optical forces. Evaporative cooling increased the phase-space density by 6 orders of magnitude within seven seconds. Condensates contained up to 5 x 105 atoms at densities exceeding 1014 cm-3. The striking signature of Bose condensation was the sudden appearance

K. B. Davis; M. O. Mewes; M. R. Andrews; Druten van N. J; D. S. Durfee; D. M. Kurn; W. Ketterle

1995-01-01

164

Dissipative dynamics of a vortex state in a trapped Bose-condensed gas  

Microsoft Academic Search

We discuss dissipative dynamics of a vortex state in a trapped Bose-condensed gas at finite temperature and draw a scenario of decay of this state in a static trap. The interaction of the vortex with the thermal cloud transfers energy from the vortex to the cloud and induces the motion of the vortex core to the border of the condensate.

P. O. Fedichev; G. V. Shlyapnikov

1999-01-01

165

Evolution of a Bose-condensed gas under variations of the confining potential  

Microsoft Academic Search

We discuss the dynamic properties of a trapped Bose-condensed gas under variations of the confining field and find analytical scaling solutions for the evolving coherent state (condensate). We further discuss the characteristic features and the depletion of this coherent state.

Yu. Kagan; E. L. Surkov; G. V. Shlyapnikov

1996-01-01

166

Increasing Well Productivity in Gas Condensate Wells in Qatar's North Field  

E-print Network

, and North Field in Qatar. The main focus of this thesis is to evaluate condensate blockage problems in the North Field, Qatar, and then propose solutions to increase well productivity in these gas condensate wells. The first step of the study involved...

Miller, Nathan

2010-07-14

167

Correlation of leak rates of various fluids with the leak rate of an inert gas in the same configuration  

NASA Technical Reports Server (NTRS)

NASA is interested in field testing for possible leakage in their fueling systems; however, many fuels are hazardous to the extent that personnel cannot be on hand when the system is being monitored. It is proposed that an inert material such as helium be used on the field test, and that those results be calibrated to simulate the actual process. A technique such as this would allow personnel to be on site during the testing and use techniques to determine the behavior of the system that could not be used otherwise. This endeavor attempts to develop such a correlation. The results show promise, but more refinement and data are needed.

Schleier, Howard

1990-01-01

168

Effects of water vapor condensation on the convection heat transfer of wet flue gas in a vertical tube  

Microsoft Academic Search

The annular thin film condensation of water vapor in wet flue gas flowing through a vertical tube was studied theoretically and experimentally. Especially discussions were conducted on the effects induced by condensation of small amount of water vapor (10–20% fraction) on convection heat transfer in a vertical tube. The convection heat transfer was enhanced by the condensation of the condensable

L. Jia; X. F. Peng; Y. Yan; J. D. Sun; X. P. Li

2001-01-01

169

Corrosion of muffler materials in automotive exhaust gas condensates  

SciTech Connect

The corrosion of automotive mufflers collected in North America was investigated. Aluminum (Al)-plated steels corroded severely in the substrate under the Al plating. Type 409 (UNS S40900) stainless steels sustained a large number of pits. The effects of ions in the condensate and activated carbon on the corrosion resistance of muffler materials were studied with a newly developed condensate corrosion test.

Ujiro, Takumi; Kitazawa, Makoto; Togashi, Fusao (Kawasaki Steel Corp., Chiba (Japan). Iron and Steel Research Lab.)

1994-12-01

170

Improvement of the sensitivity of opto-acoustic trace gas analysis by condensation  

SciTech Connect

It is suggested that the minimum detectable concentration of a trace gas in an optoacoustically monitored sample of air could be decreased by five orders of magnitude by condensing the sample and optoacoustically monitoring the liquid phase.

Slatkine, M.

1981-01-01

171

Condensation of natural gas or methane into gasoline-range hydrocarbons  

SciTech Connect

This invention relates to a new process for the direct conversion of natural gas or methane into gasoline-range hydrocarbons (i.e., synthetic transportation fuels or lower olefins) via catalytic condensation using superacid catalysts.

Olah, G.A.

1984-08-21

172

Oxidative condensation of natural gas or methane into gasoline range hydrocarbons  

SciTech Connect

This invention relates to a new process for the direct conversion of natural gas or methane into gasoline range hydrocarbons (i.e., synthetic transportation fuels or lower olefins) via catalytic condensation using superacid catalysts.

Olah, G.A.

1984-08-14

173

Dissipative dynamics of a kink state in a Bose-condensed gas  

E-print Network

We develop a theory of dissipative dynamics of a kink state in a finite-temperature Bose-condensed gas. We find that due to the interaction with the thermal cloud the kink state accelerates towards the velocity of sound and continuously transforms to the ground-state condensate. We calculate the life-time of a kink state in a trapped gas and discuss possible experimental implications.

P. O. Fedichev; A. E. Muryshev; G. V. Shlyapnikov

1999-05-18

174

Dissipative dynamics of a kink state in a Bose-condensed gas  

Microsoft Academic Search

We develop a theory of dissipative dynamics of a kink state in a\\u000afinite-temperature Bose-condensed gas. We find that due to the interaction with\\u000athe thermal cloud the kink state accelerates towards the velocity of sound and\\u000acontinuously transforms to the ground-state condensate. We calculate the\\u000alife-time of a kink state in a trapped gas and discuss possible experimental\\u000aimplications.

P. O. Fedichev; A. E. Muryshev; G. V. Shlyapnikov

1999-01-01

175

The evaluation of the pyrochemistry for the treatment of Gen IV nuclear fuels Inert matrix chlorination studies in the gas phase or molten chloride salts  

NASA Astrophysics Data System (ADS)

The structure of the fuels for the future Gen IV nuclear reactors will be totally different from those of PWR, especially for the GFR concept including a closed cycle. In these reactors, fissile materials (carbides or nitrides of actinides) should be surrounded by an inert matrix. In order to build a reprocessing process scheme, the behavior of the potential inert matrices (silicon carbide, titanium nitride, and zirconium carbide and nitride) was studied by hydro- and pyrometallurgy. This paper deals with the chlorination results at high temperature by pyrometallurgy. For the first time, the reactivity of the matrix towards chlorine gas was assessed in the gas phase. TiN, ZrN and ZrC are very reactive from 400 °C whereas it is necessary to be over 900 °C for SiC to be as fast. In molten chloride melts, the bubbling of chlorine gas is less efficient than in gas phase but it is possible to attack the matrices. Electrochemical methods were also used to dissolve the refractory materials, leading to promising results with TiN, ZrN and ZrC. The massive SiC samples used were not conductive enough to be studied and in this case specific SiC-coated carbon electrodes were used. The key point of these studies was to find a method to separate the matrix compounds from the fissile material in order to link the head to the core of the process (electrochemical separation or liquid-liquid reductive extraction in the case of a pyrochemical reprocessing).

Bourg, S.; Péron, F.; Lacquement, J.

2007-01-01

176

Non-Condensable Gas Absorption by Capillary Waves  

NASA Astrophysics Data System (ADS)

Oceans and atmosphere are constantly exchanging heat and mass; this has a direct consequence on the climate. While these exchanges are inherently multi-scales, in non-breaking waves the smallest scales strongly govern the transfer rates at the ocean-atmosphere interface. The present experimental study aims at characterizing and quantifying the exchanges of non-condensable gas at a sub-millimeter scale, in the presence of capillary waves. In oceans, capillaries are generated by high winds and are also present on the forward face of short gravity waves. Capillary waves are thus present over a large fraction of the ocean surface, but their effect on interphase phenomena is little known. In the experiment, 2D capillary waves are generated by the relaxation of a shear layer at the surface of a laminar water slab jet. Wave profile is measured with Planar Laser Induced Fluorescence (PLIF) and 2D velocity field of the water below the surface is resolved with Particle Image Velocimetry (PIV). Special optical arrangements coupled with high speed imaging allow 0.1 mm- and 0.1 ms- resolution. These data reveal the interaction of vorticity and free surface in the formation and evolution of capillaries. The effect of the capillaries on the transfer of oxygen from the ambient air to anoxic water is measured with another PLIF system. In this diagnostic, dissolved oxygen concentration field is indirectly measured using fluorescence quenching of Pyrenebutyric Acid (PBA). The three measurements performed simultaneously -surface profile, velocity field, and oxygen concentration- give deep physical insights into oxygen transfer mechanisms under capillary waves.

Andre, Matthieu A.; Bardet, Philippe M.

2013-03-01

177

Condensate fraction of a two-dimensional attractive Fermi gas  

SciTech Connect

We investigate the Bose-Einstein condensation of fermionic pairs in a two-dimensional uniform two-component Fermi superfluid obtaining an explicit formula for the condensate density as a function of the chemical potential and the energy gap. By using the mean-field extended Bardeen-Cooper-Schrieffer theory, we analyze, as a function of the bound-state energy, the off-diagonal long-range order in the crossover from the Bardeen-Cooper-Schrieffer state of weakly bound Cooper pairs to the Bose-Einstein condensate of strongly-bound molecular dimers.

Salasnich, Luca [CNR-INFM and CNISM, Dipartimento di Fisica 'Galileo Galilei', Universita di Padova, Via Marzolo 8, 35131 Padova (Italy)

2007-07-15

178

Why Condensing Steam Turbines are More Efficient than Gas Turbines  

E-print Network

and condensing steam turbine combination, 398 ESL-IE-88-09-71 Proceedings from the Tenth Annual Industrial Energy Technology Conference, Houston, TX, September 13-15, 1988 It's not a very efficient cycle le.g. neither condensate nor air preheat are usedl... through a turbine at 75'rc adiabatic efficiency to a vacuum of 2"Hg. No steam is extracted. 15,7 ~Blu/hr STACK Figure 3. Enthalpy analysis of power plant cycle. Analyzing this system points to the steam turbine condenser as the source of inefficiency...

Nelson, K. E.

179

The effect of condensate dropout on pressure transient analysis of a high-pressure gas condensate well  

E-print Network

Condensate Well. (August 1986) Frederic Jean~Louis Briens, ingenieur Ecole Centrale Chairman of Advisory Committee: Dr. Ching H. Wu Pressure transient analysis techniques are often used to determine the i'low proper ties of gas wells. Through the analysis... encouragement and interest throughout this study. Dr . James W. Jennings and Dr . Rayford G. Anthony for serving as member s of the author's Graduate Committee. Messieurs Francois Foxonet, Jean Labastie and Henri Ploton of Elf Aquitaine, for providing...

Briens, Frederic Jean-Louis

1986-01-01

180

Effect of non-condensable gas on the vapor flow in thermosiphons  

NASA Astrophysics Data System (ADS)

A detailed flow field survey was conducted to get a better insight into condensation mechanism of vapor flow onto the cooled plate in the enclosure. A two-dimensional thermosyphon was used as an experimental apparatus and special attention was paid to the effect of non-condensable gas in the thermosiphon. Generally it is understood that the non-condensable gas in the thermosiphon in its steady state operation occupies an upper region of the condensation section, and that there exists an interfacial layer separating vapor flow from non-condensable gas which will move vertically according to the heat input rate applied to the thermosiphon. However the structural properties of this interfacial layer and the boundary layer on the wall of condensation section, such as location of layers, thickness, temperature or density variation across them, have not been thoroughly investigated. A real time laser holographic interferometer was used to visualize a flow field in the thermosiphon. Temperature distribution was measured to evaluate the total heat transfer coefficient in the condensation section.

Matsumoto, T.; Kobayashi, Y.

1985-03-01

181

Alleviation of effective permeability reduction of gas-condensate due to condensate buildup near wellbore  

E-print Network

the productivity of the well. In this research a simulation study was performed to determine the range of permeabilities where the cylinder of condensate will seriously affect the wellÂ?s productivity, and the distance the removal of water around the wellbore has...

Carballo Salas, Jose Gilberto

2006-04-12

182

A new technique for the strengthening of aluminum tungsten inert gas weld metals: using carbon nanotube/aluminum composite as a filler metal.  

PubMed

The effect of multi-walled carbon nanotube (MWCNT) on the mechanical properties of aluminum multipass weld metal prepared by the tungsten inert gas (TIG) welding process was investigated. High energy ball milling was used to disperse MWCNT in the aluminum powder. Carbon nanotube/aluminum composite filler metal was fabricated for the first time by hot extrusion of ball-milled powders. After welding, the tensile strength, microhardness and MWCNT distribution in the weld metal were investigated. The test results showed that the tensile strength and microhardness of weld metal was greatly increased when using the filler metal containing 1.5 wt.% MWCNT. Therefore, according to the results presented in this paper, it can be concluded that the filler metal containing MWCNT can serve as a super filler metal to improve the mechanical properties of TIG welds of Al and its alloys. PMID:23948441

Fattahi, M; Nabhani, N; Rashidkhani, E; Fattahi, Y; Akhavan, S; Arabian, N

2013-01-01

183

Intrinsic bioremediation of petroleum hydrocarbons in a gas condensate-contaminated aquifer  

Microsoft Academic Search

A study was designed to determine if the intrinsic bioremediation of gas condensate hydrocarbons represented an important fate process in a shallow aquifer underlying a natural gas production site. For over 4 yr, changes in the groundwater, sediment, and vadose zone chemistry in the contaminated portion of the aquifer were interpreted relative to a background zone. Changes included decreased dissolved

Lisa M. Gieg; R. S. Tanner; S. H. Jr. Harris; K. L. Sublette; J. M. Suflita; R. V. Kolhatkar

1999-01-01

184

Some effects of non-condensible gas in geothermal reservoirs with steam-water counterflow  

SciTech Connect

A mathematical model is developed for fluid and heat flow in two-phase geothermal reservoirs containing non-condensible gas (CO{sub 2}). Vertical profiles of temperature, pressures and phase saturations in steady-state conditions are obtained by numerically integrating the coupled ordinary differential equations describing conservation of water, CO{sub 2}, and energy. Solutions including binary diffusion effects in the gas phase are generated for cases with net mass throughflow as well as for balanced liquid-vapor counterflow. Calculated examples illustrate some fundamental characteristics of two-phase heat transmission systems with non-condensible gas.

McKibbin, Robert; Pruess, Karsten

1988-01-01

185

The role of Causality in Tunable Fermi Gas Condensates  

E-print Network

We develop a new formalism for the description of the condensates of cold Fermi atoms whose speed of sound can be tuned with the aid of a narrow Feshbach resonance. We use this to look for spontaneous phonon creation that mimics spontaneous particle creation in curved space-time in Friedmann-Robertson-Walker and other model universes.

Jen-Tsung Hsiang; Chi-Yong Lin; Da-Shin Lee; Ray J. Rivers

2013-09-17

186

Economics of Condensing Gas Furnaces and Water Heaters Potential in Residential Single Family Homes  

SciTech Connect

Residential space and water heating accounts for over 90percent of total residential primary gas consumption in the United States. Condensing space and water heating equipment are 10-30percent more energy-efficient than conventional space and water heating. Currently, condensing gas furnaces represent 40 percent of shipments and are common in the Northern U.S. market. Meanwhile, manufacturers are planning to develop condensing gas storage water heaters to qualify for Energy Star? certification. Consumers, installers, and builders who make decisions about installing space and water heating equipment generally do not perform an analysis to assess the economic impacts of different combinations and efficiencies of space and water heating equipment. Thus, equipment is often installed without taking into consideration the potential life-cycle economic and energy savings of installing space and water heating equipment combinations. Drawing on previous and current analysis conducted for the United States Department of Energy rulemaking on amended standards for furnaces and water heaters, this paper evaluates the extent to which condensing equipment can provide life-cycle cost-effectiveness in a representative sample of single family American homes. The economic analyses indicate that significant energy savings and consumer benefits may result from large-scale introduction of condensing water heaters combined with condensing furnaces in U.S. residential single-family housing, particularly in the Northern region. The analyses also shows that important benefits may be overlooked when policy analysts evaluate the impact of space and water heating equipment separately.

Lekov, Alex; Franco, Victor; Meyers, Steve

2010-05-14

187

Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers  

SciTech Connect

Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: • An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing highmoisture, low rank coals. • Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. • Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. • Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. • Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. • Condensed flue gas water treatment needs and costs. • Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. • Results of cost-benefit studies of condensing heat exchangers.

Levy, Edward; Bilirgen, Harun; DuPont, John

2011-03-31

188

Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers  

SciTech Connect

Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: (1) An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing high-moisture, low rank coals. (2) Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. (3) Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. (4) Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. (5) Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. (6) Condensed flue gas water treatment needs and costs. (7) Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. (8) Results of cost-benefit studies of condensing heat exchangers.

Edward Levy; Harun Bilirgen; John DuPoint

2011-03-31

189

Inert electrode connection  

DOEpatents

An inert electrode connection is disclosed wherein a layer of inert electrode material is bonded to a layer of conductive material by providing at least one intermediate layer of material therebetween comprising a predetermined ratio of inert material to conductive material. In a preferred embodiment, the connection is formed by placing in a die a layer of powdered inert material, at least one layer of a mixture of powdered inert material and conductive material, and a layer of powdered conductive material. The connection is then formed by pressing the material at 15,000-20,000 psi to form a powder compact and then densifying the powder compact in an inert or reducing atmosphere at a temperature of 1200.degree.-1500.degree. C.

Weyand, John D. (Greensburg, PA); Woods, Robert W. (New Kensington, PA); DeYoung, David H. (Plum Boro, PA); Ray, Siba P. (Plum Boro, PA)

1985-01-01

190

Silurian shale origin for light oil, condensate, and gas in Algeria and the Middle East  

SciTech Connect

Two of the largest gas fields in the world, Hasi R`Mel, Algeria and North Dome, Qatar, also contain substantial condensate and light oil reserves. Gas to source rock geochemical correlation is difficult due to the paucity of molecular parameters in the former although stable isotope composition is invaluable. However, by correlating source rocks with light oils and condensates associated with gas production using traditional geochemical parameters such as biomarkers and isotopes, a better understanding of the origin of the gas is achieved. Much of the crude oil in the Ghadames/Illizi Basins of Algeria has long been thought to have been generated from Silurian shales. New light oil discoveries in Saudi Arabia have also been shown to originate in basal euxinic Silurian shales. Key sterane and terpane biomarkers as well as the stable carbon isotopic compositions of the C15+ saturate and aromatic hydrocarbon fractions allow for the typing of Silurian-sourced, thermally mature light oils in Algeria and the Middle East. Even though biomarkers are often absent due to advanced thermal maturity, condensates can be correlated to the light oils using (1) carbon isotopes of the residual heavy hydrocarbon fractions, (2) light hydrocarbon distributions (e.g., C7 composition), and (3) compound specific carbon isotopic composition of the light hydrocarbons. The carbon isotopes of the C2-C4 gas components ran then be compared to the associated condensate and light oil isotopic composition.

Zumberge, J.E. [GeoMark Research Inc., Houston, TX (United States); Macko, S. [Univ. of Virginia, Charlottesville, VA (United States)] Engel, M. [Univ. of Oklahoma, Norman, OK (United States)] [and others

1996-12-31

191

Silurian shale origin for light oil, condensate, and gas in Algeria and the Middle East  

SciTech Connect

Two of the largest gas fields in the world, Hasi R'Mel, Algeria and North Dome, Qatar, also contain substantial condensate and light oil reserves. Gas to source rock geochemical correlation is difficult due to the paucity of molecular parameters in the former although stable isotope composition is invaluable. However, by correlating source rocks with light oils and condensates associated with gas production using traditional geochemical parameters such as biomarkers and isotopes, a better understanding of the origin of the gas is achieved. Much of the crude oil in the Ghadames/Illizi Basins of Algeria has long been thought to have been generated from Silurian shales. New light oil discoveries in Saudi Arabia have also been shown to originate in basal euxinic Silurian shales. Key sterane and terpane biomarkers as well as the stable carbon isotopic compositions of the C15+ saturate and aromatic hydrocarbon fractions allow for the typing of Silurian-sourced, thermally mature light oils in Algeria and the Middle East. Even though biomarkers are often absent due to advanced thermal maturity, condensates can be correlated to the light oils using (1) carbon isotopes of the residual heavy hydrocarbon fractions, (2) light hydrocarbon distributions (e.g., C7 composition), and (3) compound specific carbon isotopic composition of the light hydrocarbons. The carbon isotopes of the C2-C4 gas components ran then be compared to the associated condensate and light oil isotopic composition.

Zumberge, J.E. (GeoMark Research Inc., Houston, TX (United States)); Macko, S. (Univ. of Virginia, Charlottesville, VA (United States)) Engel, M. (Univ. of Oklahoma, Norman, OK (United States)) (and others)

1996-01-01

192

Analysis of Vapour Liquid Equilibria in Unconventional Rich Liquid Gas Condensate Reservoirs  

NASA Astrophysics Data System (ADS)

At the beginning of 21st century, natural gas from conventional and unconventional reservoirs has become important fossil energy resource and its role as energy fuel has increased. The exploration of unconventional gas reservoirs has been discussed recently in many conferences and journals. The paper presents considerations which will be used to build the thermodynamic model that will describe the phenomenon of vapour - liquid equilibrium (VLE) in the retrograde condensation in rocks of ultra-low permeability and in the nanopores. The research will be limited to "tight gas" reservoirs (TGR) and "shale gas" reservoirs (SGR). Constructed models will take into account the phenomenon of capillary condensation and adsorption. These studies will be the base for modifications of existing compositional simulators

Kuczy?ski, Szymon

2014-12-01

193

Water production analysis and reservoir simulation of the Jilake gas condensate field  

Microsoft Academic Search

The development of the Jilake gas condensate field is dominated by production of old wells, with complication of well status, serious impact of edge-bottom water, and difficulty in development and adjustment. Through integration of formation water salinity analysis, color and density change of oil samples, diagnostic curve characteristic of modern production decline analysis and characteristic analysis of production water, the

Li Yong; Li Baozhu; Hu Yongle; Jiao Yuwei; Zhu Weihong; Xiao Xiangjiao; Niu Yu

2010-01-01

194

Impact of relative permeability models on fluid flow behavior for gas condensate reservoirs  

E-print Network

and on the quantification of their impact on reservoir fluid flow and well performance. We selected three relative permeability models to compare the results obtained in the modeling of relative permeabilities for a published North Sea gas condensate reservoir. The models...

Zapata Arango, Jose? Francisco

2002-01-01

195

Non-condensible gas fraction predictions using wet and dry bulb temperature measurements. [PWR  

Microsoft Academic Search

A technique is presented whereby non-condensible gas mass fractions in a closed system can be determined using wet bulb and dry bulb temperature and system pressure measurements. This technique would have application in situations where sampling techniques could not be used. Using an energy balance about the wet bulb wick, and expression is obtained which relates the vapor concentration difference

J. Bowman; P. Griffith

1983-01-01

196

Survey of flue gas condensation heat recovery systems. Final report February-October 1981  

Microsoft Academic Search

This program was conducted to evaluate the state of the art of commercial condensation heat recovery systems. These heat recovery systems are capable of improving boiler thermal efficiency by 10-15 percent when firing natural gas and have wide applications for fuel oil and solid fuel firing due to the combined effect of waste heat recovery and emissions reduction. Twenty-two manufacturers

Goldstick

1981-01-01

197

THE EFFECTS OF NON-CONDENSIBLE GAS AND SALINITY ON STEAM ADSORPTION  

E-print Network

THE EFFECTS OF NON-CONDENSIBLE GAS AND SALINITY ON STEAM ADSORPTION A REPORT SUBMITTED% by weight of saline solution was added to the rock sample. Addition of salt to the sample enabled.1 Effects of GO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 Effects of Salinity

Stanford University

198

Modeling of Gas Cooling and Condensation in a Piston Expansion Machine  

Microsoft Academic Search

A model of gas cooling and condensation in a piston expansion machine has been developed with allowance made for formation of nuclei of the liquid phase and growth of droplets as well as for real thermophysical properties. Internal heat release related to phase transition is taken into account in the adiabatic equation. The processes of cooling and liquefaction of methane

K. M. Aref'ev; O. V. Belyaeva; A. Zh. Greben'kov; T. A. Zayats; A. A. Mikhalevich

2004-01-01

199

PII S0016-7037(00)00550-0 Condensation from supernova gas made of free atoms  

E-print Network

PII S0016-7037(00)00550-0 Condensation from supernova gas made of free atoms D. S. EBEL 1, * and L in the deep zones of Type II supernova ejecta. We present equilibrium calculations for SN shells, and show the prediction of graphite formation, even in an O-rich supernova shell. Following up on this hypothesis, we

Grossman, Lawrence

200

The Role of Spraying Parameters and Inert Gas Shrouding in Hybrid Water-Argon Plasma Spraying of Tungsten and Copper for Nuclear Fusion Applications  

NASA Astrophysics Data System (ADS)

Tungsten-based coatings have potential application in the plasma-facing components in future nuclear fusion reactors. By the combination of refractory tungsten with highly thermal conducting copper, or steel as a construction material, functionally graded coatings can be easily obtained by plasma spraying, and may result in the development of a material with favorable properties. During plasma spraying of these materials in the open atmosphere, oxidation is an important issue, which could have adverse effects on their properties. Among the means to control it is the application of inert gas shrouding, which forms the subject of this study and represents a lower-cost alternative to vacuum or low-pressure plasma spraying, potentially applicable also for spraying of large surfaces or spacious components. It is a continuation of recent studies focused on the effects of various parameters of the hybrid water-argon torch on the in-flight behavior of copper and tungsten powders and the resultant coatings. In the current study, argon shrouding with various configurations of the shroud was applied. The effects of torch parameters, such as power and argon flow rate, and powder morphology were also investigated. Their influence on the particle in-flight behavior as well as the structure, composition and properties of the coatings were quantified. With the help of auxiliary calculations, the mass changes of the powder particles, associated with oxidation and evaporation, were assessed.

Mat?jí?ek, J.; Kavka, T.; Bertolissi, G.; Ctibor, P.; Vilémová, M.; Mušálek, R.; Nevrlá, B.

2013-06-01

201

Effects of CaF2 Coating on the Microstructures and Mechanical Properties of Tungsten Inert Gas Welded AZ31 Magnesium Alloy Joints  

NASA Astrophysics Data System (ADS)

The effects of CaF2 coating on the macromorphologies of the welded seams were studied by morphological analysis. Microstructures and mechanical properties of butt joints welded with different amounts of CaF2 coatings were investigated using optical microscopy and tensile tests. The welding defects formed in the welded seams and the fracture surfaces were analyzed by scanning electron microscopy. An increase in the amount of CaF2 coating deteriorated the appearances of the welded seams but it improved the weld penetration depth and the depth/width ( D/ W) ratio of the tungsten inert gas (TIG) welded joints. The ?-Mg grains and Mg17(Al,Zn)12 intermetallic compound (IMC) were coarser in the case of a higher amount of CaF2 coating. The increase in the amount of CaF2 coating reduced the porosities and total length of solidification cracks in the fusion zone (FZ). The ultimate tensile strength (UTS) value and elongation increased at first and then decreased sharply.

Shen, Jun; Wang, Linzhi; Peng, Dong; Wang, Dan

2012-11-01

202

Tungsten Inert Gas and Friction Stir Welding Characteristics of 4-mm-Thick 2219-T87 Plates at Room Temperature and -196 °C  

NASA Astrophysics Data System (ADS)

2219-T87 aluminum alloy is widely used for fabricating liquid rocket propellant storage tank, due to its admirable cryogenic property. Welding is the dominant joining method in the manufacturing process of aerospace components. In this study, the tungsten inert gas welding and friction stir welding (FSW) characteristics of 4-mm-thick 2219-T87 alloy plate at room temperature (25 °C) and deep cryogenic temperature (-196 °C) were investigated by property measurements and microscopy methods. The studied 2219 base alloy exhibits a low strength plane anisotropy and excellent room temperature and cryogenic mechanical properties. The ultimate tensile strength values of TIG and FSW welding joints can reach 265 and 353 MPa at room temperature, and 342 and 438 MPa at -196 °C, respectively. The base metal consists of elongated deformed grains and many nano-scaled ? (Al2Cu) aging precipitates. Fusion zone and heat-affected zone (HAZ) of the TIG joint are characterized by coarsening dendritic grains and equiaxed recrystallized grains, respectively. The FSW-welded joint consists of the weld nugget zone, thermo-mechanically affected zone (TMAZ), and HAZ. In the weld nugget zone, a micro-scaled sub-grain structure is the main microstructure characteristic. The TMAZ and HAZ are both characterized by coarsened aging precipitates and elongated deformed grains. The excellent FSW welding properties are attributed to the preservation of the working structures and homogenous chemical compositions.

Lei, Xuefeng; Deng, Ying; Yin, Zhimin; Xu, Guofu

2014-06-01

203

Confined Phase Envelope of Gas-Condensate Systems in Shale Rocks  

NASA Astrophysics Data System (ADS)

Natural gas from shales (NGS) and from tight rocks are one of the most important fossil energy resource in this and next decade. Significant increase in gas consumption, in all world regions, will be marked in the energy sector. The exploration of unconventional natural gas & oil reservoirs has been discussed recently in many conferences. This paper describes the complex phenomena related to the impact of adsorption and capillary condensation of gas-condensate systems in nanopores. New two phase saturation model and new algorithm for search capillary condensation area is discussed. The algorithm is based on the Modified Tangent Plane Criterion for Capillary Condensation (MTPCCC) is presented. The examples of shift of phase envelopes are presented for selected composition of gas-condensate systems. Gaz ziemny z ?upków (NGS) oraz z ze z?ó? niskoprzepuszczalnych (typu `tight') staje si? jednym z najwa?niejszych zasobów paliw kopalnych, w tym i nast?pnym dziesi?cioleciu. Znacz?cy wzrost zu?ycia gazu we wszystkich regionach ?wiata zaznacza si? g?ównie w sektorze energetycznym. Rozpoznawanie niekonwencjonalnych z?ó? gazu ziemnego i ropy naftowej w ostatnim czasie jest omawiane w wielu konferencjach. Niniejszy artyku? opisuje z?o?one zjawiska zwi?zane z wp?ywem adsorpcji i kapilarnej kondensacji w nanoporach w z?o?ach gazowo-kondensatowych. Pokazano nowy dwufazowy model równowagowy dwufazowy i nowy algorytm wyznaczania krzywej nasycenia w obszarze kondensacji kapilarnej. Algorytm bazuje na kryterium zmodyfikowanym p?aszczyzny stycznej dla kapilarnej kondensacji (MTPCCC). Przyk?ady zmiany krzywych nasycenia s? przedstawiane w wybranym sk?adzie systemów gazowo- kondensatowych

Nagy, Stanislaw; Siemek, Jakub

2014-12-01

204

Dissipative dynamics of a vortex state in a trapped Bose-condensed gas  

E-print Network

We discuss dissipative dynamics of a vortex state in a trapped Bose-condensed gas at finite temperature and draw a scenario of decay of this state in a static trap. The interaction of the vortex with the thermal cloud transfers energy from the vortex to the cloud and induces the motion of the vortex core to the border of the condensate. Once the vortex reaches the border, it immediately decays through the creation of excitations. We calculate the characteristic life-time of a vortex state and address the question of how the dissipative dynamics of vortices can be studied experimentally.

P. O. Fedichev; G. V. Shlyapnikov

1999-06-15

205

Application of the parallel multicanonical method to lattice gas condensation  

NASA Astrophysics Data System (ADS)

We present the speedup from a novel parallel implementation of the multicanonical method on the example of a lattice gas in two and three dimensions. In this approach, all cores perform independent equilibrium runs with identical weights, collecting their sampled histograms after each iteration in order to estimate consecutive weights. The weights are then redistributed to all cores. These steps are repeated until the weights are converged. This procedure benefits from a minimum of communication while distributing the necessary amount of statistics efficiently. Using this method allows us to study a broad temperature range for a variety of large and complex systems. Here, a gas is modeled as particles on the lattice, which interact only with their nearest neighbors. For a fixed density this model is equivalent to the Ising model with fixed magnetization. We compare our results to an analytic prediction for equilibrium droplet formation, confirming that a single macroscopic droplet forms only above a critical density.

Zierenberg, Johannes; Wiedenmann, Micha; Janke, Wolfhard

2014-05-01

206

Numerical analysis of filmwise condensation in a plate fin-and-tube heat exchanger in presence of non-condensable gas  

Microsoft Academic Search

In the present paper, a numerical model of a fin-and-tube heat exchanger is proposed. The simulation of water vapor condensation\\u000a in presence of non-condensable gas (air) between two vertical plane plates and in a plate fin-and-tube heat exchanger in a\\u000a stationary mode is performed using Fluent software. The differential equations that describe the heat and mass transfer were\\u000a integrated by

Riad Benelmir; Salim Mokraoui; Ali Souayed

2009-01-01

207

Numerical analysis of filmwise condensation in a plate fin-and-tube heat exchanger in presence of non-condensable gas  

NASA Astrophysics Data System (ADS)

In the present paper, a numerical model of a fin-and-tube heat exchanger is proposed. The simulation of water vapor condensation in presence of non-condensable gas (air) between two vertical plane plates and in a plate fin-and-tube heat exchanger in a stationary mode is performed using Fluent software. The differential equations that describe the heat and mass transfer were integrated by the finite volume method, in two and three dimensions.

Benelmir, Riad; Mokraoui, Salim; Souayed, Ali

2009-10-01

208

Altering Wettability in Gas Condensate Sandstone Reservoirs for Gas Mobillity Improvement  

E-print Network

............................................................................................ 1 1.1.1. Field Cases ................................................................................................... 4 1.2. Current Methods for Reducing Condensate Banking Effect ............................. 10 1.2.1. Hydraulic Fracturing... applicability depending on the formation and on the regulations of the region. Hydraulic fracturing is presented shortly as a solution for condensate banking, although it is an extensive subject area more known to be used in producing from low permeability...

Fernandez Martinez, Ruth Gabriela

2012-07-16

209

Numerical simulation of the gas-condensate pipeline during shutdown and restart processes by AUSM+ scheme  

NASA Astrophysics Data System (ADS)

The transient multiphase simulation has been a research focus in the related fields. In this paper a two-fluid model of the transient two phase flow in the pipeline is set up, including the continuity, momentum and energy equations. Due to its many advantages the AUSM+ scheme is introduced into the solution scheme of the two-fluid model. In order to be incorporated with the AUSM+ scheme, the conservative general formula for the two-fluid model is given. The solution scheme with AUSM+ is also described in detail. A typical long distance offshore gas-condensate pipeline is chosen as an example. The steady state of this pipeline was simulated as initial condition of the transient process. The shutdown and restart processes were simulated on the basis of steady state. From the results the transient process of the gas-condensate pipeline was investigated. The variable distribution, the wave propagation, and the liquid accumulation are all reflected by the results.

