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1

Evaporation system and method for gas jet deposition of thin film materials  

DOEpatents

A method and apparatus are disclosed for depositing thin films of materials such as metals, oxides and nitrides at low temperature relies on a supersonic free jet of inert carrier gas to transport vapor species generated from an evaporation source to the surface of a substrate. Film deposition vapors are generated from solid film precursor materials, including those in the form of wires or powders. The vapor from these sources is carried downstream in a low pressure supersonic jet of inert gas to the surface of a substrate where the vapors deposit to form a thin film. A reactant gas can be introduced into the gas jet to form a reaction product with the evaporated material. The substrate can be moved from the gas jet past a gas jet containing a reactant gas in which a discharge has been generated, the speed of movement being sufficient to form a thin film which is chemically composed of the evaporated material and reactant gases. 8 figs.

Schmitt, J.J.; Halpern, B.L.

1994-10-18

2

Method of evaporation  

NASA Technical Reports Server (NTRS)

Liquids, such as juices, milk, molten metal and the like are concentrated by forming uniformly-sized, small droplets in a precision droplet forming assembly and deploying the droplets in free fall downwardly as a central column within an evacuated column with cool walls. A portion of the solvent evaporates. The vapor flows to the wall, condenses, and usually flows down the wall as a film to condensate collector and drain. The vertical column of freely falling droplets enters the splash guard. The condensate can be collected, sent to other towers or recycled.

Dufresne, Eugene R.

1987-01-01

3

Evaporation of forsterite in H 2 gas  

Microsoft Academic Search

Kinetics of evaporation of forsterite in hydrogen gas was investigated by high temperature vacuum experiments in the pressure range plausible for the solar nebula. The evaporation rate at total pressure (Ptot) below 10?6 bar is nearly constant and is similar to that in vacuum, whereas the rate at 10?6 to 10?3 bar is dependent on Ptot. The evaporation rate, JexpFo,

Hiroko Nagahara; Kazuhito Ozawa

1996-01-01

4

Resonant gas oscillation with evaporation and condensation  

NASA Astrophysics Data System (ADS)

Resonant gas oscillation in a closed tube bounded by an oscillating plate and a vaporliquid interface is theoretically analyzed by applying the asymptotic theory to the ES-BGK Boltzmann equation for the case of M2~=Kn<<1 and a small evaporation coefficient ? = O(Kn), where M and Kn are the typical Mach number and the Knudsen number, respectively. As a result, we derive a nonlinear integro-differential equation for determining the wave profile with the evaporation and condensation in the form including ?.

Inaba, Masashi; Yano, Takeru; Watanabe, Masao; Kobayashi, Kazumichi; Fujikawa, Shigeo

2012-09-01

5

The evaporative gas turbine (EGT) cycle  

SciTech Connect

Humidification of the flow through a gas turbine has been proposed in a variety of forms. The STIG plant involves the generation of steam by the gas turbine exhaust in a heat recovery steam generator (HRSG), and its injection into or downstream of the combustion chamber. This increases the mass flow through the turbine and the power output from the plant, with a small increase in efficiency. In the evaporative gas turbine (or EGT) cycle, water is injected in the compressor discharge in a regenerative gas turbine cycle (a so-called CBTX plant--compressor [C], burner [B], turbine [T], heat exchanger [X]); the air is evaporatively cooled before it enters the heat exchanger. While the addition of water increases the turbine mass flow and power output, there is also apparent benefit in reducing the temperature drop in the exhaust stack. In one variation of the basic EGT cycle, water is also added downstream of the evaporative aftercooler, even continuously in the heat exchanger. There are several other variations on the basic cycle (e.g., the cascaded humidified advanced turbine [CHAT]). The present paper analyzes the performance of the EGT cycle. The basic thermodynamics are first discussed, and related to the cycle analysis of a dry regenerative gas turbine plant. Subsequently some detailed calculations of EGT cycles are presented. The main purpose of the work is to seek the optimum pressure ratio in the EGT cycle for given constraints (e.g., fixed maximum to minimum temperature). It is argued that this optimum has a relatively low value.

Horlock, J.H. [Whittle Lab., Cambridge (United Kingdom)

1998-04-01

6

On The Validity of the Assumed PDF Method for Modeling Binary Mixing/Reaction of Evaporated Vapor in GAS/Liquid-Droplet Turbulent Shear Flow  

NASA Technical Reports Server (NTRS)

An Investigation of the statistical description of binary mixing and/or reaction between a carrier gas and an evaporated vapor species in two-phase gas-liquid turbulent flows is perfomed through both theroetical analysis and comparisons with results from direct numerical simulations (DNS) of a two-phase mixing layer.

Miller, R. S.; Bellan, J.

1997-01-01

7

Apparatus and method for evaporator defrosting  

DOEpatents

An apparatus and method for warm-liquid defrosting of the evaporator of a refrigeration system. The apparatus includes a first refrigerant expansion device that selectively expands refrigerant for cooling the evaporator, a second refrigerant expansion device that selectively expands the refrigerant after the refrigerant has passed through the evaporator, and a defrosting control for the first refrigerant expansion device and second refrigerant expansion device to selectively defrost the evaporator by causing warm refrigerant to flow through the evaporator. The apparatus is alternately embodied with a first refrigerant bypass and/or a second refrigerant bypass for selectively directing refrigerant to respectively bypass the first refrigerant expansion device and the second refrigerant expansion device, and with the defrosting control connected to the first refrigerant bypass and/or the second refrigerant bypass to selectively activate and deactivate the bypasses depending upon the current cycle of the refrigeration system. The apparatus alternately includes an accumulator for accumulating liquid and/or gaseous refrigerant that is then pumped either to a refrigerant receiver or the first refrigerant expansion device for enhanced evaporator defrosting capability. The inventive method of defrosting an evaporator in a refrigeration system includes the steps of compressing refrigerant in a compressor and cooling the refrigerant in the condenser such that the refrigerant is substantially in liquid form, passing the refrigerant substantially in liquid form through the evaporator, and expanding the refrigerant with a refrigerant expansion device after the refrigerant substantially passes through the evaporator.

Mei, Viung C. (Oak Ridge, TN); Chen, Fang C. (Knoxville, TN); Domitrovic, Ronald E. (Knoxville, TN)

2001-01-01

8

The Sound Wave Method for Measurement of Evaporation Coefficient  

NASA Astrophysics Data System (ADS)

A new method for measurement of evaporation coefficient using sound resonance experiment is proposed on the basis of a theory of molecular gas dynamics, by which the evaporation coefficient is expressed as a function of the amplitude of standing sound wave between a planar sound source and a vapor-liquid interface facing against it. To demonstrate the applicability of this method, we carried out test experiments under the condition of neither evaporation nor condensation for several initial pressures, 30, 50, 80 and 101 kPa, at room temperature. In the experiments, we measure the amplitude of standing wave with a resonant frequency generated in a cylindrical space filled with air and closed by liquid water. We utilize the second harmonics component excited by the nonlinearity of sound to determine the evaporation coefficient, thereby eliminating the electromagnetic noises from measured signals. We find that the amplitude of the second harmonics at sound resonance decreases with the decrease in the initial pressure.

Nakamura, Shigeto; Yano, Takeru; Watanabe, Masao; Fujikawa, Shigeo

9

Gas Turbine Combustion Chambers with Film Evaporation.  

National Technical Information Service (NTIS)

The paper reports on an attempt to apply Meurer's film vaporization combustion method (M-method), originally developed for diesel motors, to the combustion chambers of gas turbines. (In the M-method, instead of distributing the fuel in the air, it is laid...

A. W. Hussmann

1968-01-01

10

Nonlinear resonant gas oscillation accompanied with evaporation and condensation  

NASA Astrophysics Data System (ADS)

Resonant gas oscillation in a closed tube bounded by an oscillating plate and a vapor-liquid interface is theoretically analyzed by applying the asymptotic theory to the ES-BGK Boltzmann equation for the case of MP ~ Kn << 1 and a small evaporation coefficient ? = O(Kn), where MP and Kn are the Mach number of the plate and the Knudsen number, respectively. As a result, we derive a nonlinear integro-differential equation for determining the wave profile with the evaporation and condensation including ?. We numerically solve the integro-differential equation with the method of Fourier series, and obtain a parameter plane for shock formation conditions and also the prediction of critical condition for shock formation.

Inaba, Masashi; Yano, Takeru; Kobayashi, Kazumichi; Watanabe, Masao

2012-11-01

11

Evaporation  

NSDL National Science Digital Library

This three-part activity consists of an activity that groups of learners develop themselves, a given procedure, and an optional demonstration. First, learners discuss examples of evaporation and then design and conduct their own test to find out whether heating water has an effect on the rate of evaporation. While waiting for their results, learners conduct another evaporation activity using single drops of water on 2 paper towels, one of which is heated. The optional demonstration compares the rate of evaporation of hot and cold water using a sensitive scale or balance. In each of these experiences with evaporation, learners will identify variables, consider how to best control them, and use their observations to conclude that heating water increases the rate of evaporation.

Kessler, James H.; Galvan, Patricia M.

2007-01-01

12

Estimation of Soil Evaporation Using the Differential Temperature Method  

Microsoft Academic Search

Estimation of evaporation from bare soil has recently been explored by using the energy balance method, and Evaporation of soil water is a major water balance component the microlysimeter method (Evett et al., 1994). Both during early growth stages of irrigated field crops, row crops with incomplete cover, and in soils with high water table. Quantification methods have the advantage

Guo Yu Qiu; J. Ben-Asher; T. Yano; K. Momii

1999-01-01

13

Saturator analysis for an evaporative gas turbine cycle  

Microsoft Academic Search

In this paper a thermodynamic assessment and a preliminary cost evaluation are given for an evaporative gas turbine (EvGT) cycle packed humidifier. Both background theory and simulation results are included.Two different approaches were used for the humidifier system modelling: the full integration of the mass-energy balance and mass transfer equations (called SAT model), and an atmospheric cooling tower-based model (called

Joao O. S. Parente; Alberto Traverso; Aristide F. Massardo

2003-01-01

14

Optical studies of lithium vapour zones produced by thermal evaporation in noble gas  

Microsoft Academic Search

We have produced two vertically well separated zones of lithium vapour above the evaporation source in a confined noble gas atmosphere by setting an appropriate condition for the gas evaporation. Optical extinction spectra of lithium atoms, dimers and clusters were obtained by time-resolved and space-resolved measurements after the beginning of the evaporation. Also, vapour species in each zone were selectively

Shosuke Mochizuki; Mie Sasaki; Raphael Ruppin

1997-01-01

15

Multilayer composite material and method for evaporative cooling  

NASA Technical Reports Server (NTRS)

A multilayer composite material and method for evaporative cooling of a person employs an evaporative cooling liquid that changes phase from a liquid to a gaseous state to absorb thermal energy. The evaporative cooling liquid is absorbed into a superabsorbent material enclosed within the multilayer composite material. The multilayer composite material has a high percentage of the evaporative cooling liquid in the matrix. The cooling effect can be sustained for an extended period of time because of the high percentage of phase change liquid that can be absorbed into the superabsorbent. Such a composite can be used for cooling febrile patients by evaporative cooling as the evaporative cooling liquid in the matrix changes from a liquid to a gaseous state to absorb thermal energy. The composite can be made with a perforated barrier material around the outside to regulate the evaporation rate of the phase change liquid. Alternatively, the composite can be made with an imperveous barrier material or semipermeable membrane on one side to prevent the liquid from contacting the person's skin. The evaporative cooling liquid in the matrix can be recharged by soaking the material in the liquid. The multilayer composite material can be fashioned into blankets, garments and other articles.

Buckley, Theresa M. (Inventor)

2002-01-01

16

Enhancement and simplification of EBIS operation by evaporative ion cooling through gas mixing  

NASA Astrophysics Data System (ADS)

The stepwise ionization in EBIS sources can be extended beyond th time at which neutralization of the electron beam space charge is reached by trapping ions from the residual gas: We have added minor amounts of argon to the residual gas in the main trap. From this gas mixture ions are formed during the whole containment time and extracted to a TOF analyser. At short containment times, the amount and the charge states of the residual gas ions increase with time - no argon seems to be present. At long containment times, argon ions dominate the spectrum more and more and increase their charge state according to time, while the total amount of charges does not increase further. The transition occurs, when the containment time equals the time, where a maximum of ions is collected. Then evaporative cooling of argon ions by residual gas ions is starting, ending at long containment times in a stationary state, where most of the residual gas ions are lost radially. This simple method to run an EBIS, first investigated with CEBIS I and besides extraction similar to EBIT operation, shows enhancement in the yield of highly charged ions by gas mixing, as it is also known from ECR sources. The gas mixing in EBIS and EBIT provides during the whole containment time colder and lower charged ions, which take up the heat from the heavier highly charged ones and by this get evaporated out of the electron beam.

Becker, R.; Kleinod, M.; Thomae, H.; Donets, E. D.

1993-06-01

17

Method and apparatus for flash evaporation of liquids  

DOEpatents

A vertical tube flash evaporator for introducing a super-heated liquid into a flash evaporation chamber includes a vertical inlet tube with a flared diffuser portion at its upper outlet end. A plurality of annular screens are positioned in axially spaced-apart relation to each other around the periphery of the vertical tube and below the diffuser portion thereof. The screens are preferably curved upward in a cup-shaped configuration. These flash evaporators are shown in an ocean thermal energy conversion unit designed for generating electric power from differential temperature gradients in ocean water. The method of use of the flash evaporators of this invention includes flowing liquid upwardly through the vertical tube into the diffuser where initial expansion and boiling occurs quite violently and explosively. Unvaporized liquid sheets and drops collide with each other to enhance surface renewal and evaporation properties, and liquid flowing over the outlet end of the diffuser falls onto the curved screens for further surface renewal and evaporation.

Bharathan, D.

1984-01-01

18

Gas Evaporation of Zn by Means of the Top-Heating Vertical Furnace  

NASA Astrophysics Data System (ADS)

Gas evaporation of Zn without convection was carried out in the top-heating furnace. The temperature distribution and the pressure of He gas in the furnace were controlled and the particles deposited at various places of temperature in the furnace were observed by scanning electron microscope. The conditions of nucleation and growth mechanisms of the evaporated Zn vapors were discussed.

Dohi, Minoru; Sawai, Shinya; Kato, Manabu; Wada, Nobuhiko

1990-11-01

19

Surface and gas-phase resistances to the evaporation of droplets.  

PubMed

Attempt has been made to asses quantitatively the magnitudes of both the gas-phase resistance and the surface resistance to the evaporation of droplets and to determine the transition point at which the evaporation changes from a diffusion-controlled to a surface-controlled process. This transition point is strongly dependent upon the ambient pressure and the droplet size. It is found that at atmospheric pressure the particle radius at which the transition takes place is in the range of 1 - 10mu for water, 0.1mu for n-dibutylphthalate, 0.1 - 1.0mu for mercury, and 0.001mu for liquid helium. Furthermore, we have found that the surface resistance and the gas-phase resistance vary with the size of the droplet in opposite direction, leading to the existence of a maximum rate of evaporation at a certain value of the droplet radius, this radius being dependent upon the characteristics of the liquid concerned. This conclusion may be useful in the search for an optimum and most efficient method of combustion of fuel sprays in automotive engines, gas turbines, and oil-burning power plants. PMID:1149699

Zung, J T

1975-01-01

20

Flash gas bypass for improving the performance of transcritical R744 systems that use microchannel evaporators  

Microsoft Academic Search

The performance of transcritical R744 systems with direct expansion (DX) can be significantly improved by implementing a Flash Gas Bypass (FGB). The idea behind the concept is to bypass refrigerant vapor, created during the isenthalpic expansion process, around the evaporator. By feeding the evaporator with liquid refrigerant, pressure drop is reduced and refrigerant distribution is improved. With R744 as the

Stefan Elbel; Pega Hrnjak

2004-01-01

21

Flow dynamics of gas-solid fluidized beds with evaporative liquid injection  

Microsoft Academic Search

The electrical capacitance tomography (ECT) with neural network multi-criteria image reconstruction technique (NN-MOIRT) is developed for real time imaging of a gas-solid fluidized bed using FCC particles with evaporative liquid injection. Some aspects of the fundamental characteristics of the gas-solid flow with evaporative liquid injection, including real time and time averaged cross-sectional solids concentration distributions, the cross-sectional solids concentration fluctuations

Bing Du; W. Warsito; Liang-Shih Fan

2006-01-01

22

Evaporation of iodine-containing off-gas scrubber solution  

DOEpatents

Mercuric nitrate-nitric acid scrub solutions containing radioiodine may be reduced in volume without excessive loss of volatile iodine. The use of concentrated nitric acid during an evaporation process oxidizes the mercury-iodide complex to a less volatile mercuric iodate precipitate.

Partridge, J.A.; Bosuego, G.P.

1980-07-14

23

Comparing the Multistep-Outflow and Evaporation Method for Determining Soil Hydraulic Properties  

NASA Astrophysics Data System (ADS)

Accurate knowledge of the soil hydraulic properties is necessary to simulate water flow in unsaturated soils. Among the transient experimental methods which allow the quick and simultaneous determination of the water retention and hydraulic conductivity function in the laboratory, the multistep-outflow and evaporation methods have become the most popular. Despite great effort to improve the experimental setups and evaluation techniques, much less attention has been devoted to the investigation of the agreement of soil hydraulic properties obtained from different methods applied to the same soil. Therefore we analyzed different soil types in order to compare the hydraulic properties obtained by the multistep-outflow method and the simplified evaporation method by Schindler (1980), advanced by Peters and Durner (2008). We found that for soils, where all requirements for the validity of the Richards equation as water flow process description are sufficiently fulfilled, i.e. for homogeneous media with consolidated pore systems and in the absence of "dynamic effects", the two methods gave very similar results. Problems arose for non-consolidated soils, where the evaporation process leads to a settling of the porous medium, or for swelling and shrinking soils. A particular problem was the establishment of identical initial conditions, when using the very same soil column for both experiments. Furthermore, dynamic effects, expressed by local non-equilibrium between water content and pressure head, and caused by limited gas-phase permeability or local heterogeneity, caused problems in the interpretation of the derived hydraulic properties.

Schelle, H.; Peters, A.; Durner, W.

2009-04-01

24

Geothermal gas sampling methods  

Microsoft Academic Search

A method for geothermal gas collection for chemical and isotopic gas analysis is described. The COâ and HâS are absorbed in a NaOH solution and the residual gas collected in a bottle. The method can be used for sampling gases from hot springs, fumaroles, steam wells, hot water wells, etc. (WHK)

A. H. Truesdell; K. L. Pering

1973-01-01

25

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

Microsoft Academic Search

In this study the mutual influence of heat and mass transfer during gas absorption and evaporation or condensation on the surface of a stagnant droplet in the presence of inert admixtures containing noncon- densable soluble gas is investigated numerically. The performed analysis is pertinent to slow droplet evapo- ration or condensation. The system of transient conjugate nonlinear energy and mass

T. Elperin; A. Fominykh; B. Krasovitov

2007-01-01

26

A model coupling the liquid and gas phases for a totally wetting evaporative meniscus  

NASA Astrophysics Data System (ADS)

An hydrodynamic model has been developed to get a complete description of an evaporative meniscus in complete wetting configuration. The coupling between the liquid and gas is explicitly taken into account. Scaling laws are derived for the different domains of the meniscus and validated by numerical simulations. Results are compared with previous models of the literature that use the electrostatic analogy proposed by Deegan and co-authors to describe the evaporative flux. We show that the different approaches differ for the description of the tip of the meniscus in the domain corresponding to the decrease of the evaporative flux but lead to the same scaling for the apparent macroscopic contact angle.

Doumenc, F.; Guerrier, B.

2011-08-01

27

Comparison of Total Evaporation (TE) and Direct Total Evaporation (DTE) methods in TIMS by using NBL CRMs  

NASA Astrophysics Data System (ADS)

The total evaporation (TE) is a well-established analytical method for safeguards measurement of uranium and plutonium isotope-amount ratios using the thermal ionization mass spectrometry (TIMS). High accuracy and precision isotopic measurements find many applications in nuclear safeguards, for e.g. assay measurements using isotope dilution mass spectrometry. To achieve high accuracy and precision in TIMS measurements, mass dependent fractionation effects are minimized by either the measurement technique or changes in the hardware components that are used to control sample heating and evaporation process. At NBL, direct total evaporation (DTE) method on the modified MAT261 instrument, uses the data system to read the ion signal intensity and its difference from a pre-determined target intensity, is used to control the incremental step at which the evaporation filament is heated. The feedback and control is achieved by proprietary hardware from SPECTROMAT that uses an analog regulator in the filament power supply with direct feedback of the detector intensity. Compared to traditional TE method on this instrument, DTE provides better precision (relative standard deviation, expressed as a percent) and accuracy (relative difference, expressed as a percent) of 0.05 to 0.08 % for low enriched and high enriched NBL uranium certified reference materials.

Hasözbek, Altug; Mathew, Kattathu; Wegener, Michael

2013-04-01

28

Water droplet evaporation in air during compression in a gas turbine engine. Technical memo  

SciTech Connect

A water fog concept is being considered for evaporative cooling of the air as it is compressed in a ship gas turbine engine. The following analysis is presented to clarify the physics associated with liquid droplet evaporation in this situation, to understand the conditions affecting the cooling, and to identify any further information required to achieve such a concept. The vaporization of small liquid drops in a warm ideal gas is controlled by the outward motion of the vapor and the inward flow of heat to cause evaporation. Following the standard analysis of Spalding, as given in `Principles of Combustion` by Kuo, it is assumed that the process is `quasi steady.` This means that the conditions far removed from the drop are constant, and that there are no time varying terms in the Eulerian description of the mass and energy flows.

Quandt, E.

1996-04-01

29

Evaporation determined by the energy-budget method for Mirror Lake, New Hampshire  

USGS Publications Warehouse

Evaporation was determined by the energy-budget method for Mirror Lake during the open water periods of 1982-1987. For all years, evaporation rates were low in spring and fall and highest during the summer. However, the times of highest evaporation rates varied during the 6 yr. Evaporation reached maximum rates in July for three of the years, in June for two of the years, and in August for one of the years. The highest evaporation rate during the 6-yr study was 0.46 cm d-1 during 27 May-4 June 1986 and 15-21 July 1987. Solar radiation and atmospheric radiation input to the lake and long-wave radiation emitted from the lake were by far the largest energy fluxes to and from the lake and had the greatest effect on evaporation rates. Energy advected to and from the lake by precipitation, surface water, and ground water had little effect on evaporation rates. In the energy-budget method, average evaporation rates are determined for energy-budget periods, which are bounded by the dates of thermal surveys of the lake. Our study compared evaporation rates calculated for short periods, usually ???1 week, with evaporation rates calculated for longer periods, usually ???2 weeks. The results indicated that the shorter periods showed more variability in evaporation rates, but seasonal patterns, with few exceptions, were similar.

Winter, T. C.; Buso, D. C.; Rosenberry, D. O.; Likens, G. E.; Sturrock, Jr. , A. M.; Mau, D. P.

2003-01-01

30

Synthesis and characterization of indium tin oxide (ITO) nanoparticle using gas evaporation process  

Microsoft Academic Search

In this paper, indium tin oxide (ITO) nanoparticle was synthesized by gas evaporation process, and its physical properties\\u000a such as particle size, specific surface area, crystal structure, and composition ratio according to the heat-treating conditions\\u000a were investigated to optimize them. The source material was charged in a chamber with vacuum circumstance of 110?5 torr, and the oxygen gas was supplied

Sung-Jei Hong; Jeong-In Han

2006-01-01

31

[Measurement and estimation methods and research progress of snow evaporation in forests].  

PubMed

Accurate measurement and estimation of snow evaporation (sublimation) in forests is one of the important issues to the understanding of snow surface energy and water balance, and it is also an essential part of regional hydrological and climate models. This paper summarized the measurement and estimation methods of snow evaporation in forests, and made a comprehensive applicability evaluation, including mass-balance methods (snow water equivalent method, comparative measurements of snowfall and through-snowfall, snow evaporation pan, lysimeter, weighing of cut tree, weighing interception on crown, and gamma-ray attenuation technique) and micrometeorological methods (Bowen-ratio energy-balance method, Penman combination equation, aerodynamics method, surface temperature technique and eddy covariance method). Also this paper reviewed the progress of snow evaporation in different forests and its influencal factors. At last, combining the deficiency of past research, an outlook for snow evaporation rearch in forests was presented, hoping to provide a reference for related research in the future. PMID:24697085

Li, Hui-Dong; Guan, De-Xin; Jin, Chang-Jie; Wang, An-Zhi; Yuan, Feng-Hui; Wu, Jia-Bing

2013-12-01

32

Test Plan for Evaluation of Preparation Method for Evaporator Samples  

SciTech Connect

This Test Plan will be used to evaluate the use of existing laboratory equipment for the determination of the organic material carried over from the feed to the condensate during evaporator waste processing. It will use existing procedures to simulate the distillation of organic compounds during the evaporator operation and to determine the organic Compounds carried over and their concentrations. Although the amounts of organics in the synthetic waste may not reflect any particular waste I-lank, the goal is to track the pathway of the various organics.

Wehner, K.B., Westinghouse Hanford

1996-09-13

33

Gas scavenging of insoluble vapors: Condensation of methyl salicylate vapor onto evaporating drops of water  

NASA Astrophysics Data System (ADS)

We have observed the evaporation of acoustically levitated water drops at 0 and 32% relative humidity in a moving gas stream which is nearly saturated with methyl salicylate vapor. The initial evaporation rate is characteristic of a pure water drop and gradually slows until the evaporation rate becomes that of pure methyl salicylate. The quantity of condensed methyl salicylate exceeds its Henry's law solubility in water by factors of more than 30-50. This apparent violation of Henry's law agrees with the concentration enhancements in the liquid phase found by glotfelty et al. (1987, Nature235, 602-605) during their field measurements of organophorus pesticides in fog water. Under our conditions, visual evidence demonstrates the presence of two liquid phases, thus invalidating the use of Henry's law. A continuum evaporation-condensation model for an immiscible two-component system which accounts for evaporative self-cooling of the drop correctly predicts the amount of methyl salicylate condensed onto the water drops.

Seaver, Mark; Peele, J. R.; Rubel, Glenn O.

34

Method for the production of synthesis gas  

SciTech Connect

A method is claimed for the continuous production of synthesis gas comprising of carbon monoxide and hydrogen through the autothermal gasification of solid combustibles in a pressure reactor. The method involves the following: introducing into a screw machine containing two parallely ordered shafts, a finely divided solid combustible; moistening and intimately mixing the solid combustible with 2 to 30% by weight of water, degasing and compressing the moist solid combustible to a pressure higher than that of the reactor; adding the gas-tight compressed and moist solid combustible to a reaction chamber-through a burner where the combustible is brought into contact with the gasification medium; evaporating the water in the compressed and moist solid combustible and producing a comminuted dispersion of the solid combustible in the mixture of the gasification medium and water vapor; reacting the combustible dispersion to give a raw synthesis gas; and removing the raw synthesis gas from the reactor.