Gong, Jing; Yin, Tienan; Wang, Zhi

2013-07-01

210

Lorentz-violating effects in the Bose-Einstein condensation of an ideal bosonic gas  

NASA Astrophysics Data System (ADS)

We have studied the effects of Lorentz-violation in the Bose-Einstein condensation (BEC) of an ideal boson gas, by assessing both the nonrelativistic and ultrarelativistic limits. Our model describes a massive complex scalar field coupled to a CPT-even and Lorentz-violating background. We first analyze the nonrelativistic case, at this level by using experimental data, we obtain upper-bounds for some LIV parameters. In the sequel, we have constructed the partition function for the relativistic ideal boson gas which to be able of a consistent description requires the imposition of severe restrictions on some LIV coefficients. In both cases, we have demonstrated that the LIV contributions are contained in an overall factor, which multiplies almost all thermodynamical properties. An exception is the fraction of the condensed particles.

Casana, Rodolfo; da Silva, Kleber A. T.

2015-02-01

211

Critical behavior of the ideal-gas Bose-Einstein condensation in the Apollonian network.  

PubMed

We show that the ideal Boson gas displays a finite-temperature Bose-Einstein condensation transition in the complex Apollonian network exhibiting scale-free, small-world, and hierarchical properties. The single-particle tight-binding Hamiltonian with properly rescaled hopping amplitudes has a fractal-like energy spectrum. The energy spectrum is analytically demonstrated to be generated by a nonlinear mapping transformation. A finite-size scaling analysis over several orders of magnitudes of network sizes is shown to provide precise estimates for the exponents characterizing the condensed fraction, correlation size, and specific heat. The critical exponents, as well as the power-law behavior of the density of states at the bottom of the band, are similar to those of the ideal Boson gas in lattices with spectral dimension d(s)=2ln(3)/ln(9/5)~/=3.74. PMID:24032807

de Oliveira, I N; dos Santos, T B; de Moura, F A B F; Lyra, M L; Serva, M

2013-08-01

212

Inert gas wave soldering evaluation  

Microsoft Academic Search

Production modules were soldered using adipic acid\\/isopropanol as a flux and atomized formic acid to further enhance oxide reduction over the molten soldered module. The objectives of the evaluation were to assess system capability, measurable performance versus conventional wave soldering equipment performance, and environmental impact. The system capability for overall machine performance, from belt speeds to repeatable solder heights and

J. E. Altpeter; L. L. Kneisel; J. D. Baker

1991-01-01

213

Inert gas ion source program  

NASA Technical Reports Server (NTRS)

THe original 12 cm hexagonal magneto-electrostatic containment discharge chamber has been optimized for argon and xenon operation. Argon mass utilization efficiencies of 65 to 77 percent were achieved at keeper-plus-main discharge energy consumptions of 200 to 458 eV/ion, respectively. Xenon performance of 84 to 96 percent mass utilization was realized at 203 to 350 eV/ion. The optimization process and test results are discussed.

Ramsey, W. D.

1978-01-01

214

Inert gas ion thruster development  

NASA Technical Reports Server (NTRS)

Two 12 cm magneto-electrostatic containment (MESC) ion thrusters were performance mapped with argon and xenon. The first, hexagonal, thruster produced optimized performance of 48.5to 79 percent argon mass utilization efficiencies at discharge energies of 240 to 425 eV/ion, respectively, Xenon mass utilization efficiencies of 78 to 95 percent were observed at discharge energies of 220 to 290 eV/ion with the same optimized hexagonal thruster. Changes to the cathode baffle reduced the discharge anode potential during xenon operation from approximately 40 volts to about 30 volts. Preliminary tests conducted with the second, hemispherical, MESC thruster showed a nonuniform anode magnetic field adversely affected thruster performance. This performance degradation was partially overcome by changes in the boundary anode placement. Conclusions drawn the hemispherical thruster tests gave insights into the plasma processes in the MESC discharge that will aid in the design of future thrusters.

Ramsey, W. D.

1980-01-01

215

Photoinduced Processes in Cobalt-Complexes: Condensed Phase and Gas Phase  

NASA Astrophysics Data System (ADS)

Femtosecond time-resolved, steady-state spectroscopic methods and quantum chemical calculations are employed to study ultrafast photoinduced processes in [Co(III)-(L-N4Me2)(dbc)](BPh4) and [Co(II)-(L-N4tBu2)(dbsq)](B(p-C6H4Cl)4) and to characterise the transient redox- and spin-states in condensed and gas phase.

Rupp, F.; Chevalier, K.; Wolf, M. M. N.; Krüger, H.-J.; Wüllen, C. v.; Nosenko, Y.; Niedner-Schatteburg, Y.; Riehn, C.; Diller, R.

2013-03-01

216

New correlations for dew-point, specific gravity and producing yield for gas condensates  

E-print Network

Test (CCE). . . . . 2. 3. 3 Constant Volume Depletion Test (CVD) 2. 4 SURFACE SEPARATION. . 10 2. 5 CALCULATION OF GAS CONDENSATE SURFACE P~ETERS . . 13 2. 5. 1 Flash Calculation. 2. 5. 2 Gas Characterization. 2. 6 STATISTICAL METHOD . 2. 6. 1...'s Correlation. . 22 23 23 2. 7, 4 Humoud" Correlation 2. 7. 5 Marrufo' er al Correlation. 23 . 24 CHAPTER III. . . . DEVELOPMENT OF CORRELATIONS. 3. 1 DATA DESCRIPTION. . 3. 2 METHODOLOGY. 3. 2. 1 Initial Conditions" 3. 2. 2 Calculations 3. 2. 3...

Ovalle Cortissoz, Adriana Patricia

2002-01-01

217

Method and apparatus for removing non-condensible gas from a working fluid in a binary power system  

DOEpatents

Apparatus for removing non-condensible gas from a working fluid utilized in a thermodynamic system comprises a membrane having an upstream side operatively connected to the thermodynamic system so that the upstream side of the membrane receives a portion of the working fluid. The first membrane separates the non-condensible gas from the working fluid. A pump operatively associated with the membrane causes the portion of the working fluid to contact the membrane and to be returned to the thermodynamic system.

Mohr, Charles M. (Idaho Falls, ID); Mines, Gregory L. (Idaho Falls, ID); Bloomfield, K. Kit (Idaho Falls, ID)

2002-01-01

218

Condensate fraction of a resonant Fermi gas with spin-orbit coupling in three and two dimensions  

SciTech Connect

We study the effects of laser-induced Rashba-like spin-orbit coupling along the Bardeen-Cooper-Schrieffer-Bose-Einstein condensate (BCS-BEC) crossover of a Feshbach resonance for a two-spin-component Fermi gas. We calculate the condensate fraction in three and two dimensions and find that this quantity characterizes the crossover better than other quantities, like the chemical potential or the pairing gap. By considering both the singlet and the triplet pairings, we calculate the condensate fraction and show that a large-enough spin-orbit interaction enhances the singlet condensate fraction in the BCS side while suppressing it on the BEC side.

Dell'Anna, L.; Mazzarella, G.; Salasnich, L. [Dipartimento di Fisica ''Galileo Galilei'' and CNISM, Universita di Padova, I-35122 Padova (Italy)

2011-09-15

219

Inert dark matter  

SciTech Connect

The lightest neutral scalar in the inert Higgs doublet model is a natural candidate for weakly interacting massive particle dark matter. In this paper, we analyzed the dark matter relic density in the inert Higgs doublet model. Various theoretical and experimental constraints are taken into account. We found that there are five distinctive regions that could provide the right amount of the relic density in the Universe. Four out of those five regions have a light particle spectrum which could be studied at the Large Hadron Collider.

Dolle, Ethan M.; Su Shufang [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)

2009-09-01

220

Transport Membrane Condenser for Water and Energy Recovery from Power Plant Flue Gas  

SciTech Connect

The new waste heat and water recovery technology based on a nanoporous ceramic membrane vapor separation mechanism has been developed for power plant flue gas application. The recovered water vapor and its latent heat from the flue gas can increase the power plant boiler efficiency and reduce water consumption. This report describes the development of the Transport Membrane Condenser (TMC) technology in details for power plant flue gas application. The two-stage TMC design can achieve maximum heat and water recovery based on practical power plant flue gas and cooling water stream conditions. And the report includes: Two-stage TMC water and heat recovery system design based on potential host power plant coal fired flue gas conditions; Membrane performance optimization process based on the flue gas conditions, heat sink conditions, and water and heat transport rate requirement; Pilot-Scale Unit design, fabrication and performance validation test results. Laboratory test results showed the TMC system can exact significant amount of vapor and heat from the flue gases. The recovered water has been tested and proved of good quality, and the impact of SO{sub 2} in the flue gas on the membrane has been evaluated. The TMC pilot-scale system has been field tested with a slip stream of flue gas in a power plant to prove its long term real world operation performance. A TMC scale-up design approach has been investigated and an economic analysis of applying the technology has been performed.

Dexin Wang

2012-03-31

221

Microbial reduction of sulfate injected to gas condensate plumes in cold groundwater.  

PubMed

Despite a rapid expansion over the past decade in the reliance on intrinsic bioremediation to remediate petroleum hydrocarbon plumes in groundwater, significant research gaps remain. Although it has been demonstrated that bacterial sulfate reduction can be a key electron accepting process in many petroleum plumes, little is known about the rate of this reduction process in plumes derived from crude oil and gas condensates at cold-climate sites (mean temperature <10 degrees C), and in complex hydrogeological settings such as silt/clay aquitards. In this field study, sulfate was injected into groundwater contaminated by gas condensate plumes at two petroleum sites in Alberta, Canada to enhance in-situ bioremediation. In both cases the groundwater near the water table had low temperature (6-9 degrees C). Monitoring data had provided strong evidence that bacterial sulfate reduction was a key terminal electron accepting process (TEAP) in the natural attenuation of dissolved hydrocarbons at these sites. At each site, water with approximately 2000 mg/L sulfate and a bromide tracer was injected into a low-sulfate zone within a condensate-contaminant plume. Monitoring data collected over several months yielded conservative estimates for sulfate reduction rates based on zero-order kinetics (4-6 mg/L per day) or first-order kinetics (0.003 and 0.01 day(-1)). These results favor the applicability of in-situ bioremediation techniques in this region, under natural conditions or with enhancement via sulfate injection. PMID:17292997

Van Stempvoort, Dale R; Armstrong, James; Mayer, Bernhard

2007-07-17

222

High-resolution gas chromatography\\/matrix isolation infrared spectrometry  

Microsoft Academic Search

An apparatus is described that allows the collection, within a matrix of condensed inert gas, of the effluent compounds from a high-resolution gas chromatograph. Each collected compound is contained within an area typically 0.3 mm in diameter yielding a concomitant high level of infrared spectral absorbance per nanogram of sample. Tests demonstrate the level of infrared sensitivity, the achievement of

Gerald T. Reedy; Deon G. Ettinger; John F. Schneider; Sidney. Bourne

1985-01-01

223

Methanol Droplet Combustion in Oxygen-Inert Environments in Microgravity  

NASA Technical Reports Server (NTRS)

The Flame Extinguishment (FLEX) experiment that is currently underway in the Combustion Integrated Rack facility onboard the International Space Station is aimed at understanding the effects of inert diluents on the flammability of condensed phase fuels. To this end, droplets of various fuels, including alkanes and alcohols, are burned in a quiescent microgravity environment with varying amounts of oxygen and inert diluents to determine the limiting oxygen index (LOI) for these fuels. In this study we report experimental observations of methanol droplets burning in oxygen-nitrogen-carbon dioxide and oxygen-nitrogen-helium gas mixtures at 0.7 and 1 atmospheric pressures. The initial droplet size varied between approximately 1.5 mm and 4 mm to capture both diffusive extinction brought about by insufficient residence time at the flame and radiative extinction caused by excessive heat loss from the flame zone. The ambient oxygen concentration varied from a high value of 30% by volume to as low as 12%, approaching the limiting oxygen index for the fuel. The inert dilution by carbon dioxide and helium varied over a range of 0% to 70% by volume. In these experiments, both freely floated and tethered droplets were ignited using symmetrically opposed hot-wire igniters and the burning histories were recorded onboard using digital cameras, downlinked later to the ground for analysis. The digital images yielded droplet and flame diameters as functions of time and subsequently droplet burning rate, flame standoff ratio, and initial and extinction droplet diameters. Simplified theoretical models correlate the measured burning rate constant and the flame standoff ratio reasonably well. An activation energy asymptotic theory accounting for time-dependent water dissolution or evaporation from the droplet is shown to predict the measured diffusive extinction conditions well. The experiments also show that the limiting oxygen index for methanol in these diluent gases is around 12% to 13% oxygen by volume.

Nayagam, Vedha; Dietrich, Daniel L.; Hicks, Michael C.; Williams, Forman A.

2013-01-01

224

Effect of inert propellant injection on Mars ascent vehicle performance  

NASA Technical Reports Server (NTRS)

A Mars ascent vehicle is limited in performance by the propellant which can be brought from Earth. In some cases the vehicle performance can be improved by injecting inert gas into the engine, if the inert gas is available as an in-situ resource and does not have to be brought from Earth. Carbon dioxide, nitrogen, and argon are constituents of the Martian atmosphere which could be separated by compressing the atmosphere, without any chemical processing step. The effect of inert gas injection on rocket engine performance was analyzed with a numerical combustion code that calculated chemical equilibrium for engines of varying combustion chamber pressure, expansion ratio, oxidizer/fuel ratio, and inert injection fraction. Results of this analysis were applied to several candidate missions to determine how the required mass of return propellant needed in low Earth orbit could be decreased using inert propellant injection.

Colvin, James E.; Landis, Geoffrey A.

1992-01-01

225

Pairing, ferromagnetism, and condensation of a normal spin-1 Bose gas  

NASA Astrophysics Data System (ADS)

We theoretically study the stability of a normal, spin disordered, homogenous spin-1 Bose gas against ferromagnetism, pairing, and condensation through a Random Phase Approximation which includes exchange (RPA-X). Repulsive spin-independent interactions stabilize the normal state against both ferromagnetism and pairing, and for typical interaction strengths leads to a direct transition from an unordered normal state to a fully ordered single particle condensate. Atoms with much larger spin-dependent interaction may experience a transition to a ferromagnetic normal state or a paired superfluid, but, within the RPA-X, there is no instability towards a normal state with spontaneous nematic order. We analyze the role of the quadratic Zeeman effect and finite system size.

Natu, Stefan; Mueller, Erich

2011-06-01

226

Method of producing hydrogen, and rendering a contaminated biomass inert  

DOEpatents

A method for rendering a contaminated biomass inert includes providing a first composition, providing a second composition, reacting the first and second compositions together to form an alkaline hydroxide, providing a contaminated biomass feedstock and reacting the alkaline hydroxide with the contaminated biomass feedstock to render the contaminated biomass feedstock inert and further producing hydrogen gas, and a byproduct that includes the first composition.

Bingham, Dennis N. (Idaho Falls, ID) [Idaho Falls, ID; Klingler, Kerry M. (Idaho Falls, ID) [Idaho Falls, ID; Wilding, Bruce M. (Idaho Falls, ID) [Idaho Falls, ID

2010-02-23

227

33 CFR 154.824 - Inerting, enriching, and diluting systems.  

Code of Federal Regulations, 2011 CFR

...used. (h) An inerting system must: (1) Supply sufficient...throughout the vapor collection system is maintained below 8.0 percent...produce the inert gas, have a hydraulic seal and non-return valve...line. (i) An enriching system must: (1) Supply...

2011-07-01

228

33 CFR 154.824 - Inerting, enriching, and diluting systems.  

Code of Federal Regulations, 2012 CFR

...used. (h) An inerting system must: (1) Supply sufficient...throughout the vapor collection system is maintained below 8.0 percent...produce the inert gas, have a hydraulic seal and non-return valve...line. (i) An enriching system must: (1) Supply...

2012-07-01

229

33 CFR 154.824 - Inerting, enriching, and diluting systems.  

Code of Federal Regulations, 2010 CFR

...used. (h) An inerting system must: (1) Supply sufficient...throughout the vapor collection system is maintained below 8.0 percent...produce the inert gas, have a hydraulic seal and non-return valve...line. (i) An enriching system must: (1) Supply...

2010-07-01

230

33 CFR 154.824 - Inerting, enriching, and diluting systems.  

Code of Federal Regulations, 2013 CFR

...used. (h) An inerting system must: (1) Supply sufficient...throughout the vapor collection system is maintained below 8.0 percent...produce the inert gas, have a hydraulic seal and non-return valve...line. (i) An enriching system must: (1) Supply...

2013-07-01

231

Investigation into the determination of trimethylarsine in natural gas and its partitioning into gas and condensate phases using (cryotrapping)\\/gas chromatography coupled to inductively coupled plasma mass spectrometry and liquid\\/solid sorption techniques  

Microsoft Academic Search

Speciation of trialkylated arsenic compunds in natural gas, pressurized and stable condensate samples from the same gas well was performed using (Cryotrapping) Gas Chromatography-Inductively Coupled Plasma Mass Spectrometry. The major species in all phases investigated was found to be trimethylarsine with a highest concentration of 17.8 ng\\/L (As) in the gas phase and 33.2 ?g\\/L (As) in the stable condensate phase. The

E. M. Krupp; C. Johnson; C. Rechsteiner; M. Moir; D. Leong; J. Feldmann

2007-01-01

232

Assessment of natural hydrocarbon bioremediation at two gas condensate production sites  

SciTech Connect

Condensate liquids are present in soil and groundwater at two gas production sites in the Denver-Julesburg Basin operated by Amoco. These sites have been closely monitored since July 1993 to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores strongly suggest that intrinsic bioremediation is occurring at these sites by multiple pathways, including aerobic oxidation, Fe(III) reduction, and sulfate reduction.

Barker, G.W. [Amoco, Houston, TX (United States); Raterman, K.T.; Fisher, J.B.; Corgan, J.M.; Trent, G.L. [Amoco, Tulsa, OK (United States); Brown, D.R. [Amoco Production Co., Denver, CO (United States); Sublette, K.L. [Univ. of Tulsa, OK (United States). Dept. of Chemical Engineering

1995-12-31

233

Theory of the charged Bose gas: Bose-Einstein condensation in an ultrahigh magnetic field  

NASA Astrophysics Data System (ADS)

The Bogoliubov-de Gennes equations and the Ginzburg-Landau-Abrikosov-Gor'kov-type theory are formulated for the charged Bose gas (CBG). The theory of the Bose-Einstein condensation of the CBG in a magnetic field is extended to ultralow temperatures and ultrahigh magnetic fields. A low-temperature dependence of the upper critical field Hc2(T) is obtained both for the particle-impurity and particle-particle scattering. The normal-state collective plasmon mode in ultrahigh magnetic fields is studied.

Alexandrov, A. S.; Beere, W. H.; Kabanov, V. V.

1996-12-01

234

pH-stabilization in the Troll gas-condensate pipelines  

SciTech Connect

Iron from corrosion in two gas-condensate pipelines caused problems in the glycol regeneration units due to iron precipitation. Even if the amount of iron did not represent any significant corrosion problem in the pipelines, the solution to this problem was to reduce the corrosion rate by use of pH stabilization. NaOH was injected to achieve a pH value of 7.4 which reduced the iron content to 10 ppm. This corresponded to a maximum corrosion rate of less than 0.1 mm/year.

Olsen, S. [Statoil Research Centre, Trondheim (Norway); Lunde, O. [Statoil, Bergen (Norway); Dugstad, A.

1999-11-01

235

Cross-sensitivity effects in non-dispersive infra-red gas analysers using condenser microphone detectors  

Microsoft Academic Search

A pair of precision gas mixing pumps has been used to investigate the effect of spectral overlap and collision broadening by sample diluents on the accuracy of three commercial non-dispersive infra-red gas analysers, sensitized for carbon dioxide and having a condenser microphone type of transducer. These effects were investigated in respect of the composition of the sample mixture and the

D. W. Hill; T. Powell

1967-01-01

236

Laboratory Evaporation Testing Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant  

SciTech Connect

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream, LAW Off-Gas Condensate, from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of canistered glass waste forms. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to be within acceptable concentration ranges in the LAW glass. Diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task examines the impact of potential future disposition of this stream in the Hanford tank farms, and investigates auxiliary evaporation to enable another disposition path. Unless an auxiliary evaporator is used, returning the stream to the tank farms would require evaporation in the 242-A evaporator. This stream is expected to be unusual because it will be very high in corrosive species that are volatile in the melter (chloride, fluoride, sulfur), will have high ammonia, and will contain carryover particulates of glass-former chemicals. These species have potential to cause corrosion of tanks and equipment, precipitation of solids, release of ammonia gas vapors, and scale in the tank farm evaporator. Routing this stream to the tank farms does not permanently divert it from recycling into the WTP, only temporarily stores it prior to reprocessing. Testing is normally performed to demonstrate acceptable conditions and limits for these compounds in wastes sent to the tank farms. The primary parameter of this phase of the test program was measuring the formation of solids during evaporation in order to assess the compatibility of the stream with the evaporator and transfer and storage equipment. The origin of this LAW Off-Gas Condensate stream will be the liquids from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW facility melter offgas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover. The soluble components are expected to be mostly sodium and ammonium salts of nitrate, chloride, and fluoride. This stream has not been generated yet, and, thus, the composition will not be available until the WTP begins operation, but a simulant has been produced based on models, calculations, and comparison with pilot-scale tests. This report discusses results of evaporation testing of the simulant. Two conditions were tested, one with the simulant at near neutral pH, and a second at alkaline pH. The neutral pH test is comparable to the conditions in the Hanford Effluent Treatment Facility (ETF) evaporator, although that evaporator operates at near atmospheric pressure and tests were done under vacuum. For the alkaline test, the target pH was based on the tank farm corrosion control program requirements, and the test protocol and equipment was comparable to that used for routine evaluation of feed compatibility studies for the 242-A evaporator. One of the

Adamson, Duane J.; Nash, Charles A.; McCabe, Daniel J.; Crawford, Charles L.; Wilmarth, William R.

2014-01-27

237

Laboratory experimental testing of inerters  

Microsoft Academic Search

This paper presents experimental results from the testing of mechanical networks involving inerter devices. The tests are carried out using a hydraulic ram actuator whose displacement is controlled in a closed-loop system. A methodology is proposed for the testing of inerter devices which amounts to the design of a buffer network to be connected in series with the inerter device

Christakis Papageorgiou; Malcolm C. Smith

2005-01-01

238

Classification of gasoline by octane number and light gas condensate fractions by origin with using dielectric or gas-chromatographic data and chemometrics tools  

Microsoft Academic Search

The approach for classification of gasoline by octane number and light gas condensate fractions by origin with using dielectric permeability data has been proposed and compared with classification of same samples on the basis of gas-chromatographic data. The precision of dielectric permeability measurements was investigated by using ANOVA. The relative standard deviation of dielectric permeability was in the range from

Vasiliy A. Rudnev; Alexander P. Boichenko; Pavel V. Karnozhytskiy

2011-01-01

239

Classification of gasoline by octane number and light gas condensate fractions by origin with using dielectric or gas-chromatographic data and chemometrics tools.  

PubMed

The approach for classification of gasoline by octane number and light gas condensate fractions by origin with using dielectric permeability data has been proposed and compared with classification of same samples on the basis of gas-chromatographic data. The precision of dielectric permeability measurements was investigated by using ANOVA. The relative standard deviation of dielectric permeability was in the range from 0.3 to 0.5% for the range of dielectric permeability from 1.8 to 4.4. The application of exploratory chemometrics tools (cluster analysis and principal component analysis) allow to explicitly differentiate the gasoline and light gas condensate fractions into groups of samples related to specific octane number or origin. The neural networks allow to perfectly classifying the gasoline and light gas condensate fractions. PMID:21482310

Rudnev, Vasiliy A; Boichenko, Alexander P; Karnozhytskiy, Pavel V

2011-05-15

240

Coherent Control of Multiphoton Transitions in the Gas and Condensed Phases with Shaped Ultrashort Pulses  

SciTech Connect

Controlling laser-molecule interactions has become an integral part of developing devices and applications in spectroscopy, microscopy, optical switching, micromachining and photochemistry. Coherent control of multiphoton transitions could bring a significant improvement of these methods. In microscopy, multi-photon transitions are used to activate different contrast agents and suppress background fluorescence; coherent control could generate selective probe excitation. In photochemistry, different dissociative states are accessed through two, three, or more photon transitions; coherent control could be used to select the reaction pathway and therefore the yield-specific products. For micromachining and processing a wide variety of materials, femtosecond lasers are now used routinely. Understanding the interactions between the intense femtosecond pulse and the material could lead to technologically important advances. Pulse shaping could then be used to optimize the desired outcome. The scope of our research program is to develop robust and efficient strategies to control nonlinear laser-matter interactions using ultrashort shaped pulses in gas and condensed phases. Our systematic research has led to significant developments in a number of areas relevant to the AMO Physics group at DOE, among them: generation of ultrashort phase shaped pulses, coherent control and manipulation of quantum mechanical states in gas and condensed phases, behavior of isolated molecules under intense laser fields, behavior of condensed phase matter under intense laser field and implications on micromachining with ultrashort pulses, coherent control of nanoparticles their surface plasmon waves and their nonlinear optical behavior, and observation of coherent Coulomb explosion processes at 10^16 W/cm^2. In all, the research has resulted in 36 publications (five journal covers) and nine invention disclosures, five of which have continued on to patenting

Marcos Dantus

2008-09-23

241

Efficient corrosion control of gas condensate pipelines by pH-stabilization  

SciTech Connect

The corrosion rate of gas condensate pipelines can be substantially reduced by increasing the pH artificially. The technique is called pH stabilization and has been used with success in gas condensate pipelines. The reduction is based on the precipitation of protective corrosion products on the steel surface. When corrosion product films are formed, it is the transport of reactants and corrosion products through the film which governs the corrosion rate. Film properties like porosity, thickness and composition therefore become important. All these properties are strongly related to the precipitation process which depends very much on supersaturation and temperature. A large number of flow loop and glass cell experiments have been carried out in order to study these aspects. In addition to the CO{sub 2} partial pressure, the hydrate preventer, the flow velocity, and the pH, a number of variables related to the steel surface conditions and the operation of a real pipeline were studied in the experiments. The last group of variables included the presence of mill scale and rust on the steel surface prior to exposure, periods without flow (shut down), draining of the pipeline and scratches in the protective film. The paper discusses how these parameters affected the performance of carbon steel in water-glycol(50%) systems with 0.6 MPa CO{sub 2} partial pressure and with sodium bicarbonate added as pH stabilizer.

Dugstad, A.; Dronen, P.E. [Inst. for Energy Technology, Kjeller (Norway)

1999-11-01

242

Bose-Einstein Condensation in a Dilute Gas; the First 70 Years and Some Recent Experiments  

NASA Astrophysics Data System (ADS)

Bose-Einstein condensation, or BEC, has a long and rich history dating from the early 1920s. In this article we will trace briefly over this history and some of the developments in physics that made possible our successful pursuit of BEC in a gas. We will then discuss what was involved in this quest. In this discussion we will go beyond the usual technical description to try and address certain questions that we now hear frequently, but are not covered in our past research papers. These are questions along the lines of ``How did you get the idea and decide to pursue it? Did you know it was going to work? How long did it take you and why?'' We will review some of our favorites from among the experiments we have carried out with BEC. There will then be a brief encore on why we are optimistic that BEC can be created with nearly any species of magnetically trappable atom. Throughout this article we will try to explain what makes BEC in a dilute gas so interesting, unique, and experimentally challenging. This article is our ``Nobel Lecture'' and as such takes a relatively personal approach to the story of the development of experimental Bose-Einstein condensation. For a somewhat more scholarly treatment of the history, the interested reader is referred to E. A. Cornell, J. R. Ensher and C. E. Wieman, ``Experiments in dilute atomic Bose-Einstein condensation in Bose-Einstein Condensation in Atomic Gases, Proceedings of the International School of Physics ``Enrico Fermi'' Course CXL'' (M. Inguscio, S. Stringari and C. E. Wieman, Eds., Italian Physical Society, 1999), pp. 15-66, which is also available as cond-mat/9903109. For a reasonably complete technical review of the three years of explosive progress that immediately followed the first observation of BEC, we recommend reading the above article in combination with the corresponding review from Ketterle, cond-mat/9904034.

Cornell, E. A.; Wieman, C. E.

243

Interaction-induced crossover versus finite-size condensation in a weakly interacting trapped one-dimensional Bose gas  

SciTech Connect

We discuss the transition from a fully decoherent to a (quasi)condensate regime in a harmonically trapped weakly interacting one-dimensional (1D) Bose gas. By using analytic approaches and verifying them against exact numerical solutions, we find a characteristic crossover temperature and crossover atom number that depend on the interaction strength and the trap frequency. We then identify the conditions for observing either an interaction-induced crossover scenario or else a finite-size Bose-Einstein condensation phenomenon characteristic of an ideal trapped 1D gas.

Bouchoule, I. [Laboratoire Charles Fabry, UMR 8501 du CNRS, 91 403 Orsay Cedex (France); Kheruntsyan, K. V. [ARC Centre of Excellence for Quantum-Atom Optics, School of Physical Sciences, University of Queensland, Brisbane, Queensland 4072 (Australia); Shlyapnikov, G. V. [Laboratoire de Physique Theorique et Modeles Statistiques, Universite Paris-Sud, 91405 Orsay Cedex (France); Van der Waals-Zeeman Institute, University of Amsterdam, 1018 XE Amsterdam (Netherlands)

2007-03-15

244

Collapse and Bose-Einstein Condensation in a Trapped Bose Gas with Negative Scattering Length  

Microsoft Academic Search

Evolution and collapse of a trapped Bose condensate with negative scattering length are predetermined by 3-body recombination of Bose-condensed atoms and by feeding of the condensate from the nonequilibrium thermal cloud. The collapse, starting once the number of condensate atoms reaches the critical value, ceases and turns to expansion when the density becomes so high that the recombination losses dominate

Yu. Kagan; A. E. Muryshev; G. V. Shlyapnikov

1998-01-01

245

Optimization of gas condensate Field A development on the basis of "reservoir - gathering facilities system" integrated model  

NASA Astrophysics Data System (ADS)

It is known that many gas condensate fields are challenged with liquid loading and condensate banking problems. Therefore, gas production is declining with time. In this paper hydraulic fracturing treatment was considered as a method to improve the productivity of wells and consequently to exclude the factors that lead to production decline. This paper presents the analysis of gas condensate Field A development optimization with the purpose of maintaining constant gas production at the 2013 level for 8 years taking into account mentioned factors . To optimize the development of the filed, an integrated model was created. The integrated model of the field implies constructing the uniform model of the field consisting of the coupling models of the reservoir, wells and surface facilities. This model allowed optimizing each of the elements of the model separately and also taking into account the mutual influence of these elements. Using the integrated model, five development scenarios were analyzed and an optimal scenario was chosen. The NPV of this scenario equals 7,277 mln RUR, cumulative gas production - 12,160.6 mln m3, cumulative condensate production - 1.8 mln tons.

Demidova, E. A.; Maksyutina, O. V.

2015-02-01

246

Effect of the Minimal Length on Bose—Einstein Condensation in the Relativistic Ideal Bose Gas  

NASA Astrophysics Data System (ADS)

Based on the generalized uncertainty principle (GUP), the critical temperature and the Helmholtz free energy of Bose—Einstein condensation (BEC) in the relativistic ideal Bose gas are investigated. At the non-relativistic limit and the ultra-relativistic limit, we calculate the analytical form of the shifts of the critical temperature and the Helmholtz free energy caused by weak quantum gravitational effects. The exact numerical results of these shifts are obtained. Quantum gravity effects lift the critical temperature of BEC. By measuring the shift of the critical temperature, we can constrain the deformation parameter ?0. Furthermore, at lower densities, omitting quantum gravitational effects may lead to a metastable state while at sufficiently high densities, quantum gravitational effects tend to make BEC unstable. Using the numerical methods, the stable-unstable transition temperature is found.

Zhang, Xiu-Ming; Tian, Chi

2015-01-01

247

Non-condensible gas fraction predictions using wet and dry bulb temperature measurements. [PWR  

SciTech Connect

A technique is presented whereby non-condensible gas mass fractions in a closed system can be determined using wet bulb and dry bulb temperature and system pressure measurements. This technique would have application in situations where sampling techniques could not be used. Using an energy balance about the wet bulb wick, and expression is obtained which relates the vapor concentration difference between the wet bulb wick and the free stream to the wet and dry bulb temperature difference and a heat to mass transfer coefficient ratio. This coefficient ratio was examined for forced and natural convection flows. This analysis was verified with forced and natural convection tests over the range of pressure and temperature from 50 to 557 psig and 415 to 576/sup 0/F. All the data could best be fit by the natural convection analysis. This is useful when no information about the flow field is known.

Bowman, J.; Griffith, P.

1983-03-01

248

Pyrolysis process for producing condensed stabilized hydrocarbons utilizing a beneficially reactive gas  

SciTech Connect

In a process for recovery of values contained in solid carbonaceous material, the solid carbonaceous material is comminuted and then subjected to pyrolysis, in the presence of a carbon containing solid particulate source of heat and a beneficially reactive transport gas in a transport flash pyrolysis reactor, to form a pyrolysis product stream. The pyrolysis product stream contains a gaseous mixture and particulate solids. The solids are separated from the gaseous mixture to form a substantially solids-free gaseous stream which comprises volatilized hydrocarbon free radicals newly formed by pyrolysis. Preferably the solid particulate source of heat is formed by oxidizing part of the separated particulate solids. The beneficially reactive transport gas inhibits the reactivity of the char product and the carbon-containing solid particulate source of heat. Condensed stabilized hydrocarbons are obtained by quenching the gaseous mixture stream with a quench fluid which contains a capping agent for stabilizing and terminating newly formed volatilized hydrocarbon free radicals. The capping agent is partially depleted of hydrogen by the stabilization and termination reaction. Hydrocarbons of four or more carbon atoms in the gaseous mixture stream are condensed. A liquid stream containing the stabilized liquid product is then treated or separated into various fractions. A liquid containing the hydrogen depleted capping agent is hydrogenated to form a regenerated capping agent. At least a portion of the regenerated capping agent is recycled to the quench zone as the quench fluid. In another embodiment capping agent is produced by the process, separated from the liquid product mixture, and recycled.

Durai-Swamy, Kandaswamy (Culver City, CA)

1982-01-01

249

Pyrolysis process for producing condensed stabilized hydrocarbons utilizing a beneficially reactive gas  

SciTech Connect

In a process for recovery of values contained in solid carbonaceous material, the solid carbonaceous material is comminuted and then subjected to pyrolysis, in the presence of a carbon containing solid particulate source of heat and a beneficially reactive transport gas in a transport flash pyrolysis reactor, to form a pyrolysis product stream. The pyrolysis product stream contains a gaseous mixture and particulate solids. The solids are separated from the gaseous mixture to form a substantially solids-free gaseous stream which comprises volatilized hydrocarbon free radicals newly formed by pyrolysis. Preferably the solid particulate source of heat is formed by oxidizing part of the separated particulate solids. The beneficially reactive transport gas inhibits the reactivity of the char product and the carbon-containing solid particulate source of heat. Condensed stabilized hydrocarbons are obtained by quenching the gaseous mixture stream with a quench fluid which contains a capping agent for stabilizing and terminating newly formed volatilized hydrocarbon free radicals. The capping agent is partially depleted of hydrogen by the stabilization and termination reaction. Hydrocarbons of four or more carbon atoms in the gaseous mixture stream are condensed. A liquid stream containing the stabilized liquid product is then treated or separated into various fractions. A liquid containing the hydrogen depleted capping agent is hydrogenated to form a regenerated capping agent. At least a portion of the regenerated capping agent is recycled to the quench zone as the quench fluid. In another embodiment capping agent is produced by the process, separated from the liquid product mixture, and recycled.

Durai-swamy, K.

1982-04-13

250

Design, fabrication, and testing of a full-scale breadboard nitrogen generator for fuel tank inerting application. Final report  

Microsoft Academic Search

Aircraft fuel tank ullage may contain a mixture of fuel vapor in air that presents a fire and explosion hazard. This hazard can be eliminated if the air is replaced by an inert gas containing insufficient oxygen to allow ignition. Fuel tank inerting systems using onboard storage of liquid nitrogen to supply the inert gas were demonstrated by the FAA

Manatt

1977-01-01

251

Performance analysis of compositional and modified black-oil models for rich gas condensate reservoirs with vertical and horizontal wells  

E-print Network

It has been known that volatile oil and gas condensate reservoirs cannot be modeled accurately with conventional black-oil models. One variation to the black-oil approach is the modified black-oil (MBO) model that allows the use of a simple...

Izgec, Bulent

2004-09-30

252

Survey of flue gas condensation heat recovery systems. Final report Feb-Oct 81. (Revised 4 Dec 81)  

Microsoft Academic Search

The program was conducted to evaluate the state of the art of commercial condensation heat recovery systems. These heat recovery systems are capable of improving boiler thermal efficiency by 10-15 percent when firing natural gas and have wide applications for fuel oil and solid fuel firing due to the combined effect of waste heat recovery and emissions reduction. Twenty-two manufacturers

Goldstick

1981-01-01

253

The potential for intrinsic bioremediation of BTEX hydrocarbons in soil/ground water contaminated with gas condensate  

SciTech Connect

Gas condensate liquids contaminate soil and ground water at two gas production sites in the Denver Basin, CO. A detailed field study was carried out at these sites to determine the applicability of intrinsic bioremediation as a remediation option. Ground water monitoring at the field sites and analysis of soil cores suggested that intrinsic bioremediation is occurring at the sites by multiple pathways, including aerobic oxidation, sulfate reduction, and possibly reduction Fe(III) reduction. Laboratory investigations were conducted to verify that the water-soluble components of the gas condensate (benzene, toluene, ethylbenzene, and xylene [BTEX]) are intrinsically biodegradable under anoxic conditions in the presence of alternate electron acceptors and soil from the field site. Slurry-phase experiments were conducted in which soil obtained from the field site was mixed with an aqueous phase containing nutrients and electron acceptors (nitrate, Fe[III], sulfate and carbon dioxide) in serum bottles. The aqueous phase also contained soluble components of gas condensate, at two different hydrocarbon concentrations, obtained from the field site. The soil was either pristine (native) soil or soil obtained from a condensate-contaminated region. 14 refs., 4 figs., 3 tabs.

Borole, A.P.; Sublette, K.L. [Univ. of Tulsa, OK (United States); Raterman, K.T. [Amoco Tulsa Technology Center, Tulsa, OK (United States)] [and others

1997-12-31

254

Wax precipitation for gas condensate fluids was studied in detail with a thermodynamic model. It was found that the precipitated  

E-print Network

Summary Wax precipitation for gas condensate fluids was studied in detail with a thermodynamic model. It was found that the precipitated wax phase can exhibit retrograde phenomena similar of precipitated wax may first increase, then decrease, then increase again. The effect of pressure on wax

Firoozabadi, Abbas

255

User's manual for the TRW gaspipe 2 program: A vapor-gas front analysis program for heat pipes containing non-condensible gas  

NASA Technical Reports Server (NTRS)

A digital computer program for design and analysis of heat pipes which contain non-condensible gases, either for temperature control or to aid in start-up from the frozen state, is presented. Some of the calculations which are possible with the program are: (1) wall temperature profile along a gas-loaded heat pipe, (2) amount of gas loading necessary to obtain desired evaporator temperature at a desired heat load, (3) heat load versus evaporator temperature for a fixed amount of gas in the pipe, and (4) heat and mass transfer along the pipe, including the vapor-gas front region.

Edwards, D. K.; Fleischman, G. L.; Marcus, B. D.

1973-01-01

256

Bose-Einstein condensates in the large-gas-parameter regime  

NASA Astrophysics Data System (ADS)

Bose-Einstein condensates of 104 85Rb atoms in a cylindrical trap are studied using a recently proposed approach based on a local-density approximation. Since the existence of a Feshbach resonance allows for widely tuning the scattering length of the atoms, values of the peak gas parameter xpk of the order of 10-2 may be attained and the standard analysis based on Gross-Pitaevskii and/or Thomas-Fermi equations may result in being questionable. Energy functionals derived from the correlated basis functions theory and the low-density expansion for a homogeneous hard-spheres gas are used to estimate corrections to the Gross-Pitaevskii equation. The two functionals give similar results, both showing large differences with respect to the Thomas-Fermi and Gross-Pitaevskii ones. The column densities at z=0 may differ by as much as ~30% and the half maximum radius by ~20%. The scattering lengths estimated by fitting the half maximum radius may differ by ~40% from those given by a Thomas-Fermi-based analysis of the experimental data.

Fabrocini, A.; Polls, A.

2001-12-01

257

Gas-Phase Condensation Reactions of SixOyHz- Oxyanions with H2O  

SciTech Connect

Water was reacted with gas-phase oxyanions having the general composition SixOyHz- that were formed and isolated in an ion trap-secondary ion mass spectrometer (IT-SIMS). The radical SiO2- reacted slowly with H2O to abstract HO, forming SiO3H-, at a rate of 8 × 10-13 cm3 molecule-1 s-1, corresponding to an efficiency of about 0.03% compared with the theoretical collision rate constant (average dipole orientation). The product ion SiO3H- underwent a consecutive condensation reaction with H2O to form SiO4H3- at a rate that was approximately 0.4-0.7% efficient. SiO4H3- did not undergo further reaction with water. The multiple reaction pathways by which radical SiO3- reacted with H2O were kinetically modeled using a stochastic approach. SiO3- reacted with water by three parallel reaction pathways: (1) abstraction of a radical H to form SiO3H-, which then reacted with a second H2O to form SiO4H3-; (2) abstraction of a radical OH to form SiO4H-, which further reacted by consecutive H abstractions to form SiO4H2- and then SiO4H3-; and (3) condensation with H2O to form SiO4H2-, which subsequently abstracted a radical H from a second H2O to form SiO4H3-. In all of these reactions, the rate constants were determined to be very slow, as determined by both direct measurement and stochastic modeling. For comparison, the even electron ion Si2O5H- was also investigated: it underwent condensation with H2O to form Si2O6H3-, with a rate constant corresponding to 50% efficiency. The reactions were also modeled using ab initio calculations at the UB3LYP/6-311+G(2d,p) level. Addition of H2O to SiO3-, SiO3H-, and Si2O5H- was calculated to be approximately 42, 45, and 55 kcal mol-1 exothermic, respectively, and encountered low activation barriers. Modeling of SiO2- and SiO3- reactions with H2O failed to produce radical abstraction reaction pathways observed in the IT-SIMS, possibly indicating that alternative reaction mechanisms are operative.

Groenewold, Gary Steven; Scott, Jill Rennee; Gianotto, Anita Kay; Hodges, Brittany DM; Kessinger, Glen Frank; Benson, Michael Timothy; Wright, J. B.

2001-09-01

258

LABORATORY OPTIMIZATION TESTS OF TECHNETIUM DECONTAMINATION OF HANFORD WASTE TREATMENT PLANT LOW ACTIVITY WASTE OFF-GAS CONDENSATE SIMULANT  

SciTech Connect

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of glass waste. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task examines the potential treatment of this stream to remove radionuclides and subsequently disposition the decontaminated stream elsewhere, such as the Effluent Treatment Facility (ETF), for example. The treatment process envisioned is very similar to that used for the Actinide Removal Process (ARP) that has been operating for years at the Savannah River Site (SRS), and focuses on using mature radionuclide removal technologies that are also compatible with longterm tank storage and immobilization methods. For this new application, testing is needed to demonstrate acceptable treatment sorbents and precipitating agents and measure decontamination factors for additional radionuclides in this unique waste stream. The origin of this LAW Off-Gas Condensate stream will be the liquids from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover. The soluble components are expected to be mostly sodium and ammonium salts of nitrate, chloride, and fluoride. This stream has not been generated yet and will not be available until the WTP begins operation, but a simulant has been produced based on models, calculations, and comparison with pilot-scale tests. One of the radionuclides that is volatile and expected to be in greatest abundance in this LAW Off-Gas Condensate stream is Technetium-99 ({sup 99}Tc). Technetium will not be removed from the aqueous waste in the Hanford WTP, and will primarily end up immobilized in the LAW glass by repeated recycle of the off-gas condensate into the LAW melter. Other radionuclides that are low but are also expected to be in measurable concentration in the LAW Off-Gas Condensate are {sup 129}I, {sup 90}Sr, {sup 137}Cs, {sup 241}Pu, and {sup 241}Am. These are present due to their partial volatility and some entrainment in the off-gas system. This report discusses results of optimized {sup 99}Tc decontamination testing of the simulant. Testing examined use of inorganic reducing agents for {sup 99}Tc. Testing focused on minimizing the quantity of sorbents/reactants added, and minimizing mixing time to reach the decontamination targets in this simulant formulation. Stannous chloride and ferrous sulfate were tested as reducing agents to determine the minimum needed to convert soluble pertechnetate to the insoluble technetium dioxide. The reducing agents were tried with and without sorbents.

Taylor-Pashow, K.; Nash, C.; McCabe, D.

2014-09-29

259

Techniques for optimizing inerting in electron processors  

NASA Astrophysics Data System (ADS)

The design of an "inert gas" distribution system in an electron processor must satisfy a number of requirements. The first of these is the elimination or control of beam produced ozone and NO x which can be transported from the process zone by the product into the work area. Since the tolerable levels for O 3 in occupied areas around the processor are <0.1 ppm, good control techniques are required involving either recombination of the O 3 in the beam heated process zone, or exhausting and dilution of the gas at the processor exit. The second requirement of the inerting system is to provide a suitable environment for completing efficient, free radical initiated addition polymerization. In this case, the competition between radical loss through de-excitation and that from O 2 quenching must be understood. This group has used gas chromatographic analysis of electron cured coatings to study the trade-offs of delivered dose, dose rate and O 2 concentrations in the process zone to determine the tolerable ranges of parameter excursions can be determined for production quality control purposes. These techniques are described for an ink:coating system on paperboard, where a broad range of process parameters have been studied (D, ?, O 2. It is then shown how the technique is used to optimize the use of higher purity (10-100 ppm O 2) nitrogen gas for inerting, in combination with lower purity (2-20, 000 ppm O 2) non-cryogenically produced gas, as from a membrane or pressure swing adsorption generators.

Rangwalla, I. J.; Korn, D. J.; Nablo, S. V.

1993-07-01

260

Synthesis of ZnO:Ge Thin Films via Plasma Gas Condensation  

NASA Astrophysics Data System (ADS)

we introduce a new method for the synthesis of Ge nanoparticle embedded ZnO thin films that are considered to be a potential candidate for photovoltaic applications. As opposed to current techniques, for the independent preparation of Ge nanoparticles, Cluster Deposition Source (CDS) utilising gas condensation of sputtered Ge atoms is used. For the synthesis of ZnO thin film host material conventional sputtering is employed. In the proposed technique independently synthesized Ge nanoparticles and ZnO thin films are combined into a composite structure on Si. XRD patterns of the samples have revealed that Ge nanoparticles preferentially settle on (113) planes on top of the (002) oriented ZnO layer. It is realized that Ge nanoparticles with sizes ranging from 16 nm to 20 nm could be embedded into a well-defined ZnO matrix. In fact, TEM studies performed on Ge nanoparticles captured on a Cu grids have manifested that Ge reach to ZnO matrix as clusters composed of particles with sizes of about 7-8 nm and then eventually grow larger due to substrate heating implemented during capping layer deposition. Optical absorption measurements have revealed that Ge nanoparticle inclusion lead to an additional absorption edge at about 2.75 eV along with 3.17 eV edge resulting from ZnO host.

Ceylan, Abdullah; Ali, Janan; Ozcan, Sadan

2013-03-01

261

Light-induced torque for the generation of persistent current flow in atomic gas Bose-Einstein condensates  

Microsoft Academic Search

We show that a persistent current flow in an atomic gas Bose-Einstein condensate could be realized when the system is subject to two counterpropagating Laguerre-Gaussian so-called doughnut beams, creating a toroidal trap. The theory is developed involving a two-photon process within three atomic levels leading to a quantized light-induced torque which rotates the atoms, generating an atomic current flow in

V. E. Lembessis; M. Babiker

2010-01-01

262

Pressurized pyrolysis of rice husk in an inert gas sweeping fixed-bed reactor with a focus on bio-oil deoxygenation.  

PubMed

The pyrolysis of rice husk was conducted in a fixed-bed reactor with a sweeping nitrogen gas to investigate the effects of pressure on the pyrolytic behaviors. The release rates of main gases during the pyrolysis, the distributions of four products (char, bio-oil, water and gas), the elemental compositions of char, bio-oil and gas, and the typical compounds in bio-oil were determined. It was found that the elevation of pressure from 0.1MPa to 5.0MPa facilitated the dehydration and decarboxylation of bio-oil, and the bio-oils obtained under the elevated pressures had significantly less oxygen and higher calorific value than those obtained under atmospheric pressure. The former bio-oils embraced more acetic acid, phenols and guaiacols. The elevation of pressure increased the formation of CH4 partially via the gas-phase reactions. An attempt is made in this study to clarify "the pure pressure effect" and "the combined effect with residence time". PMID:25463787

Qian, Yangyang; Zhang, Jie; Wang, Jie

2014-12-01

263

Thermal Effects Accompanying Spontaneous Ignitions in Gases. I. An Investigation of the Heating Effects Which Accompany the Rapid Admission of Inert Gas to an Evacuated Vessel  

Microsoft Academic Search

In experiments on spontaneous ignition of gases, transient temperature changes normally accompany the entry of gases to evacuated vessels. They may invalidate much quantitative experimental work and give rise to spurious observations. In the present investigation, temperature-time histories accompanying gas entry have been mapped with a fine (13 mu m) thermocouple for many positions in a spherical vessel. It is

D. H. Fine; P. Gray; R. Mackinven

1970-01-01

264

Sublimating comets as the source of nucleation seeds for grain condensation in the gas outflow from AGB stars  

NASA Technical Reports Server (NTRS)

A growing amount of observational and theoretical evidence suggests that most main sequence stars are surrounded by disks of cometary material. The dust production by comets in such disks is investigated when the central stars evolve up the red giant and asymptotic giant branch (AGB). Once released, the dust is ablated and accelerated by the gas outflow and the fragments become the seeds necessary for condensation of the gas. The origin of the requisite seeds has presented a well known problem for classical nucleation theory. This model is consistent with the dust production observed in M giants and supergiants (which have increasing luminosities) and the fact that earlier supergiants and most WR stars (whose luminosities are unchanging) do not have significant dust clouds even though they have significant stellar winds. Another consequence of the model is that the spatial distribution of the dust does not, in general, coincide with that of the gas outflow, in contrast to the conventional condensation model. A further prediction is that the condensation radius is greater that that predicted by conventional theory which is in agreement with IR interferometry measurements of alpha-Ori.

Whitmire, D. P.; Matese, John J.; Reynolds, R. T.

1989-01-01

265

Isotope Separation by Condensation Reduction of Laser-Excited Molecules in Wall-Cooled Subsonic Gas Streams  

SciTech Connect

Explicit relations are developed to estimate isotope enrichment factors for {sup i}QF{sub 6} vapors diluted in a carrier gas G, which are isotope selectively laser-excited and flow subsonically through a wall-cooled cylindrical cell. At gas mix pressures below 100 millitorr, laser-assisted condensation repression on cold walls can induce isotope separations for some vapors at certain cryogenic temperatures. For example, for {sup i}SF{sub 6}/N{sub 2} mixtures, narrow temperature 'windows' are found in the 70 to 90 K region where enrichments exceed {beta}{sub i} = {beta}{sub 33} = 1.7. For {sup i}UF{sub 6}/G gas mixes, enrichment under full condensation conditions is not possible since the surface potential well ({approx}1150 cm{sup -1}) of a UF{sub 6} condensate layer is higher than the vibration-to-translation conversion quantum of the v{sub 3} vibration ({approx}628 cm{sup -1}). However, for UF{sub 6}{sup *} adsorptions on a bare surface of F{sub 2}-passivated gold with well depth of 400 cm{sup -1} or less, initial isotope enrichments with {beta} {approx} 1.1 are possible before the surface is covered with UF{sub 6} condensate. Throughputs in cold-wall isotope separations are low because of low operating pressures. For enrichments of milligrams of a radioactive isotope in nuclear medicine, this is still useful and offers a low-footprint alternative to calutron or ultracentrifuge separations. Since feed and product streams are the same, the method lends itself to multistaging, with one laser irradiating four or more chambers in series.

Eerkens, J.W. [University of Missouri (United States)

2005-05-15

266

Analytical modeling of water condensation in condensing heat exchanger  

Microsoft Academic Search

An analytical model of heat and mass transfer processes in a flue gas condensing heat exchanger system was developed to predict the heat transferred from flue gas to cooling water and the condensation rate of water vapor in the flue gas. Flue gas exit temperature, cooling water outlet temperature, water vapor mole fraction, and condensation rate of water vapor were

Kwangkook Jeong; Michael J. Kessen; Harun Bilirgen; Edward K. Levy

2010-01-01

267

A Common Single-Site Pt(II)-O(OH)x- Species Stabilized by Sodium on "Active" and "Inert" Supports Catalyzes the Water-Gas Shift Reaction.  

PubMed

While it has long been known that different types of support oxides have different capabilities to anchor metals and thus tailor the catalytic behavior, it is not always clear whether the support is a mere carrier of the active metal site, itself not participating directly in the reaction pathway. We report that catalytically similar single-atom-centric Pt sites are formed by binding to sodium ions through -O ligands, the ensemble being equally effective on supports as diverse as TiO2, L-zeolites, and mesoporous silica MCM-41. Loading of 0.5 wt % Pt on all of these supports preserves the Pt in atomic dispersion as Pt(II), and the Pt-O(OH)x- species catalyzes the water-gas shift reaction from ?120 to 400 °C. Since the effect of the support is "indirect," these findings pave the way for the use of a variety of earth-abundant supports as carriers of atomically dispersed platinum for applications in catalytic fuel-gas processing. PMID:25746682

Yang, Ming; Liu, Jilei; Lee, Sungsik; Zugic, Branko; Huang, Jun; Allard, Lawrence F; Flytzani-Stephanopoulos, Maria

2015-03-18

268

Photochemical activity of Titan's low-altitude condensed haze.  

PubMed

Titan, the largest moon of Saturn and similar to Earth in many aspects, has unique orange-yellow colour that comes from its atmospheric haze, whose formation and dynamics are far from well understood. Present models assume that Titan's tholin-like haze formation occurs high in atmosphere through gas-phase chemical reactions initiated by high-energy solar radiation. Here we address an important question: Is the lower atmosphere of Titan photochemically active or inert? We demonstrate that indeed tholin-like haze formation could occur on condensed aerosols throughout the atmospheric column of Titan. Detected in Titan's atmosphere, dicyanoacetylene (C?N?) is used in our laboratory simulations as a model system for other larger unsaturated condensing compounds. We show that C4N2 ices undergo condensed-phase photopolymerization (tholin formation) at wavelengths as long as 355 nm pertinent to solar radiation reaching a large portion of Titan's atmosphere, almost close to the surface. PMID:23552063

Gudipati, Murthy S; Jacovi, Ronen; Couturier-Tamburelli, Isabelle; Lignell, Antti; Allen, Mark

2013-01-01

269

Influence of the inter-electrode distance on the production of nanoparticles by means of atmospheric pressure inert gas dc glow discharge  

NASA Astrophysics Data System (ADS)

This work is aimed at investigating the influence of the inter-electrode spacing on the production rate and size of nanoparticles generated by evaporating a cathode on an atmospheric pressure dc glow discharge. Experiments are conducted in the configuration of two vertically aligned cylindrical electrodes in upward coaxial flow with copper as a consumable cathode and nitrogen as a carrier gas. A constant current of 0.5 A is delivered to the electrodes and the inter-electrode distance spanned from 0.5 to 10 mm. Continuous stable nanoparticle production is attained by optimal coaxial flow convection cooling of the cathode. Both the particle production rate and the primary particle size increase with the inter-electrode spacing up to nearly 5 mm and strongly decrease with an increasing inter-electrode distance beyond 5 mm. Production rates in the range of 1 mg h-1 of very small nanoparticles (<10 nm) are attained by a micro glow discharge (<1 mm) while glow discharges of intermediate sizes (<5 mm) result in production rates of up to 10 mg h-1 and primary particles of sizes between 10 and 20 nm. No correlation is found between the measured spatially averaged plasma parameters and nanoparticle production. Since the latter is largely determined by the properties of the cathode surface, spatially resolved spectrometric measurements are needed to discern between the positive column and the cathode region of the glow discharge plasma.

Hontañón, Esther; María Palomares, Jose; Guo, Xiaoai; Engeln, Richard; Nirschl, Hermann; Kruis, Frank Einar

2014-10-01

270

-Based Cermet Inert Anodes for Aluminum Electrolysis  

NASA Astrophysics Data System (ADS)

The new aluminum electrolysis technology based on inert electrodes has received much interest for several decades because of the environment and energy advantages. The key to realize this technique is the inert anode. This article presents China's recent developments of NiFe2O4-based cermet inert anodes, which include the optimization of material performance, the joint between the cermet inert anode and metallic bar, as well as the results of 20 kA pilot testing for a large-size inert anode group. The problems NiFe2O4-based cermet inert anodes face are also discussed.

Tian, ZhongLiang; Lai, YanQing; Li, ZhiYou; Chai, DengPeng; Li, Jie; Liu, YeXiang

2014-11-01

271

Conversion of straight-run gas-condensate benzenes into high- octane gasolines based on modified ZSM-5 zeolites  

NASA Astrophysics Data System (ADS)

This paper describes the conversion of straight-run benzene of gas condensate into high-octane gasoline based on zeolite catalyst ZSM-5, modified in binary system oxide- based Sn (III) and Bi (III). It was defined that the introduction of the binary system oxide-based Sn(III) and Bi (III) into the basic zeolite results in the 2-fold increase of its catalytic activity.High-octane gasoline converted from straight-run benzene is characterized by a low benzol content in comparison to the high-octane benzenes produced during the catalytic reforming.

Erofeev, V.; Reschetilowski, V.; Tatarkina, A.; Khomajakov, I.; Egorova, L.; Volgina, T.

2014-08-01

272

Crossover behavior in the phase transition of the Bose-Einstein condensation in a microwave-driven magnon gas  

SciTech Connect

A magnon gas in a film of yttrium iron garnet driven by microwave radiation exhibits Bose-Einstein condensation (BEC) when the driving power exceeds a critical value. We show that the nature and the critical exponents of the BEC transition change dramatically if the BEC magnons are significantly coupled to the zone-center magnons. The theoretical results explain the diverse behavior of the order parameter inferred from the experimental data for the light scattering and the microwave emission from the BEC observed with coherent and incoherent microwave pumping.

Rezende, Sergio M. [Departamento de Fisica, Universidade Federal de Pernambuco, Recife 50670-901, PE (Brazil)

2009-09-01

273

Assessment of the effect of development of the Bovanenkovskoe gas-condensate field in the middle Yamal region on the dynamics of the polar fox population  

SciTech Connect

Based on the findings of integrated monitoring research, the state of polar fox population in a zone of heavy technogenic pressure is assessed experimentally. Networks of breeding burrows on permanent experimental and control plots were carefully examined over the course of three summer seasons. Active development of the Bovanenkovskoe gas-condensate field has led to loss of the central portion of this area as a zone of polar fox restocking. Heavy accelerated exploitation of other gas and gas-condensate fields in the Yamal Peninsula may lower the Yamal population of polar fox to the verge of extinction. 15 refs.

Dobrinskii, N.L.; Sosin, V.F. [Institute of Animal and Plant Ecology, Ekaterinburg (Russian Federation)

1995-05-01

274

Nucleation, growth and transformation of amorphous and crystalline solids condensing from the gas phase  

NASA Astrophysics Data System (ADS)

The condensation of solids was investigated from the initial stage through continuous film growth, using evaporation and high-energy ion-beam sputtering. Consideration is given to germanium condensing on a variety of amorphous and crystalline substrates. Nucleation parameters, such as the activation energies of surface diffusion and adsorption and the critical nucleus size, were determined using an atomistic model for nucleation. Two flux and temperature dependent structural-order transitions were observed in the initial nucleation stages and found to coincide with corresponding transitions in the critical nucleus size. Correlation was also established between these transitions and two structural transitions occurring during continuous film growth. All results were distinctly affected by the vapor state of the adsorbates, implying considerable correlation between condensation on solid surfaces and in a vapor.

Krikorian, E.; Sneed, R. J.

1979-09-01

275

Orgin and significance of geochemical variability among oils and gas-condensates in the Tiger Shoal Field, northern Gulf of Mexico  

SciTech Connect

Geochemical data placed in geological context is key to understanding the processes controlling the variability of oils and gas-condensates in the Tiger Shoal Field, northern Gulf of Mexico. Thermal maturity at generation and phase partitioning are the principal processes accounting for variability in the bulk and molecular properties of the oils and gas-condensates. Quantification of the extent that these processes altered the oils and gas-condensates between fault blocks and among individual sands permits: (1) documentation of the most effective migration conduits, (2) inference of deeper or shallower pay zones, (3) and assessment of vertical and lateral fluid connectivity. Calibration of bulk to molecular properties will permit rapid assessment of the type and extent of alteration using basic parameters such as API gravity and gas oil ratio (GOR). Upon mass balancing with initial reserves data, a detailed risking scheme for remaining prospects within the field can be formulated.

Kelley, P.A.; Imbus, S.W. [Texaco E& P Technology, Houston, TX (United States); McKeever, S.R. [Texaco E& P Inc., New Orleans, LA (United States)

1995-12-31

276

Mesoscopic Effects in Bose-Einstein Condensate Fluctuations of an Ideal Gas in a Box  

E-print Network

parameter (condensate wave function) forN = 100 - (dashed line),N = 1000 - (grey line), andN = 10000 - (solid black line) atoms in a box calculated via the FFT technique in ac- cord with Eq. (3.3) compared with the mean field approximation? n0 ? (T ?Tc)1...) atoms in a box calculated via the FFT technique in accord with Eq. (3.4) compared with the mean field approximation n0 ? N ?Nc in the thermodynamic limit - (dotted black line). . . . . . . . 51 10 Mean fraction of condensed atoms for N = 100 - (dashed...

Dorfman, Konstantin Evgenievich

2009-05-15

277

Laboratory Scoping Tests Of Decontamination Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant  

SciTech Connect

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of glass waste. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task seeks to examine the potential treatment of this stream to remove radionuclides and subsequently disposition the decontaminated stream elsewhere, such as the Effluent Treatment Facility (ETF), for example. The treatment process envisioned is very similar to that used for the Actinide Removal Process (ARP) that has been operating for years at the Savannah River Site (SRS), and focuses on using mature radionuclide removal technologies that are also compatible with longterm tank storage and immobilization methods. For this new application, testing is needed to demonstrate acceptable treatment sorbents and precipitating agents and measure decontamination factors for additional radionuclides in this unique waste stream. The origin of this LAW Off-Gas Condensate stream will be the liquids from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover. The soluble components are expected to be mostly sodium and ammonium salts of nitrate, chloride, and fluoride. This stream has not been generated yet and will not be available until the WTP begins operation, but a simulant has been produced based on models, calculations, and comparison with pilot-scale tests. One of the radionuclides that is volatile and expected to be in high concentration in this LAW Off-Gas Condensate stream is Technetium-99 ({sup 99}Tc). Technetium will not be removed from the aqueous waste in the Hanford WTP, and will primarily end up immobilized in the LAW glass by repeated recycle of the off-gas condensate into the LAW melter. Other radionuclides that are also expected to be in appreciable concentration in the LAW Off-Gas Condensate are {sup 129}I, {sup 90}Sr, {sup 137}Cs, and {sup 241}Am. This report discusses results of preliminary radionuclide decontamination testing of the simulant. Testing examined use of Monosodium Titanate (MST) to remove {sup 90}Sr and actinides, inorganic reducing agents for {sup 99}Tc, and zeolites for {sup 137}Cs. Test results indicate that excellent removal of {sup 99}Tc was achieved using Sn(II)Cl{sub 2} as a reductant, coupled with sorption onto hydroxyapatite, even in the presence of air and at room temperature. This process was very effective at neutral pH, with a Decontamination Factor (DF) >577 in two hours. It was less effective at alkaline pH. Conversely, removal of the cesium was more effective at alka

Taylor-Pashow, Kathryn M.; Nash, Charles A.; Crawford, Charles L.; McCabe, Daniel J.; Wilmarth, William R.

2014-01-21

278

Condensed tannin in drinking water reduces greenhouse gas precursor urea in sheep and cattle urine  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ingestion of small amounts of naturally-occurring condensed tannin (CT) by ruminants can provide several benefits including potential reduction of ammonia and nitrous oxide emissions over the long-term by reducing their urine urea excretion. However, providing grazing ruminants with sufficient amou...

279

Experimental studies of Bose-Einstein condensation in a gas Wolfgang Ketterle, MIT  

E-print Network

has soared following the discovery of the gaseous condensates in 1995 (see Fig. 1). Although atomic with the creation of the laser in 1960. The possibility of creating a matter-wave field with many atoms in a single mode of an atom trap (which is the atomic equivalent of an optical resonator) was realized

280

AN INNOVATIVE TRANSPORT MEMBRANE CONDENSER WATER RECOVERY FROM FLUE GAS AND ITS REUSE - PHASE II  

EPA Science Inventory

Although water recycle and reuse is considered good environmental practice, its implementation is highly dependent upon the economics and hence can be challenging to implement. An example is the recovery of low quality heat as water condensate from industrial flue gases. In th...

281

Origin of saline, neutral-pH, reduced epithermal waters by reaction of acidic magmatic gas condensates with wall rock  

SciTech Connect

Fluid inclusions in quartz and sphalerite of epithermal veins containing galena, sphalerite and chalcopyrite with silver sulfides and electrum commonly have salinities of 2 to 10 weight percent NaCl equivalent. Examples include Bohemia, OR, Comstock, NV, and Creede, CO. Salinities in such base metal-rich systems are apparently greater than those in gold-adularia, base metal-poor systems such as Sleeper, NV, Republic, WA, and Hishikare, Kyushu. Saline epithermal fluids are commonly assumed to have been derived from saline magmatic brines, from local host formations, as has been suggested for Creede, or from evaporative concentration (boiling) of more dilute meteoric ground water. Another possibility, which may be the most common origin, is reaction of wall rocks with magmatic gas condensates rich in HCl and sulfuric acid. A mixture of one part Augustine Volcanic gas condensate in 10 parts cold ground water has a pH of 0.7 and the dominant cation is H[sup +] by a factor of 10[sup 4]. Calculated reaction of this condensate mixture with andesite at 300 C to a water/rock ratio (w/r) of 4.6 yields an NaCl-dominated fluid with a total salinity of 2.1 wt %. and pH 3.7. Further reaction, to w/r 0.14 yields a fluid salinity of 2.6 wt % and pH of 5.7; this fluid is in equilibrium with a propylitic alteration assemblage. Aqueous sulfide accumulates during the rock reaction as sulfate is reduced to sulfide when ferrous iron is oxidized to ferric iron. Sulfide concentration in the latter fluid is 32 ppm, far exceeding sulfate concentration. In the overall reaction, hydrogen ion is exchanged for base cations (including base metals) and sulfate is reduced to sulfide.

Reed, M.H. (Univ. of Oregon, Eugene, OR (United States). Dept. of Geological Sciences)

1993-04-01

282

Metallofullerene and fullerene formation from condensing carbon gas under conditions of stellar outflows and implication to stardust.  

PubMed

Carbonaceous presolar grains of supernovae origin have long been isolated and are determined to be the carrier of anomalous (22)Ne in ancient meteorites. That exotic (22)Ne is, in fact, the decay isotope of relatively short-lived (22)Na formed by explosive nucleosynthesis, and therefore, a selective and rapid Na physical trapping mechanism must take place during carbon condensation in supernova ejecta. Elucidation of the processes that trap Na and produce large carbon molecules should yield insight into carbon stardust enrichment and formation. Herein, we demonstrate that Na effectively nucleates formation of Na@C60 and other metallofullerenes during carbon condensation under highly energetic conditions in oxygen- and hydrogen-rich environments. Thus, fundamental carbon chemistry that leads to trapping of Na is revealed, and should be directly applicable to gas-phase chemistry involving stellar environments, such as supernova ejecta. The results indicate that, in addition to empty fullerenes, metallofullerenes should be constituents of stellar/circumstellar and interstellar space. In addition, gas-phase reactions of fullerenes with polycyclic aromatic hydrocarbons are investigated to probe "build-up" and formation of carbon stardust, and provide insight into fullerene astrochemistry. PMID:24145444

Dunk, Paul W; Adjizian, Jean-Joseph; Kaiser, Nathan K; Quinn, John P; Blakney, Gregory T; Ewels, Christopher P; Marshall, Alan G; Kroto, Harold W

2013-11-01

283

Asymmetric Inert Scalar Dark Matter  

E-print Network

In the quite minimal inert scalar doublet dark matter framework, we analyze what would be the effect of a $B-L$ asymmetry that could have been produced in the Universe thermal bath at high temperature. We show that, unless the "$\\lambda_5$" scalar interaction is tiny, this asymmetry is automatically reprocessed in part into a DM asymmetry that can easily dominate the DM relic density today. This scenario requires the inert DM mass scale to lie in the few-TeV range. Two types of relic density suppressions render this scenario viable: thermalization, from the same "$\\lambda_5$" interaction, of the asymmetries at temperature below the dark matter particle threshold, and DM particle-antiparticle oscillations.