Escher, G.; Harjung, J.; Wenning, H.P.

1981-11-24

35

SET UP AND OPERATION OF A RECIRCULATING WETTED RIGID MEDIA EVAPORATIVE COOLER INSTALLED IN A GAS TURBINE COMBUSTION INLET AIR SYSTEM  

Microsoft Academic Search

A procedure for setting up and operating a recirculating evaporative cooler installed in the combustion air inlet system of a gas turbine is described. The procedure includes a recommendation for selecting the ambient operating wet and dry bulb temperatures. A description of the parameters used in the procedure and calculation methods are shown. In response to frequent inquiries about the

R. S. Johnson

36

Instabilities in a horizontal liquid layer in cocurrent gas flow with an evaporating interface.  

PubMed

The problem of a two-layer system consisting of a horizontal liquid layer in contact with its own vapor is considered. The liquid layer is bounded by a rigid wall from below, and phase change can occur at the interface. The flow of the vapor phase is driven by a constant pressure gradient in the streamwise direction. We have taken into account the effects of buoyancy, thermocapillarity, evaporation, and the dynamics of the vapor phase. A full linear stability analysis is performed using a Chebyshev spectral method. The influences of evaporation effect and the interfacial shear on the Rayleigh instability and the Marangoni instability have been studied. The results show that both the evaporation and the interfacial shear play important roles in the stability of the system. PMID:23005204

Liu, R; Kabov, O A

2012-06-01

37

A high order moment method simulating evaporation and advection of a polydisperse liquid spray  

NASA Astrophysics Data System (ADS)

In this paper, we tackle the modeling and numerical simulation of sprays and aerosols, that is dilute gas-droplet flows for which polydispersity description is of paramount importance. Starting from a kinetic description for point particles experiencing transport either at the carrier phase velocity for aerosols or at their own velocity for sprays as well as evaporation, we focus on an Eulerian high order moment method in size and consider a system of partial differential equations (PDEs) on a vector of successive integer size moments of order 0 to N, N > 2, over a compact size interval. There exists a stumbling block for the usual approaches using high order moment methods resolved with high order finite volume methods: the transport algorithm does not preserve the moment space. Indeed, reconstruction of moments by polynomials inside computational cells coupled to the evolution algorithm can create N-dimensional vectors which fail to be moment vectors: it is impossible to find a size distribution for which there are the moments. We thus propose a new approach as well as an algorithm which is second order in space and time with very limited numerical diffusion and allows to accurately describe the advection process and naturally preserves the moment space. The algorithm also leads to a natural coupling with a recently designed algorithm for evaporation which also preserves the moment space; thus polydispersity is accounted for in the evaporation and advection process, very accurately and at a very reasonable computational cost. These modeling and algorithmic tools are referred to as the Eulerian Multi Size Moment (EMSM) model. We show that such an approach is very competitive compared to multi-fluid approaches, where the size phase space is discretized into several sections and low order moment methods are used in each section, as well as with other existing high order moment methods. An accuracy study assesses the order of the method as well as the low level of numerical diffusion on structured meshes. Whereas the extension to unstructured meshes is provided, we focus in this paper on cartesian meshes and two 2D test-cases are presented: Taylor-Green vortices and turbulent free jets, where the accuracy and efficiency of the approach are assessed.

Kah, D.; Laurent, F.; Massot, M.; Jay, S.

2012-01-01

38

A comparison of several methods of estimating the evaporation of Lake Flevo  

Microsoft Academic Search

Evaporation has been computed for a large shallow lake according to the water balance method, the energy budget method, the bulk aerodynamic method, Penman's method and the pan factor method. Data for all meteorological methods were collected at one main station in the centre of the lake. At several other recording stations in and around the lake data for the

J. Q. Keijman; R. W. R. Koopmans

39

Buffer gas loading and evaporative cooling in the multi-partial-wave regime  

NASA Astrophysics Data System (ADS)

This thesis describes the study of collisions in the multi-partial-wave regime relevant to the buffer gas cooling and trapping of atoms. A quantitative model is formulated to describe the dynamics of evaporative cooling and is used to infer elastic and inelastic collision rate constants of g el = 2.15(+2.5, -1.2) x 10-10 cm 3/s and gin = 1.36(+1.2, -0.7) x 10-12 cm3/s between two chromium atoms in the temperature range of 0.02-1 K and explains a long standing discrepancy between theory and experiment. Magnetic trapping is then extended to atomic manganese where up to 2 x 1012 Mn atoms are trapped in all six hyperfine states, allowing for the exploration of the role of the hyperfine interaction in spin-exchange collisions. In addition, we simultaneously trap a 55Mn-52Cr mixture and measure an inter-species inelastic rate constant of gMn,cr = 1.5 (+/-0.2) +/- 10-13 cm3/s. Demonstrating that buffer gas loading is a viable alternative to laser cooling, we have magnetically trapped and evaporatively cooled metastable helium in large numbers. 10 11 4He* atoms are trapped at an initial temperature of 400 mK and evaporatively cooled into the ultracold regime, resulting in a cloud of 2 +/- 0.5 x 109 atoms at 1.4 +/- 0.2 mK and an increase in phase space density of 5 orders of magnitude. Efficient evaporation indicates low collisional loss for 4He* in both the ultracold and multi-partial-wave regime, in agreement with theory.

Nguyen, Scott Vinh

40

Application of Taguchi method for the optimization of system parameters of centrifugal evaporative air cooler  

NASA Astrophysics Data System (ADS)

A new evaporative cooling system based on the action of centrifugal forces is proposed. Such systems are suitable for cooling large air volumes in tropical climates. Effects of geometrical and operational parameters on system performance are optimized using Taguchi method. It is observed that disc speed, air flow rate and water flow rate are found to have major influence on system performance and other parameter, viz., disc diameter, pin geometry, evaporation chamber length and orientation of pin have less influence.

Senthilkumar, K.; Srinivasan, Pss.

2010-10-01

41

Sound Propagation in Gas-Vapor-Droplet Suspensions with Evaporation and Nonlinear Particle Relaxation  

NASA Technical Reports Server (NTRS)

The Sound attenuation and dispersion in saturated gas-vapor-droplet mixture in the presence of evaporation has been investigated theoretically. The theory is based on an extension of the work of Davidson to accommodate the effects of nonlinear particle relaxation processes of mass, momentum and energy transfer on sound attenuation and dispersion. The results indicate the existence of a spectral broadening effect in the attenuation coefficient (scaled with respect to the peak value) with a decrease in droplet mass concentration. It is further shown that for large values of the droplet concentration the scaled attenuation coefficient is characterized by a universal spectrum independent of droplet mass concentration.

Kandula, Max

2012-01-01

42

A method for evaporating silicon to form low dimensional Si lattice structures  

NASA Astrophysics Data System (ADS)

Physical deposition by evaporation is a convenient and cost effective method for generating thin layers of material. In this work, we utilise an electron-beam evaporation system retrofitted with a rotating shutter to control and reduce the deposition rate of materials. Under normal conditions, the evaporator is able to achieve a typical deposition rate of 1 A/s. In order to reduce the deposition rate, a rotating shutter was designed and retrofitted to the evaporator. The rotating shutter consists of a metal plate with a slit opening of 6° and 36°. When rotated during evaporation, a reduction in deposition rate of 1/60 and 1/10 onto a sample is expected. We can control the deposition to achieve a rate of 1 A/min. By using this modified system, we deposited Si and SiO2 onto Si substrates. In situ deposition is monitored using a quartz thickness monitor. After evaporation, film thickness is measured using AFM and verified with spectroscopic ellipsometer measurement. Using this method, we are able to reach a deposited film thickness of 3 nm. This work is expected to contribute significantly towards the fabrication of low dimensional silicon devices.

Ng, David C.; Ganesan, Kumar; Stacey, Alastair; Skafidas, Efstratios

2013-12-01

43

Nanoparticle thin films for gas sensors prepared by matrix assisted pulsed laser evaporation.  

PubMed

The matrix assisted pulsed laser evaporation (MAPLE) technique has been used for the deposition of metal dioxide (TiO(2), SnO(2)) nanoparticle thin films for gas sensor applications. For this purpose, colloidal metal dioxide nanoparticles were diluted in volatile solvents, the solution was frozen at the liquid nitrogen temperature and irradiated with a pulsed excimer laser. The dioxide nanoparticles were deposited on Si and Al(2)O(3) substrates. A rather uniform distribution of TiO(2) nanoparticles with an average size of about 10 nm and of SnO(2) nanoparticles with an average size of about 3 nm was obtained, as demonstrated by high resolution scanning electron microscopy (SEM-FEG) inspections. Gas-sensing devices based on the resistive transduction mechanism were fabricated by depositing the nanoparticle thin films onto suitable rough alumina substrates equipped with interdigitated electrical contacts and heating elements. Electrical characterization measurements were carried out in controlled environment. The results of the gas-sensing tests towards low concentrations of ethanol and acetone vapors are reported. Typical gas sensor parameters (gas responses, response/recovery time, sensitivity, and low detection limit) towards ethanol and acetone are presented. PMID:22574039

Caricato, Anna Paola; Luches, Armando; Rella, Roberto

2009-01-01

44

Nanoparticle Thin Films for Gas Sensors Prepared by Matrix Assisted Pulsed Laser Evaporation  

PubMed Central

The matrix assisted pulsed laser evaporation (MAPLE) technique has been used for the deposition of metal dioxide (TiO2, SnO2) nanoparticle thin films for gas sensor applications. For this purpose, colloidal metal dioxide nanoparticles were diluted in volatile solvents, the solution was frozen at the liquid nitrogen temperature and irradiated with a pulsed excimer laser. The dioxide nanoparticles were deposited on Si and Al2O3 substrates. A rather uniform distribution of TiO2 nanoparticles with an average size of about 10 nm and of SnO2 nanoparticles with an average size of about 3 nm was obtained, as demonstrated by high resolution scanning electron microscopy (SEM-FEG) inspections. Gas-sensing devices based on the resistive transduction mechanism were fabricated by depositing the nanoparticle thin films onto suitable rough alumina substrates equipped with interdigitated electrical contacts and heating elements. Electrical characterization measurements were carried out in controlled environment. The results of the gas-sensing tests towards low concentrations of ethanol and acetone vapors are reported. Typical gas sensor parameters (gas responses, response/recovery time, sensitivity, and low detection limit) towards ethanol and acetone are presented.

Caricato, Anna Paola; Luches, Armando; Rella, Roberto

2009-01-01

45

Evaluation and generalization of temperature-based methods for calculating evaporation  

NASA Astrophysics Data System (ADS)

Seven temperature-based equations, each representing a typical form, were evaluated and compared for determining evaporation at two climatological stations (Rawson Lake and Atikokan) in north-western Ontario, Canada. The comparison was first made using the original constant values involved in each equation, and then using the recalibrated constant values. The results show that when the original constant values were used, larger biases existed for most of the equations for both stations. When recalibrated constant values were substituted for the original constant values, six of the seven equations improved for both stations. Using locally calibrated parameter values, all seven equations worked well for determining mean seasonal evaporation values. For monthly evaporation values, the modified Blaney-Criddle method produced least error for all months for both stations, followed by the Hargreaves and Thornthwaite methods. The Linacre, Kharrufa and Hamon methods showed a significant bias in September for both stations. With properly determined constant values, the modified Blaney-Criddle, the Hargreaves and Thornthwaite methods can be recommended for estimating evaporation in the study region, as far as temperature-based methods are concerned.

Xu, C.-Y.; Singh, V. P.

2001-02-01

46

Is CoRoT-7 B the Remnant Core of an Evaporated Gas Giant?  

NASA Astrophysics Data System (ADS)

The recently discovered planet CoRoT-7 b has a density (5.7 g/cc) consistent with a rocky composition (Leger et al. 2009; Queloz et al. 2009). However, CoRoT-7 b's semi-major axis (0.0172 AU) suggests the planet has a history unlike the planets in our solar system. The strong stellar insolation received by CoRoT-7 b can quickly drive off an atmosphere and may have evaporated a few Earth masses of rocky material during the planet's lifetime. Such rapid mass loss even suggests that CoRoT-7 b may be the remnant core of a hot Jupiter whose gaseous envelope was completely evaporated. Also important are tides, which have drawn the planet in from a more distant, and possibly eccentric, orbit. As the planet neared its host star, the rate of mass loss probably increased dramatically, but mass loss slows tidal migration, resulting in a complex interplay between tides and mass loss. We combine tidal evolution and mass loss models to constrain the range of original orbits and masses of CoRoT-7 b and find, indeed, that CoRoT-7 b may once have been a gas giant planet. We discuss the plausible evolutionary pathways that allow CoRoT-7 b to have begun life as a gas giant. Our results suggest that similar processes may have influenced many other close-in exoplanets as well. Studying the coupled processes of mass loss and tidal migration may thus be crucial to unraveling the origins of the hundreds of hot super-Earths that may soon be discovered by the Kepler and CoRoT missions.

Jackson, Brian; Barnes, R.; Raymond, S. N.; Fortney, J.; Greenberg, R.

2010-01-01

47

Vertical alignment of reduced graphene oxide/Fe-oxide hybrids using the magneto-evaporation method.  

PubMed

We developed a new method for fabricating reduced graphene oxide (RGO)/Fe-oxide structures from graphene oxide (GO), and for the simultaneous vertical alignment of the RGOs using a single-step process that involves a magnetic field and the fixation of the aligned structures by means of direct evaporation of the films. PMID:21451854

Youn, Sang Cheon; Kim, Dae Woo; Yang, Seung Bo; Cho, Hye Mi; Lee, Jae Hyun; Jung, Hee-Tae

2011-05-14

48

Annatto Polymeric Microparticles: Natural Product Encapsulation by the Emulsion-Solvent Evaporation Method  

ERIC Educational Resources Information Center

In this experiment, the extract from annatto seeds was encapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) particles by the emulsion-solvent evaporation method. The particles were washed and centrifuged to remove excess stabilizer and then freeze-dried. The main compound of annatto seeds, bixin, has antioxidant properties as well…

Teixeira, Zaine; Duran, Nelson; Guterres, Silvia S.

2008-01-01

49

Screening of anthropogenic compounds in polluted sediments and soils by flash evaporation\\/pyrolysis gas chromatography-mass spectrometry  

Microsoft Academic Search

The use of flash evaporation and pyrolysis gas chromatography-mass spectrometry as a fast screening procedure for anthropogenic substances in environmental samples is demonstrated by the analysis of polluted soil and sediment samples. Polycyclic aromatic hydrocarbons, haloorganics, aliphatic hydrocarbons, heteroaromatics, elemental sulfur, cyanides, and pyrolysis products of synthetic polymers are among the anthropogenic substances that can be readily detected by this

J. W. de Leeuw; E. W. B. de Leer; J. S. Sinninghe. Damste; P. J. W. Schuyl

1986-01-01

50

Measuring sub-canopy evaporation in a forested wetland using an ensemble of methods  

NASA Astrophysics Data System (ADS)

Evaporation from the sub-canopy water surface is an integral but understudied component of the water balance in forested wetlands. Previous studies have used eddy covariance, energy balance approaches, and water-table fluctuations to assess whole-system evapotranspiration. However, partitioning evaporation from transpiration is necessary for modeling the system because of different controls over each process. Sub-canopy evaporation is a physically controlled process driven by relatively small gradients in residual energy transmitted through the canopy. The low-energy sub-canopy environment is characterized by a spatiotemporally varying light environment due to sunflecks, small and often inverse temperature and vapor gradients, and a high capacity for heat storage in flood water, which each present challenges to common evapotranspiration measurement techniques. Previous studies have examined wetland surface evaporation rates with small lysimeter experiments, but this approach does not encapsulate micrometeorological processes occurring at the scale of natural wetlands. In this study, we examine a one year time series of in situ sub-canopy flux measurements from a seasonally flooded cypress-tupelo swamp in southeast Louisiana. Our objective is to apply these data towards modeling sub-canopy energy flux responses to intra-annual hydrologic, phenologic, and climatic cycles. To assess and mitigate potential errors due to the inherent measurement challenges of this environment, we utilized multiple measurement approaches including eddy covariance, Bowen ratio energy balance (with both air to air gradients and water surface to air gradients) and direct measurement using a floating evaporation pan. Preliminary results show that Bowen ratio energy balance measurements are useful for constraining evaporation measurements when low wind speed conditions create a non-ideal setting for eddy covariance. However, Bowen ratios were often highly erratic due to the weak temperature and humidity gradients. This suggests the need to use combined methods during periods with problematic boundary layer conditions.

Allen, S. T.; Edwards, B.; Reba, M. L.; Keim, R.

2013-12-01

51

Estimation of evaporation from open water - A review of selected studies, summary of U.S. Army Corps of Engineers data collection and methods, and evaluation of two methods for estimation of evaporation from five reservoirs in Texas  

USGS Publications Warehouse

Organizations responsible for the management of water resources, such as the U.S. Army Corps of Engineers (USACE), are tasked with estimation of evaporation for water-budgeting and planning purposes. The USACE has historically used Class A pan evaporation data (pan data) to estimate evaporation from reservoirs but many USACE Districts have been experimenting with other techniques for an alternative to collecting pan data. The energy-budget method generally is considered the preferred method for accurate estimation of open-water evaporation from lakes and reservoirs. Complex equations to estimate evaporation, such as the Penman, DeBruin-Keijman, and Priestley-Taylor, perform well when compared with energy-budget method estimates when all of the important energy terms are included in the equations and ideal data are collected. However, sometimes nonideal data are collected and energy terms, such as the change in the amount of stored energy and advected energy, are not included in the equations. When this is done, the corresponding errors in evaporation estimates are not quantifiable. Much simpler methods, such as the Hamon method and a method developed by the U.S. Weather Bureau (USWB) (renamed the National Weather Service in 1970), have been shown to provide reasonable estimates of evaporation when compared to energy-budget method estimates. Data requirements for the Hamon and USWB methods are minimal and sometimes perform well with remotely collected data. The Hamon method requires average daily air temperature, and the USWB method requires daily averages of air temperature, relative humidity, wind speed, and solar radiation. Estimates of annual lake evaporation from pan data are frequently within 20 percent of energy-budget method estimates. Results of evaporation estimates from the Hamon method and the USWB method were compared against historical pan data at five selected reservoirs in Texas (Benbrook Lake, Canyon Lake, Granger Lake, Hords Creek Lake, and Sam Rayburn Lake) to evaluate their performance and to develop coefficients to minimize bias for the purpose of estimating reservoir evaporation with accuracies similar to estimates of evaporation obtained from pan data. The modified Hamon method estimates of reservoir evaporation were similar to estimates of reservoir evaporation from pan data for daily, monthly, and annual time periods. The modified Hamon method estimates of annual reservoir evaporation were always within 20 percent of annual reservoir evaporation from pan data. Unmodified and modified USWB method estimates of annual reservoir evaporation were within 20 percent of annual reservoir evaporation from pan data for about 91 percent of the years compared. Average daily differences between modified USWB method estimates and estimates from pan data as a percentage of the average amount of daily evaporation from pan data were within 20 percent for 98 percent of the months. Without any modification to the USWB method, average daily differences as a percentage of the average amount of daily evaporation from pan data were within 20 percent for 73 percent of the months. Use of the unmodified USWB method is appealing because it means estimates of average daily reservoir evaporation can be made from air temperature, relative humidity, wind speed, and solar radiation data collected from remote weather stations without the need to develop site-specific coefficients from historical pan data. Site-specific coefficients would need to be developed for the modified version of the Hamon method.

Harwell, Glenn R.

2012-01-01

52

Evaluation of evaporation estimation methods for a covered reservoir in a semi-arid climate (south-eastern Spain)  

NASA Astrophysics Data System (ADS)

SummaryThe main purpose of this study was to evaluate different methods of evaporation estimation for covered water reservoirs. A reservoir equipped with a suspended cover was fully monitored to register the evaporation rate and microclimate below the cover. The datasets were used to evaluate the performance of commonly used evaporation methods, namely energy budget, mass-transfer, combination (Penman and FAO-56 Penman-Monteith) and floating class-A pan. The mass-transfer formula based on the Sherwood number proposed for free convection conditions, which were observed to prevail below the cover, supplied reasonably good estimates of covered reservoir evaporation and it is a good option from a practical point of view, with low input data requirements. Detailed input data and modifications in the calculation of energy fluxes are required to get good evaporation estimations of covered surfaces with the energy budget and FAO-56 Penman-Monteith methods. Besides, some of the standard meteorological input data (such as wind speed at 2 m height) cannot be registered below the cover. Penman equation presented a poor performance related to the overestimation of the advective component for free convection conditions. The pan evaporation was found to be substantially higher than the reservoir evaporation, due to the particular characteristics of the tank, that increased surface temperature and hence evaporation rate. A simplified empirical mass-transfer formula was also proposed to estimate evaporation of covered water bodies from the only knowledge of the surface-to-air mixing ratio gradient.

Gallego-Elvira, B.; Baille, A.; Martín-Gorriz, B.; Maestre-Valero, J. F.; Martínez-Alvarez, V.

2012-08-01

53

DEVELOPMENT, CHARACTERIZATION AND SOLUBILITY STUDY OF SOLID DISPERSIONS OF AZITHROMYCIN DIHYDRATE BY SOLVENT EVAPORATION METHOD  

PubMed Central

Azithromycin Dihydrate (Poorly water soluble drug), when prepared as solid dispersion showed improved solubility and dissolution. So the main purpose of this investigation was to increase the solubility and dissolution rate of Azithromycin Dihydrate by the preparation of its solid dispersion with urea using solvent evaporation method. Physical mixtures and solid dispersions of Azithromycin Dihydrate were prepared by using urea as water-soluble carrier in various proportions (1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7 by weight), by employing solvent evaporation method. The drug release profile was studied and it was found that the dissolution rate and the dissolution parameters of the drug from the physical mixture as well as solid dispersion were higher than those of the intact drug. FT- IR spectra revealed no chemical incompatibility between drug and urea. Drug-polymer interactions were investigated using differential scanning calorimetry (DSC) and Powder X-Ray Diffraction (PXRD).

Arora, S.C.; Sharma, P.K.; Irchhaiya, Raghuveer; Khatkar, Anurag; Singh, Neeraj; Gagoria, Jagbir

2010-01-01

54

Single crystal growth of MgB 2 by evaporating Mg-flux method  

Microsoft Academic Search

Well hexagonal plate-shaped single crystal of magnesium diboride (MgB2) with the size of 100?m has been grown at ambient pressure by evaporating Mg-flux method which is a new practice to grow MgB2 single crystal. The superconducting transition of as-prepared crystals was measured to be at about 33.7K by superconducting quantum interference device (dc-SQUID) magnetometer. The X-ray powder diffraction (XRD) confirmed

Wei Du; Huizhong Xu; Hongbin Zhang; Dong Xu; Xinqiang Wang; Xianqin Hou; Yongzhong Wu; Fuyi Jiang; Lianjie Qin

2006-01-01

55

ARE LARGE, COMETARY-SHAPED PROPLYDS REALLY (FREE-FLOATING) EVAPORATING GAS GLOBULES?  

SciTech Connect

We report the detection of strong and compact molecular line emission (in the CO J = 3-2, 4-3, 6-5, 7-6, {sup 13}CO J = 3-2, HCN, and HCO{sup +} J = 4-3 transitions) from a cometary-shaped object (Carina-frEGG1) in the Carina star-forming region (SFR) previously classified as a photoevaporating protoplanetary disk (proplyd). We derive a molecular mass of 0.35 M{sub Sun} for Carina-frEGG1, which shows that it is not a proplyd, but belongs to a class of free-floating evaporating gas globules (frEGGs) recently found in the Cygnus SFR by Sahai et al. Archival adaptive optics near-IR (Ks) images show a central hourglass-shaped nebula. The derived source luminosity (about 8-18 L{sub Sun }), the hourglass morphology, and the presence of collimated jets seen in Hubble Space Telescope images imply the presence of a jet-driving, young, low-mass star deeply embedded in the dust inside Carina-frEGG1. Our results suggest that the true nature of many or most such cometary-shaped objects seen in massive SFRs and previously labeled as proplyds has been misunderstood, and that these are really frEGGs.

Sahai, R. [Jet Propulsion Laboratory, MS 183-900, California Institute of Technology, Pasadena, CA 91109 (United States); Guesten, R. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Morris, M. R., E-mail: raghvendra.sahai@jpl.nasa.gov [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547 (United States)

2012-12-20

56

Are Large, Cometary-shaped Proplyds Really (Free-floating) Evaporating Gas Globules?  

NASA Astrophysics Data System (ADS)

We report the detection of strong and compact molecular line emission (in the CO J = 3-2, 4-3, 6-5, 7-6, 13CO J = 3-2, HCN, and HCO+ J = 4-3 transitions) from a cometary-shaped object (Carina-frEGG1) in the Carina star-forming region (SFR) previously classified as a photoevaporating protoplanetary disk (proplyd). We derive a molecular mass of 0.35 M ? for Carina-frEGG1, which shows that it is not a proplyd, but belongs to a class of free-floating evaporating gas globules (frEGGs) recently found in the Cygnus SFR by Sahai et al. Archival adaptive optics near-IR (Ks) images show a central hourglass-shaped nebula. The derived source luminosity (about 8-18 L ?), the hourglass morphology, and the presence of collimated jets seen in Hubble Space Telescope images imply the presence of a jet-driving, young, low-mass star deeply embedded in the dust inside Carina-frEGG1. Our results suggest that the true nature of many or most such cometary-shaped objects seen in massive SFRs and previously labeled as proplyds has been misunderstood, and that these are really frEGGs.

Sahai, R.; Güsten, R.; Morris, M. R.