Dhen, Mikael

2015-01-01

284

Asymmetric Inert Scalar Dark Matter  

E-print Network

In the quite minimal inert scalar doublet dark matter framework, we analyze what would be the effect of a B-L asymmetry that could have been produced in the Universe thermal bath at high temperature. We show that, unless the "$\\lambda_5$" scalar interaction is tiny, this asymmetry is automatically reprocessed in part into a DM asymmetry that can easily dominate the DM relic density today. This scenario requires the inert DM mass scale to lie in the few-TeV range. Two types of relic density suppressions render this scenario viable: thermalization, from the same "$\\lambda_5$" interaction, of the asymmetries at temperature below the dark matter particle threshold, and DM particle-antiparticle oscillations.

Mikael Dhen; Thomas Hambye

2015-03-20

285

Rapid, conformal gas-phase formation of silica (SiO2) nanotubes from water condensates  

NASA Astrophysics Data System (ADS)

An innovative atomic layer deposition (ALD) concept, with which nanostructures of water condensates with high aspect ratio at equilibrium in cylindrical nanopores can be transformed uniformly into silica (SiO2) at near room temperature and ambient pressure, has been demonstrated for the first time. As a challenging model system, we first prove the conversion of cylindrical water condensates in porous alumina membranes to silica nanotubes (NTs) by introducing SiCl4 as a metal reactant without involving any catalytic reaction. Surprisingly, the water NTs reproducibly transformed into silica NTs, where the wall thickness of the silica NTs deposited per cycle was found to be limited by the amount of condensed water, and it was on the orders of ten nanometers per cycle (i.e., over 50 times faster than that of conventional ALD). More remarkably, the reactions only took place for 10-20 minutes or less without vacuum-related equipment. The thickness of initially adsorbed water layers in cylindrical nanopores was indirectly estimated from the thickness of formed SiO2 layers. With systematic experimental designs, we tackle the classical Kelvin equation in the nanosized pores, and the role of van der Waals forces in the nanoscale wetting phenomena, which is a long-standing issue lacking experimental insight. Moreover, we show that the present strategy is likely generalized to other oxide systems such as TiO2. Our approach opens up a new avenue for ultra-simple preparation of porous oxides and allows for the room temperature formation of dielectric layers toward organic electronic and photovoltaic applications.An innovative atomic layer deposition (ALD) concept, with which nanostructures of water condensates with high aspect ratio at equilibrium in cylindrical nanopores can be transformed uniformly into silica (SiO2) at near room temperature and ambient pressure, has been demonstrated for the first time. As a challenging model system, we first prove the conversion of cylindrical water condensates in porous alumina membranes to silica nanotubes (NTs) by introducing SiCl4 as a metal reactant without involving any catalytic reaction. Surprisingly, the water NTs reproducibly transformed into silica NTs, where the wall thickness of the silica NTs deposited per cycle was found to be limited by the amount of condensed water, and it was on the orders of ten nanometers per cycle (i.e., over 50 times faster than that of conventional ALD). More remarkably, the reactions only took place for 10-20 minutes or less without vacuum-related equipment. The thickness of initially adsorbed water layers in cylindrical nanopores was indirectly estimated from the thickness of formed SiO2 layers. With systematic experimental designs, we tackle the classical Kelvin equation in the nanosized pores, and the role of van der Waals forces in the nanoscale wetting phenomena, which is a long-standing issue lacking experimental insight. Moreover, we show that the present strategy is likely generalized to other oxide systems such as TiO2. Our approach opens up a new avenue for ultra-simple preparation of porous oxides and allows for the room temperature formation of dielectric layers toward organic electronic and photovoltaic applications. Electronic supplementary information (ESI) available: TEM gallery of silica NTs under different experimental conditions, detailed calculation of estimating the thickness of condensed water and Hamaker constants, and a comparison of processing times. See DOI: 10.1039/c3nr00906h

Bae, Changdeuck; Kim, Hyunchul; Yang, Yunjeong; Yoo, Hyunjun; Montero Moreno, Josep M.; Bachmann, Julien; Nielsch, Kornelius; Shin, Hyunjung

2013-06-01

286

Inert doublet model and LEP II limits  

SciTech Connect

The inert doublet model is a minimal extension of the standard model introducing an additional SU(2) doublet with new scalar particles that could be produced at accelerators. While there exists no LEP II analysis dedicated for these inert scalars, the absence of a signal within searches for supersymmetric neutralinos can be used to constrain the inert doublet model. This translation however requires some care because of the different properties of the inert scalars and the neutralinos. We investigate what restrictions an existing DELPHI Collaboration study of neutralino pair production can put on the inert scalars and discuss the result in connection with dark matter. We find that although an important part of the inert doublet model parameter space can be excluded by the LEP II data, the lightest inert particle still constitutes a valid dark matter candidate.

Lundstroem, Erik; Gustafsson, Michael; Edsjoe, Joakim [Department of Physics, Stockholm University, AlbaNova University Center, SE - 106 91 Stockholm (Sweden); INFN, Sezione di Padova, Department of Physics 'Galileo Galilei', Via Marzolo 8, I-35131, Padua (Italy) and Department of Physics, Stockholm University, AlbaNova University Center, SE - 106 91 Stockholm (Sweden); Department of Physics, Stockholm University, AlbaNova University Center, SE - 106 91 Stockholm (Sweden)

2009-02-01

287

Studies of cluster-assembled materials: From gas phase to condensed phase  

NASA Astrophysics Data System (ADS)

Clusters, defined as "a number of similar things that occur together" in Webster's dictionary, has different meanings depending on the given subject. To physicists and chemists, the word cluster means "a group of atoms or molecules formed by interactions ranging from very weak van der Waals interactions to strong ionic bonds." Unlike molecules, which are made by nature and are stable under ambient conditions, clusters discovered in a laboratory are often metastable. Molecules have specific stoichiometry, whereas the cluster's composition can usually be altered atom by atom. Thus, clusters can be taken as intrinsically "artificial molecules" with considerably more tunabilities in their properties. Research into the relative stability and instability of clusters has in recent years become a very active research area, especially following the study by Khanna and Castleman that first suggested that by varying size and composition, clusters can expand the periodic table to the 3 rd-dimension; that is, clusters can mimic the chemistry of atoms and may, therefore, be used as the building blocks of new materials. The discovery of Met-Cars has drawn worldwide interests and has been actively investigated by researchers from a variety of fields, including physics, chemistry and material science. However, the unsuccessful search for a solvent capable of isolating Met-Cars has impeded progress in characterizing the material in the condensed state and, hence, limited its potential applications as a novel nanoscale material. An alternative method involving the deposition of mass-gated species and the subsequent structural investigation via Transmission Electron Microscopy (TEM) has been employed. With particularly interesting results, soft-landed deposits of zirconium Met-Cars were found to form a face-centered-cubic (FCC) structure with a lattice parameter ˜ 15A. The production of Met-Cars is conducted with the direct laser vaporization (DLV) of metal/graphite composite pellets. After being mass gated in a reflectron equipped time-of-flight mass spectrometer (TOF-MS) and deposited onto TEM grids, the resultant specimens can be loaded onto high-resolution TEM investigation via electron diffraction. In conclusion, soft-landing of mass selected clusters has been shown to be a successful approach to obtain structural information on Zr-Met-Car cluster-assembled materials collected from the gas phase. TEM images indicate the richness of the morphologies associated with these cluster crystals. However, passivation methods are expected to be examined further to overcome the limited stabilities of these novel clusters. From this initial study, it's shown the promising opportunity to study other Met-Cars species and more cluster-based materials. Experimental results of reactions run with a solvothermal synthesis method obtained while searching for new Zr-C cluster assembled materials, are reported. One unexpected product in single crystal form was isolated and tentatively identified by X-ray diffraction to be [Zr6i O(OH)O12·2(Bu)4], with space group P2 1/n and lattice parameters of a = 12.44 A, b = 22.06 A, c = 18.40 A, alpha = 90°, beta = 105°, gamma = 90°, V = 4875 A3 and R 1 = 3.15% for the total observed data (I ? 2 sigma I) and oR2 = 2.82%. This novel hexanuclear Zr(IV)-oxo-hydroxide cluster anion may be the first member in polyoxometalates class with metal atoms from the IVB group and having Oh symmetry. Alternatively, it may be the first member in {[(Zr6Z)X 12]X6}m- class with halides replaced by oxo- and hydroxyl groups and with an increased oxidation state of Zr. It is predicted to bear application potentials directed by both families. This work could suggest a direction in which the preparation of Zr-C cluster-assembled materials in a liquid environment may be eventually fulfilled. 1,3-Bis(diethylphosphino)propane (depp) protected small gold clusters are studied via multiple techniques, including Electrospray Ionization Mass Spectrometry (ESI-MS), Ultraviolet-Visible Spectroscopy (Uv-Vis), Nuclear

Gao, Lin

288

Method for removing metal vapor from gas streams  

DOEpatents

A process for cleaning an inert gas contaminated with a metallic vapor, such as cadmium, involves withdrawing gas containing the metallic contaminant from a gas atmosphere of high purity argon; passing the gas containing the metallic contaminant to a mass transfer unit having a plurality of hot gas channels separated by a plurality of coolant gas channels; cooling the contaminated gas as it flows upward through the mass transfer unit to cause contaminated gas vapor to condense on the gas channel walls; regenerating the gas channels of the mass transfer unit; and, returning the cleaned gas to the gas atmosphere of high purity argon. The condensing of the contaminant-containing vapor occurs while suppressing contaminant particulate formation, and is promoted by providing a sufficient amount of surface area in the mass transfer unit to cause the vapor to condense and relieve supersaturation buildup such that contaminant particulates are not formed. Condensation of the contaminant is prevented on supply and return lines in which the contaminant containing gas is withdrawn and returned from and to the electrorefiner and mass transfer unit by heating and insulating the supply and return lines.

Ahluwalia, R. K. (6440 Hillcrest Dr., Burr Ridge, IL 60521); Im, K. H. (925 Lehigh Cir., Naperville, IL 60565)

1996-01-01

289

Method for removing metal vapor from gas streams  

DOEpatents

A process for cleaning an inert gas contaminated with a metallic vapor, such as cadmium, involves withdrawing gas containing the metallic contaminant from a gas atmosphere of high purity argon; passing the gas containing the metallic contaminant to a mass transfer unit having a plurality of hot gas channels separated by a plurality of coolant gas channels; cooling the contaminated gas as it flows upward through the mass transfer unit to cause contaminated gas vapor to condense on the gas channel walls; regenerating the gas channels of the mass transfer unit; and, returning the cleaned gas to the gas atmosphere of high purity argon. The condensing of the contaminant-containing vapor occurs while suppressing contaminant particulate formation, and is promoted by providing a sufficient amount of surface area in the mass transfer unit to cause the vapor to condense and relieve supersaturation buildup such that contaminant particulates are not formed. Condensation of the contaminant is prevented on supply and return lines in which the contaminant containing gas is withdrawn and returned from and to the electrorefiner and mass transfer unit by heating and insulating the supply and return lines. 13 figs.

Ahluwalia, R.K.; Im, K.H.

1996-04-02

290

SiO(x) nanoparticles synthesized by an evaporation and condensation process using induction melting of silicon and gas injection.  

PubMed

SiO(x) nanoparticles were synthesized using a specially designed induction melting system equipped with a segmented graphite crucible. The graphite crucible with the segmented wall was the key to enhancing the evaporation rate due to the increase of the evaporation area and convection of the silicon melt. Injection of the gas mixture of oxygen (O2) and argon (Ar) on silicon (Si) melt caused the formation of SiO(x) nanoparticles. The evaporated SiO(x) nanoparticles were then cooled and condensed in a process chamber. The effects of the O2/Ar ratio in the injection gas on the microstructures of the SiO(x) nanoparticles were then investigated. Synthesized SiO(x) nanoparticles were proven to be of a homogeneous amorphous phase with average diameters of 30-35 nm. The microstructures were independent from the O2/Ar ratio of the injected gas. However, x increased from 1.36 to 1.84 as the O2/Ar ratio increased. The purity of the synthesized nanoparticles was about 99.9%. SiO(x) nanoparticles could be applied as the active anode material in a lithium (Li) ion secondary battery. PMID:23858929

Jang, Bo Yun; Lee, Jin Seok; Kim, Joon Soo

2013-05-01

291

Biofilter application for control of BTEX compounds from glycol dehydrator condenser vent gases at oil and natural gas producing facility  

SciTech Connect

Compliance with 1990 Clean Air Act Amendments will require cost-effective control technologies to reduce air emissions for petroleum industries. EPA has also proposed a new MACT Rule for Oil and Natural Gas Producing Facilities which will require control of emissions from glycol dehydrator vents. Control of volatile organic compound (VOC) emissions such as benzene, toluene, ethylbenzene, and xylene (BTEX) is one of the major concerns for the petroleum industries. Traditional VOC control methods may not be economically feasible to meet the requirements of these regulations. Recent studies have shown that biofilters can cost-effectively remove BTEX compounds with greater than 95% efficiency. This paper describes results from field testing a biofilter at an Oil and Natural Gas Producing facility. The biofilter treats a low flow gas stream containing high concentrations of VOCs and carbon dioxide from a glycol dehydrator condenser vent. A modular high-rate vapor phase biofilter developed by BioiReaction Industries was used to investigate the feasibility of this low-cost technology. Due to the high VOC loading (BTEX compounds up to 18,000 ppm; total VOCs 50,000 to 90,000 ppm), three modular biofilters were installed in series.

Stewart, W.C. [BioiReaction Industries, Inc., Tualatin, OR (United States); Kamarthi, R.S. [Texaco E and P Technology Dept., Bellaire, TX (United States)

1997-12-31

292

Unusual well control techniques pay off. [Well drilling techniques in the Elgin gas condensate field, North Sea  

SciTech Connect

Well control and completion operations were seriously complicated by an unusual pressure phenomena encountered while drilling an appraisal well through Jurassic sandstones in a high-pressure, high-temperature (HPHT), gas and condensate field located in the United Kingdom continental shelf. The HPHT sandstone reservoir is located in the Upper Jurassic Franklin formation. Unorthodox well-control techniques were used because it was determined that the abnormally high pressure was generated by a mechanical reaction of the rock under the effect of heavy mud and equivalent circulating density, rather than by entry into the wellbore of formation fluids. This paper reviews the complex drilling fluid control procedures which had to be utilized to maintain an open bore hole during drilling.

Idelovici, J.L.

1993-07-01

293

Effect of scenedesmus acuminatus green algae extracts on the development of Candida lipolytic yeast in gas condensate-containing media  

NASA Technical Reports Server (NTRS)

Data are given of a comparative study of the growth and development as well as the characteristics of the biomass of the C. Lipolytica yeast according to the content of raw protein, protein, lipids, vitamins in the B group, and residual hydrocarbons during growth in media with de-aromatized gas-condensate FNZ as the carbon source with aqueous and alcohol extracts of S. acuminatus as the biostimulants. It is shown that the decoction and aqueous extract of green algae has the most intensive stimulating effect on the yeast growth. When a decoction of algae is added to the medium, the content of residual hydrocarbons in the biomass of C. lipolytica yeast is reduced by 4%; the quantity of protein, lipids, thamine and inositol with replacement of the yeast autolysate by the decoction of algae is altered little.

Bilmes, B. I.; Kasymova, G. A.; Runov, V. I.; Karavayeva, N. N.

1980-01-01

294

Development of turbine driven centrifugal compressors for non-condensible gas removal at geothermal power plants. Final report  

SciTech Connect

Initial field tests have been completed for a Non-Condensible Gas (NCG) turbocompressor for geothermal power plants. It provides alternate technology to steam-jet ejectors and liquid-ring vacuum pumps that are currently used for NCG removal. It incorporates a number of innovative design features to enhance reliability, reduce steam consumption and reduce O&M costs. During initial field tests, the turbocompressor has been on-line for more than 4500 hours as a third stage compressor at The Geysers Unit 11 Power Plant. Test data indicates its overall efficiency is about 25% higher than a liquid-ring vacuum pump, and 250% higher than a steam-jet ejector when operating with compressor inlet pressures of 12.2 in-Hga and flow rates over 20,000 lbm/hr.

NONE

1997-12-16

295

Dynamics and Evolution of SO2 Gas Condensation Around Prometheus-like Volcanic Plumes on Io as Seen by the Near Infrared Mapping Spectrometer  

NASA Technical Reports Server (NTRS)

Near Infrared Mapping Spectrometer data acquired during the I24, 25, and 27 Io's Fly-bys by Galileo are analyzed to map the SO2 frost abundance and granularity. This allows a better understanding of the dynamics and evolution of gas condensation around volcanic plumes. Additional information is contained in the original extended abstract.

Doute, S.; Lopes-Gautier, R.; Smythe, W. D.; Kamp, L. W.; Carlson, R.

2001-01-01

296

Mass and thermal accommodation during gas-liquid condensation of water.  

PubMed

In this Letter we report, for the first time, direct and simultaneous determinations of mass and thermal accommodation coefficients for water vapor condensation in air, based on the observation of droplet growth kinetics in an expansion cloud chamber. Our experiments exclude values below 0.85 for the thermal and below 0.4 for the mass accommodation coefficients at temperatures ranging from 250 to 290 K. Both coefficients are likely to be 1 for all studied conditions. Previously available experimental data on the mass accommodation coefficient for water span about 3 orders of magnitude. Our results provide new and firm insight to cloud microphysics and consequently to the global radiative balance. PMID:15324249

Winkler, Paul M; Vrtala, Aron; Wagner, Paul E; Kulmala, Markku; Lehtinen, Kari E J; Vesala, Timo

2004-08-13

297

Electrolyte vapor condenser  

DOEpatents

A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well. 3 figs.

Sederquist, R.A.; Szydlowski, D.F.; Sawyer, R.D.

1983-02-08

298

Electrolyte vapor condenser  

DOEpatents

A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well.

Sederquist, Richard A. (Newington, CT); Szydlowski, Donald F. (East Hartford, CT); Sawyer, Richard D. (Canton, CT)

1983-01-01

299

Cryogenic gas loading in a Mao-Bell-type diamond anvil cell for high pressure-high temperature investigations  

Microsoft Academic Search

A simple system for loading argon fluid at cryogenic temperatures in a Mao-Bell-type diamond anvil cell (DAC) has been developed. It is done in a two step process in which the piston-cylinder assembly alone is submerged in the cryogenic chamber for trapping the liquefied inert gas. Liquid nitrogen is used for condensing the argon gas. This system is now being

M. Sekar; N. R. Sanjay Kumar; P. Ch. Sahu; N. V. Chandra Shekar; N. Subramanian

2008-01-01

300

AN INNOVATIVE TRANSPORT MEMBRANE CONDENSER FOR WATER RECOVERY FROM GAS AND ITS REUSE - PHASE I  

EPA Science Inventory

Although water recycle and reuse is considered good environmental practice, its implementation is highly dependent on the economics and hence can be challenging to implement. In this project, we present a unique opportunity to recover both water and energy from boiler flue gas...

301

Modelling multi-phase halogen chemistry in the remote marine boundary layer: investigation of the influence of aerosol size resolution on predicted gas- and condensed-phase chemistry  

NASA Astrophysics Data System (ADS)

A coupled box model of photochemistry and aerosol microphysics which explicitly accounts for size-dependent chemical properties of the condensed-phase has been developed to simulate the multi-phase chemistry of chlorine, bromine and iodine in the marine boundary layer (MBL). The model contains separate seasalt and non-seasalt modes, each of which may be composed of 1-16 size-bins. By comparison of gaseous and aerosol compositions predicted using different size-resolutions with both fixed and size-dependent aerosol turnover rates, it was found that, for halogen-activation processes, the physical property initialisation of the aerosol-mode has a significant influence on gas-phase chemistry. Failure to adequately represent the appropriate physical properties can lead to substantial errors in gas-phase chemistry. The size-resolution of condensed-phase composition has a less significant influence on gas-phase chemistry.

Lowe, D.; Topping, D.; McFiggans, G.

2009-07-01

302

Modelling multi-phase halogen chemistry in the remote marine boundary layer: investigation of the influence of aerosol size resolution on predicted gas- and condensed-phase chemistry  

NASA Astrophysics Data System (ADS)

A coupled box model of photochemistry and aerosol microphysics which explicitly accounts for size-dependent chemical properties of the condensed-phase has been developed to simulate the multi-phase chemistry of chlorine, bromine and iodine in the marine boundary layer (MBL). The model contains separate seasalt and non-seasalt modes, each of which may be composed of 1-16 size-sections. By comparison of gaseous and aerosol compositions predicted using different size-resolutions with both fixed and size-dependent aerosol turnover rates, it was found that, for halogen-activation processes, the physical property initialisation of the aerosol-mode has a significant influence on gas-phase chemistry. Failure to adequately represent the appropriate physical properties can lead to substantial errors in gas-phase chemistry. The size-resolution of condensed-phase composition has a less significant influence on gas-phase chemistry.

Lowe, D.; Topping, D.; McFiggans, G.

2009-03-01

303

Gas chromatographic determination of residual hydrazine and morpholine in boiler feed water and steam condensates  

Microsoft Academic Search

Hydrazine, an oxygen scavenger in boiler water, was derivatised to the corresponding acetone azine and determined at the ng ml?1 level by gas chromatography. Morpholine, a corrosion inhibitor used in steam boilers, was estimated either directly (if >2.0 ?g ml?1) or by quantitative preconcentration (0.1 ng – 2.0 ?g ml?1). To obtain symmetrical peaks for these amines, the column packing

S. Vatsala; V. Bansal; D. K. Tuli; M. M. Rai; S. K. Jain; S. P. Srivastava; A. K. Bhatnagar

1994-01-01

304

Flammability limits of dusts: Minimum inerting concentrations  

SciTech Connect

A new flammability limit parameter has been defined as the Minimum Inerting Concentration (MIC). This is the concentration of inertant required to prevent a dust explosion regardless of fuel concentration. Previous experimental work at Fike in a 1-m{sup 3} spherical chamber has shown this flammability limit to exist for pulverized coal dust and cornstarch. In the current work, inerting experiments with aluminum, anthraquinone and polyethylene dusts as fuels were performed, using monoammonium phosphate and sodium bicarbonate as inertants. The results show that an MIC exists only for anthraquinone inerted with sodium bicarbonate. The other combustible dust and inertant mixtures did not show a definitive MIC, although they did show a strong dependence between inerting level and suspended fuel concentration. As the fuel concentration increased, the amount of inertant required to prevent an explosion decreased. Even though a definitive MIC was not found for most of the dusts an effective MIC can be estimated from the data. The use of MIC data can aid in the design of explosion suppression schemes.

Dastidar, A.G.; Amyotte, P.R. [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering] [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering; Going, J.; Chatrathi, K. [Fike Corp., Blue Springs, MO (United States)] [Fike Corp., Blue Springs, MO (United States)

1999-05-01

305

Analysis of Heating Systems and Scale of Natural Gas-Condensing Water Boilers in Northern Zones  

E-print Network

isn?t needed in the house, the cost can be saved about 30~40yuan/m2 , and it is also regulated ,according to the need of users [1,2].Therefore, it is the most energy- saving system. Comparing with heating system of gas-fried boiler in buildings... is shown in tab.1 [4.5.6]. From the tab.1, it can be seen that the first cost of low-temperature radiant floor heating system is the lowest, the one of cast-iron radiator heating system is secondary, and the one of steel radiator heating system...

Wu, Y.; Wang, S.; Pan, S.; Shi, Y.

2006-01-01

306

Hydro-gravitational fragmentation, diffusion and condensation of the primordial plasma, dark-matter and gas  

E-print Network

The first structures were proto-voids formed in the primordial plasma. Viscous and weak turbulence forces balanced gravitational forces when the scale of causal connection at time 30,000 years matched the viscous and turbulent Schwarz scales of hydro-gravitational theory (Gibson 1996). The photon viscosity allows only weak turbulence from the Reynolds number Re = 200, with fragmentation to give proto-supercluster voids, buoyancy forces, fossil vorticity turbulence, and strong sonic damping. The expanding, cooling, plasma continued fragmentation to proto-galaxy-mass with the density and rate-of-strain preserved as fossils of the weak turbulence and first structure. Turbulence fossilization by self-gravitational buoyancy explains the cosmic microwave background temperature fluctuations, not sonic oscillations in cold-dark-matter fragments. After plasma to gas transition at 300,000 years, gas fragmentation occurred within the proto-galaxies to form proto-globular-star-cluster (PGCs) clouds of small-planetary-mass primordial-fog-particles (PFPs). Dark PGC clumps of frozen PFPs persist as the inner-galaxy-halo dark matter, supporting Schild's 1996 quasar-microlensing interpretation. Non-baryonic dark matter diffused into the plasma proto-cluster-voids and later fragmented as outer-galaxy-halos at diffusive Schwarz scales, indicating light, weakly-collisional fluid particles (possibly neutrinos). Observations support the theory (Gibson and Schild 2003).

Carl H. Gibson

2003-05-19

307

High-resolution gas chromatography/matrix isolation infrared spectrometry  

SciTech Connect

An apparatus is described that allows the collection, within a matrix of condensed inert gas, of the effluent compounds from a high-resolution gas chromatograph. Each collected compound is contained within an area typically 0.3 mm in diameter yielding a concomitant high level of infrared spectral absorbance per nanogram of sample. Tests demonstrate the level of infrared sensitivity, the achievement of matrix isolation of the sample molecules, and the maintenance of compound separation achieved by the gas chromatograph. Use of the apparatus is demonstrated for PAH, PCB, dioxin, and aliphatic hydrocarbon compounds. 15 references, 12 figures.

Reedy, G.T.; Ettinger, D.G.; Schneider, J.F.; Bourne, S.

1985-07-01

308

Gamma Inert Sterilization: A Solution to Polyethylene Oxidation?  

PubMed Central

Background: In the 1990s, oxidation was found to occur in ultra-high molecular weight polyethylene total joint replacement components following gamma irradiation and prolonged shelf aging in air. Orthopaedic manufacturers developed barrier packaging to reduce oxidation during and after radiation sterilization. The present study explores the hypothesis that polyethylene components sterilized in a low-oxygen environment undergo similar in vivo oxidative mechanisms as inserts sterilized in air. In addition, the potential influence of the different sterilization processes on the wear performance of the polyethylene components was examined. Methods: An analysis of oxidation, wear, and surface damage was performed for forty-eight acetabular liners and 123 tibial inserts. The mean implantation time was 12.3 ± 3.7 years for thirty-one acetabular liners that had been gamma sterilized in air and 4.0 ± 2.5 years for the seventeen acetabular liners that had been gamma sterilized in inert gas. The mean implantation time was 11.0 ± 3.2 years for the twenty-six tibial inserts that had been sterilized in air and 2.8 ± 2.2 years for the ninety-seven tibial inserts that had been gamma sterilized in inert gas. Oxidation and hydroperoxide levels were characterized in loaded and unloaded regions of the inserts. Results: Measurable oxidation and oxidation potential were observed in all cohorts. The oxidation and hydroperoxide levels were regional. Surfaces with access to body fluids were more heavily oxidized than protected bearing surfaces were. This variation appeared to be greater in historical (gamma-in-air-sterilized) components. Regarding wear performance, historical and conventional acetabular liners showed similar wear penetration rates, whereas a low incidence of delamination was confirmed for the conventional tibial inserts in the first decade of implantation. Conclusions: The present study explores the impact of industry-wide changes in sterilization practices for polyethylene. We found lower oxidation and oxidation potential in the conventional acetabular liners and tibial inserts that had been gamma sterilized in inert gas as compared with the historical components that had been gamma sterilized in air. However, we also found strong evidence that conventional components undergo mechanisms of in vivo oxidation similar to those observed following gamma irradiation in air. In addition, gamma sterilization in inert gas did not provide polyethylene with a significant improvement in terms of wear resistance as compared with gamma sterilization in air, except for a lower incidence of delamination in the first decade of implantation for tibial inserts. Clinical Relevance: Our research demonstrates that gamma inert sterilization may have improved, but not completely solved, the problem of polyethylene oxidation for hip and knee arthroplasty. PMID:19339568

Medel, Francisco J.; Kurtz, Steven M.; Hozack, William J.; Parvizi, Javad; Purtill, James J.; Sharkey, Peter F.; MacDonald, Daniel; Kraay, Matthew J.; Goldberg, Victor; Rimnac, Clare M.

2009-01-01

309

Cement solidification of simulated off-gas condensates from vitrification of low-level nuclear waste solutions.  

PubMed

Solidification in a cementitious matrix is a viable alternative for low-level nuclear waste management; it is therefore important to understand the behavior and properties of such wasteforms. We have examined the cementitious solidification of simulated off-gas waste streams resulting from the vitrification of low-level nuclear waste. Different possible methods for scrubbing the off-gasses from a vitrifier give rise to three possible types of waste compositions: acidic (from aqueous dissolution of volatile NOx and POx carried over from the vitrifier), basic (from neutralizing the former with sodium hydroxide), and fully carbonated (arising from a direct-combustion vitrifier). Six binder compositions were tested in which ordinary Portland cement was replaced at different proportions by fly ash and/or ground granulated blast furnace slag. A high solution to binder ratio of 1l/1 kg was used to minimize the volume of the wasteform and 10% attapulgite clay was added to all mixes to ensure that the fresh mix did not segregate prior to setting. The 28-day compressive strengths decreased when a high proportion of cement was replaced with fly ash, but were increased significantly when the cement was replaced with slag. The heats of hydration at early age for the various solids compositions decreased when cement was replaced with either fly ash or slag; however, for the fly ash mix the low heat was also associated with a significant decrease in compressive strength. High curing temperature (60 degrees C) or the use of extra-fine slag did not significantly affect the compressive strength. Recommendations for choice of binder formulations and treatment of off-gas condensates are discussed. PMID:11478621

Katz, A; Brough, A R; Kirkpatrick, R J; Struble, L J; Sun, G K; Young, J F

2001-01-01

310

Method and apparatus for maintaining condensable constituents of a gas in a vapor phase during sample transport  

DOEpatents

A system for fluid transport at elevated temperatures having a conduit having a fluid inlet end and a fluid outlet end and at least one heating element disposed within the conduit providing direct heating of a fluid flowing through the conduit. The system is particularly suited for preventing condensable constituents of a high temperature fluid from condensing out of the fluid prior to analysis of the fluid. In addition, operation of the system so as to prevent the condensable constituents from condensing out of the fluid surprisingly does not alter the composition of the fluid.

Felix, Larry Gordon; Farthing, William Earl; Irvin, James Hodges; Snyder, Todd Robert

2010-05-18

311

Influence of a non-condensable gas on the performance of a piston expander for use in carbon dioxide trans-critical heat pumps  

Microsoft Academic Search

Non-condensable gas is proved to accelerate the phase change process and improve the expander performance by experimental researches on the carbon dioxide trans-critical heat pump. Using expander instead of throttle valve in carbon dioxide trans-critical heat pump can recover energy and improve system efficiency. Accelerating phase change process is a main way to improve expander efficiency. The theoretical analysis indicates

Tian Hua; Ma Yitai; Li Minxia; Guan Haiqing; Liu Zhongyan

2011-01-01

312

Kinetic boundary layers in gas mixtures: Systems described by nonlinearly coupled kinetic and hydrodynamic equations and applications to droplet condensation and evaporation  

SciTech Connect

The authors consider a mixture of heavy vapor molecules and a light carrier gas surrounding a liquid droplet. The vapor is described by a variant of the Klein-Kramers equation; the gas is described by the Navier-Stokes equations; the droplet acts as a heat source due to the released heat of condensation. The exchange of momentum and energy between the constituents of the mixture is taken into account by force terms in the kinetic equation and source terms in the Navier-Stokes equations. These are chosen to obtain maximal agreement with the irreversible thermodynamics of a gas mixture. The structure of the kinetic boundary layer around the sphere is determined from the self-consistent solution of this set of coupled equations with appropriate boundary conditions at the surface of the sphere. The kinetic equation is rewritten as a set of coupled moment equations. A complete set of solutions of these moment equations is constructed by numerical integration inward from the region far away from the droplet, where the background inhomogeneities are small. A technique developed earlier is used to deal with the numerical instability of the moment equations. The solutions obtained for given temperature and pressure profiles in the gas are then combined linearly such that they obey the boundary conditions at the droplet surface; from this solution source terms for the Navier-Stokes equation of the gas are constructed and used to determine improved temperature and pressure profiles for the background gas. For not too large temperature differneces between the droplet and the gas at infinity, self-consistency is reached after a few iterations. The method is applied to the condensation of droplets from a supersaturated vapor as well as to strong evaporation of droplets under the influence of an external heat source, where corrections of up to 40% are obtained.

Widder, M.E.; Titulaer, U.M. (Johannes-Kepler-Universitaet Linz (Austria))

1993-03-01

313

Kinetic multi-layer model of gas-particle interactions in aerosols and clouds (KM-GAP): linking condensation, evaporation and chemical reactions of organics, oxidants and water  

NASA Astrophysics Data System (ADS)

We present a novel kinetic multi-layer model for gas-particle interactions in aerosols and clouds (KM-GAP) that treats explicitly all steps of mass transport and chemical reaction of semi-volatile species partitioning between gas phase, particle surface and particle bulk. KM-GAP is based on the PRA model framework (Pöschl-Rudich-Ammann, 2007), and it includes gas phase diffusion, reversible adsorption, surface reactions, bulk diffusion and reaction, as well as condensation, evaporation and heat transfer. The size change of atmospheric particles and the temporal evolution and spatial profile of the concentration of individual chemical species can be modeled along with gas uptake and accommodation coefficients. Depending on the complexity of the investigated system and the computational constraints, unlimited numbers of semi-volatile species, chemical reactions, and physical processes can be treated, and the model shall help to bridge gaps in the understanding and quantification of multiphase chemistry and microphysics in atmospheric aerosols and clouds. In this study we demonstrate how KM-GAP can be used to analyze, interpret and design experimental investigations of changes in particle size and chemical composition in response to condensation, evaporation, and chemical reaction. For the condensational growth of water droplets, our kinetic model results provide a direct link between laboratory observations and molecular dynamic simulations, confirming that the accommodation coefficient of water at ~270 K is close to unity (Winkler et al., 2006). Literature data on the evaporation of dioctyl phthalate as a function of particle size and time can be reproduced, and the model results suggest that changes in the experimental conditions like aerosol particle concentration and chamber geometry may influence the evaporation kinetics and can be optimized for efficient probing of specific physical effects and parameters. With regard to oxidative aging of organic aerosol particles, we illustrate how the formation and evaporation of volatile reaction products like nonanal can cause a decrease in the size of oleic acid particles exposed to ozone.

Shiraiwa, M.; Pfrang, C.; Koop, T.; Pöschl, U.

2012-03-01

314

Kinetic multi-layer model of gas-particle interactions in aerosols and clouds (KM-GAP): linking condensation, evaporation and chemical reactions of organics, oxidants and water  

NASA Astrophysics Data System (ADS)

We present a novel kinetic multi-layer model for gas-particle interactions in aerosols and clouds (KM-GAP) that treats explicitly all steps of mass transport and chemical reaction of semi-volatile species partitioning between gas phase, particle surface and particle bulk. KM-GAP is based on the PRA model framework (Pöschl-Rudich-Ammann, 2007), and it includes gas phase diffusion, reversible adsorption, surface reactions, bulk diffusion and reaction, as well as condensation, evaporation and heat transfer. The size change of atmospheric particles and the temporal evolution and spatial profile of the concentration of individual chemical species can be modeled along with gas uptake and accommodation coefficients. Depending on the complexity of the investigated system, unlimited numbers of semi-volatile species, chemical reactions, and physical processes can be treated, and the model shall help to bridge gaps in the understanding and quantification of multiphase chemistry and microphysics in atmospheric aerosols and clouds. In this study we demonstrate how KM-GAP can be used to analyze, interpret and design experimental investigations of changes in particle size and chemical composition in response to condensation, evaporation, and chemical reaction. For the condensational growth of water droplets, our kinetic model results provide a direct link between laboratory observations and molecular dynamic simulations, confirming that the accommodation coefficient of water at ~270 K is close to unity. Literature data on the evaporation of dioctyl phthalate as a function of particle size and time can be reproduced, and the model results suggest that changes in the experimental conditions like aerosol particle concentration and chamber geometry may influence the evaporation kinetics and can be optimized for efficient probing of specific physical effects and parameters. With regard to oxidative aging of organic aerosol particles, we illustrate how the formation and evaporation of volatile reaction products like nonanal can cause a decrease in the size of oleic acid particles exposed to ozone.

Shiraiwa, M.; Pfrang, C.; Koop, T.; Pöschl, U.

2011-12-01

315

Relation between biomarkers in exhaled breath condensate and internal exposure to metals from gas metal arc welding.  

PubMed

Concerning possible harmful components of welding fumes, besides gases and quantitative aspects of the respirable welding fumes, particle-inherent metal toxicity has to be considered.The objective of this study was to investigate the effect markers leukotriene B4 (LTB4),prostaglandin E2 (PGE2) and 8-isoprostane (8-Iso PGF2?) as well as the acid–base balance(pH) in exhaled breath condensate (EBC) of 43 full-time gas metal arc welders (20 smokers) in relation to welding fume exposure. We observed different patterns of iron, chromium and nickel in respirable welding fumes and EBC. Welders with undetectable chromium in EBC(group A, n = 24) presented high iron and nickel concentrations. In this group, higher 8-isoPGF2? and LTB4 concentrations could be revealed compared to welders with detectable chromium and low levels of both iron and nickel in EBC (group B): 8-iso PGF2?443.3 pg mL?1 versus 247.2 pg mL?1; p = 0.001 and LTB4 30.5 pg mL?1 versus 17.3 pgmL?1; p = 0.016. EBC-pH was more acid in samples of group B (6.52 versus 6.82; p = 0.011).Overall, effect markers in welders were associated with iron concentrations in EBC according to smoking habits--non-smokers/smokers: LTB4 (rs = 0.48; p = 0.02/rs = 0.21; p = 0.37),PGE2 (rs = 0.15; p = 0.59/rs = 0.47; p = 0.07), 8-iso PGF2? (rs = 0.18; p = 0.54/rs = 0.59;p = 0.06). Sampling of EBC in occupational research provides a matrix for the simultaneous monitoring of metal exposure and effects on target level. Our results suggest irritative effects in the airways of healthy welders. Further studies are necessary to assess whether these individual results might be used to identify welders at elevated risk for developing a respiratory disease. PMID:22622358

Hoffmeyer, Frank; Raulf-Heimsoth, Monika; Weiss, Tobias; Lehnert, Martin; Gawrych, Katarzyna; Kendzia, Benjamin; Harth, Volker; Henry, Jana; Pesch, Beate; Brüning, Thomas

2012-06-01

316

Dark Matter from the Inert Doublet Model  

E-print Network

The Inert Doublet Model is an extension of the Standard Model including one extra ``Inert scalar doublet'' and an exact $Z_2$ symmetry. The ``Inert scalar'' provides a new candidate for dark matter. We present a systematic analysis of the dark matter abundance assuming the standard freeze-out mechanism and investigate the potentialities for direct and gamma indirect detection. We show that the dark matter candidate saturates the WMAP dark matter density in two rather separate mass ranges, one between 40 and 80 GeV, the other one over 400 GeV. We also show that the model should be within the range of future experiments, like GLAST and EDELWEISS II or ZEPLIN.

Laura Lopez Honorez

2007-06-01

317

Inertance Tube Optimization for Pulse Tube Refrigerators  

NASA Astrophysics Data System (ADS)

The efficiency of regenerative refrigerators is generally maximized when the pressure and flow are in phase near the midpoint of the regenerator. Such a phase relationship minimizes the amplitude of the mass flow for a given acoustic power flow through the regenerator. To achieve this phase relationship in a pulse tube refrigerator requires that the flow at the warm end of the pulse tube lag the pressure by about 60 degrees. The inertance tube allows for the flow to lag the pressure, but such a large phase shift is only possible with relatively large acoustic power flows. In small pulse tube cryocoolers the efficiency is improved by maximizing the phase shift in the inertance tube. This paper describes a simple transmission line model of the inertance tube, which is used to find the maximum phase shift and the corresponding diameter and length of the optimized inertance tube. Acoustic power flows between 1 and 100 W are considered in this study, though the model may be valid for larger systems as well. For large systems the model can be used to find the minimum reservoir volume that in combination with the inertance tube provides a phase shift of 60 degrees. This transmission line model is compared with some experimental results on a small-diameter inertance tube and found to agree quite well provided some heat transfer is taken into account. Design graphs for a frequency of 60 Hz and an average pressure of 2.5 MPa are presented for different pressure ratios and for both adiabatic and isothermal conditions.

Radebaugh, Ray; Lewis, M.; Luo, E.; Pfotenhauer, J. M.; Nellis, G. F.; Schunk, L. A.

2006-04-01

318

Two systems developed for purifying inert atmospheres  

NASA Technical Reports Server (NTRS)

Two systems, one for helium and one for argon, are used for purifying inert atmospheres. The helium system uses an activated charcoal bed at liquid nitrogen temperature to remove oxygen and nitrogen. The argon system uses heated titanium sponge to remove nitrogen and copper wool beds to remove oxygen. Both use molecular sieves to remove water vapor.

Foster, M. S.; Johnson, C. E.; Kyle, M. L.

1969-01-01

319

Passive suspensions incorporating inerters for railway vehicles  

Microsoft Academic Search

This paper investigates the possibility of improving the performance of railway vehicle suspensions by incorporating a newly developed mechanical device known as the inerter. A comparative study of several low-complexity passive suspension layouts is made. Improved performance for the lateral and vertical ride comfort, as well as lateral body movement when curving are demonstrated in comparison with the conventional suspension

Jason Zheng Jiang; Alejandra Z. Matamoros-Sanchez; Roger M. Goodall; Malcolm C. Smith

2012-01-01

320

Polyvinyl alcohol battery separator containing inert filler  

Microsoft Academic Search

A cross-linked polyvinyl alcohol battery separator is disclosed. A particulate filler, inert to alkaline electrolyte of an alkaline battery, is incorporated in the separator in an amount of 1-20% by weight, based on the weight of the polyvinyl alcohol, and is dispersed throughout the product. Incorporation of the filler enhances performance and increases cycle life of alkaline batteries when compared

D. W. Sheibley; L. C. Hsu; M. A. Manzo

1981-01-01

321

Effect of precursor supply on structural and morphological characteristics of fe nanomaterials synthesized via chemical vapor condensation method.  

PubMed

Various physical, chemical and mechanical methods, such as inert gas condensation, chemical vapor condensation, sol-gel, pulsed wire evaporation, evaporation technique, and mechanical alloying, have been used to synthesize nanoparticles. Among them, chemical vapor condensation (CVC) has the benefit of its applicability to almost all materials because a wide range of precursors are available for large-scale production with a non-agglomerated state. In this work, Fe nanoparticles and nanowires were synthesized by chemical vapor condensation method using iron pentacarbonyl (Fe(CO)5) as the precursor. The effect of processing parameters on the microstructure, size and morphology of Fe nanoparticles and nanowires were studied. In particular, we investigated close correlation of size and morphology of Fe nanoparticles and nanowires with atomic quantity of inflow precursor into the electric furnace as the quantitative analysis. The atomic quantity was calculated by Boyle's ideal gas law. The Fe nanoparticles and nanowires with various diameter and morphology have successfully been synthesized by the chemical vapor condensation method. PMID:22524015

Ha, Jong-Keun; Ahn, Hyo-Jun; Kim, Ki-Won; Nam, Tae-Hyun; Cho, Kwon-Koo

2012-01-01

322

Mechanisms controlling the global oceanic distribution of the inert gases argon, nitrogen and neon  

Microsoft Academic Search

Dissolved inert gas measurements in the ocean yield important information about processes that occur during water mass formation. We present argon, nitrogen, and neon data from the subtropical and subpolar North Pacific and the subtropical North Atlantic. All three gases were supersaturated at the surface. In the deep ocean, Ar and N2 were undersaturated while Ne re- mained supersaturated. All

Roberta C. Hamme; Steven R. Emerson

2002-01-01

323

Children's understanding of changes of state involving the gas state, Part 2: Evaporation and condensation below boiling point  

Microsoft Academic Search

Deriving from a three?year longitudinal study which explored the development of children's concept of a substance (ages 11 to 14), part 2 of this paper (see Johnson 1998b) reports findings in relation to evaporation at room temperature and condensation of atmospheric water vapour. Part one had reported findings in relation to boiling water and the development of pupils’ understanding of

Philip Johnson

1998-01-01

324

Theory of the Charged Bose Gas: Bose-Einstein condensation in an ultra-high magnetic field  

NASA Astrophysics Data System (ADS)

The theory of the Bose-Einstein condensation of the CBG in a magnetic field is extended to ultra-low temperatures and ultra-high magnetic fields. A low-temperature dependence of the upper critical field H c2 (T) is obtained both for the particle-impurity and particle-particle scattering.

Alexandrov, A. S.; Beere, W. H.; Kabanov, V. V.

1996-02-01

325

Evidence for a palaeo-oil column and alteration of residual oil in a gas-condensate field: Integrated oil inclusion and experimental results  

NASA Astrophysics Data System (ADS)

In the Phuong Dong gas condensate field, Cuu Long Basin, Vietnam, hydrocarbon inclusions in quartz trapped a variety of petroleum fluids in the gas zone. Based on the attributes of the oil inclusion assemblages (fluorescence colour of the oil, bubble size, presence of bitumen), the presence of a palaeo-oil column is inferred prior to migration of gas into the reservoir. When a palaeo-oil column is displaced by gas, a residual volume fraction of oil remains in pores. If the gas does not completely mix with the oil, molecular partitioning between the residual oil and the new gas charge may change the composition and properties of the residual oil (gas stripping or gas washing). To simulate this phenomenon in the laboratory, we sealed small amounts of crude oil (42 and 30 °API) and excess pure gas (methane, ethane, or propane) in fused silica capillary capsules (FSCCs), with and without water. These mixtures were characterized with the same methods used to characterize the fluid inclusions, heating and cooling stage microscopy, fluorescence spectroscopy, synchrotron FT-IR, and Raman spectroscopy. At room temperature, mixtures of ethane and propane with the 30 °API oil formed a new immiscible fluorescent liquid phase with colour that is visually more blue than the initial oil. The fluorescence of the original oil phase shifted to yellow or disappeared with formation of semi-solid residues. The blue-shift of the fluorescence of the immiscible phases and strong CH stretching bands in FT-IR spectra are consistent with stripping of hydrocarbon molecules from the oil. In experiments in FSCCs with water solid residues are common. At elevated temperature, reproducing geologic reservoir conditions, the fluorescence changes and therefore the molecular fractionation are enhanced. However, the precipitation of solid residues is responsible of more complex changes. Mixing experiments with the 42 °API oil do not form a new immiscible hydrocarbon liquid although the fluorescence displays a similar yellow shift when gas is added. Solid residues rarely form in mixtures with 42 °API oil. FT-IR spectra suggest that the decrease of fluorescence intensity of the original oil at short wavelengths to be due to the partitioning of low molecular weight aromatic molecules into the vapour phase and/or the new immiscible liquid phase. The decrease of fluorescence intensity at long wavelengths appears to be due to loss of high molecular weight aromatics during precipitation of solid residues by desorption of aromatics and resins from asphaltenes. Desorption of low molecular weight aromatics and resins from asphaltenes during precipitation can also increase the fluorescence intensity at short wavelengths of the residual oil. Water clearly affects the precipitation of semi-solid residues from the oil phase of the lowest API gravity oil. The change of hydrocarbon phase(s) in UV-visible fluorescence and FT-IR enclosed within the FSCCs were compared with the fluorescence patterns of natural fluid inclusions at Phuong Dong gas condensate field. The experimental results support the concept of gas-washing of residual oil and are consistent with the oil inclusion attributes from the current gas zone at Phuong Dong field. The hydrocarbon charge history of the fractured granite reservoir is interpreted to result from the trapping of residual oil after drainage of a palaeo-oil column by gas.

Bourdet, Julien; Burruss, Robert C.; Chou, I.-Ming; Kempton, Richard; Liu, Keyu; Hung, Nguyen Viet

2014-10-01

326

Numerical evaluation of surface condensers for geothermal power plants  

Microsoft Academic Search

The transport and partitioning of gases in four surface condensers for geothermal power plants has been modelled numerically. A vent condenser between the main condenser and the first stage gas ejectors improves hydrogen sulphide partitioning, particularly if the condensate from it, and from the inter- and aftercondensers, is recirculated to the main condenser tube bundles. Regardless of steam composition, hydrogen

O WERES

1984-01-01

327

Pressure Effect of Various Inert Gases on the Phase Behavior of Polystyrene-block-Poly(n-pentyl methacrylate) Copolymer  

NASA Astrophysics Data System (ADS)

We investigated the pressure effect of three inert gases (nitrogen, helium and argon) on the phase behavior of polystyrene-block-poly(n-pentylmethacrylate) copolymer (PS-b-PnPMA) showing closed-loop phase behavior and baroplasticity. Helium gas pressure enhanced the miscibility between PS and PnPMA blocks similar to the hydrostatic pressure. Very interestingly, however, with increasing nitrogen and argon gas pressure, the miscibility between the two blocks decreased even though these two are also considered as inert gases. To explain these unexpected results, we measured the amount of gas absorption into each block. The experimentally measured gas absorption results are consistent with the theoretical ones based on the Sanchez-Lacombe theory. The results in this study imply that well-known and widely employed inert gases such as nitrogen and argon could significantly affect the phase behavior of a weakly interacting block copolymer at high pressures.

Moon, Hong Chul; Kim, Hye Jeong; Cho, Junhan; Kim, Jin Kon

2013-03-01

328

Report on the source of the electrochemical impedance on cermet inert anodes  

SciTech Connect

the Inert Electrode Program at Pacific Northwest Laboratory (PNL) is supported by the Office of Industrial Processes of the US Department of Energy and is aimed at improving the energy efficiency of Hall-Heroult cells through the development of inert anodes. The inert anodes currently under study are composed of a cermet material of the general composition NiO-NiFe{sub 2}O{sub 4}-Cu. The program has three primary objectives: (a) to evaluate the anode material in a scaled-up, pilot cell facility, (b) to investigate the mechanisms of the electrochemical reactions at the anode surface, and (c) to develop sensors for monitoring anode and/or electrolyte conditions. This report covers the results of a portion of the studies on anode reaction mechanisms. The electrochemical impedances of cermet inert anodes in alumina-saturated molten cryolite as a function of frequency, current density, and time indicated that a significant component of the impedance is due to the gas bubbles produced at the anode during electrolysis. The data also showed a connection between surface structure and impedance that appears to be related to the effects of surface structure on bubble flow. Given the results of this work, it is doubtful that a resistive film contributes significantly to the electrochemical impedances on inert anodes. Properties previously assigned to such a film are more likely due to the bubbles and those factors that affect the properties and dynamics of the bubbles at the anode surface. 12 refs., 16 figs., 3 tabs.

Windisch, C.F. Jr.; Stice, N.D.

1991-02-01

329

The lateral stability of train suspension systems employing inerters  

Microsoft Academic Search

This paper investigates the benefits of lateral stability of train suspension systems employing a newly developed mechanical network element known as an inerter. An inerter was proposed as an ideal mechanical two-port element to substitute for the mass element in the mechanical\\/electrical analogy. As of now, inerters have been successfully applied to car and motorcycle suspension systems, for which significant

Fu-Cheng Wang; Min-Kai Liao

2010-01-01

330

Inerter Nonlinearities and the Impact on Suspension Control  

Microsoft Academic Search

This paper discusses the nonlinear properties of Inerters and their impact on vehicle suspension control. The Inerter was recently introduced as an ideal mechanical two-terminal element which is a substitute for the mass element with the applied force proportional to the relative acceleration across the terminals. Until now, ideal Inerters have been applied to car, motorcycle and train suspension systems,

Fu-Cheng Wang; Wei-Jiun Su

2008-01-01

331

Impact of inerter nonlinearities on vehicle suspension control  

Microsoft Academic Search

This paper discusses the nonlinear properties of inerters and their impact on vehicle suspension control. The inerter was recently introduced as an ideal mechanical two-terminal element, which is a substitute for the mass element, where the applied force is proportional to the relative acceleration across the terminals. Until now, ideal inerters have been applied to vehicle, motorcycle and train suspension

Fu-Cheng Wang; Wei-Jiun Su

2008-01-01

332

Performance analyses of building suspension control with inerters  

Microsoft Academic Search

This paper discusses the application of a new mechanical element, called inerter, to building suspension control. The inerter was proposed as a real two-terminal mechanical element, which is a substitute for the mass element, with the applied force proportional to the relative acceleration across two terminals. To investigate the performance benefits of building suspension with inerters, three building models were

Fu-Cheng Wang; Cheng-Wei Chen; Min-Kai Liao; Min-Feng Hong

2007-01-01

333

Diamondoid Characterization in Condensate by Comprehensive Two-Dimensional Gas Chromatography with Time-of-Flight Mass Spectrometry: The Junggar Basin of Northwest China  

PubMed Central

Diamondoids in crude oil are useful for assessing the maturity of oil in high maturation. However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil. In this paper, we use comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) to study the compounds in condensates from the Junggar Basin of northwest China and address their geological and geochemical applications. GC×GC-TOFMS improves the resolution and separation efficiency of the compounds. It not only separates the compounds that coelute in conventional GC-MS (e.g., 4, 8-dimethyl-diamantane and trimethyl-diamantane) but also allows the identification of compounds that were not previously detected (e.g., trimethyl-diamantane (15A)). A reversed-phase column system improves the separation capabilities over the normal phase column system. The diamondoid indexes indicate that a representative condensate from Well DX 10 is highly mature with equivalent Ro being approximately 1.5%. PMID:23109861

Li, Shuifu; Hu, Shouzhi; Cao, Jian; Wu, Ming; Zhang, Dongmei

2012-01-01

334

Desulfovibrio carbinoliphilus sp. nov., a benzyl alcohol-oxidizing, sulfate-reducing bacterium isolated from a gas condensate-contaminated aquifer.  

PubMed

Phenotypic and phylogenetic studies were performed on a novel sulfate-reducing bacterium, strain D41(T), isolated as part of a methanogenic syntrophic culture from a gas condensate-contaminated aquifer undergoing intrinsic bioremediation. The bacterium was a Gram-negative, non-spore-forming, curved rod, motile by a single polar flagellum, which oxidized several alcohols incompletely, including methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 3-methyl-1-butanol (isoamyl alcohol), ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, phenylethanol and benzyl alcohol. Additionally, the strain oxidized H(2)/CO(2), formate, lactate, pyruvate, maleate, malate and fumarate. Sulfate, thiosulfate and sulfite were used as electron acceptors. The DNA G+C content was 63 mol%. Based on phylogenetic and phenotypic evidence, the novel species Desulfovibrio carbinoliphilus sp. nov. is proposed. The type strain is D41(T) (=ATCC BAA-1241(T) =DSM 17524(T)). PMID:18523171

Allen, Toby D; Kraus, Paul F; Lawson, Paul A; Drake, Gwendolyn R; Balkwill, David L; Tanner, Ralph S

2008-06-01

335

Many-body force field models based solely on pairwise Coulomb screening do not simultaneously reproduce correct gas-phase and condensed-phase polarizability limits  

NASA Astrophysics Data System (ADS)

It is demonstrated that many-body force field models based solely on pairwise Coulomb screening cannot simultaneously reproduce both gas-phase and condensed-phase polarizability limits. Several many-body force field model forms are tested and compared with basis set-corrected ab initio results for a series of bifurcated water chains. Models are parameterized to reproduce the ab initio polarizability of an isolated water molecule, and pairwise damping functions are set to reproduce the polarizability of a water dimer as a function of dimer separation. When these models are applied to extended water chains, the polarization is over-predicted, and this over-polarization increased as a function of the overlap of molecular orbitals as the chains are compressed. This suggests that polarizable models based solely on pairwise Coulomb screening have some limitations, and that coupling with non-classical many-body effects, in particular exchange terms, may be important.

Giese, Timothy J.; York, Darrin M.

2004-06-01

336

Vertical composition gradient effects on original hydrocarbon in place volumes and liquid recovery for volatile oil and gas condensate reservoirs  

E-print Network

Around the world, volatile oil and retrograde gas reservoirs are considered as complex thermodynamic systems and even more when they exhibit vertical composition variations. Those systems must be characterized by an equation of state (EOS...

Jaramillo Arias, Juan Manuel

2000-01-01

337

Condensation of N bosons. II. Nonequilibrium analysis of an ideal Bose gas and the laser phase-transition analogy  

E-print Network

study the so-called canonical ensemble problem. It describes, in some sense, an intermediate situation as com- pared with the microcanonical ensemble and the grand- canonical ensemble. In the microcanonical ensemble, the gas is completely isolated, E...

Kocharovsky, VV; Scully, Marlan O.; Zhu, S. Y.; Zubairy, M. Suhail

2000-01-01

338

Phenomenological Modeling of Critical Condensate Saturation and  

E-print Network

water satu- ration of 20%. The critical condensate saturation was measured in a vertical dolomite corePhenomenological Modeling of Critical Condensate Saturation and Relative Permeabilities in Gas/ Condensate Systems Kewen Li, SPE, and Abbas Firoozabadi, SPE, Reservoir Engineering Research Inst. Summary

Firoozabadi, Abbas

339

The thermalization, condensation and flickering of photons  

NASA Astrophysics Data System (ADS)

Other than in a three-dimensional thermal photon gas as Planck?s blackbody radiation, photons can exhibit Bose–Einstein condensation, if the thermalization process is restricted to two motional degrees of freedom. This self-contained tutorial describes the thermalization mechanism, the condensation process and the quantum statistics of the photon condensates in detail.

Klaers, Jan

2014-12-01

340

Polyvinyl alcohol battery separator containing inert filler  

NASA Astrophysics Data System (ADS)

A cross-linked polyvinyl alcohol battery separator is disclosed. A particulate filler, inert to alkaline electrolyte of an alkaline battery, is incorporated in the separator in an amount of 1-20% by weight, based on the weight of the polyvinyl alcohol, and is dispersed throughout the product. Incorporation of the filler enhances performance and increases cycle life of alkaline batteries when compared with batteries containing a similar separator not containing filler. Suitable fillers include titanates, silicates, zirconates, aluminates, wood floor, lignin, and titania. Particle size is not greater than about 50 microns.

Sheibley, D. W.; Hsu, L. C.; Manzo, M. A.

1981-06-01

341

Polyvinyl alcohol battery separator containing inert filler  

SciTech Connect

A cross-linked polyvinyl alcohol battery separator is disclosed. A particulate filler, inert to alkaline electrolyte of an alkaline battery, is incorporated in the separator in an amount of 1-20% by weight, based on the weight of the polyvinyl alcohol, and is dispersed throughout the product. Incorporation of the filler enhences performance and increases cycle life of alkaline batteries when compared with batteries containing a similar separator not containing filler. Suitable fillers include titanates, silicates, zirconates, aluminates, wood floor, lignin, and titania. Particle size is not greater than about 50 microns.

Sheibley, D.W.; Hsu, L.C.; Manzo, M.A.

1981-06-01

342

Condensate dark matter stars  

SciTech Connect

We investigate the structure and stability properties of compact astrophysical objects that may be formed from the Bose-Einstein condensation of dark matter. Once the critical temperature of a boson gas is less than the critical temperature, a Bose-Einstein Condensation process can always take place during the cosmic history of the universe. Therefore we model the dark matter inside the star as a Bose-Einstein condensate. In the condensate dark matter star model, the dark matter equation of state can be described by a polytropic equation of state, with polytropic index equal to one. We derive the basic general relativistic equations describing the equilibrium structure of the condensate dark matter star with spherically symmetric static geometry. The structure equations of the condensate dark matter stars are studied numerically. The critical mass and radius of the dark matter star are given by M{sub crit} ? 2(l{sub a}/1fm){sup 1/2}(m{sub ?}/1 GeV){sup ?3/2}M{sub s}un and R{sub crit} ? 1.1 × 10{sup 6}(l{sub a}/1 fm){sup 1/2}(m{sub ?}/1 GeV){sup ?3/2} cm respectively, where l{sub a} and m{sub ?} are the scattering length and the mass of dark matter particle, respectively.

Li, X.Y.; Harko, T.; Cheng, K.S., E-mail: lixinyu@hku.hk, E-mail: harko@hkucc.hku.hk, E-mail: hrspksc@hkucc.hku.hk [Department of Physics and Center for Theoretical and Computational Physics, The University of Hong Kong, Pok Fu Lam Road, Hong Kong (China)

2012-06-01

343

Fundamental insights on impact of non-condensible gas evolution from coating pyrolysis and intentional injection on molten-aluminum water explosion onset during direct-chill casting  

SciTech Connect

Explosive interactions between molten aluminum and water are being studied with a focus on fundamentals to determine what causes robust-enough triggers for explosion onset, to determine the extent of protection provided from various coatings and to develop a fundamentally-based simple, cost-effective novel methodology for prevention. The workscope includes experimentation and mathematical modeling of the interactions between molten metals and water at various different coated and uncoated surfaces. Phenomenological issues related to surface wettability, gas generation from coatings, charring of coatings, inertial constraint, melt temperature, water temperature, external shocks are being investigated systematically to gage their relative impact on the triggerability of surface-assisted steam explosions. The steam explosion triggering studies (SETS) facility was designed and constructed as a rapid-turnaround, cost-effective, and safe means to address these phenomenological issues. Data from SETS tests have indicated that, non-condensible gas (NCG) generation during paint pyrolysis plays a predominant role in explosion prevention. This paper describes results of studies on impact of deliberate NCG injection on explosion prevention, via molten melt drops free-falling into water, as well as from tests using the SETS facility for studying entrapment induced explosive boiling. SETS is also being used to obtain information on time-varying and integral amounts of NCGs generated from various paints. Relevant data are presented. Results of investigations, taken together provide compelling evidence on the positive role NCGs play on explosion prevention.

Taleyarkhan, R.P.; Kim, S.H. [Oak Ridge National Lab., TN (United States); Gulec, K. [Oak Ridge Associated Universities, TN (United States)

1998-05-01

344

Equilibrium condensation in a solar nebula  

NASA Technical Reports Server (NTRS)

In attempts to reconstruct the environment of condensation of solar system materials, particularly exemplified by certain meteorite components, the relative temperatures of the gas and the solid are of critical importance. The relationships that determine the heat balance in a circumsolar grain-gas system are examined. Fundamental considerations show that regardless of opacity or gas density, the gas will always be at a higher temperature than the solid in such regions of the system where condensation is possible. Implications of the characteristic temperature differential between the gas and the condensing solid are discussed.

Arrhenius, G.; De, R. R.

1973-01-01

345

Cement solidification of simulated off-gas condensates from vitrification of low-level nuclear waste solutions  

Microsoft Academic Search

Solidification in a cementitious matrix is a viable alternative for low-level nuclear waste management; it is therefore important to understand the behavior and properties of such wasteforms. We have examined the cementitious solidification of simulated off-gas waste streams resulting from the vitrification of low-level nuclear waste. Different possible methods for scrubbing the off-gasses from a vitrifier give rise to three

A Katz; A. R Brough; R. J Kirkpatrick; L. J Struble; G. K Sun; J. F Young

2001-01-01

346

Resonance-inert stabilization for space stations  

NASA Technical Reports Server (NTRS)

An approach to stabilizing control systems is presented which structures controllers like passive mechanical systems. The controller is visualized as a structural part with a passive behavior similar to springs, dashpots, and masses. If such a controller is connected by a proper feedback arrangement, then a passive mechanical plant cannot upset stability, regardless of masses, resonances, and three-dimensional coupling. The concept of resonance-inert stabilization is explained by structuring the controller of a simple feedback loop. Reactive functions, connections, and matrices are defined and used in the stabilization concept. The realization of a possible Skylab control system is discussed and compared with the present design. This example demonstrates the applicability to three-dimensional problems with lagging controllers.

Vonpragenau, G. L.

1972-01-01

347

Inert anodes and advanced smelting of aluminum  

SciTech Connect

This report provides a broad assessment of open literature and patents that exist in the area of inert anodes and their related cathode systems and cell designs, technologies that are relevant for the advanced smelting of aluminum. The report also discusses the opportunities, barriers, and issued associated with these technologies from a technical, environmental, and economic viewpoint. It discusses the outlook for the direct retrofit of advanced reduction technologies to existing aluminum smelters, and compares retrofits to ''brown field'' usage and ''green field'' adoption of the technologies. A number of observations and recommendations are offered for consideration concerning further research and development efforts that may be directed toward these advanced technologies. The opportunities are discussed in the context of incremental progress that is being made in conventional Hall-Heroult cell systems.

ASME Technical Working Group on Inert Anode Technologies

1999-07-01

348

Dark matter in inert triplet models  

SciTech Connect

We study the inert triplet models, in which the standard model is extended to have a new SU(2){sub L} triplet scalar (Y=0 or 2) with an Z{sub 2} symmetry. We show that the neutral component of the triplet can be a good dark matter candidate. In particular, for the hypercharge Y=0 triplet model, the WMAP data favors the region where the dark matter mass is around 5.5 TeV, which is also consistent with the direct detection experiments. In contrast, for the Y=2 model, although dark matter with its mass around 2.8 TeV is allowed by WMAP, it is excluded by the direct detection experiments because the spin-independent cross section is enhanced by the Z-mediated tree-level scattering process.

Araki, Takeshi [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Geng, C. Q. [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan 300 (China); National Center for Theoretical Sciences, Hsinchu, Taiwan 300 (China); Nagao, Keiko I. [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan 300 (China)

2011-04-01

349

[Genotoxicity of stack gas condensates of Bavarian waste incineration plants. III. Emission monitoring with a simple UDS assay using the human lung cell lines NCI-H 322 and 358].  

PubMed

For the validation of the genotoxicity testing on stack gas condensates from waste incineration plants using bacterial short time tests (15), a modified UDS assay with the lung cell lines NCI-H 322 and 358 was developed. The UDS assay is more sensitive than the SOS chromotest and discriminates better between the negative or weakly positive and the clearly positive samples. It has a high sensitive and specificity and also accuracy, is practicable in a comparatively simple, speedy and reasonably priced manner and is therefore appropriate for an emission monitoring similar to simple bacterial short time tests. Especially in strongly concentrated crude and clean gas condensates, maximal induction factors were seen in the range of strong UDS inducers. From 55 samples on 16 incineration plants tested in the years 1992 to 1995, in 48 we found weak to strong UDS inductions in at least one of the two test cell lines. From three plants examined continuously in this period only two emitted stack gases with constantly low genotoxicity at the end of sampling. 5 clean gas condensates, that were taken in random samples from 3 other plants in the period 1994 to 1995, proved to be non-genotoxic in the UDS assay. However, one of these plants emitted stack gases with high cytotoxicity, which might have masked UDS-inducing single substances. It is not possible to make a statement on the human toxicological relevance. However, a clearly positive development towards more harmless stack gas condensates was established. A definite correlation could not be shown between the chemical analysis of the detected cancerogenic organic single substances of the samples and the detected UDS inductions. Further investigations for finding strong UDS inducers from the substance spectrum of municipal stack gas emissions are necessary. PMID:10084205

Raabe, F; Wichmann, G; Dautzenberg, D; Lierse, C; Zluticky, J; Metzner, G; Mücke, W

1999-02-01

350

Continuous distributions of specific ventilation recovered from inert gas washout  

NASA Technical Reports Server (NTRS)

A new technique is described for recovering continuous distributions of ventilation as a function of tidal ventilation/volume ratio from the nitrogen washout. The analysis yields a continuous distribution of ventilation as a function of tidal ventilation/volume ratio represented as fractional ventilations of 50 compartments plus dead space. The procedure was verified by recovering known distributions from data to which noise had been added. Using an apparatus to control the subject's tidal volume and FRC, mixed expired N2 data gave the following results: (a) the distributions of young, normal subjects were narrow and unimodal; (b) those of subjects over age 40 were broader with more poorly ventilated units; (c) patients with pulmonary disease of all descriptions showed enlarged dead space; (d) patients with cystic fibrosis showed multimodal distributions with the bulk of the ventilation going to overventilated units; and (e) patients with obstructive lung disease fell into several classes, three of which are illustrated.

Lewis, S. M.; Evans, J. W.; Jalowayski, A. A.

1978-01-01

351

33 CFR 157.164 - Use of inert gas system.  

Code of Federal Regulations, 2010 CFR

...TANK VESSELS CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels... (1) Before each cargo tank is crude oil washed, the oxygen content in the...cargo tank with partial bulkheads is crude oil washed, each area of that...