2012-12-01

57

Integration of Heat-Pulse and Sensible Heat Balance Methods to Estimate Evaporation From Bare Soils  

NASA Astrophysics Data System (ADS)

A critical component of the water cycle at local, regional and global scales is evaporation from soil. Because it is very difficult to measure soil evaporation and soil moisture in the field, with the exception of using a lysimeter for local measurements, numerous model based estimation methods have been proposed. Numerical approaches that attempt to estimate evaporation rates within the top several centimeters of soil often rely of empirical and semi-empirical methods. Another less well known method to determine evaporation relies on heat pulse sensors to measure soil temperature and thermal properties. This approach does not rely on knowledge of soil hydraulic properties, effectively removing the need of several common empirical methods to define the soil surface boundary condition. The objective of this study was to integrate both the heat-pulse and sensible heat balance methods into a non-isothermal multiphase flow model in order to define the boundary conditions at the land/atmosphere interface. This model was tested using precision experimental data collected under laboratory conditions and compared to more traditional numerical modeling approaches. Experimental data was generated in a two-dimensional soil tank containing an array of sensors that allowed soil temperature, soil moisture content, and relative humidity to be collected continuously and autonomously. The soil tank was placed within a wind tunnel test facility to insure that atmospheric conditions were carefully controlled and monitored throughout the duration of the experiment. Numerical results of the model using the heat pulse and sensible heat balance methods were compared to those generated using different, more traditional modeling approaches. Results demonstrate the applicability of incorporating the heat-pulse and sensible heat balance methods in numerical approaches. Further validation was provided through a comparison of the numerical results and independently determined experimental results. This numerical approach shows great ability to accurately predict soil-water evaporation rates at fine spatial and temporal scales. Results of this study will be used in future research for larger, more complex atmospheric conditions and soil heterogeneities.

Trautz, A.; Smits, K. M.; Schulte, P.; Cihan, A.; Illangasekare, T. H.

2012-12-01

58

Coupled water and heat flow in laboratory evaporation experiments and its effects on soil hydraulic properties estimated by the simplified evaporation method  

NASA Astrophysics Data System (ADS)

The prediction of water fluxes in the field requires an accurate determination of soil hydraulic parameters which define the soil water retention and hydraulic conductivity function. The evaporation method has become a standard tool to quickly and reliably determine soil hydraulic properties in the wet to medium pressure head range. Recently, the method has profited from a significant improvement of soil sensors and data evaluation methods. In most cases, the data obtained from a transient evaporation experiment are evaluated using simplifying assumptions, like the ones implicit to Schindler's or Wind's methods. In the past, the effect of these simplifications on the identification of hydraulic properties has been investigated and found to be relatively minor. These studies were based on the evaluation of computer-generated data which were created by numerical modeling of the evaporation process with the Richards equation, i.e. by assuming isothermal liquid flow. Since evaporation from bare soil will always lead to loss of energy, the assumption of constant temperature is questionable. In addition, the effects of thermal and vapor fluxes on simplified evaluation methods have so far hardly been investigated. In this contribution we analyze the effects of (1) coupled heat and water flow and (2) temperature effects on physical parameters. We firstly generated data by a numerical model which solves the coupled heat and water flow problem first derived by Philip and de Vries, and then used these data as source for the estimation of hydraulic properties with the evaluation methods of Schindler and Wind. The virtual realities covered different atmospheric forcings like changing wind speed and varying incoming shortwave radiation. The objective of this study was to identify under which atmospheric conditions, for which soil textures, and in which pressure head range the simplified evaluation methods lead to unbiased estimates of the soil hydraulic properties.

Iden, Sascha C.; Blöcher, Johanna; Diamantopoulos, Efstathios; Durner, Wolfgang

2014-05-01

59

Toward the Impact of Fuel Evaporation-Combustion Interaction on Spray Combustion in Gas Turbine Combustion Chambers. Part I: Effect of Partial Fuel Vaporization on Spray Combustion  

Microsoft Academic Search

\\u000a This work aims at investigating the impact of the interaction between evaporation process and combustion on spray combustion\\u000a characteristics in gas turbine combustion chambers. It is subdivided into two parts. The first part studies how the evaporation\\u000a process affects the behavior of partially pre-vaporized spray combustion. The second part attempts to answer the question\\u000a how the fuel evaporation process behaves

Amsini Sadiki; W. Ahmadi; Mouldi Chrigui; J. Janicka

60

Gas-evaporation in low-gravity field (cogelation mechanism of metal vapors) (M-14)  

NASA Technical Reports Server (NTRS)

When metal and alloy compounds are heated and vaporized in a rare gas such as helium, argon, or xenon, the vaporized substances diffused in the rare gas are supersaturated resulting in a smoke of fine particles of the material congealing as snow or fog. The gas vaporizing method is a fine particle generation method. Though the method has a variety of applications, the material vapor flow is disturbed by gravitational convection on Earth. The inability to elucidate the fine particle generation mechanism results in an obstruction to improving the method to mass production levels. As no convection occurs in microgravity in space, the fine particle generation mechanism influenced only by diffusion can be investigated. Investigators expect that excellent particles with homogeneous diameter distribution can be obtained. Experiment data and facts will assist in improving efficiency, quality, and scale or production processes including element processes such as vaporization, diffusion, and condensation. The objective of this experiment is to obtain important information related to the mechanism of particle formation in the gas atmosphere (smoke particles) and the production of submicron powders of extremely uniform size.

Wada, N.

1993-01-01

61

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

62

One-step Double-layer Thermal Evaporation Method for Organic Light Emitting Diodes  

NASA Astrophysics Data System (ADS)

A new one-step double-layer thermal evaporation method was used to fabricate organic light emitting diodes (OLEDs) with device structure of: ITO (anode)/N,N_-diphenyl-N,N_-bis(3-methylphenyl)-1,1_-diphenyl-4,4_-diamine (TPD) /tris-(8-hydroxyquinoline)aluminum(3) (Alq3)/Al (cathode). These OLEDs were fabricated in cleanroom on the ITO-coated glass with a sheet resistivity of 20?/sq and an optical transmittance of 90%. The I-V and brightness characteristic showed that the new method could produce better performance achieving lower turn-on voltage (-2V), higher peak current efficiency (+29%) and higher brightness (+36%).

Kee, Y. Y.; Yong, T. K.; Ong, D. S.; Tou, T. Y.

2011-03-01

63

Shocked and Scorched - Free-Floating Evaporating Gas Globules and StarFormation  

NASA Astrophysics Data System (ADS)

Massive stars have a strong feedback effect on their environment, via their winds, UV radiation, and ultimately, supernova blast waves, all of which can alter the likelihood for the formation of stars in nearby clouds and limit the accretion process of nearby protostars. Free-floating Evaporating Gaseous Globules, or frEGGs, are a newly recognized class of stellar nurseries embedded within the giant HII regions found in massive star-formation region (MSFRs). We recently discovered the prototype frEGG in the Cygnus MSFR with HST. Further investigation using the Spitzer and Herschel archives have revealed a much larger number (>50) in Cygnus and other MSFRs. Our molecular-line observations of these show the presence of dense clouds with total masses of cool molecular gas exceeding 0.5 to a few Msun associated with these objects, thereby disproving the initial hypothesis based on their morphology that these have an origin similar to the proplyds (cometary-shaped photoevaporating protoplanetary disks) found in Orion. We report the results of our molecular-line studies and detailed high-resolution optical (with HST) or near-IR (with AO at the Keck Observatory) imaging of a few frEGGs in Cygnus, Carina and the W5 MSFRs. The images show the presence of young stars with associated outflow cavities and/or jets in the heads of the tadpole-shaped frEGGs. These results support our hypothesis that frEGGs are density concentrations originating in giant molecular clouds, that, when subject to the compression by the strong winds and ionization from massive stars in these MSFRs, become active star-forming cores. In summary, by virtue of their distinct, isolated morphologies, frEGGs offer us a clean probe of triggered star formation on small scales in the vicinity of massive stars.

Sahai, Raghvendra; Morris, Mark

2014-07-01

64

Preparation of AgInSe2 thin films grown by vacuum evaporation method  

NASA Astrophysics Data System (ADS)

Polycrystalline AgInSe2 thin films were successfully grown on glass substrates by an evaporation method. The starting materials were stoichiometrically mixed Ag2Se and In2Se3 powders. X-ray diffraction revealed that the sample annealed at 600 °C consisted of AgInSe2 single phase, with (112) orientation and a large grain size. The lattice constant (a axis) was close to JCPDS values. From optical transmittance and reflectance measurements, the bandgap energy was estimated to be 1.17 eV.

Matsuo, H.; Yoshino, K.; Ikari, T.

2006-09-01

65

Waste Disposal Study. Evaluation of Methods to Recover Reusable Chemicals from Evaporated Photowastes.  

National Technical Information Service (NTIS)

The feasibility of recovering usable chemicals from evaporated photoprocessing wastes was studied. About 50-70% of the evaporated waste consists of sodium thiosulfate and sodium sulfite. Recovery of thiosulfate and sulfite was achieved via solubilization ...

G. A. Lorenzo T. N. Hendrickson

1976-01-01

66

Effect of oxides on the adhesion of Cu films deposited onto stainless steel by electron shower and thermal evaporation methods  

Microsoft Academic Search

When Cu films were deposited by thermal evaporation onto stainless steel substrates at 30°C, the oxygen gas in the vacuum chamber (1.5 x 10 Torr) caused the adhesion of Cu films to increase from 3 to 5 MPa. Moreover, it increased further from 13 to 16 MPa when deposited at 300°C. The Cu film was not peeled off when deposited

H. Yumoto; S. Shimada; C. Minami; T. Inoue; S. J. Li; M. Ishihara

1997-01-01

67

Preparation of 3,4-diaminopyridine microparticles by solvent-evaporation methods.  

PubMed

The present study compares two methods of preparation of microparticles of 3,4-diaminopyridine (3,4-DAP) for the treatment for multiple sclerosis and Lambert-Eaton myasthenia syndrome. Poly( epsilon -caprolactone) microparticles were prepared with a solvent-evaporation W/O method. The 3,4-DAP was dispersed in dichloromethane, leading to a suspension. The dispersion and the solidification of the dichloromethane droplets in an aqueous phase have led to microparticles of 55.3+/-34.7 microm. The incorporation of the drug by milligram of powder was very low (1.91 micrograms/mg) and the scanning electron microscopy (SEM) did not show any crystal but marks of dissolved crystals were observed on the polymeric surface. EudragitRS microspheres containing 3,4-DAP were prepared by a solvent-evaporation technique using light mineral oil as continuous phase. The drug and the polymer were completely dissolved in an acetone solution, used as discontinuous phase. This formulation have led to a higher incorporation of the drug (88.25 micrograms/mg). The particle size was 91.8+/-44.3 microm. The observation, by SEM, shows many crystals on the surface and inside the microparticles. A slow-release of the drug in a phosphate buffer pH 7.4 was observed (50% in 60 min and about 70% in 4 h). PMID:12176246

Gibaud, Stéphane; Bonneville, Aurélie; Astier, Alain

2002-08-21

68

Nanoprecipitation is more efficient than emulsion solvent evaporation method to encapsulate cucurbitacin I in PLGA nanoparticles  

PubMed Central

Cucurbitacin I is a hydrophobic molecule that exerts a degree of polarity, which is expected to complicate its loading in PLGA nanoparticles by the classical emulsion solvent evaporation technique. In the current study, variants of emulsion solvent evaporation method were used to prepare PLGA nanoparticles of cucurbitacin: CI-NP1 (single emulsion starting with 1000 ?g drug), CI-NP2 (double emulsion starting with 250 ?g drug), and CI-NP3 (double emulsion starting with 500 ?g drug). On the other hand, CI-NP4 was prepared by nanoprecipitation (starting with 1000 ?g drug). In CI-NP1, cucurbitacin I encapsulation efficiency (EE) was 1.29%. The employment of double emulsion, in CI-NP2 and CI-NP3, increased cucurbitacin I EE to 4.8% and 7.96%, respectively. Nanoprecipitation significantly increased the EE of cucurbitacin I to 48.79% in CI-NP4. It is likely that cucurbitacin I escapes with the organic solvent after the emulsification step to the aqueous phase leading to ineffective entrapment in the polymeric matrix. Avoiding emulsification seems efficient in increasing cucurbitacin I disposition in the instantly-precipitating NPs. Therefore, nanoprecipitation method increases cucurbitacin I entrapment in PLGA NPs and possibly other water-insoluble polar drugs.

Alshamsan, Aws

2013-01-01

69

Development, characterization and solubility study of solid dispersions of Cefuroxime Axetil by the solvent evaporation method  

PubMed Central

Cefuroxime Axetil (Poorly water soluble drug), when prepared as solid dispersion showed improved solubility and dissolution. Therefore, the main purpose of this investigation was to increase the solubility and dissolution rate of Cefuroxime Axetil by the preparation of its solid dispersion with urea, using the solvent evaporation method. Physical mixtures and solid dispersions of Cefuroxime Axetil were prepared by using urea as a water-soluble carrier in various proportions (1:1, 1:2, 1:3, 1:4, 1:5, 1:6, and 1:7 by weight), by employing the solvent evaporation method. The drug release profile was studied and it was found that the dissolution rate and the dissolution parameters of the drug from the physical mixture as well as solid dispersion were higher than those of the intact drug. The Fourier Transform Infrared (FTIR) spectra revealed no chemical incompatibility between the drug and urea. Drug-polymer interactions were investigated using differential scanning calorimetry (DSC) and Powder X-Ray Diffraction (PXRD).

Arora, S. C.; Sharma, P. K.; Irchhaiya, Raghuveer; Khatkar, Anurag; Singh, Neeraj; Gagoria, Jagbir

2010-01-01

70

Uranium and Calcium Isotope Ratio Measurements using the Modified Total Evaporation Method in TIMS  

NASA Astrophysics Data System (ADS)

A new version of the "modified total evaporation" (MTE) method for isotopic analysis by multi-collector thermal ionization mass spectrometry (TIMS), with high analytical performance and designed in a more user-friendly and routinely applicable way, is described in detail. It is mainly being used for nuclear safeguards measurements of U and Pu and nuclear metrology, but can readily be applied to other scientific tasks in geochemistry, e.g. for Sr, Nd and Ca, as well. The development of the MTE method was organized in collaboration of several "key nuclear mass spectrometry laboratories", namely the New Brunswick Laboratory (NBL), the Institute for Transuranium Elements (ITU), the Safeguards Analytical Laboratory (now Safeguards Analytical Services, SGAS) of the International Atomic Energy Agency (IAEA) and the Institute for Reference Materials and Measurements (IRMM), with IRMM taking the leading role. The manufacturer of the TRITON TIMS instrument, Thermo Fisher Scientific, integrated this method into the software of the instrument. The development has now reached its goal to become a user-friendly and routinely useable method for uranium isotope ratio measurements with high precision and accuracy. Due to the use of the “total evaporation” (TE) method the measurement of the "major" uranium isotope ratio 235U/238U is routinely being performed with a precision of 0.01% to 0.02%. The use of a (certified) reference material measured under comparable conditions is emphasized to achieve an accuracy at a level of 0.02% - depending on the stated uncertainty of the certified value of the reference material. In contrast to the total evaporation method (TE), in the MTE method the total evaporation sequence is interrupted on a regular basis to allow for correction for background from peak tailing, internal calibration of a secondary electron multiplier (SEM) detector versus the Faraday cups, and ion source re-focusing. Therefore, the most significant improvement using the MTE method is in the analytical performance achieved for the "minor" ratios 234U/238U and 236U/238U. The MTE method is now routinely used at all collaborating laboratories and possibly more in the future. Additional applications for the MTE method, e.g. to take advantage of the good external precision in combination with the possibilities of internal background and detector calibrations or mass jumps between different cup configurations, are presented as well. One interesting application concerns new absolute isotope ratio measurements for Ca with an unprecedented level of accuracy. This is important because up to now most reported Ca isotope data are only calculated as relative deviations from a standard like NIST-SRM 915. Using the MTE method measurements on new gravimetrically prepared Ca isotope mixtures were performed. A significantly improved level of accuracy at the level of about 0.02% for both the 42Ca/40Ca and 44Ca/40Ca ratios was obtained.

Richter, S.; Kuehn, H.; Berglund, M.; Hennessy, C.

2010-12-01

71

Method and apparatus for fuel gas moisturization and heating  

DOEpatents

Fuel gas is saturated with water heated with a heat recovery steam generator heat source. The heat source is preferably a water heating section downstream of the lower pressure evaporator to provide better temperature matching between the hot and cold heat exchange streams in that portion of the heat recovery steam generator. The increased gas mass flow due to the addition of moisture results in increased power output from the gas and steam turbines. Fuel gas saturation is followed by superheating the fuel, preferably with bottom cycle heat sources, resulting in a larger thermal efficiency gain compared to current fuel heating methods. There is a gain in power output compared to no fuel heating, even when heating the fuel to above the LP steam temperature.

Ranasinghe, Jatila (Niskayuna, NY); Smith, Raub Warfield (Ballston Lake, NY)

2002-01-01

72

Dissociation of temperature-gradient and evaporative heat loss during cold gas hyperventilation in cold-induced asthma.  

PubMed

We examined temperature-gradient and evaporative energy losses during cold gas inhalation challenges in patients with exercise-induced asthma by using gases with similar water-carrying capacities but significantly different volume heat capacities. Seven subjects were asked to hyperventilate mixtures of 80% helium/20% oxygen (HeO2) or 80% sulfur hexafluoride/20% oxygen (SF6O2) for 5 min at a fixed target minute ventilation of 20 x FEV1 and an inspired gas temperature of 0 degrees C. Each subject equilibrated his or her lungs with the appropriate gas mixture prior to testing: PETCO2 and FIO2 were monitored and maintained at constant values (CO2 = 0.05; O2 = 0.20) by CO2 scrubbing and addition of compressed gas to the system. Gas composition, inspired and expired flow rates, and gas temperatures at the airway opening were recorded in real time using a computer-based data collection system that calculated respiratory heat loss on a per breath basis. Bronchoconstriction was quantitated using specific airway conductance measured before and serially after each challenge. The degree of bronchoconstriction correlated closely with evaporative respiratory heat loss (r = 0.658 p less than 0.05), but poorly with both temperature-gradient (r = 0.114, p greater than 0.20) and total (r = 0.268, p greater than 0.15) heat loss. These findings suggest that total respiratory heat loss is not the primary stimulus in exercise-induced asthma, and further suggest that total water loss, or focal heat/water loss, may be important in inducing bronchospasm in this subset of asthmatics. PMID:3202410

Ingenito, E; Solway, J; Lafleur, J; Lombardo, A; Drazen, J M; Pichurko, B

1988-09-01

73

Gas-phase saturation and evaporative cooling effects during wet compression of a fuel aerosol under RCM conditions  

SciTech Connect

Wet compression of a fuel aerosol has been proposed as a means of creating gas-phase mixtures of involatile diesel-representative fuels and oxidizer + diluent gases for rapid compression machine (RCM) experiments. The use of high concentration aerosols (e.g., {proportional_to}0.1 mL{sub fuel}/L{sub gas}, {proportional_to}1 x 10{sup 9} droplets/L{sub gas} for stoichiometric fuel loading at ambient conditions) can result in droplet-droplet interactions which lead to significant gas-phase fuel saturation and evaporative cooling during the volumetric compression process. In addition, localized stratification (i.e., on the droplet scale) of the fuel vapor and of temperature can lead to non-homogeneous reaction and heat release processes - features which could prevent adequate segregation of the underlying chemical kinetic rates from rates of physical transport. These characteristics are dependent on many factors including physical parameters such as overall fuel loading and initial droplet size relative to the compression rate, as well as fuel and diluent properties such as the boiling curve, vaporization enthalpy, heat capacity, and mass and thermal diffusivities. This study investigates the physical issues, especially fuel saturation and evaporative cooling effects, using a spherically-symmetric, single-droplet wet compression model. n-Dodecane is used as the fuel with the gas containing 21% O{sub 2} and 79% N{sub 2}. An overall compression time and compression ratio of 15.3 ms and 13.4 are used, respectively. It is found that smaller droplets (d{sub 0}{proportional_to} 2-3 {mu}m) are more affected by 'far-field' saturation and cooling effects, while larger droplets (d{sub 0}{proportional_to} 14 {mu}m) result in greater localized stratification of the gas-phase due to the larger diffusion distances for heat and mass transport. Vaporization of larger droplets is more affected by the volumetric compression process since evaporation requires more time to be completed even at the same overall fuel loading. All of the cases explored here yield greater compositional stratification than thermal stratification due to the high Lewis numbers of the fuel-air mixtures (Le{sub g} {proportional_to} 3.8). (author)

Goldsborough, S.S. [Department of Mechanical Engineering, Marquette University, Milwaukee, WI (United States); Johnson, M.V. [Energy Systems Division, Argonne National Laboratory, IL (United States); Zhu, G.S. [HDEP Performance and Emissions, DTNA - Detroit Diesel Corporation, Detroit, MI (United States); Aggarwal, S.K. [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 1030 Engineering Research Facility, Chicago, IL (United States)

2011-01-15

74

Gas chemical sensitivity of a CMOS MEMS cantilever functionalized via evaporation driven assembly  

NASA Astrophysics Data System (ADS)

This work demonstrates an electrostatically actuated resonant microcantilever fabricated in a complementary metal oxide semiconductor process and functionalized with a chemically sorbent polymer layer for the detection of volatile organic compounds. Deposition of the chemically sorbent layer is controlled through evaporation-driven assembly. Analytical and finite element analysis models of the deposited polymer layer on the microcantilever resonant frequency and mass sensitivity are presented. Fabrication of the chemical sensor, including a description of polymer deposition through evaporation-driven assembly within a capillary, is detailed. The completely functionalized resonator demonstrates a limit of detection of 1.6 ppm for toluene. An optimal polymer sensitive layer deposition of 42% of the total beam length is measured from frequency instability and sensitivity tests.

Dorsey, K. L.; Bedair, S. S.; Fedder, G. K.

2014-07-01

75

Catalyst free growth of ZnO nanorods by thermal evaporation method  

SciTech Connect

In this work, we report catalyst free growth of ZnO nanorods on n-Si substrate by a low cost thermal evaporation method. The surface morphology, chemical composition and crystalline structure of ZnO nanorods have been determined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) spectroscopy respectively. It is found that, the as -deposited ZnO seed layer reduces lattice mismatching between ZnO and Si from 40.3 to 0.28%, therefore enhances the subsequent growth and crystalline quality of ZnO nanorods on Si substrate. The present methodology is simple, cost effective and highly applicable for synthesis of ZnO nanorods for optoelectronics applications.

Somvanshi, Divya; Jit, S. [Centre for Research in Microelectronics (CRME), Department of Electronics Engineering Indian Institute of Technology (Banaras Hindu University), Varanasi Uttar Pradesh-221005 (India)

2013-06-03

76

Single crystal growth of MgB 2 by evaporating Mg-flux method  

NASA Astrophysics Data System (ADS)

Well hexagonal plate-shaped single crystal of magnesium diboride (MgB 2) with the size of 100 ?m has been grown at ambient pressure by evaporating Mg-flux method which is a new practice to grow MgB 2 single crystal. The superconducting transition of as-prepared crystals was measured to be at about 33.7 K by superconducting quantum interference device (dc-SQUID) magnetometer. The X-ray powder diffraction (XRD) confirmed the MgB 2 phase, and the electron diffraction patterns measured by using high-resolution transmission electron microscope (HRTEM) confirmed the structure of MgB 2 single crystal. The single crystal images were observed by scanning electron microscope (SEM) and metallographic microscope (MM). The micromechanism of crystal growth is also proposed through the investigations of SEM and MM.

Du, Wei; Xu, Huizhong; Zhang, Hongbin; Xu, Dong; Wang, Xinqiang; Hou, Xianqin; Wu, Yongzhong; Jiang, Fuyi; Qin, Lianjie

2006-04-01

77

Fabrication and photoluminescence of P doped ZnO nanobelts by thermal evaporation method  

NASA Astrophysics Data System (ADS)

Uniform and flat single crystal ZnO:P nanobelts (NBs) were fabricated on Si (1 0 0) substrates by the thermal evaporation method. The growth process, free-catalyst self-assembly vapor-solid (V-S) mechanism, was described and investigated deeply in terms of thermodynamics and kinetics. Then, the photoluminescence (PL) properties of ZnO NBs were studied in a temperature range from 10 to 270 K. At 10 K the recombination of acceptor-bound exciton ( A0X) was predominant in the PL spectrum, and was attributed to the transition of P Zn-2V Zn complex bound exciton. The active energy of A0X and acceptor binding energy were calculated to be 17.2 and 172 meV, respectively. The calculated acceptor binding energy of P doped ZnO nanostructure is in good agreement with that of P doped ZnO film.

Zang, C. Y.; Zang, C. H.; Wang, B.; Jia, Z. X.; Yue, S. R.; Li, Y. S.; Yang, H. Q.; Zhang, Y. S.

2011-09-01

78

Catalyst free growth of ZnO nanorods by thermal evaporation method  

NASA Astrophysics Data System (ADS)

In this work, we report catalyst free growth of ZnO nanorods on n-Si substrate by a low cost thermal evaporation method. The surface morphology, chemical composition and crystalline structure of ZnO nanorods have been determined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) spectroscopy respectively. It is found that, the as -deposited ZnO seed layer reduces lattice mismatching between ZnO and Si from 40.3 to 0.28%, therefore enhances the subsequent growth and crystalline quality of ZnO nanorods on Si substrate. The present methodology is simple, cost effective and highly applicable for synthesis of ZnO nanorods for optoelectronics applications.

Somvanshi, Divya; Jit, S.

2013-06-01

79

Evaluation of the energy budget method of determining evaporation at Williams Lake, Minnesota, using alternative instrumentation and study approaches  

USGS Publications Warehouse

Best estimates of evaporation were determined by the energy budget method using optimum sensors and optimum placement of sensors. For most of the data substitutions that affected the Bowen ratio, new values of evaporation differed little from best estimates. The three data substitution methods that caused the largest deviations from the best evaporation estimates were (1) using changes in the daily average surface water temperature as an indicator of the lake heat storage term, (2) using shortwave radiation, air temperature, and atmospheric vapor pressure data from a site 110 km away, and (3) using an analog surface water temperature probe. Recalculations based on these data substitutions resulted in differences from the best estimates as much as 89%, 21% and 10%, respectively. The data substitution method that provided evaporation values that most closely matched the best estimates was measurement of the lake heat storage term at one location in the lake, rather than at 16 locations. Evaporation values resulting from this substitution method usually were within 2% of the best estimates. -from Authors

Rosenberry, D. O.; Sturrock, A. M.; Winter, T. C.

1993-01-01

80

One-dimensional model of evaporation and condensation in the presence of a noncondensable gas with applications to cryogenic fluid storage  

Microsoft Academic Search

This paper considers the one-dimensional flow of vapor between two liquid surfaces due to evaporation and condensation taking into account diffusion through a noncondensable gas and nonequilibrium interfacial kinetics. An explicit relationship is developed for the mass flux J as a function of the characteristic mole ratio of noncondensable gas X, and several simplifications are made to arrive at an

Charles Panzarella; Mohammad Kassemi

2009-01-01

81

The structure and optical properties of silicon ultrafine particles deposited by the gas-evaporation technique with a supersonic jet nozzle  

Microsoft Academic Search

The structure and properties of silicon (Si) ultrafine particles deposited on Si or SiO2 substrates at 300 K by the gas-evaporation technique with a supersonic jet nozzle were studied. The technique is designed to deposit Si ultrafine particles at the supersonic speed, resulting from the differential pressure between the Si evaporation and the Si deposition chamber. The size of Si

Hiroshi Ono; Shinji Nozaki; Hiroshi Morisaki

1997-01-01

82

Laboratory Evaporation of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant.  