2010-07-01

352

Neuroprotective and neurotoxic properties of the 'inert' gas, xenon  

Microsoft Academic Search

Background. Antagonists of the N-methyl-D-aspartate (NMDA) subtype of glutamate recep- tors have been shown not only to have neuroprotective effects but also to exhibit neurotoxic properties. In this study, we used c-Fos, a protein product of an immediate early gene, as a marker of neuronal injury to compare the neuroprotective effects of xenon and the neurotoxic properties of xenon, nitrous

D. Ma; S. Wilhelm; M. Maze; N. P. Franks

2002-01-01

353

Studying Flammability in a Commercial Transport Fuel Tank with Inerting  

Microsoft Academic Search

As part of the continued emphasis on fuel tank safety, the Federal Aviation Administration (FAA) has developed a demonstration fuel tank inerting system and has tested it on a NASA -operated Boeing 747 aircraft. To support this, the FAA developed two models to predict both fuel tank oxygen concentration and flammability in an inerted ullage, based on pre viously developed

William M. Cavage; Steven M. Summer; Robert I. Ochs; C. E. Polymeropoulos

2005-01-01

354

Electrolytic production of high purity aluminum using ceramic inert anodes  

DOEpatents

A method of producing commercial purity aluminum in an electrolytic reduction cell comprising ceramic inert anodes is disclosed. The method produces aluminum having acceptable levels of Fe, Cu and Ni impurities. The ceramic inert anodes used in the process may comprise oxides containing Fe and Ni, as well as other oxides, metals and/or dopants.

Ray, Siba P. (Murrysville, PA); Liu, Xinghua (Monroeville, PA); Weirauch, Douglas A. (Murrysville, PA); DiMilia, Robert A. (Baton Rouge, LA); Dynys, Joseph M. (New Kensington, PA); Phelps, Frankie E. (Apollo, PA); LaCamera, Alfred F. (Trafford, PA)

2002-01-01

355

Electrolytic production of high purity aluminum using inert anodes  

DOEpatents

A method of producing commercial purity aluminum in an electrolytic reduction cell comprising inert anodes is disclosed. The method produces aluminum having acceptable levels of Fe, Cu and Ni impurities. The inert anodes used in the process preferably comprise a cermet material comprising ceramic oxide phase portions and metal phase portions.

Ray, Siba P. (Murrysville, PA); Liu, Xinghua (Monroeville, PA); Weirauch, Jr., Douglas A. (Murrysville, PA)

2001-01-01

356

Inhibition of hydrogen sulfide, methane, and total gas production and sulfate-reducing bacteria in in vitro swine manure by tannins, with focus on condensed quebracho tannins.  

PubMed

Management practices from large-scale swine production facilities have resulted in the increased collection and storage of manure for off-season fertilization use. Odor and emissions produced during storage have increased the tension among rural neighbors and among urban and rural residents. Production of these compounds from stored manure is the result of microbial activity of the anaerobic bacteria populations during storage. In the current study, the inhibitory effects of condensed quebracho tannins on in vitro swine manure for reduction of microbial activity and reduced production of gaseous emissions, including the toxic odorant hydrogen sulfide produced by sulfate-reducing bacteria (SRB), was examined. Swine manure was collected from a local swine facility, diluted in anaerobic buffer, and mixed with 1 %?w/v fresh feces. This slurry was combined with quebracho tannins, and total gas and hydrogen sulfide production was monitored over time. Aliquots were removed periodically for isolation of DNA to measure the SRB populations using quantitative PCR. Addition of tannins reduced overall gas, hydrogen sulfide, and methane production by greater than 90 % after 7 days of treatment and continued to at least 28 days. SRB population was also significantly decreased by tannin addition. qRT-PCR of 16S rDNA bacteria genes showed that the total bacterial population was also decreased in these incubations. These results indicate that the tannins elicited a collective effect on the bacterial population and also suggest a reduction in the population of methanogenic microorganisms as demonstrated by reduced methane production in these experiments. Such a generalized effect could be extrapolated to a reduction in other odor-associated emissions during manure storage. PMID:23149758

Whitehead, Terence R; Spence, Cheryl; Cotta, Michael A

2013-09-01

357

A plagioclase-olivine-spinel-magnetite inclusion from Maralinga (CK): evidence for sequential condensation and solid-gas exchange  

NASA Astrophysics Data System (ADS)

We report a detailed petrography, mineral chemistry, and trace element study of MaTroc, a large calcium-aluminum-rich inclusion (CAI) (5 × 2.5 mm) of irregular triangular shape. The inclusion has a zonal structure: The core consists of a porous plagioclase-olivine-Ca-rich pyroxene intergrowth with subordinate apatite. Its texture is meta-gabbro-like, similar to other plagioclase-olivine inclusions (POIs). The mantle has variable thickness (0.1-1.5 mm) and consists of a compact symplectitic intergrowth of spinel (hercynite) and plagioclase with abundant dispersed magnetite, subordinate Ca-rich pyroxene, and traces of sulfides. The thin (5-50 ?m) discontinuous crust of MaTroc consists mainly of plagioclase with some olivine and magnetite. The Mg-Fe phases of MaTroc are Fe-rich: olivine has Fa33.2 and high NiO content, similar to that in the host rock, Ca-rich pyroxene has much lower TiO 2 and Cr 2O 3 contents than that of the host chondrite, and plagioclase is An55-An74. Magnetites have variable compositions, are poorer in Al 2O 3 and Cr 2O 3 and richer in NiO than those in the host. Spinels have also variable compositions, rich in FeO, NiO, and ZnO. Despite their different mineralogy, both core and mantle have bulk trace element abundances similar to those in average group II CAIs. However, the mantle is richer in Nb and U and poorer in Eu, Be, B, Sr, and Li than the core. All minerals have high trace element contents. Minerals in the core show signs of incomplete equilibration of trace elements within and between them. Mantle minerals are far from equilibrium with each other and the bulk system. Spinel and anorthite carry the trace element signature of their precursor melilite (or hibonite), and magnetite contains large amounts of a heterogeneously distributed remnant extremely rich in trace elements ("obscurite"), possibly of a former perovskite. Inclusion MaTroc has a complex history. The POI core probably formed by reaction of an unknown precursor(s) of condensation origin with a vapor to form olivine, plagioclase, clinopyroxene, apatite, and (an) unknown phase(s) that vanished, leaving abundant void space. The spinel-rich mantle is also a secondary mineral assemblage that formed by breakdown of and solid-vapor reactions with a precursor or precursors, possibly melilite (or hibonite). The abundant magnetite formed by reaction of perovskite with an oxidizing vapor and by precipitation from such a vapor. All phases of the inclusion experienced the metasomatic addition of Fe, Ni, and moderately volatile elements such as V, Be, Li, Cr, and Mn - similar to all other constituents of the Maralinga CK chondrite. Phases in MaTroc and in the host rock are close to equilibrium in the distribution of Fe, Mg, Ni, and Mn but far from equilibrium in the distribution of M +3 and M +4 ions. The minor and trace element abundances in the magnetite of the host rock and of MaTroc preclude an origin by oxidation of a metal precursor.

Kurat, Gero; Zinner, Ernst; Brandstätter, Franz

2002-09-01

358

Photochemical activity of Titan’s low-altitude condensed haze  

NASA Astrophysics Data System (ADS)

Titan, the largest moon of Saturn and similar to Earth in many aspects, has unique orange-yellow colour that comes from its atmospheric haze, whose formation and dynamics are far from well understood. Present models assume that Titan’s tholin-like haze formation occurs high in atmosphere through gas-phase chemical reactions initiated by high-energy solar radiation. Here we address an important question: Is the lower atmosphere of Titan photochemically active or inert? We demonstrate that indeed tholin-like haze formation could occur on condensed aerosols throughout the atmospheric column of Titan. Detected in Titan’s atmosphere, dicyanoacetylene (C4N2) is used in our laboratory simulations as a model system for other larger unsaturated condensing compounds. We show that C4N2 ices undergo condensed-phase photopolymerization (tholin formation) at wavelengths as long as 355?nm pertinent to solar radiation reaching a large portion of Titan’s atmosphere, almost close to the surface.

Gudipati, Murthy S.; Jacovi, Ronen; Couturier-Tamburelli, Isabelle; Lignell, Antti; Allen, Mark

2013-04-01

359

Condensation polyimides  

NASA Technical Reports Server (NTRS)

Polyimides belong to a class of polymers known as polyheterocyclics. Unlike most other high temperature polymers, polyimides can be prepared from a variety of inexpensive monomers by several synthetic routes. The glass transition and crystalline melt temperature, thermooxidative stability, toughness, dielectric constant, coefficient of thermal expansion, chemical stability, mechanical performance, etc. of polyimides can be controlled within certain boundaries. This versatility has permitted the development of various forms of polyimides. These include adhesives, composite matrices, coatings, films, moldings, fibers, foams and membranes. Polyimides are synthesized through both condensation (step-polymerization) and addition (chain growth polymerization) routes. The precursor materials used in addition polyimides or imide oligomers are prepared by condensation method. High molecular weight polyimide made via polycondensation or step-growth polymerization is studied. The various synthetic routes to condensation polyimides, structure/property relationships of condensation polyimides and composite properties of condensation polyimides are all studied. The focus is on the synthesis and chemical structure/property relationships of polyimides with particular emphasis on materials for composite application.

Hergenrother, P. M.

1989-01-01

360

Agglomeration of Ni-nanoparticles in the gas phase under gravity and microgravity conditions  

NASA Astrophysics Data System (ADS)

The agglomeration of metallic nanoparticles can be performed using the well-known inert gas condensation process. Unfortunately, thermal effects such as convection are created by the heating source and as a result the turbulent aerosol avoids ideal conditions. In addition, the sedimentation of large particles and/or agglomerates influences the self-assembly of particles. These negative effects can be eliminated by using microgravity conditions. Here we present the results of the agglomeration of nanoscale Ni-particles under gravity and microgravity conditions, the latter provided by adapted microgravity platforms namely the European sounding rocket MAXUS 8 and the European Parabolic Flight aircraft, Airbus A300 Zero-G.

Lösch, S.; Iles, G. N.; Schmitz, B.; Günther, B. H.

2011-12-01

361

Behavior of Fission Products in YSZ-Based Inert Matrix Fuel  

SciTech Connect

Pu disposal has led to increased interest in the possibility of ''burning'' actinides in inert-matrix fuels. Yttria-stabilized cubic zirconia (YSZ) is a promising candidate material. The effects of fission product incorporation on the microstructure of YSZ (with 9.5 mol% of yttria) were investigated by ion implantation (using 70- to 440-keV Cs{sup +}, Sr{sup +}, and I{sup +} ions) and transmission electron microscopy (TEM) in order to evaluate the material's performance as both an inert fuel matrix and a nuclear waste form. It was found that incorporation of an excess amount of cesium (>8 at.%) at room temperature causes amorphization of the cubic zirconia structure, which may lead to a higher leaching rate in the waste repository. On the other hand, iodine and strontium precipitate out in gas bubbles or secondary phases, respectively, at elevated temperature, leading to a lower release rate of the radionuclides.

Wang, L.M.; Zhu, S.; Ewing, R.C.

2001-06-17

362

Distribution of inert gases in fines from the Cayley-Descartes region  

NASA Technical Reports Server (NTRS)

The inert gases in 14 different fines and in one sample of 2 to 4 mm fines from Apollo 16 were measured by mass spectroscopy with respect to trapped solar wind gases, cosmogenic gases, and 'parentless' Ar-40. Such studies are helpful for the understanding of regolith evolution, of transport of regolith fines, and of the lunar atmosphere. The Apollo 16 soils are unique because they represent, after Luna 20, the second and much more extensive record from the lunar highlands. The landing site presents the problem of materials from the Cayley Formation vs those from the Descartes Formation. There are two large, relatively fresh craters in the area, North Ray and South Ray, whose ejecta patterns may be recognized in the inert-gas record.

Walton, J. R.; Lakatos, S.; Heymann, D.

1973-01-01

363

Growth and development in inert non-aqueous liquids. [of higher plants  

NASA Technical Reports Server (NTRS)

A preview is presented of the survival and growth capabilities of higher plants in non-aqueous, inert liquids. The two media which were used are mineral (white) oil and fluorochemical inert liquid FC-75. Both liquids dissolve oxygen and carbon dioxide readily, but are insoluble in water. Consequently, plants submerged in these liquids are capable of gas exchange with the atmosphere, but possess a water impermeable coating the dimensions of which are determined by the size of the liquid holding container. In a sense, growing plants in a tank of mineral oil imparts on them a cuticle. Plants plus prescribed volumes of water were innoculated into mineral oil. Organisms with minimal water supplied could then be observed. Also, submersed plants covered with an oil slick were shown to be capable of growth in dessicating atmospheres.

Siegel, S. M.

1974-01-01

364

Improved Back-Side Purge-Gas Chambers For Plasma Arc Welding  

NASA Technical Reports Server (NTRS)

Improved chambers for inert-gas purging of back sides of workpieces during plasma arc welding in keyhole (full-penetration) mode based on concept of directing flows of inert gases toward, and concentrating them on, hot weld zones. Tapered chamber concentrates flow of inert gas on plasma arc plume and surrounding metal.

Ezell, Kenneth G.; Mcgee, William F.; Rybicki, Daniel J.

1995-01-01

365

Technical basis for storage of Zircaloy-clad spent fuel in inert gases  

SciTech Connect

This report summarizes the technical bases to establish safe conditions for dry storage of Zircaloy-clad fuel. Dry storage of fuel with zirconium alloy cladding has been licensed in Canada, the Federal Republic of Germany, and Switzerland. In addition, dry storage demonstrations, hot cell tests, and modeling have been conducted using Zircaloy-clad fuel. The demonstrations have included irradiated boiling water reactor, pressurized heavy-water reactor, and pressurized water reactor (PWR) fuel assemblies. Irradiated fuel has been emplaced in and retrieved from metal casks, dry wells, silos, and a vault. Dry storage tests and demonstrations have involved {similar_to}5,000 fuel rods, and {similar_to}600 rods have been monitored during dry storage in inert gases with maximum cladding temperatures ranging from 50 to 570{sup 0}C. Although some tests and demonstrations are still in progress, there is currently no evidence that any rods exposed to inert gases have failed (one PWR rod exposed to an air cover gas failed at {similar_to}70{sup 0}C). Based on this favorable experience, it is concluded that there is sufficient information on fuel rod behavior, storage conditions, and potential cladding failure mechanisms to support licensing of dry storage in the United States. This licensing position includes a requirement for inert cover gases and a maximum cladding temperature guideline of 380{sup 0}C for Zircaloy-clad fuel. Using an inert cover gas assures that even if fuel with cladding defects were placed in dry storage, or if defects develop during storage, the defects would not propagate. Tests and demonstrations involving Zircaloy-clad rods and assemblies with maximum cladding temperatures above 400{sup 0}C are in progress. When the results from these tests have been evaluated, the viability of higher temperature limits should be examined. Acceptable conditions for storage in air and dry storage of consolidated fuel are issues yet to be resolved.

Johnson, A.B. Jr.; Gilbert, E.R.

1983-09-01

366

40 CFR 174.705 - Inert ingredients from sexually compatible plant.  

Code of Federal Regulations, 2014 CFR

...Inert ingredients from sexually compatible plant. 174.705 Section 174.705 Protection...PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS List of Approved...Inert ingredients from sexually compatible plant. An inert ingredient, and...

2014-07-01

367

40 CFR 174.705 - Inert ingredients from sexually compatible plant.  

Code of Federal Regulations, 2013 CFR

...Inert ingredients from sexually compatible plant. 174.705 Section 174.705 Protection...PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS List of Approved...Inert ingredients from sexually compatible plant. An inert ingredient, and...

2013-07-01

368

40 CFR 174.705 - Inert ingredients from sexually compatible plant.  

Code of Federal Regulations, 2012 CFR

...Inert ingredients from sexually compatible plant. 174.705 Section 174.705 Protection...PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS List of Approved...Inert ingredients from sexually compatible plant. An inert ingredient, and...

2012-07-01

369

75 FR 7560 - Public Availability of Identities of Inert Ingredients in Pesticides; Extension of Comment Period  

Federal Register 2010, 2011, 2012, 2013, 2014

...FRL-8813-3] Public Availability of Identities of Inert Ingredients in Pesticides...increase public availability of the identities of the inert ingredients in pesticide...increase public availability of the identities of the inert ingredients in...

2010-02-22

370

Dropwise condensation  

PubMed Central

Dropwise condensation of water vapor from a naturally cooling, hot water reservoir onto a hydrophobic polymer film and a silanized glass slide was studied by direct observation and simulations. The observed drop growth kinetics suggest that smallest drops grow principally by the diffusion of water adsorbed on the substrate to the drop perimeter, while drops larger than 50 ?m in diameter grow principally by direct deposition from the vapor onto the drop surface. Drop coalescence plays a critical role in determining the drop size distribution, and stimulates the nucleation of new, small drops on the substrates. Simulations of drop growth incorporating these growth mechanisms provide a good description of the observed drop size distribution. Because of the large role played by coalescence, details of individual drop growth make little difference to the final drop size distribution. The rate of condensation per unit substrate area is especially high for the smallest drops, and may help account for the high heat transfer rates associated with dropwise condensation relative to filmwise condensation in heat exchange applications. PMID:17014129

Leach, R. N.; Stevens, F.; Langford, S. C.; Dickinson, J. T.

2008-01-01

371

Preliminary Design Report Shippingport Spent Fuel Drying and Inerting System  

SciTech Connect

A process description and system flow sheets have been prepared to support the design/build package for the Shippingport Spent Fuel Canister drying and inerting process skid. A process flow diagram was prepared to show the general steps to dry and inert the Shippingport fuel loaded into SSFCs for transport and dry storage. Flow sheets have been prepared to show the flows and conditions for the various steps of the drying and inerting process. Calculations and data supporting the development of the flow sheets are included.

JEPPSON, D.W.

2000-05-18

372

Gas shielding apparatus  

DOEpatents

An apparatus is disclosed for preventing oxidation by uniformly distributing inert shielding gas over the weld area of workpieces such as pipes being welded together. The apparatus comprises a chamber and a gas introduction element. The chamber has an annular top wall, an annular bottom wall, an inner side wall and an outer side wall connecting the top and bottom walls. One side wall is a screen and the other has a portion defining an orifice. The gas introduction element has a portion which encloses the orifice and can be one or more pipes. The gas introduction element is in fluid communication with the chamber and introduces inert shielding gas into the chamber. The inert gas leaves the chamber through the screen side wall and is dispersed evenly over the weld area. 3 figs.

Brandt, D.

1985-12-31

373

Gas shielding apparatus  

DOEpatents

An apparatus for preventing oxidation by uniformly distributing inert shielding gas over the weld area of workpieces such as pipes being welded together. The apparatus comprises a chamber and a gas introduction element. The chamber has an annular top wall, an annular bottom wall, an inner side wall and an outer side wall connecting the top and bottom walls. One side wall is a screen and the other has a portion defining an orifice. The gas introduction element has a portion which encloses the orifice and can be one or more pipes. The gas introduction element is in fluid communication with the chamber and introduces inert shielding gas into the chamber. The inert gas leaves the chamber through the screen side wall and is dispersed evenly over the weld area.

Brandt, Daniel (Los Alamos, NM)

1985-01-01

374

Gas shielding apparatus  

DOEpatents

An apparatus for preventing oxidation by uniformly distributing inert shielding gas over the weld area of workpieces such as pipes being welded together. The apparatus comprises a chamber and a gas introduction element. The chamber has an annular top wall, an annular bottom wall, an inner side wall and an outer side wall connecting the top and bottom walls. One side wall is a screen and the other has a portion defining an orifice. The gas introduction element has a portion which encloses the orifice and can be one or more pipes. The gas introduction element is in fluid communication with the chamber and introduces inert shielding gas into the chamber. The inert gas leaves the chamber through the screen side wall and is dispersed evenly over the weld area.

Brandt, D.

1984-06-05

375

Results from electrolysis test of a prototype inert anode: Inert Electrode Program  

SciTech Connect

Nonconsumable or inert anodes are being developed at the Pacific Northwest Laboratory (PNL)({sup a}) for use in the electrolytic production of aluminum. A series of laboratory test on the laboratory scale (Hart et al. 1987; Strachan et al. 1989; Marschman 1989) has shown the technology to be potentially feasible. A series of larger-scale experiments are now being run to determine the viability of the technology on a commercial scale. The results reported here are from a test performed at the Reynolds Metals Company, Manufacturing Technology Laboratory, Sheffield, Alabama, using a prototype anode. The prototype anode was approximately 15 cm in diameter and 20 cm high (Figure 1.1). The objectives of the test were to determine if an anode, produced by a commercial vendor, could survive in a test under conditions approximating those found in a commercial electrolysis cell; to familiarize the Reynolds staff with the operation of such an anode in a subsequent pilot cell test of the inert anode technology; and to familiarize the PNL staff with the operations at the Reynolds Metals Company facility. 8 refs., 39 figs., 9 tabs.

Strachan, D.M.; Windisch, C.F. Jr.; Koski, O.H.; Morgan, L.G. (Pacific Northwest Lab., Richland, WA (USA)); Peterson, R.D.; Richards, N.E.; Tabereaux, A.T. (Reynolds Metals Co., Sheffield, AL (USA). Mfg. Technology Lab.)

1990-05-01

376

High-Performance Air Cooling Condenser With Liquid-Vapor Separation  

Microsoft Academic Search

In this investigation, an innovative idea was introduced to design a new kind of high-performance air cooling condensers. This kind of condenser functions to automatically separate liquid from gas and makes condensation always occur in droplet and unsteady thin film condensation mode everywhere in the whole condenser, which results in very high average heat transfer coefficient. An introduction is presented

Di Wu; Zhen Wang; Gui Lu; Xiaofeng Peng

2010-01-01

377

Numerical evaluation of contact and hybrid condensers for geothermal power plants  

Microsoft Academic Search

-The transport and partitioning of gases in two contact condensers in use at The Geysers has been modelled numerically. Improvements on these designs have been investigated. Adding a surface type vent condenser between the main condenser and the first stage gas ejectors improves hydrogen sulphide partitioning dramatically. This ''hybrid condenser'' can match the performance of a surface condenser. Adding a

O WERES

1984-01-01

378

Analyzing the safety impact of containment inerting at Vermont Yankee  

E-print Network

Post-accident hydrogen generation in BWR containments is analyzed as a function of engineered hydrogen control system, assumed either nitrogen inerting or air dilution. Fault tree analysis was applied to assess the failure ...

Heising, Carolyn D. (Carolyn DeLane), 1952-

1980-01-01

379

Inert electrodes program: Fiscal Year 1987 Annual Report  

SciTech Connect

The Inert Electrodes Program is being conducted at the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE), Office of Industrial Programs (OIP). The purpose of the program is to develop long-lasting, energy-efficient anodes, cathodes, and ancillary equipment for Hall-Heroult cells used by aluminum industry. The program is divided into three tasks with the following objectives: Inert Anode Development - to improve the energy efficiency of Hall-Heroult cells by development of inert anodes; Stable Cathode Studies - to develop methods for retrofitting Hall-Heroult cells with TiB/sub 2/-based cathode materials; and Sensor Development - to devise sensors to control the chemistry of Hall-Heroult Cells using stable anodes and cathodes. This Inert Electrodes Program annual report highlights the major technical accomplishment of FY 1987. The accomplishments are presented in the following sections: Management, Materials Development and Testing, Materials Evaluation, Stable Cathode Studies, and Sensor Development. 50 refs., 47 figs.

Koski, O.H.; Marschman, S.C.; Schilling, C.H.; Windisch, C.F.

1988-12-01

380

Fractionation in the solar nebula - Condensation of yttrium and the rare earth elements  

Microsoft Academic Search

The condensation of Y and the rare earth elements (REE) from the solar nebula may be controlled by thermodynamic equilibrium between gas and condensed solids. Highly fractionated REE patterns may result if condensates are removed from the gas before condensation is complete. It is found that the fractionation is not a smooth function of REE ionic radius but varies in

W. V. Boynton

1975-01-01

381

The inert doublet model of dark matter revisited  

Microsoft Academic Search

The inert doublet model, a minimal extension of the Standard Model by a second higgs doublet with no direct couplings to quarks\\u000a or leptons, is one of the simplest scenarios that can explain the dark matter. In this paper, we study in detail the impact\\u000a of dark matter annihilation into the three-body final state on the phenomenology of the inert

Laura Lopez Honorez; Carlos E. Yaguna

2010-01-01

382

Simple Techniques For Assessing Impacts Of Oil And Gas Operations On Public Lands: A Field Evaluation Of A Photoionization Detector (PID) At A Condensate Release Site, Padre Island National Seashore, Texas  

USGS Publications Warehouse

Simple, cost-effective techniques are needed for land managers to assess the environmental impacts of oil and gas production activities on public lands, so that sites may be prioritized for remediation or for further, more formal assessment. Field-portable instruments provide real-time data and allow the field investigator to extend an assessment beyond simply locating and mapping obvious disturbances. Field investigators can examine sites for the presence of hydrocarbons in the subsurface using a soil auger and a photoionization detector (PID). The PID measures volatile organic compounds (VOC) in soil gases. This allows detection of hydrocarbons in the shallow subsurface near areas of obvious oil-stained soils, oil in pits, or dead vegetation. Remnants of a condensate release occur in sandy soils at a production site on the Padre Island National Seashore in south Texas. Dead vegetation had been observed by National Park Service personnel in the release area several years prior to our visit. The site is located several miles south of the Malaquite Beach Campground. In early 2001, we sampled soil gases for VOCs in the area believed to have received the condensate. Our purpose in this investigation was: 1) to establish what sampling techniques might be effective in sandy soils with a shallow water and contrast them with techniques used in an earlier study; and 2) delineate the probable area of condensate release. Our field results show that sealing the auger hole with a clear, rigid plastic tube capped at the top end and sampling the soil gas through a small hole in the cap increases the soil VOC gas signature, compared to sampling soil gases in the bottom of an open hole. This sealed-tube sampling method increases the contrast between the VOC levels within a contaminated area and adjacent background areas. The tube allows the PID air pump to draw soil gas from the volume of soil surrounding the open hole below the tube in a zone less influenced by atmospheric air. In an open hole, the VOC readings seem to be strongly dependent on the degree of diffusion and advection of soil gas VOCs into the open hole from the surrounding soil, a process that may vary with soil and wind conditions. Making measurements with the sealed hole does take some additional time (4-7 minutes after the hole is augered) compared to the open-hole technique (1-2 minutes). We used the rigid-plastic tube technique to survey for soil gas VOCs across the entire site, less than ? acre. Condensate has impacted at least 0.28 acres. The impacted area may extend northwest of the surveyed area.

Otton, James K.; Zielinski, Robert A.

2001-01-01

383

Process and apparatus for igniting a burner in an inert atmosphere  

DOEpatents

According to this invention there is provided a process and apparatus for the ignition of a pilot burner in an inert atmosphere without substantially contaminating the inert atmosphere. The process includes the steps of providing a controlled amount of combustion air for a predetermined interval of time to the combustor then substantially simultaneously providing a controlled mixture of fuel and air to the pilot burner and to a flame generator. The controlled mixture of fuel and air to the flame generator is then periodically energized to produce a secondary flame. With the secondary flame the controlled mixture of fuel and air to the pilot burner and the combustion air is ignited to produce a pilot burner flame. The pilot burner flame is then used to ignited a mixture of main fuel and combustion air to produce a main burner flame. The main burner flame then is used to ignite a mixture of process derived fuel and combustion air to produce products of combustion for use as an inert gas in a heat treatment process.

Coolidge, Dennis W. (Katy, TX); Rinker, Franklin G. (Perrysburg, OH)

1994-01-01

384

Polariton condensates  

SciTech Connect

Most students of physics know about the special properties of Bose-Einstein condensates (BECs) as demonstrated in the two best-known examples: superfluid helium-4, first reported in 1938, and condensates of trapped atomic gases, first observed in 1995. (See the article by Wolfgang Ketterle in PHYSICS TODAY, December 1999, page 30.) Many also know that superfluid {sup 3}He and superconducting metals contain BECs of fermion pairs. An underlying principle of all those condensed-matter systems, known as quantum fluids, is that an even number of fermions with half-integer spin can be combined to make a composite boson with integer spin. Such composite bosons, like all bosons, have the property that below some critical temperature--roughly the temperature at which the thermal de Broglie wavelength becomes comparable to the distance between the bosons--the total free energy is minimized by having a macroscopic number of bosons enter a single quantum state and form a macroscopic, coherent matter wave. Remarkably, the effect of interparticle repulsion is to lead to quantum mechanical exchange interactions that make that state robust, since the exchange interactions add coherently.

Snoke, David; Littlewood, Peter [University of Pittsburgh, Pennsylvania (United States); University of Cambridge (United Kingdom)

2010-08-15

385

46 CFR 153.964 - Discharge by gas pressurization.  

Code of Federal Regulations, 2010 CFR

...not authorize cargo discharge by gas pressurization unless: ...or a nonflammable, nontoxic gas inert to the cargo; and ...tank; or (2) For an inert gas medium: (i) A safety relief valve with a cross sectional flow area at least equal to that of...

2010-10-01

386

Extractive stripping of inert-rich hydrocarbon gases with a preferential physical solvent  

SciTech Connect

A process is described for treating a natural gas stream containing methane, heavier hydrocarbons, and an inert gas, an improvement comprising: selectivity extracting natural gas liquids from the natural gas stream with a preferential physical solvent which provides selective capability for recovery according to the selected degree of: (a) ethane in amounts ranging from 2-98%, (b) propane in amounts ranging from 2-99%, (c) butanes in amounts ranging from 2-100%, or (d) pentanes and higher molecular weight hydrocarbons in amounts ranging up to 100%, the improvement comprising the following steps: A. selecting the preferential physical solvent which is selective for ethane and heavier hydrocarbon components of the gas stream such that: (1) relative volatility of methane over ethane is at least 5.0 and the hydrocarbon loading capacity, defined as solubility of ethane in the solvent, is at least 0.25 standard cubic feet of ethane per gallon of the solvent, or (2) the preferential factor, determined by the multiplication of relative volatility of methane over ethane by the solubility of ethane in solvent, in standard cubic feet of ethane per gallon of solvent, is at least 1.25; B. selectively extracting and stripping the natural gas stream with the physical solvent to produce an inert gas stream and a rich solvent stream containing methane and the hydrocarbons heavier than methane; and C. distilling the rich solvent stream to produce a stream vent to form a solution having a molar ratio of silicon alkoxide to water in the range of about 1 to about 10.

Mehra, Y.R.

1987-07-14

387

Cosmological tachyon condensation  

SciTech Connect

We consider the prospects for dark matter/energy unification in k-essence type cosmologies. General mappings are established between the k-essence scalar field, the hydrodynamic and braneworld descriptions. We develop an extension of the general relativistic dust model that incorporates the effects of both pressure and the associated acoustic horizon. Applying this to a tachyon model, we show that this inhomogeneous 'variable Chaplygin gas' does evolve into a mixed system containing cold dark matter like gravitational condensate in significant quantities. Our methods can be applied to any dark energy model, as well as to mixtures of dark energy and traditional dark matter.

Bilic, Neven; Tupper, Gary B.; Viollier, Raoul D. [Rudjer Boskovic Institute, 10002 Zagreb (Croatia); Centre of Theoretical Physics and Astrophysics, University of Cape Town, Rondebosch 7701 (South Africa)

2009-07-15

388

Optimizing Steam & Condensate System: A Case Study  

E-print Network

Optimization of Steam & Condensate systems in any process plant results in substantial reduction of purchased energy cost. During periods of natural gas price hikes, this would benefit the plant in controlling their fuel budget significantly...

Venkatesan, V. V.; Norris, C.

2011-01-01

389

Condensation coefficient of water in a weak condensation state  

NASA Astrophysics Data System (ADS)

The condensation coefficient of water at a vapor-liquid interface is determined by combining shock tube experiments and numerical simulations of the Gaussian-BGK Boltzmann equation. The time evolution in thickness of a liquid film, which is formed on the shock tube endwall behind the shock wave reflected at the endwall, is measured with an optical interferometer consisting of the physical beam and the reference one. The reference beam is utilized to eliminate systematic noises from the physical beam. The growth rate of the film is evaluated from the measured time evolution and it is incorporated into the kinetic boundary condition for the Boltzmann equation. From a numerical simulation using the boundary condition, the condensation coefficient of water is uniquely deduced. The results show that, in a condition of weak condensation near a vapor-liquid equilibrium state, the condensation coefficient of water is almost equal to the evaporation coefficient estimated by molecular dynamics simulations near a vapor-liquid equilibrium state and it decreases as the system becomes a nonequilibrium state. The condensation coefficient of water is nearly identical with that of methanol [Mikami, S., Kobayashi, K., Ota, T., Fujikawa, S., Yano, T., Ichijo, M., 2006. Molecular gas dynamics approaches to interfacial phenomena accompanied with condensation. Exp. Therm. Fluid Sci. 30, 795-800].

Kobayashi, Kazumichi; Watanabe, Shunsuke; Yamano, Daigo; Yano, Takeru; Fujikawa, Shigeo

2008-07-01

390

Bose-Einstein condensate strings  

NASA Astrophysics Data System (ADS)

We consider the possible existence of gravitationally bound general relativistic strings consisting of Bose-Einstein condensate (BEC) matter which is described, in the Newtonian limit, by the zero temperature time-dependent nonlinear Schrödinger equation (the Gross-Pitaevskii equation), with repulsive interparticle interactions. In the Madelung representation of the wave function, the quantum dynamics of the condensate can be formulated in terms of the classical continuity equation and the hydrodynamic Euler equations. In the case of a condensate with quartic nonlinearity, the condensates can be described as a gas with two pressure terms, the interaction pressure, which is proportional to the square of the matter density, and the quantum pressure, which is without any classical analogue, though, when the number of particles in the system is high enough, the latter may be neglected. Assuming cylindrical symmetry, we analyze the physical properties of the BEC strings in both the interaction pressure and quantum pressure dominated limits, by numerically integrating the gravitational field equations. In this way we obtain a large class of stable stringlike astrophysical objects, whose basic parameters (mass density and radius) depend sensitively on the mass and scattering length of the condensate particle, as well as on the quantum pressure of the Bose-Einstein gas.

Harko, Tiberiu; Lake, Matthew J.

2015-02-01

391

Diffusion layer theory for turbulent vapor condensation with noncondensable gases  

SciTech Connect

In turbulent condensation with noncondensable gas, a thin noncondensable layer accumulates and generates a diffusional resistance to condensation and sensible heat transfer. By expressing the driving potential for mass transfer as a difference in saturation temperatures and using appropriate thermodynamic relationships, here an effective [open quotes]condensation[close quotes] thermal conductivity is derived. With this formulation, experimental results for vertical tubes and plates demonstrate that condensation obeys the heat and mass transfer analogy, when condensation and sensible heat transfer are considered simultaneously. The sum of the condensation and sensible heat transfer coefficients becomes infinite at small gas concentrations, and approaches the sensible heat transfer coefficient at large concentrations. The [open quotes]condensation[close quotes] thermal conductivity is easily applied to engineering analysis, and the theory further demonstrates that condensation on large vertical surfaces is independent of the surface height. 19 refs., 6 figs., 1 tab.

Peterson, P.F.; Schrock, V.E.; Kageyama, T. (Univ. of California, Berkeley, CA (United States))

1993-11-01

392

Inert Gas Buffered Milling and Particle Size Separation of Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?¯Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?Â?Ã?­m-Scale Superconducting Precursor Powders - Final Report  

SciTech Connect

The project developed an aerosol system for the met milling and particle size separation of the precursor powders used in fabrication of powder-in-tube superconductors. The work builds upon the results of a previous SBIR-funded development that proved the basic principles of the virtual impactor (VI) technology and its efficacy for the powders of interest. The new project extended that work in three respects: it integrated provisions for recirculating the aerosol flow using inert gas to avoid contamination from O2, CO2 and water in ambient air; a quad configuration of VI subassemblies to support kg/hr throughput; and it incorporated design features that eliminate error trajectories which would introduce trace contamination of larger particles into the separated flow. The project demonstrated the technical effectiveness of the process and established its economic feasibility by achieving kg/hr throughput within a cost profile that would be profitable within the range of competitive toll fees. The project is beneficial to the public through its potential to improve the performance of superconducting materials for research and for biomedicine. It also conveys potential benefits for powders used in high-performance ceramics (for example for engines for automobiles and for aircraft) and for high-performance electrical insulators for telecommunications circuitry.

P. McIntyre and S. Seshadri

2008-06-20

393

Bose-Einstein Condensation of Lithium: Observation of Limited Condensate Number  

Microsoft Academic Search

Bose-Einstein condensation of ⁷Li has been studied in a magnetically trapped gas. Because of the effectively attractive interactions between ⁷Li atoms, many-body quantum theory predicts that the occupation number of the condensate is limited to about 1400atoms. We observe the condensate number to be limited to a maximum value between 650 and 1300atoms. The measurements were made using a versatile

C. C. Bradley; C. A. Sackett; R. G. Hulet

1997-01-01

394

Understanding Condensation  

NSDL National Science Digital Library

Monica Hartman, Assistant Director for Science in St. Clair County, Michigan, conducted this research while she was the learning specialist in a small suburban district just outside a large Midwestern city. While teaching full time in this district she was also completing her doctoral program in education at the University of Michigan. In this chapter, she tells the story of a "science talk" about condensation among fifth graders. She acted as a source and facilitator of change as she and the fifth-grade teacher worked collaboratively to help students share responsibility for their own learning. She describes their continual assessment of student understanding that occurred as their students struggled to explain observations and as they, the teachers, carefully resisted the temptation to end the struggle by saying "that's right!"

Monica Hartman

2007-12-01

395

Hydrocarbon gas separation  

SciTech Connect

A cryogenic process for separating methane from ethane and heavier hydrocarbons in which a high pressure gas feed is divided into two gas streams. The gas is cooled either before or after it is divided and this step may include some condensation in which case the condensate is separated from the gas. One of the divided gas streams is expanded through a work expansion machine down to the pressure of the fractionation column. Any separated condensate is also expanded to the column pressure. The second divided gas stream is further cooled by heat exchange and then expanded down to an intermediate pressure whereby a portion is condensed. This condensate is separated from the remaining gas and then expanded to the column pressure. The remaining gas is further cooled and expanded and fed to the column as the top feed.

Huebel, R. R.

1985-05-28

396

Inert Electrodes Program fiscal year 1988 annual report  

SciTech Connect

The Inert Electrodes Program, being conducted by Pacific Northwest Laboratory (PNL), involves improving the Hall-Heroult cells used by the Aluminum Industry for the electrochemical production of aluminum. The PNL research centers on developing more energy efficient, longer-lasting anodes and cathodes and ancillary equipment. Major accomplishments for Fiscal Year 1988 are summarized below. 14 refs., 56 figs., 9 tabs.

Strachan, D.M.; Marschman, S.C.; Davis, N.C.; Friley, J.R.; Schilling, C.H.

1989-10-01

397

Constraints on inert dark matter from metastability of electroweak vacuum  

E-print Network

Inert scalar doublet model of dark matter can be valid upto the Planck scale. We briefly review the bounds on the model in such a scenario and identify parameter spaces that lead to absolute stability and metastability of the electroweak vacuum.

Khan, Najimuddin

2015-01-01

398

Dark matter with two inert doublets plus one Higgs doublet  

NASA Astrophysics Data System (ADS)

Following the discovery of a Higgs boson, there has been renewed interest in the general 2-Higgs-Doublet Model (2HDM). A model with One Inert Doublet plus One Higgs Doublet (I(1+1)HDM), where one of the scalar doublets is "inert" (since it has no vacuum expectation value and does not couple to fermions) has an advantage over the 2HDM since it provides a good Dark Matter (DM) candidate, namely the lightest inert scalar. Motivated by the existence of three fermion families, here we consider a model with two scalar doublets plus one Higgs doublet (I(2+1)HDM), where the two scalar doublets are inert. The I(2+1)HDM has a richer phenomenology than either the I(1+1)HDM or the 2HDM. We discuss the new regions of DM relic density in the I(2+1)HDM with simplified couplings and address the possibility of constraining the model using recent results from the Large Hadron Collider (LHC) and DM direct detection experiments.

Keus, Venus; King, Stephen F.; Moretti, Stefano; Sokolowska, Dorota

2014-11-01

399

Impedance Measurements of Inertance Tubes at High Frequency and Pressure  

NASA Astrophysics Data System (ADS)

Previously measured and calculated impedances of inertance tubes were compared at frequencies below 70 Hz and average pressures below 3 MPa. In this paper we present similar comparisons for frequencies up to 150 Hz and average pressures up to 3.5 MPa. Measurements were made on inertance tube diameters from 1.0 mm to about 3.0 mm, as well as on a double diameter arrangement. Pressure ratios were varied from 1.1 to 1.45, and acoustic powers were varied up to about 80 W. In these measurements the use of higher frequencies has the potential of reducing the size of both the pressure oscillator and the cold finger for a given refrigeration power. The smaller cold finger also leads to faster cool-down. In these experiments, flow at the entrance to the inertance tube was determined from measurements of the calibrated pressure drop through a transfer line from the compressor. The wide range of frequencies and acoustic powers covered in these measurements enable us to separate the effects of compliance and inertance in the comparisons with a transmission line model.

Lewis, M. A.; Taylor, R.; Bradley, P. E.; Radebaugh, R.; Grossman, G.; Gan, Z.

2008-03-01

400

Combustion of hydrocarbon fuels within porous inert media  

Microsoft Academic Search

There has been a recent surge of interest in the combustion of hydrocarbon fuels within porous inert media. The interest has been directed by the needs of industry to develop high performance radiant heaters while complying with increasingly stringent emissions regulations. This paper reviews the processes associated with non-catalytic combustion within porous media, and describes related experimental and modeling research.

J. R. Howell; M. J. Hall; J. L. Ellzey

1996-01-01

401

Significant Gamma Lines from Inert Higgs Dark Matter  

Microsoft Academic Search

One way to unambiguously confirm the existence of particle dark matter and determine its mass would be to detect its annihilation into monochromatic gamma-rays in upcoming telescopes. One of the most minimal models for dark matter is the inert doublet model, obtained by adding another Higgs doublet with no direct coupling to fermions. For a mass between 40 and 80

Michael Gustafsson; Erik Lundström; Lars Bergström; Joakim Edsjö

2007-01-01

402

Influence of inert gases on the reactive high power pulsed magnetron sputtering process of carbon-nitride thin films  

SciTech Connect

The influence of inert gases (Ne, Ar, Kr) on the sputter process of carbon and carbon-nitride (CN{sub x}) thin films was studied using reactive high power pulsed magnetron sputtering (HiPIMS). Thin solid films were synthesized in an industrial deposition chamber from a graphite target. The peak target current during HiPIMS processing was found to decrease with increasing inert gas mass. Time averaged and time resolved ion mass spectroscopy showed that the addition of nitrogen, as reactive gas, resulted in less energetic ion species for processes employing Ne, whereas the opposite was noticed when Ar or Kr were employed as inert gas. Processes in nonreactive ambient showed generally lower total ion fluxes for the three different inert gases. As soon as N{sub 2} was introduced into the process, the deposition rates for Ne and Ar-containing processes increased significantly. The reactive Kr-process, in contrast, showed slightly lower deposition rates than the nonreactive. The resulting thin films were characterized regarding their bonding and microstructure by x-ray photoelectron spectroscopy and transmission electron microscopy. Reactively deposited CN{sub x} thin films in Ar and Kr ambient exhibited an ordering toward a fullerene-like structure, whereas carbon and CN{sub x} films deposited in Ne atmosphere were found to be amorphous. This is attributed to an elevated amount of highly energetic particles observed during ion mass spectrometry and indicated by high peak target currents in Ne-containing processes. These results are discussed with respect to the current understanding of the structural evolution of a-C and CN{sub x} thin films.

Schmidt, Susann; Czigany, Zsolt; Greczynski, Grzegorz; Jensen, Jens; Hultman, Lars [Thin Film Physics Div., Department of Physics (IFM), Linkoeping University, SE-581 83 (Sweden); Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Konkoly Thege Miklos ut 29-33. H-1121 Budapest (Hungary); Thin Film Physics Div., Department of Physics (IFM), Linkoeping University, SE-581 83 (Sweden)

2013-01-15

403

All optical O2 sensors using innovative phase fluorimetry for monitoring of headspace in ullage for FAA mandated inerting fuel tanks of commercial airlines  

Microsoft Academic Search

This paper explores the design and development of an all optical O2 sensor system that can be used for monitoring of headspace gases in the ullage of inerting fuel tanks of commercial airplanes. Also included is detailed discussion of the various test and measurement techniques used to estimate the O2 gas concentration .We compare the various intensity based approaches and

Allen Panahi

2011-01-01

404

Condensation model for the ESBWR passive condensers  

SciTech Connect

In the General Electric's Economic simplified boiling water reactor (GE-ESBWR) the passive containment cooling system (PCCS) plays a major role in containment pressure control in case of an loss of coolant accident. The PCCS condenser must be able to remove sufficient energy from the reactor containment to prevent containment from exceeding its design pressure following a design basis accident. There are three PCCS condensation modes depending on the containment pressurization due to coolant discharge; complete condensation, cyclic venting and flow through mode. The present work reviews the models and presents model predictive capability along with comparison with existing data from separate effects test. The condensation models in thermal hydraulics code RELAP5 are also assessed to examine its application to various flow modes of condensation. The default model in the code predicts complete condensation well, and basically is Nusselt solution. The UCB model predicts through flow well. None of condensation model in RELAP5 predict complete condensation, cyclic venting, and through flow condensation consistently. New condensation correlations are given that accurately predict all three modes of PCCS condensation. (authors)

Revankar, S. T. [Pohang Univ. of Science and Technology, 400 Central Drive, West Lafayette, IN 47906 (United States); Zhou, W.; Wolf, B.; Oh, S. [Purdue Univ., West Lafayette, IN 47906 (United States)

2012-07-01

405

Results of experimental studies of the gas-dynamic behavior of airflow in the circulation line of the air condenser of steam-turbine plants  

NASA Astrophysics Data System (ADS)

The results of experimental studies and a physical model of the three-dimensional flow of cooling air in the circulation line (CL) of a dummy air condenser (AC) incorporating a fan, heat-exchange modules, a shell, and other auxiliary components are analyzed. The local air velocity fields determined experimentally at the AC CL inlet and at the fan diffuser outlet are presented. The guidelines for determining the head-capacity characteristics of the airflow through the AC CL are proposed.

Fedorov, V. A.; Mil'man, O. O.; Gribin, V. G.; Anan'ev, P. A.

2014-12-01

406

I. I. Rabi Prize Lecture: Paradox Lost and Paradox Regained: Recent Experimental Results in Dilute-Gas Bose-Einstein Condensation  

NASA Astrophysics Data System (ADS)

In the two years since Bose-Einstein condensation was first observed [1,2,3] in dilute vapors of the alkali metals, a wide variety of experimental studies has been performed on these exotic systems. Some of the recent results out of JILA (for instance a critical temperature measurement [4]) have been in excellent agreement with theeoretical expectations. Others (for instance the behavior of low-lying condensate excitations at finite-T [5]) have been more puzzling. I will discuss the recently observed two-component condensates [6] and provide also an overview of recent studies [7] of the coherence properties of condensates. ([1] M. H. Anderson, J. R. Ensher, M. R. Matthews, C. E. Wieman and E. A. Cornell, Science 269, 198 (1995). [2] K. B. Davis, M.-O. Mewes, M. R. Andrews, N. J. van Druten, D. S. Durfee, D. M. Kurn, W. Kettle, Phys. Rev. Lett. 75, 3696 (1995). [3] C. C. Bradley, C. A. Sackett, and R. G. Hulet, Phys. Rev. Lett. (in press). [4] J. R. Ensher, D. S. Jin, M. R. Matthews, C. E. Wieman and E. A. Cornell, Phys. Rev. Lett. 77, 4984 (1996). [5] D. S. Jin, M. R. Matthews, J. R. Ensher, C. E. Wieman and E. A. Cornell, Phys. Rev. Lett. (in press). [6] C. J. Myatt, E. A. Burt, R. W. Ghrist, E. A. Cornell and C. E. Wieman, Phys. Rev. Lett. (in press). [7] M. R. Andrews, C. G. Townsend, H.-J. Miesner, D. S. Durfee, D. M. Kurn and W. Ketterle, Science (in press).)

Cornell, Eric A.

1997-04-01

407

Cryogenic gas loading in a Mao-Bell-type diamond anvil cell for high pressure-high temperature investigations.  

PubMed

A simple system for loading argon fluid at cryogenic temperatures in a Mao-Bell-type diamond anvil cell (DAC) has been developed. It is done in a two step process in which the piston-cylinder assembly alone is submerged in the cryogenic chamber for trapping the liquefied inert gas. Liquid nitrogen is used for condensing the argon gas. This system is now being efficiently used for loading liquid argon in the DAC for high pressure-high temperature experiments. The success rate of trapping liquefied argon in the sample chamber is about 75%. The performance of the gas loading system is successfully tested by carrying out direct conversion of pyrolitic graphite to diamond under high pressure-high temperature using laser heated DAC facility. PMID:18681740

Sekar, M; Kumar, N R Sanjay; Sahu, P Ch; Chandra Shekar, N V; Subramanian, N

2008-07-01

408

Cryogenic gas loading in a Mao-Bell-type diamond anvil cell for high pressure-high temperature investigations  

NASA Astrophysics Data System (ADS)

A simple system for loading argon fluid at cryogenic temperatures in a Mao-Bell-type diamond anvil cell (DAC) has been developed. It is done in a two step process in which the piston-cylinder assembly alone is submerged in the cryogenic chamber for trapping the liquefied inert gas. Liquid nitrogen is used for condensing the argon gas. This system is now being efficiently used for loading liquid argon in the DAC for high pressure-high temperature experiments. The success rate of trapping liquefied argon in the sample chamber is about 75%. The performance of the gas loading system is successfully tested by carrying out direct conversion of pyrolitic graphite to diamond under high pressure-high temperature using laser heated DAC facility.

Sekar, M.; Kumar, N. R. Sanjay; Sahu, P. Ch.; Chandra Shekar, N. V.; Subramanian, N.

2008-07-01

409

Condensation and Evaporation of Solar System Materials  

NASA Astrophysics Data System (ADS)

It is widely believed that the materials making up the solar system were derived from a nebular gas and dust cloud that went through an early high-temperature stage during which virtually all of the material was in the gas phase. At one time, it was thought that the entire inner solar nebula was hot, but it is now believed that most material was processed through regions where high temperatures were achieved. Certainly some material, such as presolar grains (cf., Mendybaev et al., 2002a), has never been exposed to high temperatures. As the system cooled, solids and perhaps liquids began to condense, but at some point the partially condensed materials became isolated from the remaining gas. Various lines of evidence support this view. At the largest scale, there is the observation that the Earth, Moon, Mars, and all chondritic meteorites except for the CI chondrites are depleted to varying degrees in the abundances of moderately volatile elements relative to bulk solar system composition. The CI chondrites reflect the bulk composition of the solar system for all but hydrogen, carbon, nitrogen, oxygen, and the rare gases, the most volatile elements (see Chapter 1.03; Palme et al., 1988; McDonough and Sun, 1995; Humayun and Cassen, 2000). The depletions in moderately volatile elements are, to a significant degree, correlated with condensation temperature, suggesting progressive removal of gas as condensation proceeded ( Cassen, 1996). Additional observations that can be explained by partial condensation are that various particularly primitive components of meteorites (e.g., calcium-, aluminum-rich refractory inclusions, and certain metal grains) have mineralogy and/or details of their chemical composition that are remarkably similar to what is calculated for equilibrium condensates from a solar composition gas. For example, the calcium-, aluminum-rich inclusions (CAIs) in chondritic meteorites have compositions very similar to that calculated for the first 5% of total condensable matter (see Chapter 1.08; Grossman, 1973; Wänke et al., 1974; Grossman and Ganapathy, 1976; Grossman et al., 1977), where CI chondrites are taken to represent total condensable matter.Elemental abundance patterns ordered by volatility certainly could have been produced by partial condensation, but they could also have been caused by partial evaporation. The relative importance of these opposite processes is still subject to debate and uncertainty. It should be remembered that condensation calculations typically assume chemical equilibrium in a closed system, in which case the system has no memory of the path by which it arrived at a given state, and thus the chemical and isotopic composition of the condensed phase cannot be used to distinguish between partial condensation and partial evaporation. Humayun and Clayton (1995) have taken a somewhat different view by arguing that condensation and evaporation are distinguishable, in that evaporation, but not condensation, will produce isotopically fractionated residues. With this idea in mind, they carefully measured the potassium isotopic compositions of a broad range of solar system materials with different degrees of potassium depletion and found them to be indistinguishable. This they took as evidence that evaporation could not have been a significant process in determining the diverse elemental abundance patterns of the various solar system materials they measured, because had evaporation been important in fractionating potassium it would have also fractionated the potassium isotopes. We will qualify this line of reasoning by arguing that evaporation and condensation can under certain conditions produce isotopically fractionated condensed phases (i.e., that partial evaporation can produce isotopically heavy residues and that partial condensation can produce isotopically light condensates) but that under other conditions both can produce elemental fractionations without significant isotopic fractionation. The absence of isotopic fractionation in a volatile element-depleted condensed phase is more a

Davis, A. M.; Richter, F. M.

2003-12-01

410

46 CFR 194.15-17 - Compressed gases other than inert gases.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Compressed gases other than inert gases. 194.15-17 Section 194...AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194.15-17 Compressed gases other than inert gases....

2013-10-01

411

46 CFR 194.15-17 - Compressed gases other than inert gases.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Compressed gases other than inert gases. 194.15-17 Section 194...AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194.15-17 Compressed gases other than inert gases....

2014-10-01

412

46 CFR 194.15-17 - Compressed gases other than inert gases.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Compressed gases other than inert gases. 194.15-17 Section 194...AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194.15-17 Compressed gases other than inert gases....

2012-10-01

413

Advances towards the qualification of an aircraft fuel tank inert environment fiber optic oxygen sensor system  

NASA Astrophysics Data System (ADS)

An all optical pressure and temperature compensated fiber optic oxygen sensor (FOxSenseTM) system is under qualification for use in the in-situ closed-loop-control of the inert atmosphere environment inside fuel tanks of military and commercial aircraft. The all-optical oxygen environment control sensor is a passive, intrinsically safe, fiber-optic sensor device with no electrical connections leading to the sensors installed within the fuel tanks of an aircraft. To control the fuel tank environment, an array of multiple sensors is deployed throughout the fuel tanks of an aircraft, and a remote multi-channel optoelectronic system is used to monitor the status of all the sensors in real time to provide feedback oxygen environment information to the on-board inert gas generating system (OBIGS). Qualification testing of the all optical sensor have demonstrated the ability to monitor the oxygen environment inside a simulated fuel tank environment in the oxygen range from 0% to 21% oxygen concentrations, temperatures from (-) 40°C to (+) 60°C, and altitudes from sea level to 40,000 feet. Fiber optic oxygen sensors with built-in temperature compensation as well as the conduit fiber optic cables have passed DO-160E including acoustic noise and burn test.

Mendoza, Edgar A.; Esterkin, Yan; Kempen, Cornelia; Sun, Songjian; Susko, Kenneth; Goglia, John

2011-06-01

414

Inert matrix and thoria fuel irradiation at an international research reactor  

NASA Astrophysics Data System (ADS)

A major issue in the public debate on nuclear power, is how to break down the large plutonium stockpiles. Different concepts have been developed during the last years to burn plutonium. Two such concepts are stabilised zirconia based inert matrix (IM) and thoria (T) fuels. By using of IM fuels a larger fraction of plutonium could potentially be consumed without breeding new plutonium in comparison with todays MOX fuels. The aim of the presented study is to measure the general thermal behaviour of IM, inert matrix doped with thoria (IMT) and thoria under irradiation conditions similar to those in current light water reactor (LWRs). Of particular interest are the fuel thermal conductivity (and its degradation with burnup), fission gas release (FGR), fuel densification and fuel swelling. The irradiation is performed under HBWR conditions and a target burnup of ˜400-450 kW d cm -3, which is equivalent to ˜40-45 MW d kg -1 for the MOX fuel, is envisaged. Among other things considerably higher operating temperatures in the IM and IMT rods have been observed compared with those in the thoria fuel. The higher temperatures, which were caused by the lower thermal conductivity of IM, result in higher FGR of the IM and IMT fuel. This work gives the obtained results after 6 cycles (671 days) of irradiation.

Streit, M.; Tverberg, T.; Wiesenack, W.; Vettraino, F.

2006-06-01

415

Yttrium stabilised zirconia inert matrix fuel irradiation at an international research reactor  

NASA Astrophysics Data System (ADS)

Different concepts have been developed during the last decade to transmute transuranium elements (TRU) using uranium-free inert matrix fuels (IMF) in a once-through-cycle to reduce the amount of TRU in the nuclear waste. For today's LWRs yttrium stabilised zirconia (YSZ) and other oxides like alumina, spinel or ceria have been proposed as inert matrix materials. By employing IMF, a larger fraction of plutonium can potentially be consumed in comparison with MOX fuels without breeding new plutonium. The aim of the presented study is to measure the general thermal behaviour of YSZ-based IMF under irradiation conditions similar to those in current LWRs in direct comparison to standard MOX fuel. Of particular interest are the fuel thermal conductivity (and its degradation with burnup), fission gas release (FGR), fuel densification and fuel swelling. A secondary aim is the direct comparison of the fuel performance between YSZ-based IMF and MOX fuel. The irradiation is performed under HBWR conditions and has reached an average assembly burnup of ˜300 kW d cm -3 until the end of 2004, which is equivalent to ˜29 MW d kg -1 for the MOX fuel.

Streit, M.; Wiesenack, W.; Tverberg, T.; Hellwig, Ch.; Oberländer, B. C.

2006-06-01

416

Molecular equilibrium with condensation. [In astrophysics  

SciTech Connect

Minimization of the Gibbs energy of formation for species of chemical elements and compounds in their gas and condensed phases determines their relative abundances in a mixture in chemical equilibrium. The procedure is more general and more powerful than previous abundance determinations in multiphase astrophysical mixtures. Some results for astrophysical equations of state are presented, and the effects of condensation on opacity are briefly indicated. 18 refs.

Sharp, C.M.; Huebner, W.F. (Los Alamos National Laboratory, NM (USA) Southwest Research Institute, San Antonio, TX (USA))

1990-02-01

417

Molecular equilibrium with condensation. [in astrophysics  

NASA Technical Reports Server (NTRS)

Minimization of the Gibbs energy of formation for species of chemical elements and compounds in their gas and condensed phases determines their relative abundances in a mixture in chemical equilibrium. The procedure is more general and more powerful than previous abundance determinations in multiphase astrophysical mixtures. Some results for astrophysical equations of state are presented, and the effects of condensation on opacity are briefly indicated.

Sharp, C. M.; Huebner, W. F.

1990-01-01

418

Unidentified Inert Ingredients in Pesticides: Implications for Human and Environmental Health  

Microsoft Academic Search

BACKGROUND: By statute or regulation in the United States and elsewhere, pesticide ingredients are divided into two categories: active and inert (sometimes referred to as other ingredients, adjuvants, or coformulants). Despite their name, inert ingredients may be biologically or chemically active and are labeled inert only because of their function in the formulated product. Most of the tests required to

Caroline Cox; Michael Surgan

2006-01-01

419

The performance improvements of train suspension systems with mechanical networks employing inerters  

Microsoft Academic Search

This paper investigates the performance benefits of train suspension systems employing a new mechanical network element called an inerter. An inerter is a true mechanical two-terminal element with the applied force proportional to the relative acceleration across the terminals. Until now, ideal inerters have been applied to car and motorcycle suspension systems, for which a significant performance improvement was reported.

Fu-Cheng Wang; Min-Kai Liao; Bo-Huai Liao; Wei-Jiun Su; Hsiang-An Chan

2009-01-01

420

Reduced temperature aluminum production in an electrolytic cell having an inert anode  

DOEpatents

Aluminum is produced by electrolytic reduction of alumina in a cell having a cathode, an inert anode and a molten salt bath containing metal fluorides and alumina. The inert anode preferably contains copper, silver and oxides of iron and nickel. Reducing the molten salt bath temperature to about 900-950.degree. C. lowers corrosion on the inert anode constituents.

Dawless, Robert K. (Monroeville, PA); Ray, Siba P. (Murrysville, PA); Hosler, Robert B. (Sarver, PA); Kozarek, Robert L. (Apollo, PA); LaCamera, Alfred F. (Trafford, PA)

2000-01-01

421

Inert scalars and vacuum metastability around the electroweak scale  

E-print Network

We analyze effective potential around the electroweak (EW) scale in the Standard Model (SM) extended with heavy inert scalars. We show that the additional scalars can have a strong impact on the issue of vacuum stability. Although the additional heavy scalars may improve the behavior of running Higgs self-coupling at large field values, we prove that they can destabilize the vacuum due to EW-scale effects. A new EW symmetry conserving minimum of the effective potential can appear rendering the electroweak symmetry breaking (EWSB) minimum meta- or unstable. However, for the case of the inert doublet model (IDM) with a 125 GeV Higgs boson we demonstrate that the parameter space region where the vacuum is meta- or unstable cannot be reconciled with the constraints from perturbative unitarity, electroweak precision tests (EWPT) and dark matter relic abundance measurements.

Swiezewska, Bogumila

2015-01-01

422

Significant gamma lines from inert Higgs dark matter.  

PubMed

One way to unambiguously confirm the existence of particle dark matter and determine its mass would be to detect its annihilation into monochromatic gamma-rays in upcoming telescopes. One of the most minimal models for dark matter is the inert doublet model, obtained by adding another Higgs doublet with no direct coupling to fermions. For a mass between 40 and 80 GeV, the lightest of the new inert Higgs particles can give the correct cosmic abundance of cold dark matter in agreement with current observations. We show that for this scalar dark matter candidate, the annihilation signal of monochromatic gammagamma and Zgamma final states would be exceptionally strong. The energy range and rates for these gamma-ray line signals make them ideal to search for with the soon upcoming GLAST satellite. PMID:17678348

Gustafsson, Michael; Lundström, Erik; Bergström, Lars; Edsjö, Joakim

2007-07-27

423

Significant Gamma Lines from Inert Higgs Dark Matter  

E-print Network

One way to unambiguously confirm the existence of particle dark matter and determine its mass would be to detect its annihilation into monochromatic gamma-rays in upcoming telescopes. One of the most minimal models for dark matter is the inert doublet model, obtained by adding another Higgs doublet with no direct coupling to fermions. For a mass between 40 and 80 GeV, the lightest of the new inert Higgs particles can give the correct cosmic abundance of cold dark matter in agreement with current observations. We show that for this scalar dark matter candidate, the annihilation signal of monochromatic \\gamma\\gamma and Z\\gamma final states would be exceptionally strong. The energy range and rates for these gamma-ray line signals make them ideal to search for with the soon upcoming GLAST satellite.

Michael Gustafsson; Erik Lundstrom; Lars Bergstrom; Joakim Edsjo

2007-10-05

424

Vortices and turbulence in trapped atomic condensates  

PubMed Central

After more than a decade of experiments generating and studying the physics of quantized vortices in atomic gas Bose–Einstein condensates, research is beginning to focus on the roles of vortices in quantum turbulence, as well as other measures of quantum turbulence in atomic condensates. Such research directions have the potential to uncover new insights into quantum turbulence, vortices, and superfluidity and also explore the similarities and differences between quantum and classical turbulence in entirely new settings. Here we present a critical assessment of theoretical and experimental studies in this emerging field of quantum turbulence in atomic condensates. PMID:24704880

White, Angela C.; Anderson, Brian P.; Bagnato, Vanderlei S.

2014-01-01

425

Inert supports for lactic acid fermentation —a technological assessment  

Microsoft Academic Search

Production of lactic acid using Lactobacillus delbrueckii NRRL B445 recently renamed L. rhamnosus was studied in continuously recycled packed reactors at pH 6.3 and 42° C. Four inert adsorbent supports were used for immobilization: Raschig rings of sintered glass (Schott, FRG), beads of sintered glass (Schott), beads of porous glass (Poraver; Dennert, FRG) and irregular ceramic particles (Otto Feuerfest, FRG).

L. M. D. Gonçalves; M. T. O. Barreto; A. M. B. R. Xavier; M. J. T. Carrondo; J. Klein

1992-01-01

426

Evolution of weak disturbances in inert binary mixtures  

NASA Technical Reports Server (NTRS)

The evolution of weak disturbances in inert binary mixtures is determined for the one-dimensional piston problem. The interaction of the dissipative and nonlinear mechanisms is described by Burgers' equation. The binary mixture diffusion mechanisms enter as an additive term in an effective diffusivity. Results for the impulsive motion of a piston moving into an ambient medium and the sinusoidally oscillating piston are used to illustrate the results and elucidate the incorrect behavior pertaining to the associated linear theory.

Rasmussen, M. L.

1977-01-01

427

Scalar Dark Matter Candidates in Two Inert Higgs Doublet Model  

E-print Network

We study a two scalar inert doublet model (IDMS$_3$) which is stabilized by a $S_3$ symmetry. We consider two scenarios: i) two of the scalars in each charged sector are mass degenerated due to a residual $Z_2$ symmetry, ii) there is no mass degeneracy because of the introduction of soft terms that break the $Z_2$ symmetry. We show that both scenarios provide good dark matter candidates for some range of parameters.

E. C. F. S. Fortes; A. C. B. Machado; J. Montaño; V. Pleitez

2014-07-17

428

The inert doublet model of dark matter revisited  

Microsoft Academic Search

The inert doublet model, a minimal extension of the Standard Model by a second higgs doublet with no direct couplings to quarks or leptons, is one of the simplest scenarios that can explain the dark matter. In this paper, we study in detail the impact of dark matter annihilation into the three-body final state W{W^*}left( { to Wfbar{f}'} right) on

Laura Lopez Honorez; Carlos E. Yaguna

2010-01-01

429

Gas stream purifier  

NASA Technical Reports Server (NTRS)

A gas stream purifier has been developed that is capable of removing corrosive acid, base, solvent, organic, inorganic, and water vapors as well as particulates from an inert mixed gas stream using only solid scrubbing agents. This small, lightweight purifier has demonstrated the ability to remove contaminants from an inert gas stream with a greater than 99 percent removal efficiency. The Gas Stream Purifier has outstanding market and sales potential in manufacturing, laboratory and science industries, medical, automotive, or any commercial industry where pollution, contamination, or gas stream purification is a concern. The purifier was developed under NASA contract NAS9-18200 Schedule A for use in the international Space Station. A patent application for the Gas Stream Purifier is currently on file with the United States Patent and Trademark Office.

Adam, Steven J.

1994-01-01

430

Condensation during Titan's Polar Winter  

NASA Astrophysics Data System (ADS)

Titan is currently experiencing winter in its northern hemisphere and the lower atmosphere of its north polar region has been in prolonged darkness since the solstice in October 2002. As a result, the north polar region is currently characterised by cold stratospheric temperatures and there is enrichment of trace gases due to downward atmospheric motion (e.g. Teanby et al., Icarus 181 pp. 243-255, 2006). These conditions make the polar winter very suitable for cloud formation in the stratosphere. A simple transport and condensation model has been made to explore condensation processes in Titan's northern stratosphere. In the model, the atmosphere is advected downwards and clouds are formed as the saturation pressure of various gases is reached. Upper limits of the gases C4N2 and propionitrile (C2H5CN) were determined from Cassini Composite Infrared Spectrometer data to assess scenarios of chemical disequilibrium where the gas phase is far less abundant than the solid phase. The upper limit for C4N2 is 9e-9, which discounts the massive C4N2 build-up in the polar winter proposed by Samuelson et al. (PSS 45, pp. 941-948, 1997) to explain the observed C4N2 cloud at the Voyager epoch. The propionitrile upper limit is 8e-9, which is several orders of magnitude less than needed to create the condensate feature at 220 cm-1 of Khanna (Icarus 177, pp. 116-121) and de Kok et al. (Icarus, in press), assuming it is propionitrile ice, under the steady-state conditions explored by the aformentioned model. HCN ice seems to play an important role in the formation of a massive polar cloud (Haze B in de Kok et al., Icarus, in press), because of the unavailability of sufficient condensable gas other than HCN (and possibly HC3N) to produce the condensate features seen in far-infrared spectra at 220 cm-1.

de Kok, Remco; Irwin, P. G.; Teanby, N. A.; Fletcher, L. N.; Howett, C. J.; Calcutt, S. B.; Bowles, N. E.; Taylor, F. W.