National Technical Information Service (NTIS)

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 strea...

C. A. Nash C. L. Crawford D. J. Adamson D. J. McCabe W. R. Wilmarth

2014-01-01

83

Alternative Methods for the Reduction of Evaporation: Practical Exercises for the Science Classroom  

ERIC Educational Resources Information Center

Across the world, freshwater is valued as the most critically important natural resource, as it is required to sustain the cycle of life. Evaporation is one of the primary environmental processes that can reduce the amount of quality water available for use in industrial, agricultural and household applications. The effect of evaporation becomes…

Schouten, Peter; Putland, Sam; Lemckert, Charles J.; Parisi, Alfio V.; Downs, Nathan

2012-01-01

84

Evaluation and generalization of radiation-based methods for calculating evaporation  

NASA Astrophysics Data System (ADS)

Eight radiation-based equations for determining evaporation were evaluated and expressed in five generalized forms. Five evaporation equations (Abtew, Hargreaves, Makkink, Priestley and Taylor and Turc), where each represents one generalized form, were then compared with pan evaporation measured at Changins station in Switzerland. The comparison was first made using the original constant values involved in each equation, and then using the recalibrated constant values. Evaluation of the Priestley and Taylor equation requires net radiation data as input, in this study, net radiation was estimated using Equation (16) owing to the lack of observation data. The results showed that when the original constant values were used, large errors resulted for most of the equations. When recalibrated constant values were substituted for the original constant values, four of the five equations improved greatly, and all five equations performed well for determining mean annual evaporation. For seasonal and monthly evaporation, the Hargreaves and Turc equations showed a significant bias, especially for cold months. With properly determined constant values, the Makkink and modified Priestley and Taylor equations resulted in monthly evaporation values that agreed most closely with pan evaporation in the study region. The simple Abtew equation can also be used when other meteorological data except radiation are not available.

Xu, C.-Y.; Singh, V. P.

2000-02-01

85

Interface conditions governing evaporation of stored liquids in presence of non-condensable gas  

Microsoft Academic Search

Experiments were conducted to determine the variation of interface temperatures during the storage and draining of liquid nitrogen from large containers in the presence of the non-condensable gas. A chilled layer was seen to be formed at the interface in the presence of the non-condensable gas and this layer advanced into the warm liquid at speeds higher than the characteristic

K. Ramamurthi; S. Sunil Kumar; B. S. Chaitanya

2006-01-01

86

Study of n-ZnO/ p-SiNW heterostructures grown by thermal evaporation method  

NASA Astrophysics Data System (ADS)

Recently SiNW (silicon nanowire) based devices have attracted great attention in the development of novel nanoelectronic devices due to their unique one-dimensional nature and associated electrical and optical properties compared to bulk silicon. In this work, n-type ZnO (Zinc Oxide) nanowire (NW) thin film was grown on p-type SiNW (silicon nanowire) arrays by simple and cost effective thermal evaporation method to obtain an n-ZnONW/ p-SiNW based heterojunction diode without using any seed layer. The SiNW arrays used for the growth of ZnONWs were developed on a p-Si wafer by using the electroless etching method. The large area ohmic contacts at top and bottom of the structure were fabricated by depositing silver and aluminium respectively. The SEM and XRD data demonstrate a good crystalline quality of the ZnONWs grown on the SiNWs. The current-voltage characteristics of the nanowire-based heterostructure device show the non-ideal diode characteristics with a high current rectification ratio of 190 and a low leakage current of 1.86×10-8 A.

Hazra, Purnima; Jit, S.

2013-06-01

87

Fabrication and characterization of bismuth–telluride-based alloy thin film thermoelectric generators by flash evaporation method  

Microsoft Academic Search

Bismuth–telluride-based alloy thin film thermoelectric generators are fabricated by a flash evaporation method. We prepare Bi0.4Te3.0Sb1.6 (p-type) and Bi2.0Te2.7Se0.3 (n-type) powders for the fabrication of the flash evaporated thin films. The overall size of the thin film thermoelectric generators, which consist of seven pairs of legs connected by aluminum electrodes, is 20mm by 15mm. Each leg is 15mm long, 1mm

M. Takashiri; T. Shirakawa; K. Miyazaki; H. Tsukamoto

2007-01-01

88

A comparison of short-term measurements of lake evaporation using eddy correlation and energy budget methods  

USGS Publications Warehouse

Concurrent short-term measurements of evaporation from a shallow lake, using eddy correlation and energy budget methods, indicate that sensible and latent heat flux between lake and atmosphere, and energy storage in the lake, may vary considerably across the lake. Measuring net radiation with a net radiometer on the lake appeared to be more accurate than measuring incoming radiation nearby and modeling outgoing radiation. Short-term agreement between the two evaporation measurements was obtained by using an energy storage term that was weighted to account for the area-of-influence of the eddy correlation sensors. Relatively short bursts of evaporation were indicated by the eddy correlation sensors shortly after midnight on two of three occasions. ?? 1991.

Stannard, D. I.; Rosenberry, D. O.

1991-01-01

89

Synthesis gas method and apparatus  

DOEpatents

A method and apparatus for producing a synthesis gas product having one or more oxygen transport membrane elements thermally coupled to one or more catalytic reactors such that heat generated from the oxygen transport membrane element supplies endothermic heating requirements for steam methane reforming reactions occurring within the catalytic reactor through radiation and convention heat transfer. A hydrogen containing stream containing no more than 20 percent methane is combusted within the oxygen transport membrane element to produce the heat and a heated combustion product stream. The heated combustion product stream is combined with a reactant stream to form a combined stream that is subjected to the reforming within the catalytic reactor. The apparatus may include modules in which tubular membrane elements surround a central reactor tube.

Kelly, Sean M.; Kromer, Brian R.; Litwin, Michael M.; Rosen, Lee J.; Christie, Gervase Maxwell; Wilson, Jamie R.; Kosowski, Lawrence W.; Robinson, Charles

2013-01-08

90

A Comparison of Methods for Estimating Open-Water Evaporation in Small Wetlands  

Microsoft Academic Search

We compared evaporation measurements from a floating pan, land pan, chamber, and the Priestley-Taylor (PT) equation. Floating\\u000a pan, land pan, and meteorological data were collected from June 6 to July 21, 2005, at a small wetland in the Canadian River\\u000a alluvium in central Oklahoma, USA. Evaporation measured with the floating pan compared favorably to 12 h chamber measurements.\\u000a Differences between chamber

Jason R. Masoner; David I. Stannard

2010-01-01

91

Preparation of Protein-Stabilized ?-Carotene Nanodispersions by Emulsification–Evaporation Method  

Microsoft Academic Search

This work was initiated to prepare protein-stabilized ?-carotene nanodispersions using emulsification–evaporation. A pre-mix\\u000a of the aqueous phase composed of a protein and hexane containing ?-carotene was subjected to high-pressure homogenization\\u000a using a microfluidizer. Hexane in the resulting emulsion was evaporated under reduced pressures, causing crystallization and\\u000a precipitation of ?-carotene inside the droplets and formation of ?-carotene nanoparticles. Sodium caseinate (SC)

Boon-Seang Chu; Sosaku Ichikawa; Sumiyo Kanafusa; Mitsutoshi Nakajima

2007-01-01

92

Could CoRoT-7b and Kepler-10b be remnants of evaporated gas or ice giants?  

PubMed Central

We present thermal mass loss calculations over evolutionary time scales for the investigation if the smallest transiting rocky exoplanets CoRoT-7b (?1.68REarth) and Kepler-10b (?1.416REarth) could be remnants of an initially more massive hydrogen-rich gas giant or a hot Neptune-class exoplanet. We apply a thermal mass loss formula which yields results that are comparable to hydrodynamic loss models. Our approach considers the effect of the Roche lobe, realistic heating efficiencies and a radius scaling law derived from observations of hot Jupiters. We study the influence of the mean planetary density on the thermal mass loss by placing hypothetical exoplanets with the characteristics of Jupiter, Saturn, Neptune, and Uranus to the orbital location of CoRoT-7b at 0.017 AU and Kepler-10b at 0.01684 AU and assuming that these planets orbit a K- or G-type host star. Our findings indicate that hydrogen-rich gas giants within the mass domain of Saturn or Jupiter cannot thermally lose such an amount of mass that CoRoT-7b and Kepler-10b would result in a rocky residue. Moreover, our calculations show that the present time mass of both rocky exoplanets can be neither a result of evaporation of a hydrogen envelope of a “Hot Neptune” nor a “Hot Uranus”-class object. Depending on the initial density and mass, these planets most likely were always rocky planets which could lose a thin hydrogen envelope, but not cores of thermally evaporated initially much more massive and larger objects.

Leitzinger, M.; Odert, P.; Kulikov, Yu.N.; Lammer, H.; Wuchterl, G.; Penz, T.; Guarcello, M.G.; Micela, G.; Khodachenko, M.L.; Weingrill, J.; Hanslmeier, A.; Biernat, H.K.; Schneider, J.

2011-01-01

93

Could CoRoT-7b and Kepler-10b be remnants of evaporated gas or ice giants?  

PubMed

We present thermal mass loss calculations over evolutionary time scales for the investigation if the smallest transiting rocky exoplanets CoRoT-7b (?1.68REarth) and Kepler-10b (?1.416REarth) could be remnants of an initially more massive hydrogen-rich gas giant or a hot Neptune-class exoplanet. We apply a thermal mass loss formula which yields results that are comparable to hydrodynamic loss models. Our approach considers the effect of the Roche lobe, realistic heating efficiencies and a radius scaling law derived from observations of hot Jupiters. We study the influence of the mean planetary density on the thermal mass loss by placing hypothetical exoplanets with the characteristics of Jupiter, Saturn, Neptune, and Uranus to the orbital location of CoRoT-7b at 0.017 AU and Kepler-10b at 0.01684 AU and assuming that these planets orbit a K- or G-type host star. Our findings indicate that hydrogen-rich gas giants within the mass domain of Saturn or Jupiter cannot thermally lose such an amount of mass that CoRoT-7b and Kepler-10b would result in a rocky residue. Moreover, our calculations show that the present time mass of both rocky exoplanets can be neither a result of evaporation of a hydrogen envelope of a "Hot Neptune" nor a "Hot Uranus"-class object. Depending on the initial density and mass, these planets most likely were always rocky planets which could lose a thin hydrogen envelope, but not cores of thermally evaporated initially much more massive and larger objects. PMID:21969736

Leitzinger, M; Odert, P; Kulikov, Yu N; Lammer, H; Wuchterl, G; Penz, T; Guarcello, M G; Micela, G; Khodachenko, M L; Weingrill, J; Hanslmeier, A; Biernat, H K; Schneider, J

2011-10-01

94

Could CoRoT-7b and Kepler-10b be remnants of evaporated gas or ice giants?  

NASA Astrophysics Data System (ADS)

We present thermal mass loss calculations over evolutionary time scales for the investigation if the smallest transiting rocky exoplanets CoRoT-7b ( ˜1.68REarth) and Kepler-10b ( ˜1.416REarth) could be remnants of an initially more massive hydrogen-rich gas giant or a hot Neptune-class exoplanet. We apply a thermal mass loss formula which yields results that are comparable to hydrodynamic loss models. Our approach considers the effect of the Roche lobe, realistic heating efficiencies and a radius scaling law derived from observations of hot Jupiters. We study the influence of the mean planetary density on the thermal mass loss by placing hypothetical exoplanets with the characteristics of Jupiter, Saturn, Neptune, and Uranus to the orbital location of CoRoT-7b at 0.017 AU and Kepler-10b at 0.01684 AU and assuming that these planets orbit a K- or G-type host star. Our findings indicate that hydrogen-rich gas giants within the mass domain of Saturn or Jupiter cannot thermally lose such an amount of mass that CoRoT-7b and Kepler-10b would result in a rocky residue. Moreover, our calculations show that the present time mass of both rocky exoplanets can be neither a result of evaporation of a hydrogen envelope of a "Hot Neptune" nor a "Hot Uranus"-class object. Depending on the initial density and mass, these planets most likely were always rocky planets which could lose a thin hydrogen envelope, but not cores of thermally evaporated initially much more massive and larger objects.

Leitzinger, M.; Odert, P.; Kulikov, Yu. N.; Lammer, H.; Wuchterl, G.; Penz, T.; Guarcello, M. G.; Micela, G.; Khodachenko, M. L.; Weingrill, J.; Hanslmeier, A.; Biernat, H. K.; Schneider, J.

2011-10-01

95

A Study for Health Hazard Evaluation of Methylene Chloride Evaporated from the Tear Gas Mixture  

PubMed Central

This study explored the health hazard of those exposed to methylene chloride by assessing its atmospheric concentration when a tear gas mixture was aerially dispersed. The concentration of methylene chloride ranged from 311.1-980.3 ppm (geometric mean, 555.8 ppm), 30 seconds after the dispersion started. However, the concentration fell rapidly to below 10 ppm after dispersion was completed. The concentration during the dispersion did not surpass the National Institute for Occupational Safety and Health 'immediately dangerous to life or health' value of 2,300 ppm, but did exceed the American Conference of Governmental Industrial Hygienists excursion limit of 250 ppm. Since methylene chloride is highly volatile (vapor pressure, 349 mmHg at 20?), the postdispersion atmospheric concentration can rise instantaneously. Moreover, the o-chlorobenzylidenemalononitrile formulation of tear gas (CS gas) is an acute upper respiratory tract irritant. Therefore, tear gas mixtures should be handled with delicate care.

Chung, Eun-Kyo; Yi, Gwang-Yong; Chung, Kwang-Jae; Shin, Jung-Ah; Lee, In-Seop

2010-01-01

96

Paclitaxel loaded niosome nanoparticle formulation prepared via reverse phase evaporation method: an in vitro evaluation.  

PubMed

Niosoms are nanoparticles used in drug delivery systems. Niosomes are prepared by various methods. In this research niosoms were prepared by reverse phase evaporation and the factors affecting the niosomes formation were studied. Percent of paclitaxel pegylated and non-pegylated prepared with Span 60 were 95 and 92, respectively while for those of pegylated and non-pegylated niosomes with Span 20, 94 and 90, respectively. In addition, the average diameters of pegylated and no-pegylated prepared with Span 60 and 20 were determined to be 191, 214, 244 and 284 nm, respectively. The amount of released drug (48 h) from pegylated and non pegylated formulations in the presence of Spans 60 and 20 were 8, 10, 6, 7%, respectively. Cytotoxicities ofpaclitaxel niosom polyethyleneglycol, paclitaxel niosome and free paclitaxel on MCF-7 cell line after 48 hours were studied by MTT assay. The results showed the formulation prepared with Span 60 is more effective than that of Span 20 and the IC50 of the former was decreased twice while IC50 of the later decreased 1.5 times. PMID:24498794

Zarei, M; Norouzian, D; Honarvar, B; Mohammadi, M; Shamabadi, H Ebrahimi; Akbarzadeh, A

2013-03-15

97

On modeling evaporation  

Microsoft Academic Search

We develop a theoretical model for evaporation of a pure liquid drop on a thermally conductive solid substrate. We discuss\\u000a a variety of effects regarding evaporation regime, the state of the liquid\\/gas interface and the content of gas phase. Then,\\u000a we further consider two models: the one resulting from the one-sided non-equilibrium assumption and the other that assumes\\u000a diffusion-limited regime

Nebojsa Murisic; Lou Kondic

2008-01-01

98

Water retention curves of loamy-sandy soils: Transient evaporation method versus steady-state tension and pressure techniques  

NASA Astrophysics Data System (ADS)

Water retention curves of loamy-sandy soils at the agricultural test site Wagna (Austria) were measured using both the simplified evaporation method according to Schindler (Arch. Acker- u. Pflanzenbau u. Bodenkd. Berlin 24, 1-7, 1980) and steady-state tension and pressure techniques. The soil was sampled with 250-ccm and 100-ccm steel pipes for the evaporation method and the steady-state technique, respectively. In the transient evaporation method two tensiometers with a measurement range between 0 and 850 hPa are installed at a depth of 1.25 cm and 3.75 cm in a sample of 5 cm in height; the mean values of the two tensiometers and the water contents measured by weighing are used to obtain the water retention curve. The steady-state method employs a tension table (sand box) at tensions below 100 hPa and a pressure extractor at tensions between 300 hPa and 15,000 hPa; the water content is measured by weighing after the sample has equilibrated at the tension value set on the table or plate. First results of both methods suggest that the soil samples release water over the entire tension range measured. In particular, the release of water at very low tension values may suggest the presence of macropores. Despite the generally good agreement between the two methods, the values appear to deviate systematically close to saturation. This is potentially caused by the large relative error of the tension measurement close to saturation. Alternatively, the different size of the samples used for the evaporation experiment (250 ccm) and the steady-state method (100 ccm) might play a role. Because of the limited measurement range of the tensiometers used for the evaporation method, the measured curve must be extrapolated between 850 hPa and 15,000 hPa to allow comparison with the steady-state method. To this end, it was attempted to match the Brooks-Corey, the Van-Genuchten, and a bimodal Van-Genuchten retention function to the data from the evaporation experiments. This involves a simultaneous fit of both water-retention and hydraulic-conductivity function. Only the bimodal Van-Genuchten model was found to be able to produce satisfactory fits to the data. The extrapolated water retention curves, however, do not match the data from the steady-state method. This suggests that alternative soil hydraulic functions are needed to provide an adequate representation of the water retention characteristics of the loamy-sandy soils considered in this investigation.

Winkler, G.; Eberhard, E.; Fank, J.; Birk, S.

2009-12-01

99

Atmospheric pressure matrix-assisted laser desorption ionization as a plume diagnostic tool in laser evaporation methods  

NASA Astrophysics Data System (ADS)

Laser evaporation techniques, including matrix-assisted pulsed laser evaporation (MAPLE), are attracting increasing attention due to their ability to deposit thin layers of undegraded synthetic and biopolymers. Laser evaporation methods can be implemented in reflection geometry with the laser and the substrate positioned on the same side of the target. In some applications (e.g. direct write, DW), however, transmission geometry is used, i.e. the thin target is placed between the laser and the substrate. In this case, the laser pulse perforates the target and transfers some target material to the substrate. In order to optimize evaporation processes it is important to know the composition of the target plume and the material deposited from the plume. We used a recently introduced analytical method, atmospheric pressure matrix-assisted laser desorption ionization (AP-MALDI) to characterize the ionic components of the plume both in reflection and in transmission geometry. This technique can also be used to directly probe materials deposited on surfaces (such as glass slides) by laser evaporation methods. The test compound (small peptides, e.g. Angiotensin I, ATI or Substance P) was mixed with a MALDI matrix (?-cyano-4-hydroxycinnamic acid (CHCA), sinapinic acid (SA) or 2,5-dihydroxybenzoic acid (DHB)) and applied to the stainless steel (reflection geometry) or transparent conducting (transmission geometry) target holder. In addition to the classical dried droplet method, we also used electrospray target deposition to gain better control of crystallite size, thickness and homogeneity. The target was mounted in front of the inlet orifice of an ion trap mass spectrometer (IT-MS) that sampled the ionic components of the plume generated by a nitrogen laser. We studied the effect of several parameters, such as, the orifice to target distance, illumination geometry, extracting voltage distribution and sample preparation on the generated ions. Various analyte-matrix and matrix-matrix cluster ions were observed with relatively low abundance of the matrix ions.

Callahan, John H.; Galicia, Marsha C.; Vertes, Akos

2002-09-01

100

Large-scale organic single-crystal thin films and transistor arrays via the evaporation-controlled fluidic channel method.  

PubMed

We report a facile and versatile approach for fabricating large-area organic thin film transistor (OTFTs) arrays via a fluidic channel method. Evaporation-controlled fluidic channel-containing organic semiconductors easily produce large-area organic single-crystalline thin films in a quite uniform manner. The unidirectional movement of the meniscus and the subsequent film growth via solvent evaporation inside the fluidic channel correspond to the simulation based on the finite element method. Utilizing this fluidic channel method, we fabricated high-performance 6,13-bis(triisopropylsilylethynyl)pentacene OTFT arrays with average and maximal mobilities of 0.71 and 2.18 cm(2) V(-1) s(-1), respectively, while exhibiting current on:off ratios of >1 × 10(6). We claim that this scalable fluidic channel method offers a competitive way to fabricate high-performance and large-area organic semiconductor devices for a variety of applications. PMID:24807870

Kim, Jaekyun; Cho, Sangho; Kang, Jingu; Kim, Yong-Hoon; Park, Sung Kyu

2014-05-28

101

Formation of Ultrafine Metal Particles by Gas-Evaporation Technique. IV. Crystal Habits of Iron and Fcc Metals, Al, Co, Ni, Cu, Pd, Ag, In, Au and Pb  

Microsoft Academic Search

Fine metal crystallites with diameters 200˜2000 Å made by evaporating a metal in an atmosphere of an inactive gas were studied by electron microscopy. It is found that the crystal habit common to Be, Cr, Mn and Fe, which are bcc just below the melting point, is rhombic dodecahedra truncated by {100}. Fcc metals show six different types of crystal

Takayoshi Hayashi; Takehisa Ohno; Shigeki Yatsuya; Ryozi Uyeda

1977-01-01

102

Gas production apparatus and method  

Microsoft Academic Search

This invention relates generally to the production of gases, and more particularly to the production of tritium gas in a reliable long operating lifetime systems that employs solid lithium to overcome the heretofore known problems of material compatibility and corrosion, etc., with liquid metals. The solid lithium is irradiated by neutrons inside low activity means containing a positive pressure gas

W. E. Winsche; F. T. Miles; J. R. Powell

2009-01-01

103

A rapid HPLC with evaporative light scattering method for quantification of forskolin in multi-herbal weight-loss solid oral dosage forms.  

PubMed

A rapid reverse-phase HPLC method with evaporative light scattering detection (ELSD) was developed for the determination of forskolin in weight loss multi-herbals products. The analysis was performed by water-acetonitrile gradient elution at a temperature of 40 degrees C and a flow rate of 1.0 mL/min. The evaporator tube temperature of ELSD was set at 35 degrees C, and with the nebulizing gas flow-rate (pressure) of 3.0 bar. The method was validated for linearity, accuracy, precision and limits of detection (LOD) and quantification (LOQ). Good linear relationships were obtained with correlation coefficients exceeding 0.9995. The average recovery of forskolin ranged from 99.4% to 100.4% with RSDs below 3%. The percent relative standard deviations (%RSD) of intra- and inter-day precision varied by less than 2.1%. LOD and LOQ were 0.95 microg/ml and 3.21 microg/ml, respectively. The validated ELSD method permits a shorter determination time without compromising accuracy and demonstrates that it can be used for quantification of forskolin incorporated in multi-herbal solid oral dosage forms. PMID:20503921

Virgona, N; Taki, Y; Umegaki, K

2010-05-01

104

Selecting the optimal method to calculate daily global reference potential evaporation from CFSR reanalysis data  

NASA Astrophysics Data System (ADS)

Potential evaporation (PET) is one of the main inputs of hydrological models. Yet, there is limited consensus on which PET equation is most applicable in hydrological climate impact assessments. In this study six different methods to derive global scale reference PET time series from CFSR reanalysis data are compared: Penman-Monteith, Priestley-Taylor and original and modified versions of the Hargreaves and Blaney-Criddle method. The calculated PET time series are (1) evaluated against global monthly Penman-Monteith PET time series calculated from CRU data and (2) tested on their usability for modeling of global discharge cycles. The lowest root mean squared differences and the least significant deviations (95 % significance level) between monthly CFSR derived PET time series and CRU derived PET were obtained for the cell specific modified Blaney-Criddle equation. However, results show that this modified form is likely to be unstable under changing climate conditions and less reliable for the calculation of daily time series. Although often recommended, the Penman-Monteith equation did not outperform the other methods. In arid regions (e.g., Sahara, central Australia, US deserts), the equation resulted in relatively low PET values and, consequently, led to relatively high discharge values for dry basins (e.g., Orange, Murray and Zambezi). Furthermore, the Penman-Monteith equation has a high data demand and the equation is sensitive to input data inaccuracy. Therefore, we preferred the modified form of the Hargreaves equation, which globally gave reference PET values comparable to CRU derived values. Although it is a relative efficient empirical equation, like Blaney-Criddle, the equation considers multiple spatial varying meteorological variables and consequently performs well for different climate conditions. In the modified form of the Hargreaves equation the multiplication factor is uniformly increased from 0.0023 to 0.0031 to overcome the global underestimation of CRU derived PET obtained with the original equation. It should be noted that the bias in PET is not linearly transferred to actual evapotranspiration and runoff, due to limited soil moisture availability and precipitation. The resulting gridded daily PET time series provide a new reference dataset that can be used for future hydrological impact assessments or, more specifically, for the statistical downscaling of daily PET derived from raw GCM data.

Sperna Weiland, F. C.; Tisseuil, C.; Dürr, H. H.; Vrac, M.; van Beek, L. P. H.

2011-07-01

105

Evaporation Investigation  

NSDL National Science Digital Library

This is a hands-on lab activity about evaporation. Learners will conduct experiments to observe the process of evaporation. They will then describe the process of evaporation, and the general water cycle, through discussion and pictures. Background information, common preconceptions, a glossary and more is included. This activity is part of the Aquarius Hands-on Laboratory Activities.

106

Method for liquefaction of natural gas  

US Patent & Trademark Office Database

A method of altering the heating value of a liquefied natural gas by adding higher heating value components is disclosed. A portion of the liquefied natural gas is used to cool the higher heating value component stream prior to combining the higher heating value components with the liquefied natural gas to obtain a combined stream having a heating value greater than the liquefied natural gas.

2013-02-26

107

Flue gas desulfurization apparatus and method  

SciTech Connect

A method of desulfurizing boiler flue gas by intimate contact thereof with dry particles of a reactant or absorbent, such as hydrated lime, preferably with recirculation of the flue gas and entrained reactant or absorbent particles. An apparatus suitable for carrying out the method comprises an upstanding conduit defining a vertical gas flow path in communication with a source of SO2-and particulate-laden flue gas, a conveyor for introducing a dry reactant or absorbent into the gas flow path, and a rotatable slinger mounted within the gas flow path for uniformly distributing the reactant or absorbent thereacross. In its preferred form, the apparatus includes recirculation means, preferably an eductor, mounted above the slinger for recirculation of gas and entrained reactant or absorbent within the gas flow path to enhance gas-solid contact time, a tangential gas inlet for creating vortical gas flow within the conduit, a gas expansion section at the conduit's discharge end and means for reversing the gas flow direction to enhance separation of particulates.