2007-10-01

431

Condensate fluctuations of interacting Bose gases within a microcanonical ensemble  

SciTech Connect

Based on counting statistics and Bogoliubov theory, we present a recurrence relation for the microcanonical partition function for a weakly interacting Bose gas with a finite number of particles in a cubic box. According to this microcanonical partition function, we calculate numerically the distribution function, condensate fraction, and condensate fluctuations for a finite and isolated Bose-Einstein condensate. For ideal and weakly interacting Bose gases, we compare the condensate fluctuations with those in the canonical ensemble. The present approach yields an accurate account of the condensate fluctuations for temperatures close to the critical region. We emphasize that the interactions between excited atoms turn out to be important for moderate temperatures.

Wang Jianhui; He Jizhou; Ma Yongli [Department of Physics, Nanchang University, Nanchang 330031 (China); Department of Physics, Fudan University, Shanghai 200433 (China)

2011-05-15

432

Dark Matter with Topological Defects in the Inert Doublet Model  

E-print Network

We examine the production of dark matter by decaying topological defects in the high mass region $m_{\\mathrm{DM}} \\gg m_W$ of the Inert Doublet Model, extended with an extra U(1) gauge symmetry. The density of dark matter states (the neutral Higgs states of the inert doublet) is determined by the interplay of the freeze-out mechanism and the additional production of dark matter states from the decays of topological defects, in this case cosmic strings. These decays increase the predicted relic abundance compared to the standard freeze-out only case, and as a consequence the viable parameter space of the Inert Doublet Model can be widened substantially. In particular, for a given dark matter annihilation rate lower dark matter masses become viable. We investigate the allowed mass range taking into account constraints on the energy injection rate from the diffuse $\\gamma$-ray background and Big Bang Nucleosynthesis, together with constraints on the dark matter properties coming from direct and indirect detectio...

Hindmarsh, Mark; No, Jose Miguel; West, Stephen M

2014-01-01

433

CONDENSED MATTER: STRUCTURE, THERMAL AND MECHANICAL PROPERTIES: High density gas state at water/graphite interface studied by molecular dynamics simulation  

NASA Astrophysics Data System (ADS)

In this paper molecular dynamics simulations are performed to study the accumulation behaviour of N2 and H2 at water/graphite interface under ambient temperature and pressure. It finds that both N2 and H2 molecules can accumulate at the interface and form one of two states according to the ratio of gas molecules number to square of graphite surface from our simulation results: gas films (pancake-like) for a larger ratio and nanobubbles for a smaller ratio. In addition, we discuss the stabilities of nanobubbles at different environment temperatures. Surprisingly, it is found that the density of both kinds of gas states can be greatly increased, even comparable with that of the liquid N2 and liquid H2. The present results are expected to be helpful for the understanding of the stable existence of gas film (pancake-like) and nanobubbles.

Wang, Chun-Lei; Li, Zhao-Xia; Li, Jing-Yuan; Xiu, Peng; Hu, Jun; Fang, Hai-Ping

2008-07-01

434

Gas mixtures for spark gap closing switches  

DOEpatents

Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low molecular weight, inert buffer gases. To this can be added a third gas having a low ionization potential relative to the buffer gas. The gas mixtures presented possess properties that optimized the efficiency spark gap closing switches. 6 figs.

Christophorou, L.G.; McCorkle, D.L.; Hunter, S.R.

1987-02-20

435

Theoretical analysis of condensation in the presence of noncondensable gases as applied to open cycle OTEC condensers  

NASA Astrophysics Data System (ADS)

The open cycle ocean thermal energy conversion condenser was analyzed from a theoretical standpoint. Interfacial temperature profiles and gas concentrations in the axial direction were determined, and their effects on the rate of condensation studied. For the analysis, the vapor phase was modeled using diffusion equations for simultaneous heat and mass transfer processes, while the liquid phase was modeled using a falling film analysis. This analysis was then applied to a plate fin condenser, and the effect of varying the fin density along the condenser lengths was investigated. General engineering aspects of heat exchanger design are discussed for condensation of vapor mixtures in the presence of noncondensable gases.

Panchal, C. B.; Bell, K. J.

436

Condensate Mixtures and Tunneling  

SciTech Connect

The experimental study of condensate mixtures is a particularly exciting application of the recently developed atomic-trap Bose-Einstein condensate (BEC) technology: such multiple condensates represent the first laboratory systems of distinguishable boson superfluid mixtures. In addition, as the authors point out in this paper, the possibility of inter-condensate tunneling greatly enhances the richness of the condensate mixture physics. Not only does tunneling give rise to the oscillating particle currents between condensates of different chemical potentials, such as those studied extensively in the condensed matter Josephson junction experiments, it also affects the near-equilibrium dynamics and stability of the condensate mixtures. In particular, the stabilizing influence of tunneling with respect to spatial separation (phase separation) could be of considerable practical importance to the atomic trap systems. Furthermore, the creation of mixtures of atomic and molecular condensates could introduce a novel type of tunneling process, involving the conversion of a pair of atomic condensate bosons into a single molecular condensate boson. The static description of condensate mixtures with such type of pair tunneling suggests the possibility of observing dilute condensates with the liquid-like property of a self-determined density.

Timmermans, E.

1998-09-14

437

Experimental research of the effect of hydrogen in argon as a shielding gas in arc welding of high-alloy stainless steel  

Microsoft Academic Search

The paper treats the effect of hydrogen in argon as a shielding gas in arc welding of austenitic stainless steel. The studies were carried out in TIG (Tungsten Inert Gas) welding with a non-consumable electrode and MIG (Metal Inert Gas) welding with a consumable electrode, in both cases with different volume additions of hydrogen to the argon shielding gas, i.e.,

M. Suban

2000-01-01

438

Detailed Studies on Flame Extinction by Inert Particles in Normal- and Micro-gravity  

NASA Technical Reports Server (NTRS)

The combustion of dusty flows has been studied to lesser extent than pure gas phase flows and sprays. Particles can have a strong effect by modifying the dynamic response and detailed structure of flames through the dynamic, thermal, and chemical couplings between the two phases. A rigorous understanding of the dynamics and structure of two-phase flows can be attained in stagnation flow configurations, which have been used by others to study spray combustion as well as reacting dusty flows. In earlier studies on reacting dusty flows, the thermal coupling between the two phases as well as the effect of gravity on the flame response were not considered. However, in Ref. 6, the thermal coupling between chemically inert particles and the gas was addressed in premixed flames. The effects of gravity was also studied showing that it can substantially affect the profiles of the particle velocity, number density, mass flux, and temperature. The results showed a strong dynamic and thermal dependence of reacting dusty flows to particle number density. However, the work was only numerical and limited to twin-flames, stagnation, premixed flames. In Ref. 7 the effects of chemically inert particle clouds on the extinction of strained premixed and non-premixed flames were studied both experimentally and numerically at 1-g. It was shown and explained that large particles can cause more effective flame cooling compared to smaller particles. The effects of flame configuration and particle injection orientation were also addressed. The complexity of the coupling between the various parameters in such flows was demonstrated and it was shown that it was impossible to obtain a simple and still meaningful scaling that captured all the pertinent physics.

Andac, M. G.; Egolfopoulos, F. N.; Campbell, C. S.

2001-01-01

439

Two Heat-Transfer Improvements for Gas Liquefiers  

NASA Technical Reports Server (NTRS)

Two improvements in heat-transfer design have been investigated with a view toward increasing the efficiency of refrigerators used to liquefy gases. The improvements could contribute to the development of relatively inexpensive, portable oxygen liquefiers for medical use. A description of the heat-transfer problem in a pulse-tube refrigerator is prerequisite to a meaningful description of the first improvement. In a pulse-tube refrigerator in particular, one of in-line configuration heat must be rejected from two locations: an aftercooler (where most of the heat is rejected) and a warm heat exchanger (where a small fraction of the total input power must be rejected as heat). Rejection of heat from the warm heat exchanger can be problematic because this heat exchanger is usually inside a vacuum vessel. When an acoustic-inertance tube is used to provide a phase shift needed in the pulse-tube cooling cycle, another problem arises: Inasmuch as the acoustic power in the acoustic-inertance tube is dissipated over the entire length of the tube, the gas in the tube must be warmer than the warm heat exchanger in order to reject heat at the warm heat exchanger. This is disadvantageous because the increase in viscosity with temperature causes an undesired increase in dissipation of acoustic energy and an undesired decrease in the achievable phase shift. Consequently, the overall performance of the pulse-tube refrigerator decreases with increasing temperature in the acoustic-inertance tube. In the first improvement, the acoustic-inertance tube is made to serve as the warm heat exchanger and to operate in an approximately isothermal condition at a lower temperature, thereby increasing the achievable phase shift and the overall performance of the refrigerator. This is accomplished by placing the acoustic-inertance tube inside another tube and pumping a cooling fluid (e.g., water) in the annular space between the tubes. Another benefit of this improvement is added flexibility of design to locate the warm heat-rejection components outside the vacuum vessel. The second improvement is the development of a compact radial-flow condenser characterized by a very high heat transfer coefficient and a small pressure drop.

Martin, Jerry L.

2005-01-01

440

Steam Condensation Induced Waterhammer  

E-print Network

exceed 1000 psi. This is enough pressure to fracture a cast iron valve. blowout a steam gasket, or burst an accordion type expansion joint. And. in fact. failure ofeach ofthese compo nents in separate condensation induced water hammer accidents has..., TX, April 5-6, 2000 Condensation Induced Waterhammer A condensation induced water hammer is a rapid condensation event. It could also be aptly termed a "rapid steam bubble collapse". It occurs when a steam pocket becomes totally entrapped in sub...

Kirsner, W.

441

in Condensed Matter Physics  

E-print Network

Master in Condensed Matter Physics ­ Master académique #12;2 #12;3 Students at the University. Condensed matter physics is about explaining and predicting the relationship between the atomic, and broad education in the field of condensed matter physics · introduce you to current research topics

van der Torre, Leon

442

Modeling unit cell interactions for the microstructure of a heterogeneous explosive: detonation diffraction past an inert sphere  

SciTech Connect

We describe an approach being used to model multi-phase blast explosive, that is mostly condensed explosive by volume with inert embedded particles. The asymptotic theory of detonation shock dynamics is used to describe the detonation shock propagation in the explosive. The shock motion rule in the explosive requires that the shock move at a normal speed that depends on the shock curvature. The angle that the shock makes with the particle boundary is also prescribed. We describe theory that can be used to predict the behavior of a collection of such detonation shock/particle interactions in the larger aggregate. A typical unit cell problem of a detonation shock diffraction over a sphere is analyzed by analytical and numerical means and the properties of an ensemble of such unit cell problems is discussed with implications for the macroscopic limiting behavior of the heterogeneous explosive.

Bdzil, John B [Los Alamos National Laboratory; Stewart, Donald S [Los Alamos National Laboratory; Walter, John W [Los Alamos National Laboratory; Aida, Toru [Los Alamos National Laboratory

2009-01-01

443

In situ observation of sub-Poissonian atom-number fluctuations in a repulsive 1D Bose gas: quantum quasi-condensate and strongly interacting regimes  

E-print Network

In situ observation of sub-Poissonian atom-number fluctuations in a repulsive 1D Bose gas: quantum for Quantum-Atom Optics, School of Mathematics and Physics, University of Queensland, Brisbane, Queensland 4072, Australia (Dated: March 21, 2011) We report on local measurements of atom number fluctuations

444

Dynamics and Structure of Dusty Reacting Flows: Inert Particles in Strained, Laminar, Premixed Flames  

NASA Technical Reports Server (NTRS)

A detailed numerical study was conducted on the dynamics and thermal response of inert, spherical particles in strained, laminar, premixed hydrogen/air flames. The modeling included the solution of the steady conservation equations for both the gas and particle phases along and around the stagnation streamline of an opposed-jet configuration, and the use of detailed descriptions of chemical kinetics and molecular transport, For the gas phase, the equations of mass, momentum, energy, and species are considered, while for the particle phase, the model is based on conservation equations of the particle momentum balance in the axial and radial direction, the particle number density, and the particle thermal energy equation. The particle momentum equation includes the forces as induced by drag, thermophoresis, and gravity. The particle thermal energy equation includes the convective/conductive heat exchange between the two phases, as well as radiation emission and absorption by the particle. A one-point continuation method is also included in the code that allows for the description of turning points, typical of ignition and extinction behavior. As expected, results showed that the particle velocity can be substantially different than the gas phase velocity, especially in the presence of large temperature gradients and large strain rates. Large particles were also found to cross the gas stagnation plane, stagnate, and eventually reverse as a result of the opposing gas phase velocity. It was also shown that the particle number density varies substantially throughout the flowfield, as a result of the straining of the flow and the thermal expansion. Finally, for increased values of the particle number density, substantial flame cooling to extinction states and modification of the gas phase fluid mechanics were observed. As also expected, the effect of gravity was shown to be important for low convective velocities and heavy particles. Under such conditions, simulations indicate that the magnitude and direction of the gravitational force can substantially affect the profiles of the particle velocity, number density, mass flux, and temperature.

Egolfopoulos, Fokion N.; Campbell, Charles S.

1999-01-01

445

Dynamics and Structure of Dusty Reacting Flows: Inert Particles in Strained, Laminar, Premixed Flames  

NASA Technical Reports Server (NTRS)

A detailed numerical study was conducted on the dynamics and thermal response of inert spherical particles in strained, laminar, premixed hydrogen/air flames. The modeling included the solution of the steady conservation equations for both the gas and particle phases along and around the stagnation streamline of an opposed-jet configuration, and the use of detailed descriptions of chemical kinetics and molecular transport. For the gas phase, the equations of mass, momentum, energy, and species are considered, while for the particle phase, the model is based on conservation equations of the particle momentum balance in the axial and radial direction, the particle number density, and the particle thermal energy equation. The particle momentum equation includes the forces as induced by drag, thermophoresis, and gravity. The particle thermal energy equation includes the convective/conductive heat exchange between the two phases, as well as radiation emission and absorption by the particle. A one-point continuation method is also included in the code that allows for the description of turning points, typical of ignition and extinction behavior. As expected, results showed that the particle velocity can be substantially different than the gas phase velocity, especially in the presence of large temperature gradients and large strain rates. Large particles were also found to cross the gas stagnation plane, stagnate, and eventually reverse as a result of the opposing gas phase velocity. It was also shown that the particle number density varies substantially throughout the flowfield, as a result of the straining of the flow and the thermal expansion. Finally, for increased values of the particle number density, substantial flame cooling to extinction states and modification of the gas phase fluid mechanics were observed. As also expected, the effect of gravity was shown to be important for low convective velocities and heavy particles. Under such conditions, simulations indicate that the magnitude and direction of the gravitational force can substantially affect the profiles of the particle velocity, number density, mass flux, and temperature.

Egolfopoulos, Fokion N.; Campbell, Charles S.; Wu, Ming-Shin (Technical Monitor)

1999-01-01

446

Inert Electrodes Program: Fiscal year 1990 annual report  

SciTech Connect

The Inert Electrodes Program, conducted by Pacific Northwest Laboratory (PNL), involves improving the Hall-Heroult Cells used by the aluminum industry for the electrochemical production of aluminum. The PNL research centers on developing more energy-efficient, longer-lasting anodes, cathodes, and ancillary equipment. During the FY 1989 and FY 1990, preparations for the pilot cell test continued. Numerous unanticipated problems were encountered that delayed the test schedule. The delays resulted primarily from three factors: (1) modifications for anode design based on the results obtained from the prototype test (documented here); (2) difficulties in procuring a manufacturer for the cermet inert anodes to be used in the pilot cell; and (3) problems in the actual scale-up activities, both in the production of the ferrite powder and in the fabrication of the anodes themselves. Issues related to scaling up the fabrication of the anodes are still being addressed in FY 1991. Important accomplishments in FY 1989 and FY 1990 include the completion of laboratory cell tests in which the effects of current density, pre-corrosion, and silica content on anode performance were confirmed; the performance of tests that resulted in the identification of the reaction layer on cermet anodes; the initiation of electrochemical tests to determine the source of the anode impedance; the completion of studies to identify and summarize optimal fabrication conditions for the cermet inert anodes, including advanced compositions; the testing of anodes with advanced composition; the refinement of the electrical connection for the anode; and modeling the dynamics of the anode array to be used in the pilot cell. 15 refs., 23 figs.

Windisch, C.F. Jr; Strachan, D.M.

1991-08-01

447

Angiographic Results in Intracranial Aneurysms Treated with Inert Platinum Coils  

PubMed Central

Summary This study was designed in an attempt to identify the risk factors that could be significantly associated with angiographic recurrences after selective endovascular treatment of aneurysms with inert platinum coils. A retrospective analysis of all patients with selective endovascular coil occlusion of intracranial aneurysms was prospectively collected from 1999 to 2003. There were 455 aneurysms treated with inert platinum coils and followed by digital subtraction angiography. Angiographic results were classified according Roy and Raymond's classification. Recurrences were subjectively divided into minor and major. The most significant predictors for angiographic recurrences were determined by ANOVAs logistic regression, Cochran-Mantel-Haenszel test, Fisher exact probability. Short-term (4.3±1.4 months) follow-up angiograms were available in 377 aneurysms, middle-term (14.1±4.0 months) in 327 and long-term (37.4±11.5 months) in 180. Recurrences were found in 26.8% of treated aneurysms with a mean of 21±15.7 months of follow-up. Major recurrences needing retreatment were present in 8.8% during a mean period follow-up of 17.9±12.29 months after the initial endovascular treatment. One patient (0.2%) experienced a bleed during the follow-up period. Recurrences after endovascular treatment of aneurysms with inert platinum coils are frequent, but hemorrhages are unusual. Single aneurysm, ruptured aneurysm, neck greater than 4 mm and time of follow-up were risk factors for recurrence after endovascular treatment. The retreatment of recurrent aneurysm decreases the risk of major recurrences 9.8 times. Long-term angiogram monitoring is necessary for the population with significant recurrence predictors. PMID:23217634

Vanzin, J.R.; Mounayer, C.; Abud, D.G.; D'agostini Annes, R.; Moret, J.

2012-01-01

448

Bose-Einstein Condensation in Quasi2D Trapped Gases  

Microsoft Academic Search

We discuss Bose-Einstein condensation (BEC) in quasi-2D trapped gases and find that well below the transition temperature Tc the equilibrium state is a true condensate, whereas at intermediate temperatures Tcondensate with fluctuating phase). The mean-field interaction in a quasi-2D gas is sensitive to the frequency omega0 of the (tight) confinement in the ``frozen'' direction, and

D. S. Petrov; M. Holzmann; G. V. Shlyapnikov

2000-01-01

449

Inert Anode Life in Low Temperature Reduction Process  

SciTech Connect

The production of aluminum metal by low temperature electrolysis utilizing metal non-consumable anodes and ceramic cathodes was extensively investigated. Tests were performed with traditional sodium fluoride--aluminum fluoride composition electrolytes, potassium fluoride-- aluminum fluoride electrolytes, and potassium fluoride--sodium fluoride--aluminum fluoride electrolytes. All of the Essential First-Tier Requirements of the joint DOE-Aluminum Industry Inert Anode Road Map were achieved and those items yet to be resolved for commercialization of this technology were identified. Methods for the fabrication and welding of metal alloy anodes were developed and tested. The potential savings of energy and energy costs were determined and potential environmental benefits verified.

Bradford, Donald R.

2005-06-30

450

Polyvinyl alcohol battery separator containing inert filler. [alkaline batteries  

NASA Technical Reports Server (NTRS)

A cross-linked polyvinyl alcohol battery separator is disclosed. A particulate filler, inert to alkaline electrolyte of an alkaline battery, is incorporated in the separator in an amount of 1-20% by weight, based on the weight of the polyvinyl alcohol, and is dispersed throughout the product. Incorporation of the filler enhances performance and increases cycle life of alkaline batteries when compared with batteries containing a similar separator not containing filler. Suitable fillers include titanates, silicates, zirconates, aluminates, wood floor, lignin, and titania. Particle size is not greater than about 50 microns.

Sheibley, D. W.; Hsu, L. C.; Manzo, M. A. (inventors)

1981-01-01

451

Inert scalar dark matter in an extra dimension inspired model  

NASA Astrophysics Data System (ADS)

In this paper we analyze a dark matter model inspired by theories with extra dimensions. The dark matter candidate corresponds to the first Kaluza-Klein mode of an real scalar added to the Standard Model. The tower of new particles enriches the calculation of the relic abundance. For large mass splitting, the model converges to the predictions of the inert singlet dark matter model. For nearly degenerate mass spectrum, coannihilations increase the cross-sections used for direct and indirect dark matter searches. Moreover, the Kaluza-Klein zero mode can mix with the SM higgs and further constraints can be applied.

Lineros, R. A.; Pereira dos Santos, F. A.

2014-10-01

452

Asymptotic analysis of stationary adiabatic premixed flames in porous inert media  

SciTech Connect

The structure of adiabatic premixed flames within porous inert media is investigated using the asymptotic expansion method. For this, the flame structure is divided into three characteristic length scales. The two innermost length scales, the gas-phase diffusion length scale and the reaction length scale, are the same scales defined in the classical premixed flame structure analysis. The outermost length scale, the solid-phase diffusion length scale, is related to the heat conduction in the porous matrix. The differences among these three characteristic length-scales result in large temperature differences between the phases and justify the application of asymptotic expansions to determine an approximate (analytical) solution. Since the main focus of this work is the examination of the processes in the outer and the first inner regions, the simplest kinetic mechanism of one global step is adopted to represent the fuel and oxygen consumption. Then, the description of the reaction zone is obtained using the large activation energy asymptotic method. The description of the problem of the order of the gas-phase length scale is obtained using the boundary layer expansion. This work evaluates the influence of the equivalence ratio, the ratio of the solid to the gas thermal conductivities, the porosity of the medium and the fuel Lewis number on such flames. A parameter that universalizes the flame properties is then identified and discussed. (author)

Pereira, Fernando M.; Oliveira, Amir A.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Fachini, Fernando F. [Instituto Nacional de Pesquisas Espaciais, 12630-000 Cachoeira Paulista, SP (Brazil)

2009-01-15

453

Asymptotic analysis of stationary adiabatic premixed flames in porous inert media  

SciTech Connect

The structure of adiabatic premixed flames within porous inert media is investigated using the asymptotic expansion method. For this, the flame structure is divided into three characteristic length scales. The two innermost length scales, the gas-phase diffusion length scale and the reaction length scale, are the same scales defined in the classical premixed flame structure analysis. The outermost length scale, the solid-phase diffusion length scale, is related to the heat conduction in the porous matrix. The differences among these three characteristic length-scales result in large temperature differences between the phases and justify the application of asymptotic expansions to determine an approximate (analytical) solution. Since the main focus of this work is the examination of the processes in the outer and the first inner regions, the simplest kinetic mechanism of one global step is adopted to represent the fuel and oxygen consumption. Then, the description of the reaction zone is obtained using the large activation energy asymptotic method. The description of the problem of the order of the gas-phase length scale is obtained using the boundary layer expansion. This work evaluates the influence of the equivalence ratio, the ratio of the solid to the gas thermal conductivities, the porosity of the medium and the fuel Lewis number on such flames. A parameter that universalizes the flame properties is then identified and discussed. (author)

Pereira, Fernando M.; Oliveira, Amir A.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Fachini, Fernando F. [Instituto Nacional de Pesquisas Espaciais, 12630-000 Cachoeira Paulista, SP (Brazil)

2008-11-15

454

Sources of ore-forming fluid in fumaroles of Kudryavyi Volcano, Kuril islands: Pb isotopic composition of gas condensates and sublimate minerals  

Microsoft Academic Search

Kudryavyi Volcano is an example of the modern ore-forming system related to island-arc andesite volcanism. A direct study of high-temperature gas?hydrothermal process in the volcanic edifice is of fundamental significance for understanding the formation conditions of ore deposits in the modern recycling zones of the oceanic crust. This research was aimed at determining the sources of ore matter during formation

A. V. Chugaev; M. A. Yudovskaya; V. V. Distler; I. V. Chaplygin; A. V. Eremina

2007-01-01

455

Investigation of the Noncondensable Effect and the Operational Modes of the Passive Condenser System  

SciTech Connect

An experimental study is performed to investigate the effect of noncondensable gas in a passive condenser system. A vertical condenser tube is submerged in a water pool where the heat transferred from the condenser tube is removed through boiling. Data are obtained for three operational modes of the passive condenser. Degradation of the condensation with noncondensable gas is investigated. The condensation heat transfer rate is enhanced by increasing the inlet steam flow rate and the system pressure. For the condenser submerged in a saturated water pool, strong primary pressure dependency is observed. A boundary layer-based condensation model and a simple condensation model with the interfacial friction factor correlation are developed. The model predictions are compared with the pure steam data, and the agreement is satisfactory.

Oh, Seungmin; Revankar, Shripad T. [Purdue University (United States)

2005-10-15

456

Experimental and Thermalhydraulic Code Assessment of the Transient Behavior of the Passive Condenser System in an Advanced Boiling Water Reactor  

Microsoft Academic Search

The main goal of the project was to study analytically and experimentally the condensation heat transfer for the passive condenser system such as GE Economic Simplified Boiling Water Reactor (ESBWR). The effect of noncondensable gas in condenser tube and the reduction of secondary pool water level to the condensation heat transfer coefficient was the main focus in this research. The

S. T. Revankar; W. Zhou; Gavin Henderson

2008-01-01

457

IDMS: Inert Dark Matter Model with a complex singlet  

E-print Network

Within the Inert Doublet Model (IDM) there is a viable dark matter candidate. This simple model can provide a strong enough first order phase transition, which is required in order to account for the matter-antimatter asymmetry in the Universe (BAU). However, another necessary ingredient is missing, as there is no additional source of CP violation in the IDM, besides the standard CKM phase from the Standard Model. Additional CP violating phase can appear if a complex singlet of $SU(3)_C \\times SU(2)_W \\times U(1)_Y$ with a non-zero vacuum expectation value is added to the scalar sector of the IDM. We construct the scalar potential of the inert doublet plus singlet model (IDMS), assuming an exact $Z_2$ symmetry, with singlet being $Z_2$-even. To simplify the model we use a softly broken $U(1)$ symmetry, which allows a reduction of the number of free parameters in the potential. We study the masses and interactions of scalar particles for a few benchmark scenarios. Constraints from collider physics, in particular from the Higgs signal observed at LHC with $M_h\\approx 125$ GeV are discussed, as well as constraints from the dark matter experiments.

Cesar Bonilla; Dorota Sokolowska; Neda Darvishi; J. Lorenzo Diaz-Cruz; Maria Krawczyk

2015-04-13

458

Teflon films for chemically-inert microfluidic valves and pumps.  

PubMed

We present a simple method for fabricating chemically-inert Teflon microfluidic valves and pumps in glass microfluidic devices. These structures are modeled after monolithic membrane valves and pumps that utilize a featureless polydimethylsiloxane (PDMS) membrane bonded between two etched glass wafers. The limited chemical compatibility of PDMS has necessitated research into alternative materials for microfluidic devices. Previous work has shown that spin-coated amorphous fluoropolymers and Teflon-fluoropolymer laminates can be fabricated and substituted for PDMS in monolithic membrane valves and pumps for space flight applications. However, the complex process for fabricating these spin-coated Teflon films and laminates may preclude their use in many research and manufacturing contexts. As an alternative, we show that commercially-available fluorinated ethylene-propylene (FEP) Teflon films can be used to fabricate chemically-inert monolithic membrane valves and pumps in glass microfluidic devices. The FEP Teflon valves and pumps presented here are simple to fabricate, function similarly to their PDMS counterparts, maintain their performance over extended use, and are resistant to virtually all chemicals. These structures should facilitate lab-on-a-chip research involving a vast array of chemistries that are incompatible with native PDMS microfluidic devices. PMID:18497911

Grover, William H; von Muhlen, Marcio G; Manalis, Scott R

2008-06-01

459

IDMS: Inert Dark Matter Model with a complex singlet  

E-print Network

Within the Inert Doublet Model (IDM) there is a viable dark matter candidate. This simple model can provide a strong enough first order phase transition, which is required in order to account for the matter-antimatter asymmetry in the Universe (BAU). However, another necessary ingredient is missing, as there is no additional source of CP violation in the IDM, besides the standard CKM phase from the Standard Model. Additional CP violating phase can appear if a complex singlet of $SU(3)_C \\times SU(2)_W \\times U(1)_Y$ with a non-zero vacuum expectation value is added to the scalar sector of the IDM. We construct the scalar potential of the inert doublet plus singlet model (IDMS), assuming an exact $Z_2$ symmetry, with singlet being $Z_2$-even. To simplify the model we use a softly broken $U(1)$ symmetry, which allows a reduction of the number of free parameters in the potential. We study the masses and interactions of scalar particles for a few benchmark scenarios. Constraints from collider physics, in particular from the Higgs signal observed at LHC with $M_h\\approx 125$ GeV are discussed, as well as constraints from the dark matter experiments.

Cesar Bonilla; Dorota Sokolowska; J. Lorenzo Diaz-Cruz; Maria Krawczyk; Neda Darvishi

2014-12-30

460

Electron-induced damage of biotin studied in the gas phase and in the condensed phase at a single-molecule level  

NASA Astrophysics Data System (ADS)

Biotin is an essential vitamin that is, on the one hand, relevant for the metabolism, gene expression and in the cellular response to DNA damage and, on the other hand, finds numerous applications in biotechnology. The functionality of biotin is due to two particular sub-structures, the ring structure and the side chain with carboxyl group. The heterocyclic ring structure results in the capability of biotin to form strong intermolecular hydrogen and van der Waals bonds with proteins such as streptavidin, whereas the carboxyl group can be employed to covalently bind biotin to other complex molecules. Dissociative electron attachment (DEA) to biotin results in a decomposition of the ring structure and the carboxyl group, respectively, within resonant features in the energy range 0-12 eV, thereby preventing the capability of biotin for intermolecular binding and covalent coupling to other molecules. Specifically, the fragment anions (M-H)-, (M-O)-, C3N2O-, CH2O2-, OCN-, CN-, OH- and O- are observed, and exemplarily the DEA cross section of OCN- formation is determined to be 3 × 10-19 cm2. To study the response of biotin to electrons within a complex condensed environment, we use the DNA origami technique and determine a dissociation yield of (1.1 ± 0.2) × 10-14 cm2 at 18 eV electron energy, which represents the most relevant energy for biomolecular damage induced by secondary electrons. The present results thus have important implications for the use of biotin as a label in radiation experiments.

Keller, Adrian; Kopyra, Janina; Gothelf, Kurt V.; Bald, Ilko

2013-08-01

461

Proceedings: Condenser technology conference  

SciTech Connect

Seam surface condenser and associated systems performance strongly affects availability and heat rate in nuclear and fossil power plants. Thirty-six papers presented at a 1990 conference discuss research results, industry experience, and case histories of condenser problems and solutions. This report contains papers on life extension, performance improvement, corrosion and failure analysis, fouling prevention, and recommendation for future R D. The information represents recent work on condenser problems and solutions to improve the procurement, operation, and maintenance functions of power plant personnel. Several key points follow: A nuclear and a fossil power plant report show that replacing titanium tube bundles improves condenser availability and performance. One paper reports 10 years of experience with enhanced heat transfer tubes in utility condensers. The newly developed enhanced condenser tubes could further improve condensing heat transfer. A new resistance summation method improves the accuracy of condenser performance prediction, especially for stainless steel and titanium tubed condensers. Several papers describe improved condenser fouling monitoring techniques, including a review of zebra mussel issues.

Tsou, J.L. (ed.)(Electric Power Research Inst., Palo Alto, CA (United States)); Mussalli, Y.G. (comp.)(Stone and Webster Engineering Corp., Boston, MA (United States))

1991-08-01

462

Fiber optic oxygen sensor using fluorescence quenching for aircraft inerting fuel tank applications  

NASA Astrophysics Data System (ADS)

On July 18, 2008, the FAA mandated that new aircraft are to include inerting technology to significantly reduce the potential for flammable vapor spaces in center wing fuel tanks. All passenger aircraft constructed since 1991 must also be retrofitted with this technology. This ruling is the result of 18 aircraft that have experienced fuel tank flammable vapor ignition incidents since 1960. Included in these are the TWA 800 and Avianca Flight 203 incidents that resulted in 337 total fatalities. Comprised of heavier hydrocarbon components, jet fuel is much less volatile, with Jet A having a flash point of approximately 100°F and JP-4 having a flash point of approximately 0°F. In contrast, straight-run gasoline has a flash point of approximately -40°F. The flash point is the minimum temperature where a liquid fuel can generate enough vapor to form a flammable mixture with air. If the temperature is below the flash point there isn't enough fuel evaporating to form a flammable fuel-air mixture. Since jet fuel and gasoline have similar flammable concentration limits, gasoline must produce much more vapor at a given temperature to have such a low flash point; hence gasoline is much more volatile than jet fuel. In this paper we explore Fluorescence Technology as applied to the design and development of O2 sensors that can be used for this application and discuss the various test and measurement techniques used to estimate the O2 gas concentration. We compare the various intensity based approaches and contrast them with the frequency domain techniques that measure phase to extract fluorescent lifetimes. The various inerting fuel tank requirements are explained and finally a novel compact measurement system using that uses the frequency heterodyning cross correlation technique that can be used for various applications is described in detail while the benefits are explored together with some test data collected.

Panahi, Allen

2009-05-01

463

Fabrication and characterization of inert-substrate-supported tubular single cells by dip-coating process  

NASA Astrophysics Data System (ADS)

A tubular single cell supported by an inert substrate with a configuration of porous yttria-stabilized zirconia (YSZ) supporter/Ni anode current collector/Ni-Ce0.8Sm0.2O1.9 anode/YSZ/Ce0.8Sm0.2O1.9 bi-layer electrolyte/La0.6Sr0.4Co0.2Fe0.8O3-? cathode has been fabricated by a cold isostatic pressing and dip-coating process. The effects of pore morphology and porosity of the YSZ supporter on the mechanical strength and electrochemical performance of the single cell have been investigated with respect to the content of poly (methyl methacrylate) (PMMA) pore former. The average pore size and porosity of the YSZ supporter increase with the amount of pore former used, facilitating the gas diffusion process at the anode and reducing the polarization resistance of the single cell whereas leading to a decline of the mechanical strength. A preferred pore former content is determined to be 25 wt.% based on a trade-off of the mechanical strength and electrochemical performance. The single cell with 25 wt.% PMMA in YSZ supporter shows a bending strength of 21 ± 1 MPa and a maximum power density of 337 mW cm-2 at 800 °C in hydrogen. Moreover, the inert-substrate-supported tubular single cell displays a satisfactory redox cycling stability, maintaining 95% of its initial performance within seven redox cycles.

Zhao, Kai; Kim, Bok-Hee; Xu, Qing; Ahn, Byung-Guk

2014-01-01