Flick, F.S.; Hollett, G.T.

1981-06-16

108

Epitaxial Growth of SrTiO3 Films on Si(100) Substrates Using a Focused Electron Beam Evaporation Method  

Microsoft Academic Search

A novel epitaxial growth method of SrTiO3 films on Si(100) substrates is presented in which, in order to reduce the surface oxide layers of the substrates, thin Sr layers are deposited prior to deposition of SrTiO3 films. It has been shown that the film composition becomes nearly stoichiometric when single-crystalline SrTiO3 sources are evaporated by a focused electron beam and

Hiroyuki Mori; Hiroshi Ishiwara

1991-01-01

109

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

110

Insight into the molecular mechanism of water evaporation via the finite temperature string method  

NASA Astrophysics Data System (ADS)

The process of water's evaporation at its liquid/air interface has proven challenging to study experimentally and, because it constitutes a rare event on molecular time scales, presents a challenge for computer simulations as well. In this work, we simulated water's evaporation using the classical extended simple point charge model water model, and identified a minimum free energy path for this process in terms of 10 descriptive order parameters. The measured free energy change was 7.4 kcal/mol at 298 K, in reasonable agreement with the experimental value of 6.3 kcal/mol, and the mean first-passage time was 1375 ns for a single molecule, corresponding to an evaporation coefficient of 0.25. In the observed minimum free energy process, the water molecule diffuses to the surface, and tends to rotate so that its dipole and one O-H bond are oriented outward as it crosses the Gibbs dividing surface. As the water molecule moves further outward through the interfacial region, its local density is higher than the time-averaged density, indicating a local solvation shell that protrudes from the interface. The water molecule loses donor and acceptor hydrogen bonds, and then, with its dipole nearly normal to the interface, stops donating its remaining hydrogen bond. At that point, when the final, accepted hydrogen bond is broken, the water molecule is free. We also analyzed which order parameters are most important in the process and in reactive trajectories, and found that the relative orientation of water molecules near the evaporating molecule, and the number of accepted hydrogen bonds, were important variables in reactive trajectories and in kinetic descriptions of the process.

Musolino, Nicholas; Trout, Bernhardt L.

2013-04-01

111

Mg2Si buffer layers on Si(100) prepared by a simple evaporation method  

Microsoft Academic Search

The formation of Mg2Si(100), ao= 6.39Å, on Si(100) substrates has been investigated. Mg was first evaporated onto Si(100) surfaces and Mg2Si (100) films were formed in a subsequent annealing process. The Mg2Si layers were characterized by x-ray diffraction and transmission electron microscopy analysis. Optical and scanning electron microscopy analysis show the surface morphology to be smooth. The films are stable

G. S. Tompa; Y. B. Li; D. Agassi; S. I. Kim; S. K. Hong

1996-01-01

112

Insight into the molecular mechanism of water evaporation via the finite temperature string method  

PubMed Central

The process of water's evaporation at its liquid/air interface has proven challenging to study experimentally and, because it constitutes a rare event on molecular time scales, presents a challenge for computer simulations as well. In this work, we simulated water's evaporation using the classical extended simple point charge model water model, and identified a minimum free energy path for this process in terms of 10 descriptive order parameters. The measured free energy change was 7.4 kcal/mol at 298 K, in reasonable agreement with the experimental value of 6.3 kcal/mol, and the mean first-passage time was 1375 ns for a single molecule, corresponding to an evaporation coefficient of 0.25. In the observed minimum free energy process, the water molecule diffuses to the surface, and tends to rotate so that its dipole and one O–H bond are oriented outward as it crosses the Gibbs dividing surface. As the water molecule moves further outward through the interfacial region, its local density is higher than the time-averaged density, indicating a local solvation shell that protrudes from the interface. The water molecule loses donor and acceptor hydrogen bonds, and then, with its dipole nearly normal to the interface, stops donating its remaining hydrogen bond. At that point, when the final, accepted hydrogen bond is broken, the water molecule is free. We also analyzed which order parameters are most important in the process and in reactive trajectories, and found that the relative orientation of water molecules near the evaporating molecule, and the number of accepted hydrogen bonds, were important variables in reactive trajectories and in kinetic descriptions of the process.

Musolino, Nicholas; Trout, Bernhardt L.

2013-01-01

113

Use of GC/MS and Microtome Techniques as Methods to Evaluate ODC Free Cleaner Diffusion and Evaporation in Insulation and Phenolic Case Material  

NASA Technical Reports Server (NTRS)

Because of the 1990 Clean Air Act Amendment (CAAA) many chlorinated solvents used in the aerospace industry are being phased out. Replacement of the ODC (ozone-depleting chemicals) with less volatile, non-ozone depleting cleaners has been extensively studied over the past seven years at Thiokol Propulsion, a Division of Cordant Technologies, Inc. The down selection of ODC replacement cleaners has been based on several factors including the diffusion evaporation of the cleaners in selected substrates. Methodologies were developed to evaluate the cleaner content in substrates. Methods of cutting thin slices of material (microtoming) were combined with GC/MS (gas chromatography/mass spectroscopy) analysis. Substrates evaluated in this study include potential solid rocket motor materials: ASNBR (asbestos-filled nitrile butadiene rubber) and CFEPDM (carbon-filled ethylene propylene dimonomer) insulation and glass (GCP), carbon (CCP) and silica (SCP) cloth phenolic substrates with fibers either parallel (0 deg) or perpendicular (90 deg) to the surface. Residue profiles indicate both cleaner and substrate composition affect the diffusion and subsequent evaporation of the cleaner from the substrate surface.

Biegert, L. L.

2001-01-01

114

Quantification of the evaporative cooling in an ethanol spray created by a gasoline direct-injection system measured by multiline NO-LIF gas-temperature imaging.  

PubMed

Two-dimensional gas-phase temperature fields were quantitatively measured in an evaporating ethanol spray with multiline excitation thermometry based on laser-induced fluorescence of nitric oxide (NO-LIF). This technique yields absolute temperature fields without calibration and simultaneously detects the spray position. The accuracy of the presented temperature measurements is +/-1 K. Systematic errors of the scanned multiline thermometry approach due to time averaging in turbulent systems were investigated and found to be negligible. The pulsed spray was generated by a gasoline direct-injection nozzle with swirl injecting ethanol into air in a flow cell at room temperature and atmospheric pressure. The gas temperature inside the spray cloud was found to decrease by 10 K at approximately 5-10 ms after injection. Different injection pressures influence the evaporation behavior. PMID:18059675

Kronemayer, Helmut; Omerbegovic, Kemal; Schulz, Christof

2007-12-01

115

Quantification of the evaporative cooling in an ethanol spray created by a gasoline direct-injection system measured by multiline NO-LIF gas-temperature imaging  

NASA Astrophysics Data System (ADS)

Two-dimensional gas-phase temperature fields were quantitatively measured in an evaporating ethanol spray with multiline excitation thermometry based on laser-induced fluorescence of nitric oxide (NO-LIF). This technique yields absolute temperature fields without calibration and simultaneously detects the spray position. The accuracy of the presented temperature measurements is ±1 K. Systematic errors of the scanned multiline thermometry approach due to time averaging in turbulent systems were investigated and found to be negligible. The pulsed spray was generated by a gasoline direct-injection nozzle with swirl injecting ethanol into air in a flow cell at room temperature and atmospheric pressure. The gas temperature inside the spray cloud was found to decrease by 10 K at ~5-10 ms after injection. Different injection pressures influence the evaporation behavior.

Kronemayer, Helmut; Omerbegovic, Kemal; Schulz, Christof

2007-12-01

116

Method for detecting gas turbine engine flashback  

DOEpatents

A method for monitoring and controlling a gas turbine, comprises predicting frequencies of combustion dynamics in a combustor using operating conditions of a gas turbine, receiving a signal from a sensor that is indicative of combustion dynamics in the combustor, and detecting a flashback if a frequency of the received signal does not correspond to the predicted frequencies.

Singh, Kapil Kumar; Varatharajan, Balachandar; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin Paul

2012-09-04

117

Acetone and ethanol solid-state gas sensors based on TiO 2 nanoparticles thin film deposited by matrix assisted pulsed laser evaporation  

Microsoft Academic Search

Matrix assisted pulsed laser evaporation (MAPLE) is a new promising laser-based technique thought for polymer or biomaterial thin films deposition. In this work, the MAPLE technique has been used for the deposition of titania (TiO2) nanoparticle thin films to be used for gas sensor applications. For this purpose, an aqueous solution of TiO2 nanoparticles, synthesized by a novel chemical route,

R. Rella; J. Spadavecchia; M. G. Manera; S. Capone; A. Taurino; M. Martino; A. P. Caricato; T. Tunno

2007-01-01

118

Evaporation characteristics of fuel spray and low emissions in a lean premixed-prevaporization combustor for a 100 kW automotive ceramic gas turbine  

Microsoft Academic Search

A lean premixed-prevaporization combustor (PPL-1) for a 100 kW automotive ceramic gas turbine has been developed to meet the Japanese emission standards for passenger cars without using an aftertreatment system. The design of a fuel injector and a prevaporization-premixing tube (PP-tube) in the PPL-1 combustor is a key subject for promotion of evaporation of fuel spray. The Sauter mean diameter

Yoichiro Ohkubo; Yoshinori Idota; Yoshihiro Nomura

1997-01-01

119

Quantification of the evaporative cooling in an ethanol spray created by a gasoline direct-injection system measured by multiline NO-LIF gas-temperature imaging  

Microsoft Academic Search

Two-dimensional gas-phase temperature fields were quantitatively measured in an evaporating ethanol spray with multiline excitation thermometry based on laser-induced fluorescence of nitric oxide (NO-LIF). This technique yields absolute temperature fields without calibration and simultaneously detects the spray position. The accuracy of the presented temperature measurements is ±1 K. Systematic errors of the scanned multiline thermometry approach due to time averaging

Helmut Kronemayer; Kemal Omerbegovic; Christof Schulz

2007-01-01

120

GLIMM'S METHOD FOR GAS DYNAMICS  

SciTech Connect

We investigate Glimm's method, a method for constructing approximate solutions to systems of hyperbolic conservation laws in one space variable by sampling explicit wave solutions. It is extended to several space variables by operator splitting. We consider two functional problems. 1) We propose a highly accurate form of the sampling procedure, in one space variable, based on the van der Corput sampling sequence. We test the improved sampling procedure numerically in the case of inviscid compressible flow in one space dimension and find that it gives high resolution results both in the smooth parts of the solution, as well as the discontinuities. 2) We investigate the operator splitting procedure by means of which the multidimensional method is constructed. An 0(1) error stemming from the use of this procedure near shocks oblique to the spatial grid is analyzed numerically in the case of the equations for inviscid compressible flow in two space dimensions. We present a hybrid method which eliminates this error, consisting of Glimm's method, used in continuous parts of the flow, and the nonlinear Godunov's method, used in regions where large pressure jumps are generated. The resulting method is seen to be a substantial improvement over either of the component methods for multidimensional calculations.

Colella, Phillip

1980-07-01

121

Method for dismantling a natural gas holder  

SciTech Connect

This patent describes a method of dismantling a natural gas holder. The holder has vertical support columns disposed around the periphery of the holder to which the enclosure shell of the holder is attached.

Settlemier, B.R.; Bone, S.R.; Tolivaisa, J.; Nugent, J.E.

1990-10-30

122

Gas sensitive materials for gas detection and method of making  

DOEpatents

A gas sensitive material comprising SnO2 nanocrystals doped with In2O3 and an oxide of a platinum group metal, and a method of making the same. The platinum group metal is preferably Pd, but also may include Pt, Ru, Ir, and combinations thereof. The SnO2 nanocrystals have a specific surface of 7 or greater, preferably about 20 m2/g, and a mean particle size of between about 10 nm and about 100 nm, preferably about 40 nm. A gas detection device made from the gas sensitive material deposited on a substrate, the gas sensitive material configured as a part of a current measuring circuit in communication with a heat source.

Trakhtenberg, Leonid Israilevich; Gerasimov, Genrikh Nikolaevich; Gromov, Vladimir Fedorovich; Rozenberg, Valeriya Isaakovna

2012-12-25

123

Effect of argon gas flow rate on properties of film electrodes prepared by thermal vacuum evaporation from synthesized Cu2SnSe3 source  

NASA Astrophysics Data System (ADS)

This work describes a new technique to enhance photoresponse of metal chalcogenide-based semiconductor film electrodes deposited by thermal vacuum evaporation under argon gas flow from synthesized Cu2SnSe3 sources. SnSe formation with Cu-doped was obtained under higher argon gas flow rate (VA = 25 cm3/min). Higher value of photoresponse was observed for films deposited under VA = 25 cm3/min which was 9.1%. This finding indicates that Cu atoms inside the SnSe film were important to increase carrier concentrations that promote higher photoresponse.

Sabli, Nordin; Talib, Zainal Abidin; Yunus, Wan Mahmood Mat; Zainal, Zulkarnain; Hilal, Hikmat S.; Fujii, Masatoshi

2014-03-01

124

Hybrid Evaporative - Condenser Cooling Tower  

Microsoft Academic Search

The need to save energy in power producing and power consuming systems and the fact that evaporative cooling is the most efficient method for heat rejection led to the design and testing of a model of a special cooling tower, fn this hybrid system an evaporative condenser is being built into the cooling tower and the advantages of evaporative cooling

Uriyel Fisher; Wolfgang Leidenfrost; Jiashang Li

1981-01-01

125

Performance of a showcase refrigeration system with multi-evaporator during on–off cycling and hot-gas bypass defrost  

Microsoft Academic Search

During the defrosting process, the temperature in the cabinet of a showcase becomes higher than the set point. This phenomenon is undesirable for foods or products stored. It is essential to develop an efficient defrosting method to prevent large temperature fluctuations. In the present study, the performance of the showcase refrigeration system with three evaporators was measured during on–off cycling

Honghyun Cho; Yongchan Kim; Inkyu Jang

2005-01-01

126

One-step preparation of chitosan-coated cationic liposomes by an improved supercritical reverse-phase evaporation method.  

PubMed

High-pressure carbon dioxide in contact with water dissolves to form carbonic acid, causing a decrease in pH. By use of these characteristics of a CO2/H2O biphasic system, chitosan-coated cationic liposomes of l-alpha-dipalmitoylphosphatidylcholine were successfully prepared by an improved supercritical reverse-phase evaporation (ISCRPE) method. Liposome-chitosan complexes carrying a positive charge were prepared in a single-step procedure without the use of acid or organic solvent, including ethanol. The maximum trapping efficiency of liposomes prepared by the ISCRPE method was 17%, with or without the addition of chitosan, compared to only 2% for liposomes prepared by the Bangham method. Furthermore, the liposomal dispersion was stable at room temperature in a sealed tube for over 30 days. PMID:16618144

Otake, Katsuto; Shimomura, Takeshi; Goto, Toshihiro; Imura, Tomohiro; Furuya, Takeshi; Yoda, Satoshi; Takebayashi, Yoshihiro; Sakai, Hideki; Abe, Masahiko

2006-04-25

127

Synthesis and characteristics of continuous mesoporous carbon films by a rapid solvent evaporation method  

NASA Astrophysics Data System (ADS)

Carbon films with a well-developed meso-porosity were synthesized directly by the carbonization of sulfuric-acid-treated P123 triblock copolymer/silica nanocomposite films, which were prepared from dip-coating technique through an association of sol-gel and evaporation-induced self-assembly process, and the residual silica was removed subsequently via HF-etching. P123 was employed as both structuring agent for self-assembly of tetraethyl orthosilicate and carbon precursor. The sulfuric acid solution was used as a catalyst for cross-linking of P123/silica in order to improve the carbon yield for the continuity of carbon films. Investigations by Field emission scanning electron microscopy (FESEM), X-ray diffraction, nitrogen adsorption measurement and transmission electron microscopy (TEM) indicate that the hybrid carbon/silica mesoporous films are preserved perfectly after the carbonization. When the silica is removed by acid treatment, continuous carbon films with an ordered symmetric structure are still kept well. The carbon films obtained are composed of carbon nanotubes with the diameter of around 6 nm, and the lengths of nanotubes affiliating with each other vary from about 100 nm to several micrometers, which were measured by FESEM and TEM.

Wang, Xiaoxian; Li, Tiehu; Ji, Yongbin; Ai, Yanling; Lin, Qilang

2008-12-01

128

RPC gas recovery by open loop method  

NASA Astrophysics Data System (ADS)

RPC detectors require to be flushed with small but continuous flow of gas mixture. Dealing with large number of detectors, gas consumption to very large volumes. Gas flow is a running expense and constituent gases are too expensive to be treated as consumables. Exhaust gas mixture from detectors is a potential environmental hazard if discharged directly into the atmosphere. Storage of gases on a large scale also leads to inventory- and safety-related problems. A solution to these problems is the recovery and reuse of exhaust gas mixture from RPC detectors. Close loop method employs recirculation of exhausted gas mixture after purification, analysis and addition of top-up quantities. In open loop method, under consideration here, individual component gases are separated from gas mixture and reused as source. During open loop process, gases liquefiable at low pressures are separated from ones liquefiable at high pressure. The gas phase components within each group are successively separated by either fractional condensation or gravity separation. Gas mixture coming from RPC exhaust is first desiccated by passage through molecular sieve adsorbent type (3A+4A). Subsequent scrubbing over basic activated alumina removes toxic and acidic contaminants such as S 2F 10 produced during corona (arcing) discharge. In the first stage of separation isobutane and freon are concentrated by diffusion and liquefied by fractional condensation by cooling upto -30 °C. Liquefied gases are returned to source tanks. In the second stage of separation, argon and sulphur hexafluoride, the residual gases, are concentrated by settling due to density difference. SF 6 is stored for recovery by condensation at high pressure while argon is further purified by thermal cracking of crossover impurities at 1000 °C followed by wet scrubbing.

Joshi, Avinash; Kalmani, S. D.; Mondal, N. K.; Satyanarayana, B.

2009-05-01

129

Method for improved gas-solids separation  

DOEpatents

Methods are disclosed for the removal of particulate solids from a gas stream at high separation efficiency, including the removal of submicron size particles. The apparatus includes a cyclone separator type of device which contains an axially mounted perforated cylindrical hollow rotor. The rotor is rotated at high velocity in the same direction as the flow of an input particle-laden gas stream to thereby cause enhanced separation of particulate matter from the gas stream in the cylindrical annular space between the rotor and the sidewall of the cyclone vessel. Substantially particle-free gas passes through the perforated surface of the spinning rotor and into the hollow rotor, from where it is discharged out of the top of the apparatus. Separated particulates are removed from the bottom of the vessel. 4 figs.

Kusik, C.L.; He, B.X.

1990-11-13

130

Method for improved gas-solids separation  

DOEpatents

Methods are disclosed for the removal of particulate solids from a gas stream at high separation efficiency, including the removal of submicron size particles. The apparatus includes a cyclone separator type of device which contains an axially mounted perforated cylindrical hollow rotor. The rotor is rotated at high velocity in the same direction as the flow of an input particle-laden gas stream to thereby cause enhanced separation of particulate matter from the gas stream in the cylindrical annular space between the rotor and the sidewall of the cyclone vessel. Substantially particle-free gas passes through the perforated surface of the spinning rotor and into the hollow rotor, from when it is discharged out of the top of the apparatus. Separated particulates are removed from the bottom of the vessel.

Kusik, Charles L. (Lincoln, MA) [Lincoln, MA; He, Bo X. (Newton, MA) [Newton, MA

1990-01-01

131

Method for designing gas tag compositions  

DOEpatents

For use in the manufacture of gas tags such as employed in a nuclear reactor gas tagging failure detection system, a method for designing gas tagging compositions utilizes an analytical approach wherein the final composition of a first canister of tag gas as measured by a mass spectrometer is designated as node No. 1. Lattice locations of tag nodes in multi-dimensional space are then used in calculating the compositions of a node No. 2 and each subsequent node so as to maximize the distance of each node from any combination of tag components which might be indistinguishable from another tag composition in a reactor fuel assembly. Alternatively, the measured compositions of tag gas numbers 1 and 2 may be used to fix the locations of nodes 1 and 2, with the locations of nodes 3-N then calculated for optimum tag gas composition. A single sphere defining the lattice locations of the tag nodes may be used to define approximately 20 tag nodes, while concentric spheres can extend the number of tag nodes to several hundred. 5 figures.

Gross, K.C.

1995-04-11

132

Method for designing gas tag compositions  

DOEpatents

For use in the manufacture of gas tags such as employed in a nuclear reactor gas tagging failure detection system, a method for designing gas tagging compositions utilizes an analytical approach wherein the final composition of a first canister of tag gas as measured by a mass spectrometer is designated as node #1. Lattice locations of tag nodes in multi-dimensional space are then used in calculating the compositions of a node #2 and each subsequent node so as to maximize the distance of each node from any combination of tag components which might be indistinguishable from another tag composition in a reactor fuel assembly. Alternatively, the measured compositions of tag gas numbers 1 and 2 may be used to fix the locations of nodes 1 and 2, with the locations of nodes 3-N then calculated for optimum tag gas composition. A single sphere defining the lattice locations of the tag nodes may be used to define approximately 20 tag nodes, while concentric spheres can extend the number of tag nodes to several hundred.

Gross, Kenny C. (1433 Carriage La., Bolingbrook, IL 60440)

1995-01-01

133

Comparison of soil moisture retention characteristics obtained by the extended evaporation method and the pressure plate/sand box apparatus  

NASA Astrophysics Data System (ADS)

The water retention curve (WRC) characterizes the capacity of soil to hold water at specified soil matric potentials. It is a key property in any soil hydrologic application. To determine water retention data accurately and in turn use them to draw the whole curve by optimizing parameters of a proper soil hydraulic equation, it is of crucial importance to choose a suitable measurement procedure. For many years, the sand box-pressure plate apparatus are widely accepted as a reference laboratory procedure. To overcome shortcomings of the pressure plate, the evaporation method was introduced, besides many others. The method is not dependent on hydrostatic equilibrium conditions, thus allowing much quicker measurements, and yields the WRC in very high resolution. The method furthermore enables to quantify the unsaturated hydraulic conductivity function. We investigated a set of 40 fine-textured soils with both methods. The samples were packed from aggregated, dried and sieved material. Eight (-5, -10, -33, -100, -400, -700,-1000 and -1500kPa) water retention data points were obtained from sand box-pressure plate apparatus. Evaporation measurements were performed with the commercial apparatus HYPROP by UMS GmbH, Munich, applying the extended method, which yields water retention data in the range from 0 to -500kPa. We found that the sand box-pressure plate method lead to immediate drainage of water, whereas in HYPROP water started to drain only after reaching an air-entry point of pF 1.2-1.3. Accordingly, HYPROP gave higher water contents until pF 2, compared to the sand box/pressure plate apparatus, but from this point on both curves begin to be close and around the field capacity (pF 2.5) they overlap. Both methods show that the textural pore system starts to drain much later, around pF 3.5. We hypothesize that the reason for the different drainage behaviour of the interaggrate pore system lies in the saturation procedure. For HYPROP, samples were saturated under vacuum, yielding 100% saturation, whereas for the traditional method saturation took place by capillary uptake.

Öztürk, Hasan S.; Durner, Wolfgang; Haghverdi, Amir; Walter, Birgit

2013-04-01

134

Simulation of temporal and spatial distribution of required irrigation water by crop models and the pan evaporation coefficient method  

NASA Astrophysics Data System (ADS)

Hebei Plain is the most important agricultural belt in North China. Intensive irrigation, low and uneven precipitation have led to severe water shortage on the plain. This study is an attempt to resolve this crucial issue of water shortage for sustainable agricultural production and water resources management. The paper models distributed regional irrigation requirement for a range of cultivated crops on the plain. Classic crop models like DSSAT- wheat/maize and COTTON2K are used in combination with pan-evaporation coefficient method to estimate water requirements for wheat, corn, cotton, fruit-trees and vegetables. The approach is more accurate than the static approach adopted in previous studies. This is because the combination use of crop models and pan-evaporation coefficient method dynamically accounts for irrigation requirement at different growth stages of crops, agronomic practices, and field and climatic conditions. The simulation results show increasing Required Irrigation Amount (RIA) with time. RIA ranges from 5.08×109 m3 to 14.42×109 m3 for the period 1986~2006, with an annual average of 10.6×109 m3. Percent average water use by wheat, fruit trees, vegetable, corn and cotton is 41%, 12%, 12%, 11%, 7% and 17% respectively. RIA for April and May (the period with the highest irrigation water use) is 1.78×109 m3 and 2.41×109 m3 respectively. The counties in the piedmont regions of Mount Taihang have high RIA while the central and eastern regions/counties have low irrigation requirement.

Yang, Yan-Min; Yang, Yonghui; Han, Shu-Min; Hu, Yu-Kun

2009-07-01

135

Spectroscopic methods in gas hydrate research.  

PubMed

Gas hydrates are crystalline structures comprising a guest molecule surrounded by a water cage, and are particularly relevant due to their natural occurrence in the deep sea and in permafrost areas. Low molecular weight molecules such as methane and carbon dioxide can be sequestered into that cage at suitable temperatures and pressures, facilitating the transition to the solid phase. While the composition and structure of gas hydrates appear to be well understood, their formation and dissociation mechanisms, along with the dynamics and kinetics associated with those processes, remain ambiguous. In order to take advantage of gas hydrates as an energy resource (e.g., methane hydrate), as a sequestration matrix in (for example) CO(2) storage, or for chemical energy conservation/storage, a more detailed molecular level understanding of their formation and dissociation processes, as well as the chemical, physical, and biological parameters that affect these processes, is required. Spectroscopic techniques appear to be most suitable for analyzing the structures of gas hydrates (sometimes in situ), thus providing access to such information across the electromagnetic spectrum. A variety of spectroscopic methods are currently used in gas hydrate research to determine the composition, structure, cage occupancy, guest molecule position, and binding/formation/dissociation mechanisms of the hydrate. To date, the most commonly applied techniques are Raman spectroscopy and solid-state nuclear magnetic resonance (NMR) spectroscopy. Diffraction methods such as neutron and X-ray diffraction are used to determine gas hydrate structures, and to study lattice expansions. Furthermore, UV-vis spectroscopic techniques and scanning electron microscopy (SEM) have assisted in structural studies of gas hydrates. Most recently, waveguide-coupled mid-infrared spectroscopy in the 3-20 ?m spectral range has demonstrated its value for in situ studies on the formation and dissociation of gas hydrates. This comprehensive review summarizes the importance of spectroscopic analytical techniques to our understanding of the structure and dynamics of gas hydrate systems, and highlights selected examples that illustrate the utility of these individual methods. PMID:22094590

Rauh, Florian; Mizaikoff, Boris

2012-01-01

136

Hydrogen gas sensor and method of manufacture  

DOEpatents

A sensor for measuring the pressure of hydrogen gas in a nuclear reactor, and method of manufacturing the same. The sensor comprises an elongated tube of hydrogen permeable material which is connected to a pressure transducer through a feedthrough tube which passes through a wall at the boundary of the region in which hydrogen is present. The tube is pressurized and flushed with hydrogen gas at an elevated temperature during the manufacture of the sensor in order to remove all gasses other than hydrogen from the device.

McKee, John M. (Hinsdale, IL)

1991-01-01

137

Single crystal growth of copper phthalocyanine using exaltation–evaporation growth method  

Microsoft Academic Search

A new method of growing single crystal for ?-form copper phthalocyanine (CuPc) is presented in this paper. Melted anthracene was used as solvent of CuPc. The method, vaporizing the solvent using an automatic exaltation machine, was employed to grow CuPc single crystals. The needle-like single crystals of CuPc up to 11.6mm in length were obtained by applying this method. The

Wenhai Jiang; Xu Wang; Yuchun Chang; Shukun Yu; Chunyu Ma; Kaiqi Ye; Chuanhui Cheng; Guotong Du

2006-01-01

138

Conversion method for gas streams containing hydrocarbons  

DOEpatents

An apparatus and a method of using the apparatus are provided for converting a gas stream containing hydrocarbons to a reaction product containing effluent molecules having at least one carbon atom, having at least one interior surface and at least one exterior surface, a first electrode and a second electrode with the first and second electrodes being selectively movable in relation to each other and positioned within the housing so as to be spatially disposed a predetermined distance from each other, a plasma discharge generator between the first and second electrodes, gas stream introducer and a collector for collecting the reaction product effluent produced by the reaction of the gas stream containing hydrocarbons with the plasma discharge between the first and second electrodes.

Mallinson, Richard G. (Norman, OK) [Norman, OK; Lobban, Lance (Norman, OK) [Norman, OK; Liu, Chang-jun (Tianjin, CN) [Tianjin, CN

2000-01-01

139

Evaporative Cooler  

NSDL National Science Digital Library

Explore the concept of evaporative cooling through a hands-on experiment. Use a wet cloth and fan to model an air-conditioner and use temperature and relative humidity sensors to collect data. Then digitally plot the data using graphs in the activity. In an optional extension, make your own modifications to improve the cooler's efficiency.

Consortium, The C.

2011-12-12

140

Development of a thermal evaporation cell for gas-phase infrared absorption spectroscopy of compounds with low volatility.  

PubMed

To facilitate in-depth hazard prediction models, we must understand the spectral properties of expulsion plumes from conventional weapon attacks. Precise data on the spectral absorption of three chemical weapon agent simulants, in the infrared regime, are required to properly determine the mass of simulant in expulsion plumes from field demonstrations and small scale tests. Data for triethyl phosphate (a Soman simulant), triethyl phosphite (a Sarin simulant), and tributyl phosphate (a VX simulant) are presented. A thermal evaporation cell was designed and built that incorporated features that are not commercially available. PMID:18028706

Ingram, John M; Fountain, Augustus W

2007-11-01

141

Analysis of the climate variability on Lake Nasser evaporation based on the Bowen ratio energy budget method.  

PubMed

Variations in lake evaporation have a significant impact on the energy and water budgets of lakes. Understanding these variations and the role of climate is important for water resources management as well as predicting future changes in lake hydrology as a result of climate change. This study presents a comprehensive, 10-year analysis of seasonal, intraseasonal, and interannual variations in lake evaporation for Lake Nasser in South Egypt. Meteorological and lake temperature measurements were collected from an instrumented platform (Raft floating weather station) at 2 km upstream ofthe Aswan High Dam. In addition to that, radiation measurements at three locations on the lake: Allaqi, Abusembel and Arqeen (respectively at 75, 280 and 350 km upstream of the Aswan High Dam) are used. The data were analyzed over 14-day periods from 1995 to 2004 to provide bi-weekly energy budget estimates of evaporation rate. The mean evaporation rate for lake Nasser over the study period was 5.88 mm day(-1), with a coefficient of variation of 63%. Considerable variability in evaporation rates was found on a wide range of timescales, with seasonal changes having the highest coefficient of variation (32%), followed by the intraseasonal (28%) and interannual timescales (11.6%; for summer means). Intraseasonal changes in evaporation were primarily associated with synoptic weather variations, with high evaporation events tending to occur during incursions of cold, dry air (due, in part, to the thermal lag between air and lake temperatures). Seasonal variations in evaporation were largely driven by temperature and net energy advection, but are out-of-phase with changes in wind speed. On interannual timescales, changes in summer evaporation rates were strongly associated with changes in net energy advection and showed only moderate connections to variations in temperature or humidity. PMID:23424853

Elsawwaf, Mohamed; Willems, Patrick

2012-04-01

142

Streamer Evaporation  

NASA Technical Reports Server (NTRS)

Evaporation is the consequence of heating near the top of streamers in ideal Magnetohydrodynamics (MHD) models, where the plasma is weakly contained by the magnetic field. Heating causes slow opening of field lines and release of new solar wind. It was discovered in simulations and, due to the absence of loss mechanisms, the ultimate end point is the complete evaporation of the streamer. Of course streamers do not behave in this way because there are losses by thermal conduction and radiation. Physically, heating is also expected to depend on ambient conditions. We use our global MHD model with thermal conduction to examine the effect of changing the heating scale height. We also apply and extend an analytic model of streamers developed by Pneuman (1968) to show that steady streamers are unable to contain plasma for temperatures near the cusp greater than approximately 2 x 10(exp 6) K.

Suess, S. T.; Wang, A.-H.; Wu, S. T.; Nerney, S. F.

1998-01-01

143

Vacuum flash evaporated polymer composites  

DOEpatents

A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

Affinito, J.D.; Gross, M.E.

1997-10-28

144

Method and apparatus for producing synthesis gas  

DOEpatents

A method and apparatus for reacting a hydrocarbon containing feed stream by steam methane reforming reactions to form a synthesis gas. The hydrocarbon containing feed is reacted within a reactor having stages in which the final stage from which a synthesis gas is discharged incorporates expensive high temperature materials such as oxide dispersed strengthened metals while upstream stages operate at a lower temperature allowing the use of more conventional high temperature alloys. Each of the reactor stages incorporate reactor elements having one or more separation zones to separate oxygen from an oxygen containing feed to support combustion of a fuel within adjacent combustion zones, thereby to generate heat to support the endothermic steam methane reforming reactions.

Hemmings, John William (Katy, TX); Bonnell, Leo (Houston, TX); Robinson, Earl T. (Mentor, OH)

2010-03-03

145

Bénard instabilities in a binary-liquid layer evaporating into an inert gas: Stability of quasi-stationary and time-dependent reference profiles  

NASA Astrophysics Data System (ADS)

This study treats an evaporating horizontal binary-liquid layer in contact with the air with an imposed transfer distance. The liquid is an aqueous solution of ethanol (10% wt). Due to evaporation, the ethanol mass fraction can change and a cooling occurs at the liquid-gas interface. This can trigger solutal and thermal Rayleigh-Bénard-Marangoni instabilities in the system, the modes of which corresponding to an undeformable interface form the subject of the present work. The decrease of the liquid-layer thickness is assumed to be slow on the diffusive time scales (quasi-stationarity). First we analyse the stability of quasi-stationary reference profiles for a model case within which the mass fraction of ethanol is assumed to be fixed at the bottom of the liquid. Then this consideration is generalized by letting the diffusive reference profile for the mass fraction in the liquid be transient (starting from a uniform state), while following the frozen-time approach for perturbations. The critical liquid thickness below which the system is stable at all times quite expectedly corresponds to the one obtained for the quasi-stationary profile. As a next step, a more realistic, zero-flux condition is used at the bottom in lieu of the fixed-concentration one. The critical thickness is found not to change much between these two cases. At larger thicknesses, the critical time at which the instability first appears proves, as can be expected, to be independent of the type of the concentration condition at the bottom. It is shown that solvent (water) evaporation plays a stabilizing role as compared to the case of a non-volatile solvent. At last, an effective approximate Pearson-like model is invoked making use in particular of the fact that the solutal Marangoni is by far the strongest as an instability mechanism here.

Machrafi, H.; Rednikov, A.; Colinet, P.; Dauby, P. C.

2011-02-01

146

Gas Sensing Properties of TiO2WO3 and TiO2MO3 Based Thin Film Prepared by Ion-Assisted E-Beam Evaporation  

Microsoft Academic Search

This work presents new results on the gas sensing studies of WO 3 and MO3 doped TiO2 thin films prepared by ion-assisted e-beam evaporation process. N-type TiO2 gas-sensing layers have been deposited with different doping concentrations. Structural and morphological characterization has been carried out by means of SEM and XRI in order to correlate physical properties with gas sensing performance.

A. Wisitsoraat; A. Tuantranont; E. Comini; G. Sberveglieri; W. Wlodarski

2005-01-01

147

Effect of Pd Reactant on One-Dimensional Growth of ZnO on Si Substrate by Thermal Evaporation Method  

NASA Astrophysics Data System (ADS)

ZnO nanostructures were developed on a Si(100) substrate from the powder mixture of ZnO and x mol % Pd (ZP-x) as reactants using a thermal evaporation method. The effect of Pd on the growth characteristics of one-dimensional ZnO nanostructures was investigated. High temperature X-ray diffraction patterns obviously revealed that Pd assisted the reduction of ZnO at temperatures higher than 1000 °C. Needle-like ZnO nanorod array, developed from ZP-x (x? 2) mixture, was well aligned vertically on the Si substrate at 1100 °C while nano-crystalline ZnO layer was only obtained from pure ZnO powder. Thus, it is considered that Pd is responsible for the growth of ZnO nanorod on the Si substrate at 1100 °C by providing the Zn vapor for the Zn/ZnOx droplets with reducing ZnO in the reactant. The developed ZnO nanorod exhibited growth direction along [001] with defect-free high crystallinity.

Kim, Kyoung-bum; Jeong, Young Hun; Kim, Chang-il; Lee, Young-jin; Cho, Jeong-ho; Paik, Jong-hoo

2011-05-01

148

Release Kinetic Studies of Aspirin Microcapsules from Ethyl Cellulose, Cellulose Acetate Phthalate and their Mixtures by Emulsion Solvent Evaporation Method  

PubMed Central

The present study was oriented towards microencapsulation of aspirin and the study of its release kinetics. The desired encapsulation was achieved by emulsion solvent evaporation method using ethyl cellulose (EC), cellulose acetate phthalate (CAP) and their mixture (1:1) of polymeric constituents. Characterization of the formulations was performed by size, shape, drug loading efficiency and in-vitro drug release analysis. The in-vitro release profiles from different polymeric microcapsules were applied on different kinetic models. The prepared microcapsules were found free flowing and almost spherical in shape with particle sizes ranging from 300–700?m, having a loading efficiency of 75–85%. The best fit model with the highest correlation coefficient was observed in Higuchi model, indicating diffusion controlled principle. The n value obtained from Korsemeyer-Peppas model varied between 0.5–0.7, confirming that the mechanism of drug release was diffusion controlled. Comparative studies revealed that the release of aspirin from EC microcapsules was slower as compared to that of CAP and their binary mixture.

Dash, Vikas; Mishra, Sujeet K.; Singh, Manoj; Goyal, Amit K.; Rath, Goutam

2010-01-01

149

Release kinetic studies of aspirin microcapsules from ethyl cellulose, cellulose acetate phthalate and their mixtures by emulsion solvent evaporation method.  

PubMed

The present study was oriented towards microencapsulation of aspirin and the study of its release kinetics. The desired encapsulation was achieved by emulsion solvent evaporation method using ethyl cellulose (EC), cellulose acetate phthalate (CAP) and their mixture (1:1) of polymeric constituents. Characterization of the formulations was performed by size, shape, drug loading efficiency and in-vitro drug release analysis. The in-vitro release profiles from different polymeric microcapsules were applied on different kinetic models. The prepared microcapsules were found free flowing and almost spherical in shape with particle sizes ranging from 300â700Îm, having a loading efficiency of 75â85%. The best fit model with the highest correlation coefficient was observed in Higuchi model, indicating diffusion controlled principle. The n value obtained from Korsemeyer-Peppas model varied between 0.5â0.7, confirming that the mechanism of drug release was diffusion controlled. Comparative studies revealed that the release of aspirin from EC microcapsules was slower as compared to that of CAP and their binary mixture. PMID:21179372

Dash, Vikas; Mishra, Sujeet K; Singh, Manoj; Goyal, Amit K; Rath, Goutam

2010-01-01

150

Multiresidue determination of 256 pesticides in lavandin essential oil by LC/ESI/sSRM: advantages and drawbacks of a sampling method involving evaporation under nitrogen.  

PubMed

The determination of 256 multiclass pesticides in lavandin essential oil has been performed by liquid chromatography-electrospray ionization tandem mass spectrometry using the scheduled selected reaction monitoring mode available on a quadrupole-linear ion trap mass spectrometer. With the aim of improving the limits of quantification (LOQs) of the target molecules, a sampling step based on evaporation of the essential oil under a nitrogen flow assisted by controlled heating was tested. The LOQs determined in this case were compared with the values obtained with the classic dilution preparation method. With sampling by dilution, 247 pesticides were detected and quantified at low concentration, with 74 % of the pesticides having LOQs of 10 ?g L(-1) or less. With the evaporation method, a global improvement of the LOQs was observed, with lower LOQs for 92 active substances and LOQs of 10 ?g L(-1) or less for 82.8 % of the pesticides. Almost twice as many active substances had an LOQ of 1 ?g L(-1) or less when the evaporation method was used. Some pesticides exhibited poor recovery or high variance caused by volatilization or degradation during the evaporation step. This behavior was evidenced by the case of thiophanate-methyl, which is degraded to carbendazim. PMID:24366405

Fillâtre, Yoann; Rondeau, David; Daguin, Antoine; Jadas-Hecart, Alain; Communal, Pierre-Yves

2014-02-01

151

Video-taped sample evaporation in hot chambers simulating gas chromatography split and splitless injectors. II. Injection with band formation.  

PubMed

The processes in devices imitating a vaporising injector were video-taped using perylene as a fluorescent marker for non-evaporated sample. Processes are summarised which are observed after the sample liquid passed through a cool needle and left as a band of liquid moving at high velocity (as typical for injection by fast autosamplers). This liquid is shot past the column entrance unless stopped either by a packing, e.g., wool or by suitable obstacles. Packings of low thermal mass are locally cooled to the solvent boiling point and suck in the liquid. Stopping the liquid by obstacles is more difficult because solvent vapours prevent contact of the liquid with the hot surfaces, and was reliably achieved only by the laminar liner. For the same reason, transfer onto the liner wall only occurs for higher boiling liquids. PMID:11128209

Grob, K; Biedermann, M

2000-11-01

152

Method for controlling gas metal arc welding  

DOEpatents

The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

Smartt, Herschel B. (Idaho Falls, ID); Einerson, Carolyn J. (Idaho Falls, ID); Watkins, Arthur D. (Idaho Falls, ID)

1989-01-01

153

Method for controlling gas metal arc welding  

DOEpatents

The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

1987-08-10

154

Kinetic approach to the evaporation and condensation problem  

NASA Technical Reports Server (NTRS)

In the paper, the Boltzmann equation governing the evaporation and condensation phenomena is solved by the Monte Carlo method. Based on the kinetic theory of gas the role of the non-equilibrium Knudsen layer and the growth of the hydrodynamic region outside the layer as time proceeds are simulated. Results show two possible types of transient developments in the vapor phase. The effects of the molecular absorption coefficient of the phase surface are examined. Except in the case of very strong evaporation the kinematic effects of binary collisions among vapor molecules on the mass flux rate are not serious. The limiting case of the quasi-steady evaporation and the maximal value of the evaporation rate are obtained.

Murakami, M.; Oshima, K.

1974-01-01

155

A new method for simulating the late stages of island coarsening in thin film growth: The role of island diffusion and evaporation  

NASA Astrophysics Data System (ADS)

We have developed a method for simulating the evolution of an ensemble of one-atom-high islands from deposition and nucleation to coarsening. Using this method we have studied three regimes of coarsening; coarsening due to island coalescence, coarsening driven by evaporation, and the case in which both mechanisms act simultaneously. The parameters have been chosen to mimic coarsening of Ag on Ag(001); they are not meant to reproduce the experimental results for Ag quantitatively, but to provide simulations relevant to metal-on-metal homoepitaxy. We find that the scaling laws proposed by the mean-field theory for the time dependence of the number of islands and the island size distribution function work well in the limiting case when coarsening is dominated by island diffusion and coalescence. In the opposite limit, when coarsening is dominated by evaporation, the scaling predicted for the island size works well, but the island size distribution predicted by the mean-field theory is narrower than the one found in simulations. In the case when island migration and evaporation are both important, the evolution of the number of islands shows a crossover; at early times it scales as if coarsening takes place by island coalescence, and at later times it scales as if coarsening is dominated by evaporation. Regardless of the coarsening mechanism, most islands disappear by coalescence.

Mattsson, Thomas R.; Mills, Greg; Metiu, Horia

1999-06-01

156

Black hole evaporation: a paradigm  

Microsoft Academic Search

A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: (i) resolution of the Schwarzschild singularity using quantum geometry methods and (ii) time evolution of black holes in the trapping and dynamical horizon frameworks. Quantum geometry effects introduce a major modification in the traditional spacetime diagram of black hole evaporation, providing

Abhay Ashtekar; Martin Bojowald

2005-01-01

157

Method for gas-metal arc deposition  

DOEpatents

Method and apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites are disclosed. The apparatus contains an arc chamber for confining a D.C. electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment with the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspension of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite. 1 fig.

Buhrmaster, C.L.; Clark, D.E.; Smartt, H.B.

1990-11-13

158

Method for gas-metal arc deposition  

DOEpatents

Method and apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites. The apparatus contains an arc chamber for confining a D.C. electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment wiht the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspension of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite.

Buhrmaster, Carol L. (Corning, NY); Clark, Denis E. (Idaho Falls, ID); Smartt, Herschel B. (Idaho Falls, ID)

1990-01-01

159

Clearance control method for gas turbine engine  

SciTech Connect

This patent describes a method for modulating a cooling flow of air to a gas turbine engine operating within a power range. It comprises determining a desired minimum clearance between a plurality of rotating blade tips within the gas turbine engine and a surrounding annular shroud; establishing a cooling air flow rate schedule responsive to engine power within the power range, including the steps of establishing a first cooling air flow rate corresponding to a maximum, steady state, engine power level within the power range, the first cooling air flow being sufficient to result in the blade tip to shroud clearance being equal to the determined minimum clearance; determining, for each of a plurality of other engine power levels within the operating range, the magnitude of a corresponding transient clearance decrease resulting from a step change in engine power from the other engine power level to the maximum power level, and establishing, responsive to the determined transient clearance displacement, a plurality of corresponding air flow rates for the plurality of other engine steady state power levels.

Schwarz, F.M.; Crawley, C.J. Jr.; Rausco, A.F.; Lagueux, K.R.

1991-04-09

160

Streamer Evaporation  

NASA Technical Reports Server (NTRS)

Evaporation is the consequence of slow plasma heating near the tops of streamers where the plasma is only weakly contained by the magnetic field. The form it takes is the slow opening of field lines at the top of the streamer and transient formation of new solar wind. It was discovered in polytropic model calculations, where due to the absence of other energy loss mechanisms in magnetostatic streamers, its ultimate endpoint is the complete evaporation of the streamer. This takes, for plausible heating rates, weeks to months in these models. Of course streamers do not behave this way, for more than one reason. One is that there are losses due to thermal conduction to the base of the streamer and radiation from the transition region. Another is that streamer heating must have a characteristic time constant and depend on the ambient physical conditions. We use our global Magnetohydrodynamics (MHD) model with thermal conduction to examine a few examples of the effect of changing the heating scale height and of making ad hoc choices for how the heating depends on ambient conditions. At the same time, we apply and extend the analytic model of streamers, which showed that streamers will be unable to contain plasma for temperatures near the cusp greater than about 2xl0(exp 6) K. Slow solar wind is observed to come from streamers through transient releases. A scenario for this that is consistent with the above physical process is that heating increases the near-cusp temperature until field lines there are forced open. The subsequent evacuation of the flux tubes by the newly forming slow wind decreases the temperature and heating until the flux tubes are able to reclose. Then, over a longer time scale, heating begins to again refill the flux tubes with plasma and increase the temperature until the cycle repeats itself. The calculations we report here are first steps towards quantitative evaluation of this scenario.

Suess, Steven T.; Wang, A. H.; Wu, Shi T.; Nerney, S.

1998-01-01

161

Identification and quantification of (polymeric) hindered-amine light stabilizers in polymers using pyrolysis-gas chromatography-mass spectrometry and liquid chromatography-ultraviolet absorbance detection-evaporative light scattering detection.  

PubMed

Direct analysis of polymers containing polymeric hindered amine light stabilizers (HALS) by using pyrolysis coupled to GC-MS is applied successfully for fast and straightforward identification of these HALS additives. Each of the HALS additives shows different pyrolysis gas chromatograms containing characteristic pyrolysis products. As a result, HALS additives with very similar chemical structures, e.g. Chimassorb 944 and Chimassorb 2020, can be distinguished. A HPLC method with both ultraviolet (UV) and evaporative light scattering detection (ELSD) is developed to quantify the various HALS additives in extracts of polymers. The critical factor of the HPLC method is the use of a basic amine, like n-hexylamine, as a solvent additive to facilitate the elution of HALS additives. The various HALS additives can be distinguished according to retention time and peak shape and by using different detection methods. The suitability of the developed methods is demonstrated by the analytical performance of the HPLC method and the identification and determination of the actual content of HALS additives in polyolefines using pyrolysis GC-MS and HPLC. The HPLC method can also be used for the determination of the specific migration of HALS additives from food contact materials. PMID:15679160

Coulier, L; Kaal, E R; Tienstra, M; Hankemeier, Th

2005-01-14

162

Water augmented indirectly-fired gas turbine systems and method  

DOEpatents

An indirectly-fired gas turbine system utilizing water augmentation for increasing the net efficiency and power output of the system is described. Water injected into the compressor discharge stream evaporatively cools the air to provide a higher driving temperature difference across a high temperature air heater which is used to indirectly heat the water-containing air to a turbine inlet temperature of greater than about 1,000.degree. C. By providing a lower air heater hot side outlet temperature, heat rejection in the air heater is reduced to increase the heat recovery in the air heater and thereby increase the overall cycle efficiency.

Bechtel, Thomas F. (Lebanon, PA); Parsons, Jr., Edward J. (Morgantown, WV)

1992-01-01

163

Method of detecting oxygen in a gas  

NASA Technical Reports Server (NTRS)

The presence of oxygen in a gas is detected by contacting an article, such as a film, comprising poly(ethylenenaphthalene-dicarboxylate) with a gas and simultaneously exposing the article to ultraviolet light. The article is subsequently heated and the presence of oxygen in the gas is indicated by thermoluminescence.

Hendricks, H. D. (inventor)

1973-01-01

164

Could CoRoT-7b and Kepler10b be remnants of evaporated gas or ice giants?  

Microsoft Academic Search

We present thermal mass loss calculations over evolutionary time scales for the investigation if the smallest transiting rocky exoplanets CoRoT-7b (?1.68REarth) and Kepler-10b (?1.416REarth) could be remnants of an initially more massive hydrogen-rich gas giant or a hot Neptune-class exoplanet. We apply a thermal mass loss formula which yields results that are comparable to hydrodynamic loss models. Our approach considers

M. Leitzinger; P. Odert; Yu. N. Kulikov; H. Lammer; G. Wuchterl; T. Penz; M. G. Guarcello; G. Micela; M. L. Khodachenko; J. Weingrill; A. Hanslmeier; H. K. Biernat; J. Schneider

2011-01-01

165

System and method for detecting gas  

DOEpatents

A system to detect a presence of a specific gas in a mixture of gaseous byproducts comprising moisture vapor is disclosed. The system includes an electrochemical cell, a transport to deliver the mixture of gaseous byproducts from the electrochemical cell, a gas sensor in fluid communication with the transport, the sensor responsive to a presence of the specific gas to generate a signal corresponding to a concentration of the specific gas, and a membrane to prevent transmission of liquid moisture, the membrane disposed between the transport and the gas sensor.

Chow, Oscar Ken (Simsbury, CT); Moulthrop, Lawrence Clinton (Windsor, CT); Dreier, Ken Wayne (Madison, CT); Miller, Jacob Andrew (Dexter, MI)

2010-03-16

166

Arrangement and method for the production of liquid natural gas  

SciTech Connect

An arrangement and a method for the increase in the production of liquid natural gas and the conservation of energy and reduction of flash gas in a liquid natural gas manufacturing installation and, more particularly, the reduction in the quantity of formed flash gas through the novel utilization of a hydraulic expander in the installation for extracting work from the flow of liquid natural gas prior to flashing thereof.

Brundige, V.L. Jr.

1984-06-26

167

Method and apparatus for manufacturing gas tags  

DOEpatents

For use in the manufacture of gas tags employed in a gas tagging failure detection system for a nuclear reactor, a plurality of commercial feed gases each having a respective noble gas isotopic composition are blended under computer control to provide various tag gas mixtures having selected isotopic ratios which are optimized for specified defined conditions such as cost. Using a new approach employing a discrete variable structure rather than the known continuous-variable optimization problem, the computer controlled gas tag manufacturing process employs an analytical formalism from condensed matter physics known as stochastic relaxation, which is a special case of simulated annealing, for input feed gas selection. For a tag blending process involving M tag isotopes with N distinct feed gas mixtures commercially available from an enriched gas supplier, the manufacturing process calculates the cost difference between multiple combinations and specifies gas mixtures which approach the optimum defined conditions. The manufacturing process is then used to control tag blending apparatus incorporating tag gas canisters connected by stainless-steel tubing with computer controlled valves, with the canisters automatically filled with metered quantities of the required feed gases. 4 figs.

Gross, K.C.; Laug, M.T.

1996-12-17

168

Method and apparatus for manufacturing gas tags  

DOEpatents

For use in the manufacture of gas tags employed in a gas tagging failure detection system for a nuclear reactor, a plurality of commercial feed gases each having a respective noble gas isotopic composition are blended under computer control to provide various tag gas mixtures having selected isotopic ratios which are optimized for specified defined conditions such as cost. Using a new approach employing a discrete variable structure rather than the known continuous-variable optimization problem, the computer controlled gas tag manufacturing process employs an analytical formalism from condensed matter physics known as stochastic relaxation, which is a special case of simulated annealing, for input feed gas selection. For a tag blending process involving M tag isotopes with N distinct feed gas mixtures commercially available from an enriched gas supplier, the manufacturing process calculates the cost difference between multiple combinations and specifies gas mixtures which approach the optimum defined conditions. The manufacturing process is then used to control tag blending apparatus incorporating tag gas canisters connected by stainless-steel tubing with computer controlled valves, with the canisters automatically filled with metered quantities of the required feed gases.

Gross, Kenny C. (Bolingbrook, IL); Laug, Matthew T. (Idaho Falls, ID)

1996-01-01

169

Synthesis Methods, Microscopy Characterization and Device Integration of Nanoscale Metal Oxide Semiconductors for Gas Sensing  

PubMed Central

A comparison is made between SnO2, ZnO, and TiO2 single-crystal nanowires and SnO2 polycrystalline nanofibers for gas sensing. Both nanostructures possess a one-dimensional morphology. Different synthesis methods are used to produce these materials: thermal evaporation-condensation (TEC), controlled oxidation, and electrospinning. Advantages and limitations of each technique are listed. Practical issues associated with harvesting, purification, and integration of these materials into sensing devices are detailed. For comparison to the nascent form, these sensing materials are surface coated with Pd and Pt nanoparticles. Gas sensing tests, with respect to H2, are conducted at ambient and elevated temperatures. Comparative normalized responses and time constants for the catalyst and noncatalyst systems provide a basis for identification of the superior metal-oxide nanostructure and catalyst combination. With temperature-dependent data, Arrhenius analyses are made to determine activation energies for the catalyst-assisted systems.

Vander Wal, Randy L.; Berger, Gordon M.; Kulis, Michael J.; Hunter, Gary W.; Xu, Jennifer C.; Evans, Laura

2009-01-01

170

DWPF RECYCLE EVAPORATOR FLOWSHEET EVALUATION (U)  

SciTech Connect

The Defense Waste Processing Facility (DWPF) converts the high level waste slurries stored at the Savannah River Site into borosilicate glass for long-term storage. The vitrification process results in the generation of approximately five gallons of dilute recycle streams for each gallon of waste slurry vitrified. This dilute recycle stream is currently transferred to the H-area Tank Farm and amounts to approximately 1,400,000 gallons of effluent per year. Process changes to incorporate salt waste could increase the amount of effluent to approximately 2,900,000 gallons per year. The recycle consists of two major streams and four smaller streams. The first major recycle stream is condensate from the Chemical Process Cell (CPC), and is collected in the Slurry Mix Evaporator Condensate Tank (SMECT). The second major recycle stream is the melter offgas which is collected in the Off Gas Condensate Tank (OGCT). The four smaller streams are the sample flushes, sump flushes, decon solution, and High Efficiency Mist Eliminator (HEME) dissolution solution. These streams are collected in the Decontamination Waste Treatment Tank (DWTT) or the Recycle Collection Tank (RCT). All recycle streams are currently combined in the RCT and treated with sodium nitrite and sodium hydroxide prior to transfer to the tank farm. Tank Farm space limitations and previous outages in the 2H Evaporator system due to deposition of sodium alumino-silicates have led to evaluation of alternative methods of dealing with the DWPF recycle. One option identified for processing the recycle was a dedicated evaporator to concentrate the recycle stream to allow the solids to be recycled to the DWPF Sludge Receipt and Adjustment Tank (SRAT) and the condensate from this evaporation process to be sent and treated in the Effluent Treatment Plant (ETP). In order to meet process objectives, the recycle stream must be concentrated to 1/30th of the feed volume during the evaporation process. The concentrated stream must be pumpable to the DWPF SRAT vessel and should not precipitate solids to avoid fouling the evaporator vessel and heat transfer coils. The evaporation process must not generate excessive foam and must have a high Decontamination Factor (DF) for many species in the evaporator feed to allow the condensate to be transferred to the ETP. An initial scoping study was completed in 2001 to evaluate the feasibility of the evaporator which concluded that the concentration objectives could be met. This initial study was based on initial estimates of recycle concentration and was based solely on OLI modeling of the evaporation process. The Savannah River National Laboratory (SRNL) has completed additional studies using simulated recycle streams and OLI{reg_sign} simulations. Based on this work, the proposed flowsheet for the recycle evaporator was evaluated for feasibility, evaporator design considerations, and impact on the DWPF process. This work was in accordance with guidance from DWPF-E and was performed in accordance with the Technical Task and Quality Assurance Plan.

Stone, M

2005-04-30

171

Vertically aligned ZnO nanowires produced by a catalyst-free thermal evaporation method and their field emission properties  

Microsoft Academic Search

Vertically aligned ZnO nanowires have been synthesized on Si substrate by catalyst-free thermal evaporating metallic zinc powder at a low temperature of 600 [degree sign]C. Studies found that the ZnO nanowires are single-crystalline wurtzite structures with 70 nm in diameter and 10 [mu]m in length. The turn on field of the ZnO nanowires was about 6.2 V\\/[mu]m at a current

Heon Ham; Guozhen Shen; Jung Hee Cho; Tae Jae Lee; Sung Ho Seo; Cheol Jin Lee

2005-01-01

172

Encapsulation of water-soluble drugs by a modified solvent evaporation method. I. Effect of process and formulation variables on drug entrapment.  

PubMed

Pseudoephedrine HCl, a highly water-soluble drug, was entrapped within poly (methyl methacrylate) microspheres by a water/oil/water emulsification-solvent evaporation method. An aqueous drug solution was emulsified into a solution of the polymer in methylene chloride, followed by emulsification of this primary emulsion into an external aqueous phase to form a water/oil/water emulsion. The middle organic phase separated the internal drug-containing aqueous phase from the continuous phase. Microspheres were formed after solvent evaporation and polymer precipitation. The drug content of the microspheres increased with increasing theoretical drug loading, increasing amounts of organic solvent, polymer and polymeric stabilizer, and decreased with increasing stirring time, increasing pH of the continuous phase and increased volume of the internal and external aqueous phase. PMID:2384837

Alex, R; Bodmeier, R

1990-01-01

173

Measurement of leaf hydraulic conductance and stomatal conductance and their responses to irradiance and dehydration using the Evaporative Flux Method (EFM).  

PubMed

Water is a key resource, and the plant water transport system sets limits on maximum growth and drought tolerance. When plants open their stomata to achieve a high stomatal conductance (gs) to capture CO2 for photosynthesis, water is lost by transpiration(1,2). Water evaporating from the airspaces is replaced from cell walls, in turn drawing water from the xylem of leaf veins, in turn drawing from xylem in the stems and roots. As water is pulled through the system, it experiences hydraulic resistance, creating tension throughout the system and a low leaf water potential (?(leaf)). The leaf itself is a critical bottleneck in the whole plant system, accounting for on average 30% of the plant hydraulic resistance(3). Leaf hydraulic conductance (K(leaf) = 1/ leaf hydraulic resistance) is the ratio of the water flow rate to the water potential gradient across the leaf, and summarizes the behavior of a complex system: water moves through the petiole and through several orders of veins, exits into the bundle sheath and passes through or around mesophyll cells before evaporating into the airspace and being transpired from the stomata. K(leaf) is of strong interest as an important physiological trait to compare species, quantifying the effectiveness of the leaf structure and physiology for water transport, and a key variable to investigate for its relationship to variation in structure (e.g., in leaf venation architecture) and its impacts on photosynthetic gas exchange. Further, K(leaf) responds strongly to the internal and external leaf environment(3). K(leaf) can increase dramatically with irradiance apparently due to changes in the expression and activation of aquaporins, the proteins involved in water transport through membranes(4), and K(leaf) declines strongly during drought, due to cavitation and/or collapse of xylem conduits, and/or loss of permeability in the extra-xylem tissues due to mesophyll and bundle sheath cell shrinkage or aquaporin deactivation(5-10). Because K(leaf) can constrain gs and photosynthetic rate across species in well watered conditions and during drought, and thus limit whole-plant performance they may possibly determine species distributions especially as droughts increase in frequency and severity(11-14). We present a simple method for simultaneous determination of K(leaf) and gs on excised leaves. A transpiring leaf is connected by its petiole to tubing running to a water source on a balance. The loss of water from the balance is recorded to calculate the flow rate through the leaf. When steady state transpiration (E, mmol • m(-2) • s(-1)) is reached, gs is determined by dividing by vapor pressure deficit, and K(leaf) by dividing by the water potential driving force determined using a pressure chamber (K(leaf)= E /- ??(leaf), MPa)(15). This method can be used to assess K(leaf) responses to different irradiances and the vulnerability of K(leaf) to dehydration(14,16,17). PMID:23299126

Sack, Lawren; Scoffoni, Christine

2012-01-01

174

Measurement of Leaf Hydraulic Conductance and Stomatal Conductance and Their Responses to Irradiance and Dehydration Using the Evaporative Flux Method (EFM)  

PubMed Central

Water is a key resource, and the plant water transport system sets limits on maximum growth and drought tolerance. When plants open their stomata to achieve a high stomatal conductance (gs) to capture CO2 for photosynthesis, water is lost by transpiration1,2. Water evaporating from the airspaces is replaced from cell walls, in turn drawing water from the xylem of leaf veins, in turn drawing from xylem in the stems and roots. As water is pulled through the system, it experiences hydraulic resistance, creating tension throughout the system and a low leaf water potential (?leaf). The leaf itself is a critical bottleneck in the whole plant system, accounting for on average 30% of the plant hydraulic resistance3. Leaf hydraulic conductance (Kleaf = 1/ leaf hydraulic resistance) is the ratio of the water flow rate to the water potential gradient across the leaf, and summarizes the behavior of a complex system: water moves through the petiole and through several orders of veins, exits into the bundle sheath and passes through or around mesophyll cells before evaporating into the airspace and being transpired from the stomata. Kleaf is of strong interest as an important physiological trait to compare species, quantifying the effectiveness of the leaf structure and physiology for water transport, and a key variable to investigate for its relationship to variation in structure (e.g., in leaf venation architecture) and its impacts on photosynthetic gas exchange. Further, Kleaf responds strongly to the internal and external leaf environment3. Kleaf can increase dramatically with irradiance apparently due to changes in the expression and activation of aquaporins, the proteins involved in water transport through membranes4, and Kleaf declines strongly during drought, due to cavitation and/or collapse of xylem conduits, and/or loss of permeability in the extra-xylem tissues due to mesophyll and bundle sheath cell shrinkage or aquaporin deactivation5-10. Because Kleaf can constrain gs and photosynthetic rate across species in well watered conditions and during drought, and thus limit whole-plant performance they may possibly determine species distributions especially as droughts increase in frequency and severity11-14. We present a simple method for simultaneous determination of Kleaf and gs on excised leaves. A transpiring leaf is connected by its petiole to tubing running to a water source on a balance. The loss of water from the balance is recorded to calculate the flow rate through the leaf. When steady state transpiration (E, mmol • m-2 • s-1) is reached, gs is determined by dividing by vapor pressure deficit, and Kleaf by dividing by the water potential driving force determined using a pressure chamber (Kleaf= E /- ??leaf, MPa)15. This method can be used to assess Kleaf responses to different irradiances and the vulnerability of Kleaf to dehydration14,16,17.

Sack, Lawren; Scoffoni, Christine

2012-01-01

175

A method of determining combustion gas flow  

NASA Technical Reports Server (NTRS)

Zirconium oxide coating enables the determination of hot gas flow patterns on liquid rocket injector face and baffle surfaces to indicate modifications that will increase performance and improve combustion stability. The coating withstands combustion temperatures and due to the coarse surface and coloring of the coating, shows the hot gas patterns.

Bon Tempi, P. J.

1968-01-01

176

Evaporation from open microchannel grooves.  

PubMed

The evaporation of water from open u-shaped microchannel grooves was investigated with particular emphasis on the roles of channel width and air flow conditions. Given the small dimensions of the microchannels, all measurements were conducted in a range where convection and diffusion are of equal importance and known correlations for the calculation of mass transfer coefficients cannot be applied. The evaporation rates were measured using a new optical method and a gravimetric method. Both measurement methods yielded mass transfer coefficients that are in agreement with each other. The observed relation between mass transfer coefficient, air velocity and channel width vastly differs from the predictions obtained from macroscopic structures. With respect to diagnostic devices we conclude that analyte concentration in an open microchannel groove strongly increases even within short times due to the evaporation process and we show that wider channels are more favourable in terms of minimizing the relative evaporation rate. PMID:24345870

Kachel, Sibylle; Zhou, Ying; Scharfer, Philip; Vran?i?, Christian; Petrich, Wolfgang; Schabel, Wilhelm

2014-02-21

177

Calculation Method for Gas Release from Uranium Dioxide Compacts.  

National Technical Information Service (NTIS)

Described is the method for calculation of gas release from the compacted uranium dioxide. The method is based on the gas atomic diffusion in the fuel. With this method in use the code GRETA has been developed intended for calculation of temperatures and ...

V. S. Sulaberidze A. V. Pershin

1983-01-01

178

Blue-Green Emitting SrS:Ce, Cl Thin-Film Electroluminescent Devices Prepared by Reactive Evaporation Using H2S Gas  

NASA Astrophysics Data System (ADS)

SrS:Ce, Cl phosphor films were deposited by evaporating Sr metal and CeCl3 in H2S gas. The crystallinity, luminance, and emission spectra of the films were investigated in relation to the deposition conditions. X-ray diffraction intensity from the (200) plane of the SrS films was found to increase with the substrate temperature when the H2S pressure was kept constant, and had the maximum value at the H2S pressure of 1× 10-2 Pa when the substrate temperature was kept constant. The variation of luminance in relation to the H2S pressure and the substrate temperature was similar to that of the (200) diffraction intensity. The luminance of 600 cd/m2 and the maximum emission efficiency as high as 1 lm/W were obtained at 1 kHz 30 ?s wide ac pulse excitation for the films deposited at 600°C and H2S pressure of 1× 10-2 Pa, although the emission color was not blue but whitish green.

Tohda, Takao; Okajima, Michio; Yamamoto, Makoto; Matsuoka, Tomizo

1991-11-01

179

Evaporation of forsterite in the primordial solar nebula; rates and accompanied isotopic fractionation  

Microsoft Academic Search

Evaporation rates of forsterite in the primordial solar nebula were modeled. There are 3 evaporation regimes expected: 1. free evaporation-dominated (FED) regime, where forsterite evaporates as free evaporation, 2. hydrogen reaction-dominated (HRD) regime, where the evaporation is affected by H2 gas, and 3. H2O\\/H2 buffer-dominated (HBD) regime, where the evaporation is controlled by redox states buffered by the H2O\\/H2 ratio

Akira Tsuchiyama; Shogo Tachibana; Toshio Takahashi

1999-01-01

180

Vertically aligned ZnO nanowires produced by a catalyst-free thermal evaporation method and their field emission properties  

Microsoft Academic Search

Vertically aligned ZnO nanowires have been synthesized on Si substrate by catalyst-free thermal evaporating metallic zinc powder at a low temperature of 600°C. Studies found that the ZnO nanowires are single-crystalline wurtzite structures with 70nm in diameter and 10?m in length. The turn on field of the ZnO nanowires was about 6.2V\\/?m at a current density of 0.1?A\\/cm2, and the

Heon Ham; Guozhen Shen; Jung Hee Cho; Tae Jae Lee; Sung Ho Seo; Cheol Jin Lee

2005-01-01

181

Heterodyne method for high specificity gas detection.  

NASA Technical Reports Server (NTRS)

This paper describes a new technique for measuring trace quantities of gases. The technique involves the use of a reference cell (containing a known amount of the gas being sought) and a sample cell (containing an unknown amount of the same gas) wherein the gas densities are modulated. Light passing through the two cells in sequence is modulated in intensity at the vibrational-rotational lines characteristic of the absorption spectrum for the gas of interest. Since the absorption process is nonlinear, modulating the two absorption cells at two different frequencies gives rise to a heterodyning effect, which in turn introduces sum and difference frequencies in the detected signal. Measuring the ratio of the difference frequency signal for example, to the signal introduced by the reference cell provides a normalized measure of the amount of the gas in the sample cell. The readings produced are thereby independent of source intensity, window transparency, and detector sensitivity. Experimental evaluation of the technique suggests that it should be applicable to a wide range of gases, that it should be able to reject spurious signals due to unwanted gases, and that it should be sensitive to concentrations of the order of 10 to the minus 8th power when used with a sample cell of only 20 cm length.

Dimeff, J.; Donaldson, R. W.; Gunter, W. D., Jr.; Jaynes, D. N.; Margozzi, A. P.; Deboo, G. J.; Mcclatchie, E. A.; Williams, K. G.

1971-01-01

182

Effect of gas flow swirling on coating deposition by the cold gas-dynamic spray method  

NASA Astrophysics Data System (ADS)

The effect of gas flow swirling on the process of coating deposition onto a target by the cold gas-dynamic spray method is studied experimentally and numerically. Flow swirling is found to change the gas flow field and to reduce the gas flow rate under typical conditions of cold gas-dynamic spray. In a non-swirled flow, the shape of the deposited spot is similar to a sharp cone. In contrast, the deposited spot in a swirled flow is shaped as a crater without particles at the center of this crater. It is found that this effect is caused by centrifugal forces acting on particles in a swirled gas flow.

Kiselev, S. P.; Kiselev, V. P.; Zaikovskii, V. N.

2012-03-01

183

Lattice gas methods on curved surfaces  

NASA Astrophysics Data System (ADS)

We present a hydrodynamic lattice gas model for two-dimensional flows on curved surfaces with dynamical geometry. This model is the extension to two dimensions of a dynamical geometry lattice gas model studied in one-dimension. We expand upon a variation of the two-dimensional flat space model created and studied by Frisch, Hasslacher and Pomeau in 1986. Rules for dynamic geometry are constructed using the Pachner moves, which change the triangulation of our manifold but not the topology. Prior work defined the model and showed that the number of triangles lattice grows with time as, closely matching the mean field prediction. We present preliminary results of a Chapman-Enskog analysis generalized to treat the case of a lattice gas flowing on a curved two-dimensional surface.

Cianci, Dan; Needell, Zachary; Love, Peter

2010-03-01

184

Preparation of spinel ZnGa 2O 4 films on MgO substrates by the solvent evaporation epitaxy method  

NASA Astrophysics Data System (ADS)

Oriented thin films of ZnGa 2O 4 have been obtained on an MgO(001) substrate by the solvent evaporation epitaxy method. The results of EPMA suggest that the ratio of Zn to Ga is almost stoichiometric and nearly all of the solvent of PbF 2 is removed. The crystal structure of the film is cubic spinel with a lattice constant of a = 8.33(3) Å. The X-ray precession photographs prove that the a- and b-axes of the film are strictly parallel to those of the substrate, respectively.

Yan, Zheng; Koike, Masayoshi; Takei, Humihiko

1996-07-01

185

The effect of particle microstructure on the somatostatin release from poly(lactide) microspheres prepared by a W\\/O\\/W solvent evaporation method  

Microsoft Academic Search

Somatostatin acetate-containing poly(lactide) microspheres were prepared by a W\\/O\\/W multiple emulsion solvent evaporation method. The resulting microspheres were characterized with respect to encapsulation efficiency, drug release and morphological properties (scanning electron microscopy). The addition of various buffers (pH 2.2, 3.0, 4.0 or 5.0) or salts (NaCl or CaCl2) to the internal aqueous and\\/or external aqueous phase affected the osmotic pressure

Joachim Herrmann; Roland Bodmeier

1995-01-01

186

Hot gas desulfurization sorbent and method.  

National Technical Information Service (NTIS)

A multiple metal oxide sorbent supported on a zeolite of substantially silicon oxide is used for the desulfurization of process gas streams, such as from a coal gasifier, at temperatures in the range of about 1200(degrees) to about 1600(degrees)F. The sor...

L. D. Gasper-Galvin A. T. Atimtay

1991-01-01

187

Computations of turbulent evaporating sprays  

NASA Technical Reports Server (NTRS)

A computational study of turbulent evaporating sprays is reported. The major focus is to examine the sensitivity of the vaporization behavior of turbulent sprays to the transient liquid-phase processes. Three models considered to represent these processes are the thin skin, infinite diffusion, and diffusion limit models. Favre-averaged equations with k-epsilon-g turbulence model are employed for the gas phase. The Lagrangian approach with a stochastic separated flow method is used for the liquid phase where the effects of gas turbulence on droplet trajectories and interphase transport rates are considered using random-walk computations. Also the variable-property effects are considered in detail. Results indicate that, depending upon the boiling temperature and heat of vaporization of the fuel considered, the vaporization behavior of turbulent sprays may be quite sensitive to the modeling of transient liquid-phase processes. Thus, it is important that for most hydrocarbon fuels these processes be adequately represented in any comprehensive spray computations. The present results also provide further support to the conclusions of earlier studies which have been based on simplified spray configurations.

Aggarwal, S. K.; Chitre, S.

1989-01-01

188

The evaporation of spherical clouds in a hot gas. II - Effects of radiation. [for supernova remnants, interstellar medium and galactic clusters  

NASA Technical Reports Server (NTRS)

The effects of radiation on the evaporation of spherical clouds in a hot medium are considered. The critical cloud radius at which radiative losses balance conductive heating is determined as a function of the external temperature and density. Smaller clouds evaporate, and larger clouds condense. The conditions under which the surfaces of the clouds may be detected are discussed. Net radiative losses for evaporating clouds are calculated, and an effective cooling function for a cloudy medium is obtained. The results may be applied to clouds in supernova remnants, in the interstellar medium, and in clusters of galaxies.

Mckee, C. F.; Cowie, L. L.

1977-01-01

189

A Method for Direct Assessment of the "Non Rainfall" Atmospheric Water Cycle: Input and Evaporation From the Soil  

NASA Astrophysics Data System (ADS)

"Non rainfall" atmospheric water (dew, fog, vapour adsorption) supplies a small amount of water to the soil surface that may be important for arid soil micro-hydrology and ecology. Research into the direct effects of this water on soil is, however, lacking due to instrument and technical constraints. We report on the design, development, construction and findings of an automated microlysimeter instrument to directly measure this soil water cycle in Stellenbosch, South Africa during winter. Performance of the microlysimeter was satisfactory and results obtained were compared to literature and fell within the expected range. "Non rainfall" atmospheric water input into bare soil (river sand) was between 0.88 and 1.10 mm per night while evaporation was between 1.39 and 2.71 mm per day. The study also attempted to differentiate the composition of "non rainfall" atmospheric water and results showed that vapour adsorption contributed the bulk of this input.

Kaseke, Kudzai Farai; Mills, Anthony J.; Brown, Roger; Esler, Karen J.; Henschel, Johannes. R.; Seely, Mary K.

2012-05-01

190

Endwall Treatment and Method for Gas Turbine  

NASA Technical Reports Server (NTRS)

An endwall treatment for a gas turbine engine having at least one rotor blade extending from a rotatable hub and a casing circumferentially surrounding the rotor and the hub, the endwall treatment including, an inlet formed in an endwall of the gas turbine engine adapted to ingest fluid from a region of a higher-pressure fluid, an outlet formed in the endwall and located in a region of lower pressure than the inlet, wherein the inlet and the outlet are in a fluid communication with each other, the outlet being adapted to inject the fluid from the inlet in the region of lower pressure, and wherein the outlet is at least partially circumferentially offset relative to the inlet.

Hathaway, Michael D. (Inventor); Strazisar, Anthony J. (Inventor); Suder, Kenneth L. (Inventor)

2006-01-01

191

Evaluation of two gas-dilution methods for instrument calibration  

NASA Technical Reports Server (NTRS)

Two gas dilution methods were evaluated for use in the calibration of analytical instruments used in air pollution studies. A dual isotope fluorescence carbon monoxide analyzer was used as the transfer standard. The methods are not new but some modifications are described. The rotary injection gas dilution method was found to be more accurate than the closed loop method. Results by the two methods differed by 5 percent. This could not be accounted for by the random errors in the measurements. The methods avoid the problems associated with pressurized cylinders. Both methods have merit and have found a place in instrument calibration work.

Evans, A., Jr.

1977-01-01

192

Effect of Mass Transfer on Heat Transfer during Evaporation of a Liquid from an Exposed Surface in a Rarefied Gas Atmosphere.  

National Technical Information Service (NTIS)

The evaporation of a liquid from an open surface was investigated. The mechanism of the effect of mass transfer on heat transfer for vaporization in free convection was established on the basis of an experimental study.

P. A. Novikov V. I. Balakhonova V. M. Subach

1973-01-01

193

Method for nonlinear optimization for gas tagging and other systems  

DOEpatents

A method and system are disclosed for providing nuclear fuel rods with a configuration of isotopic gas tags. The method includes selecting a true location of a first gas tag node, selecting initial locations for the remaining n-1 nodes using target gas tag compositions, generating a set of random gene pools with L nodes, applying a Hopfield network for computing on energy, or cost, for each of the L gene pools and using selected constraints to establish minimum energy states to identify optimal gas tag nodes with each energy compared to a convergence threshold and then upon identifying the gas tag node continuing this procedure until establishing the next gas tag node until all remaining n nodes have been established. 6 figs.

Chen, T.; Gross, K.C.; Wegerich, S.

1998-01-06

194

Method for nonlinear optimization for gas tagging and other systems  

DOEpatents

A method and system for providing nuclear fuel rods with a configuration of isotopic gas tags. The method includes selecting a true location of a first gas tag node, selecting initial locations for the remaining n-1 nodes using target gas tag compositions, generating a set of random gene pools with L nodes, applying a Hopfield network for computing on energy, or cost, for each of the L gene pools and using selected constraints to establish minimum energy states to identify optimal gas tag nodes with each energy compared to a convergence threshold and then upon identifying the gas tag node continuing this procedure until establishing the next gas tag node until all remaining n nodes have been established.

Chen, Ting (Chicago, IL); Gross, Kenny C. (Bolingbrook, IL); Wegerich, Stephan (Glendale Heights, IL)

1998-01-01

195

Gas migration modeling improves volumetric method of well control  

SciTech Connect

In the volumetric method, gas expansion during gas migration is allowed for by bleeding small quantities of fluid through the choke. When gas first reaches the choke, the influx is distributed near the surface in the annulus. Rapid gas migration then occurs, and mud and gas may need to be bled to maintain constant bottom hole pressure. The volumetric method is a technique for controlling gas kicks when circulation is not possible. The industry-recognized method is based on simple calculations which assume a single bubble of gas, the classic kick. This technique can now be evaluated by using more realistic, deterministic kick models. The results from such models cast double on some of the conventional procedures taught and used in the industry. This article details the analysis of influx behavior following a typical volumetric method. Numerical modeling of fluid losses as the surface pressure rises, gas migration, and dispersion are included to correspond accurately with field observations of kicks. Revised procedures are suggested to deal with these events better, such that the goals of the volumetric method are still attained.

Leach, C.P.; Quentin, K.M. (Well Control and Systems Design, Houston, TX (United States))

1994-12-26

196

System and method for producing substitute natural gas from coal  

DOEpatents

The present invention provides a system and method for producing substitute natural gas and electricity, while mitigating production of any greenhouse gasses. The system includes a hydrogasification reactor, to form a gas stream including natural gas and a char stream, and an oxygen burner to combust the char material to form carbon oxides. The system also includes an algae farm to convert the carbon oxides to hydrocarbon material and oxygen.

Hobbs, Raymond (Avondale, AZ)

2012-08-07

197

Method and apparatus for recovering a gas from a gas hydrate located on the ocean floor  

DOEpatents

A method and apparatus for recovering a gas from a gas hydrate on the ocean floor includes a flexible cover, a plurality of steerable base members secured to the cover, and a steerable mining module. A suitable source for inflating the cover over the gas hydrate deposit is provided. The mining module, positioned on the gas hydrate deposit, is preferably connected to the cover by a control cable. A gas retrieval conduit or hose extends upwardly from the cover to be connected to a support ship on the ocean surface.

Wyatt, Douglas E. (Aiken, SC)

2001-01-01

198

Falling film evaporation on enhanced tubes, part 1: Experimental results for pool boiling, onset of dryout and falling film evaporation  

Microsoft Academic Search

Horizontal falling film evaporators have the potential of displacing ooded evaporators as the standard in the refrigeration industry due to compelling advantages, such as smaller refrigerant charge and lower pressure drop. How- ever, there is a need to improve the understanding of falling film evapora-tion mechanisms to provide accurate thermal design methods. In this work, falling film evaporation measurements on

M. Christians; J. R. Thome

199

A steady-state non-equilibrium molecular dynamics approach for the study of evaporation processes  

NASA Astrophysics Data System (ADS)

Two non-equilibrium methods (called bubble method and splitting method, respectively) have been developed and tested to study the steady state evaporation of a droplet surrounded by its vapor, where the evaporation continuously occurs at the vapor-liquid interface while the droplet size remains constant. In the bubble method, gas molecules are continuously reinserted into a free volume (represented by a bubble) located at the centre of mass of the droplet to keep the droplet size constant. In the splitting method, a molecule close to the centre of mass of the droplet is split into two: In this way, the droplet size is also maintained during the evaporation. By additional local thermostats confined to the area of insertion, the effect of frequent insertions on properties such as density and temperature can be limited to the immediate insertion area. Perturbations are not observed in other parts of the droplet. In the end, both the bubble method and the splitting method achieve steady-state droplet evaporation. Although these methods have been developed using an isolated droplet, we anticipate that they will find a wide range of applications in the study of the evaporation of isolated films and droplets or thin films on heated substrates or under confinement. They can in principle also be used to study the steady-state of other physical processes, such as the diffusion or permeation of gas molecules or ions in a pressure gradient or a concentration gradient.

Zhang, Jianguo; Müller-Plathe, Florian; Yahia-Ouahmed, Méziane; Leroy, Frédéric

2013-10-01

200

A steady-state non-equilibrium molecular dynamics approach for the study of evaporation processes.  

PubMed

Two non-equilibrium methods (called bubble method and splitting method, respectively) have been developed and tested to study the steady state evaporation of a droplet surrounded by its vapor, where the evaporation continuously occurs at the vapor-liquid interface while the droplet size remains constant. In the bubble method, gas molecules are continuously reinserted into a free volume (represented by a bubble) located at the centre of mass of the droplet to keep the droplet size constant. In the splitting method, a molecule close to the centre of mass of the droplet is split into two: In this way, the droplet size is also maintained during the evaporation. By additional local thermostats confined to the area of insertion, the effect of frequent insertions on properties such as density and temperature can be limited to the immediate insertion area. Perturbations are not observed in other parts of the droplet. In the end, both the bubble method and the splitting method achieve steady-state droplet evaporation. Although these methods have been developed using an isolated droplet, we anticipate that they will find a wide range of applications in the study of the evaporation of isolated films and droplets or thin films on heated substrates or under confinement. They can in principle also be used to study the steady-state of other physical processes, such as the diffusion or permeation of gas molecules or ions in a pressure gradient or a concentration gradient. PMID:24116576

Zhang, Jianguo; Müller-Plathe, Florian; Yahia-Ouahmed, Méziane; Leroy, Frédéric

2013-10-01

201

Method for removal of sulfur compounds from a gas stream  

SciTech Connect

This invention relates to a process for the removal of sulfur compounds from a gas stream. More specifically, this invention relates to an improvement in the iron oxide method of sulfur removal from a gas stream through the use of hydrogen peroxide.

Frech, K.J.; Tazuma, J.J.

1982-01-19

202

Method for removal of sulfur compounds from a gas stream  

Microsoft Academic Search

This invention relates to a process for the removal of sulfur compounds from a gas stream. More specifically, this invention relates to an improvement in the iron oxide method of sulfur removal from a gas stream through the use of hydrogen peroxide.

K. J. Frech; J. J. Tazuma

1982-01-01

203

Method for scrubbing pollutants from an exhaust gas stream  

Microsoft Academic Search

This patent describes a method of treatment of an exhaust gas stream containing as pollutants at least one of the acidic oxides of sulfur, nitrogen, carbon, and halogens and acidic halogen compounds, whose temperature exceeds the dew point of the gas, for producing scrubbed exhaust and useful or benign by-products. It comprises: providing a basic aqueous slurry of ash, the

1992-01-01

204

In vitro Evaluation of Novel Sustained Release Microspheres of Glipizide Prepared by the Emulsion Solvent Diffusion-Evaporation Method  

PubMed Central

The objective of the current investigation is to reduce dosing frequency and improve patient compliance by designing and systematically evaluating sustained release microspheres of Glipizide. An anti-diabetic drug, Glipizide, is delivered through the microparticulate system using ethyl cellulose as the controlled release polymer. Microspheres were developed by the emulsion solvent diffusion-evaporation technique by using the modified ethanol,-dichloromethane co-solvent system. The polymer mixture of ethyl cellulose and Eudragit® S100 was used in different ratios (1:0, 1:1, 2:3, 1:4 and 0:1) to formulate batches F1 to F5. The resulting microspheres were evaluated for particle size, densities, flow properties, morphology, recovery yield, drug content, and in vitro drug release behavior. The formulated microspheres were discrete, spherical with relatively smooth surface, and with good flow properties. Among different formulations, the fabricated microspheres of batch F3 had shown the optimum percent drug encapsulation of microspheres and the sustained release of the Glipizide for about 12 h. Release pattern of Glipizide from microspheres of batch F3 followed Korsmeyers-peppas model and zero-order release kinetic model. The value of ‘n’ was found to be 0.960, which indicates that the drug release was followed by anomalous (non-fickian) diffusion. The data obtained thus suggest that a microparticulate system can be successfully designed for sustained delivery of Glipizide and to improve dosage form characteristics for easy formulation.

Phutane, P; Shidhaye, S; Lotlikar, V; Ghule, A; Sutar, S; Kadam, V

2010-01-01

205

Dependence of the Properties of Cu(In,Ga)S2/Mo Films Prepared by Two-Stage Evaporation Method on Degree of Vacuum during Deposition  

NASA Astrophysics Data System (ADS)

The influence of background pressure in multisource evaporation is not straightforward to explain, but it is clear that the amount of absorbed gases on the surface of the growing grains change with pressure. This may influence surface energies, and consequently the growth mechanism. We investigated the relation between the orientation of Cu(In,Ga)S2 films and pressure during deposition. We varied the background pressure during the deposition of the precursor film (first stage) by varying the temperature of the sulphur source, by throttling the vacuum pump, or by introducing N2 gas. We found that Cu(In,Ga)S2 films prepared from In--Ga--S precursors show (112) orientation if the pressure during precursor deposition is less than 0.03 Pa when the pressure is mainly attributable to sulphur. When it is mainly due to N2 gas, the pressure at which the orientation changes is 0.14 Pa. The orientation of the final film reflects the orientation of the (In,Ga)2S3 precursor immediately before entering the second stage.

Kaigawa, Ryuji; Souza, Diogo M.; Satake, Yasuhiro; Klenk, Reiner

2012-10-01

206

Method and apparatus for off-gas composition sensing  

DOEpatents

An apparatus and method for non-intrusive collection of off-gas data in a steelmaking furnace includes structure and steps for transmitting a laser beam through the off-gas produced by a steelmaking furnace, for controlling the transmitting to repeatedly scan the laser beam through a plurality of wavelengths in its tuning range, and for detecting the laser beam transmitted through the off-gas and converting the detected laser beam to an electrical signal. The electrical signal is processed to determine characteristics of the off-gas that are used to analyze and/or control the steelmaking process.

Ottesen, David Keith (Livermore, CA); Allendorf, Sarah Williams (Fremont, CA); Hubbard, Gary Lee (Richmond, CA); Rosenberg, David Ezechiel (Columbia, MD)

1999-01-01

207

Method and composition for generating nitrogen gas  

SciTech Connect

A solid composition is described for generating nitrogen gas substantially free of noxious and toxic impurities for inflating an air cushion in a vehicle passenger restraint system and capable of substantially fully inflating such cushion in the elapsed time between the occurrence of a primary collision of the vehicle with another object and secondary collisions occurring as a result thereof; comprising a mixture of alkali metal azide and at least a stoichiometric amount of a metal oxide selected from the group consisting of iron, titanium and copper oxides and mixtures thereof. The metal oxide is capable of reacting exothermically with the alkaki metal azide and wherein the metal of the oxide is lower in the electromotive series than the alkali metal of the azide and is a metal other than (the) an alkali metal.

Pietz, J.F.

1988-01-26

208

Method for making a lightweight bipolar metal-gas battery  

Microsoft Academic Search

A method is described for constructing a multi-cell bipolar metal-gas battery stack, in which a metal and a primary gas are reactants. The method consists of: fabricating a dielectric frame generally in the shape of a hollowed-out prism having inner width and inner length dimensions defining the common width and the common length of each stacked cell; placing, within the

G. vanOmmering; C. W. Koehler

1986-01-01

209

Method for making hydrogen rich gas from hydrocarbon fuel  

DOEpatents

A method of forming a hydrogen rich gas from a source of hydrocarbon fuel in which the hydrocarbon fuel contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion at a temperature not less than about 400 C for a time sufficient to generate the hydrogen rich gas while maintaining CO content less than about 5 volume percent. There is also disclosed a method of forming partially oxidized hydrocarbons from ethanes in which ethane gas contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion for a time and at a temperature sufficient to form an oxide. 4 figs.

Krumpelt, M.; Ahmed, S.; Kumar, R.; Doshi, R.

1999-07-27

210

Method for making hydrogen rich gas from hydrocarbon fuel  

DOEpatents

A method of forming a hydrogen rich gas from a source of hydrocarbon fuel in which the hydrocarbon fuel contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion at a temperature not less than about 400.degree. C. for a time sufficient to generate the hydrogen rich gas while maintaining CO content less than about 5 volume percent. There is also disclosed a method of forming partially oxidized hydrocarbons from ethanes in which ethane gas contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion for a time and at a temperature sufficient to form an oxide.

Krumpelt, Michael (Naperville, IL); Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Doshi, Rajiv (Downers Grove, IL)

1999-01-01

211

Evaporation in space manufacturing  

NASA Technical Reports Server (NTRS)

'Normal evaporation' equations for predicting the compositional changes with time and temperature have been developed and correlated with actual experimental data. An evaporative congruent temperature is defined and used to explain, predict, or plan space experiments on anomalous constitutional melting (on cooling) or solidification (on heating). Uneven evaporation causes reactive jetting forces capable of initiating new convection currents, nongravitational accelerations, surface vibrations, or other disturbances. Applications of evaporation to space manufacturing are described concerning evaporative purification, surface cooling, specimen selection, particles splitting, freezing data interpretation, material loss and dimensional control, and surface contamination or compositional changes.

Li, C. H.

1974-01-01

212

A diagram to determine the evaporation status of extrasolar planets  

NASA Astrophysics Data System (ADS)

Aims:To describe the evaporation status of extrasolar planets, we consider an energy diagram in which the potential energy of the planets is plotted versus the energy received by the upper atmosphere. Methods: Here we present a basic method to estimate these quantities. For the potential energy, we include the modification of the gravity field by the tidal forces from the parent stars. Results: This description allows a rapid estimate of both the escape rate of the atmospheric gas and the lifetime of a planet against the evaporation process. In the energy diagram, we find an evaporation-forbidden region in which a gaseous planet would evaporate in less than 5 billion years. With their observed characteristics, all extrasolar planets are found outside this evaporation-forbidden region. The escape rates are estimated to be in the range 105 g s-1 to 1012 g s-1, with a few cases above 1011 g s-1. The estimated escape rate for HD 209458 b is consistent with the lower limit of 1010 g s-1 obtained from interpretation of the H i Lyman-? observations. This diagram suggests possibilities for the nature of the recently discovered Neptune-mass planets. We find that GJ 436 b, 55 Cnc e and HD 69830 b cannot be low mass gaseous planets. With a density that must be above 0.5 g cm-3 to survive evaporation, these planets must contain a large fraction of solid/liquid material. We find that GJ 876 d must have a density greater than ~3 g cm-3 to survive the strong EUV energy flux from its nearby parent star. GJ 876 d must contain a large fraction of massive elements.

Lecavelier Des Etangs, A.

2007-01-01

213

A component prediction method for flue gas of natural gas combustion based on nonlinear partial least squares method.  

PubMed

Quantitative analysis for the flue gas of natural gas-fired generator is significant for energy conservation and emission reduction. The traditional partial least squares method may not deal with the nonlinear problems effectively. In the paper, a nonlinear partial least squares method with extended input based on radial basis function neural network (RBFNN) is used for components prediction of flue gas. For the proposed method, the original independent input matrix is the input of RBFNN and the outputs of hidden layer nodes of RBFNN are the extension term of the original independent input matrix. Then, the partial least squares regression is performed on the extended input matrix and the output matrix to establish the components prediction model of flue gas. A near-infrared spectral dataset of flue gas of natural gas combustion is used for estimating the effectiveness of the proposed method compared with PLS. The experiments results show that the root-mean-square errors of prediction values of the proposed method for methane, carbon monoxide, and carbon dioxide are, respectively, reduced by 4.74%, 21.76%, and 5.32% compared to those of PLS. Hence, the proposed method has higher predictive capabilities and better robustness. PMID:24772020

Cao, Hui; Yan, Xingyu; Li, Yaojiang; Wang, Yanxia; Zhou, Yan; Yang, Sanchun

2014-01-01

214

A Component Prediction Method for Flue Gas of Natural Gas Combustion Based on Nonlinear Partial Least Squares Method  

PubMed Central

Quantitative analysis for the flue gas of natural gas-fired generator is significant for energy conservation and emission reduction. The traditional partial least squares method may not deal with the nonlinear problems effectively. In the paper, a nonlinear partial least squares method with extended input based on radial basis function neural network (RBFNN) is used for components prediction of flue gas. For the proposed method, the original independent input matrix is the input of RBFNN and the outputs of hidden layer nodes of RBFNN are the extension term of the original independent input matrix. Then, the partial least squares regression is performed on the extended input matrix and the output matrix to establish the components prediction model of flue gas. A near-infrared spectral dataset of flue gas of natural gas combustion is used for estimating the effectiveness of the proposed method compared with PLS. The experiments results show that the root-mean-square errors of prediction values of the proposed method for methane, carbon monoxide, and carbon dioxide are, respectively, reduced by 4.74%, 21.76%, and 5.32% compared to those of PLS. Hence, the proposed method has higher predictive capabilities and better robustness.

Cao, Hui; Yan, Xingyu; Li, Yaojiang; Wang, Yanxia; Zhou, Yan; Yang, Sanchun

2014-01-01

215

The Calculation Method of Puffer Pressure in Gas Circuit Breaker Taking Decomposition Gas Effect into Consideration  

NASA Astrophysics Data System (ADS)

A blast pressure analysis program for gas circuit breaker taking ablation, arc energy and decomposition effect into consideration was developed. In general, it is well known that SF6 gas accompanies dissociation and ionization in high temperature region, so we cannot apply the equation of state of ideal gas to high temperature region. Thus, it is necessary that the rate of specific heat, specific heat at constant pressure and gas constant are dealt with functions of gas pressure and temperature when SF6 arc and/or high temperature SF6 gas calculates. In this paper, first, we evaluated the decomposition gas model by comparing Pressure-Temperature (P-T) characteristic calculated by the decomposition gas model with P-T characteristic that derived by the summing partial pressures of all dissociated chemical species. Next, using its calculation method, we calculated pressure analysis in gas circuit breaker. Finally, we compared theoretical value was calculated by this program with experimental value tested in 145kV, 40kA class gas circuit breaker. As a result of this simulation, theoretical analysis agreed very well with experimental results.

Osawa, Naoki; Yoshioka, Yoshio

216

Thickness and temperature dependence of electrical resistivity of p-type Bi0.5Sb1.5Te3 thin films prepared by flash evaporation method  

NASA Astrophysics Data System (ADS)

P-type Bi0.5Sb1.5Te3 thin films with thicknesses in the range 80-320 nm have been deposited by the flash evaporation method on glass substrates at 473 K. XRD and field emission scanning electron microscope were performed to characterize the thin films. The results show that the thin films are polycrystalline and the grain size of the thin films increases with increasing thickness of the thin films. Compositional analysis of the thin films was also carried out by energy-dispersive x-ray analysis. A near linear relationship was observed between the electrical resistivity and the inverse thickness of the annealed thin films, and it agrees with Tellier's model. Electrical resistivity of the annealed thin films was studied in the temperature range 300-350 K, and their thermal activation behaviour was characterized, the activation energy for conduction decreases with increasing thickness of the thin films.

Duan, Xingkai; Yang, Junyou; Zhu, W.; Fan, X. A.; Bao, S. Q.

2006-12-01

217

Rate of runaway evaporative cooling  

NASA Astrophysics Data System (ADS)

Evaporative cooling is a process that is essential in creating Bose-Einstein condensates in dilute atomic gasses. This process has often been simulated based on a model using a truncated Boltzmann distribution. This model assumes that the energy distribution up to the threshold energy can still be described by a Boltzmann distribution: it assumes detailed balance up to the threshold energy. However, the evolution of the distribution function in time is not taken into account. Here we solve the kinetic Boltzmann equation for a gas undergoing evaporative cooling in a harmonic and linear trap in order to determine the evolution of the energy distribution. The magnitude of the discrepancy with the truncated Boltzmannmodel is calculated by including a polynomial expansion of the distribution function. We find that up to 35% fewer particles are found in the high-energy tail of the distribution with respect to the truncated Boltzmann distribution and up to 15% more collisions are needed to reach quantum degeneracy. Supported by a detailed investigation of the particle loss rate at different energies, we conclude that the limited occupation of high-energy states during the evaporation process causes the lowering of the evaporation speed and efficiency.

van de Groep, J.; van der Straten, P.; Vogels, J. M.

2011-09-01

218

Rain scavenging of soluble gases by non-evaporating and evaporating droplets from inhomogeneous atmosphere  

NASA Astrophysics Data System (ADS)

We suggest a one-dimensional model of precipitation scavenging of soluble gaseous pollutants by non-evaporating and evaporating droplets that is valid for arbitrary initial vertical distribution of soluble trace gases in the atmosphere. It is shown that for low gradients of soluble trace gases in the atmosphere, scavenging of gaseous pollutants is governed by a linear wave equation that describes propagation of a wave in one direction. The derived equation is solved by the method of characteristics. Scavenging coefficient and the rates of precipitation scavenging are calculated for wet removal of sulfur dioxide (SO2) and ammonia (NH3) using measured initial distributions of trace gases. It is shown that scavenging coefficient for arbitrary initial vertical distribution of soluble trace gases in the atmosphere is non-stationary and height-dependent. In case of exponential initial distribution of soluble trace gases in the atmosphere, scavenging coefficient for non-evaporating droplets in the region between the ground and the position of a scavenging front is a product of rainfall rate, solubility parameter, and the growth constant in the formula for the initial profile of a soluble trace gas in the atmosphere. This expression yields the same estimate of scavenging coefficient for sulfur dioxide scavenging by rain as field estimates presented in McMahon and Denison (1979). It is demonstrated that the smaller the slope of the concentration profile the higher the value of a scavenging coefficient.

Elperin, Tov; Fominykh, Andrew; Krasovitov, Boris

2013-11-01

219

Method and device for removal of ethylene oxide gas  

US Patent & Trademark Office Database

A method and a device for the removal of ethylene oxide gas present at high concentrations, for example, 1,000 to 1,000,000 ppm, in exhaust gas is described, which is especially suitable for exhaust gases of gas sterilization chambers. It is suggested to adsorb ethylene oxide from the exhaust gas with a dry adsorbing medium. In an alternative it is suggested to absorb and/or catalytically convert ethylene oxide with an absorbing medium and/or a catalyst carrier in the presence of water and a catalyst. A further variant of the method suggests to oxidize or reduce ethylene oxide by adding an oxidizing or reducing agent and water in the presence of a carrier for the oxidizing or reducing agent, whereby the carrier, depending on the oxidizing or reducing agent used, acts simultaneously as a catalyst and/or filling material.

1998-04-21

220

A new gas dilution method for measuring body volume.  

PubMed Central

This study was designed to examine the validity of a new gas dilution method (GD) for measuring human body volume and to compare its accuracy with the results obtained by the underwater weighing method (UW). We measured the volume of plastic bottles and 16 subjects (including two females), aged 18-42 years with each method. For the bottles, the volume measured by hydrostatic weighing was correlated highly (r = 1.000) with that measured by the new gas dilution method. For the subjects, the body volume determined by the two methods was significantly correlated (r = 0.998). However, the subject's volume measured by the gas dilution method was significantly larger than that by underwater weighing method. There was significant correlation (r = 0.806) between GD volume-UW volume and the body mass index (BMI), so that UW volume could be predicted from GD volume and BMI. It can be concluded that the new gas dilution method offers promising possibilities for future research in the population who cannot submerge underwater.

Nagao, N; Tamaki, K; Kuchiki, T; Nagao, M

1995-01-01

221

Electrical-modulation method for molecular-gas absorption spectra  

Microsoft Academic Search

The authors describe a method of modulating the vibrational-rotational absorption spectra of polar molecules by means of an electric field, which is based on filtering the nonmonochromatic radiation from the source with the gas, which is in a special cell. A model of the method is presented. The apparatus for recording the spectra was based on an IKS-31 infrared spectrometer.

R. I. Mukhtarov; E. R. Petrosyan

1986-01-01

222

A comparative study on pure, L-arginine and glycine doped ammonium dihydrogen orthophosphate single crystals grown by slow solvent evaporation and temperature-gradient method  

NASA Astrophysics Data System (ADS)

Single crystals of pure, L-arginine and glycine doped ammonium dihydrogen orthophosphate (ADP) were grown by both the slow solvent evaporation method and the temperature-gradient method of Sankaranarayanan-Ramasamy (SR). The metastable zone width for different saturation temperatures of pure glycine and L-arginine added solutions were carried out. The grown crystals were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), optical transmission, dielectric constant, dielectric loss, and Vickers microhardness. The DSC and TG curves of the grown crystals indicated that they were stable up to 200 °C. The XRD study confirmed the structure of the grown crystal. The optical transmission analysis revealed that the pure and doped ADP crystals had very high percentage of transmission in the entire visible region. The important optical parameters such as reflectance and extinction coefficients of the grown crystals were calculated. L-arginine and glycine were used as dopants to reduce dielectric constant of ADP. The a.c. resistivity and a.c. conductivity were calculated. Dielectric loss of the doped ADP crystals grown by the SR method is lower than the doped ADP crystals grown by the conventional method. Larger hardness value for the SR method grown crystals confirmed greater crystalline perfection.

Pattanaboonmee, N.; Ramasamy, P.; Yimnirun, R.; Manyum, P.

2011-01-01

223

Evaporation From Lake Superior  

NASA Astrophysics Data System (ADS)

Evaporation is a critical component of the water balance of each of the Laurentian Great Lakes, and understanding the magnitude and physical controls of evaporative water losses are important for several reasons. Recently, low water levels in Lakes Superior and Michigan/Huron have had socioeconomic, ecological, and even meteorological impacts (e.g. water quality and quantity, transportation, invasive species, recreation, etc.). The recent low water levels may be due to increased evaporation, but this is not known as operational evaporation estimates are currently calculated as the residual of water or heat budgets. Perhaps surprisingly, almost nothing is known about evaporation dynamics from Lake Superior and few direct measurements of evaporation have been made from any of the Laurentian Great Lakes. This research is the first to attempt to directly measure evaporation from Lake Superior by deploying eddy covariance instrumentation. Results of evaporation rates, their patterns and controlling mechanisms will be presented. The direct measurements of evaporation are used with concurrent satellite and climate model data to extrapolate evaporation measurements across the entire lake. This knowledge could improve predictions of how climate change may impact the lake's water budget and subsequently how the water in the lake is managed.

Spence, C.; Blanken, P.; Hedstrom, N.; Leshkevich, G.; Fortin, V.; Charpentier, D.; Haywood, H.

2009-05-01

224

A Stirling engine analysis method based upon moving gas nodes  

NASA Technical Reports Server (NTRS)

A Lagrangian nodal analysis method for Stirling engines (SEs) is described, validated, and applied to a conventional SE and an isothermalized SE (with fins in the hot and cold spaces). The analysis employs a constant-mass gas node (which moves with respect to the solid nodes during each time step) instead of the fixed gas nodes of Eulerian analysis. The isothermalized SE is found to have efficiency only slightly greater than that of a conventional SE.

Martini, W. R.

1986-01-01

225

The Future of Lattice-Gas and Lattice Boltzmann Methods  

Microsoft Academic Search

\\u000a Although the lattice-gas automata (LGA) or lattice-gas cellular automata (LGCA) and the lattice Boltzmann equation (LBE) have\\u000a a rather short history extending only over a decade or so, they have attracted much attention among physicists in various\\u000a disciplines. The reason is that the methods of LGA and LBE have demonstrated their great potentials to study various complex\\u000a systems such as

Li-Shi Luo

226

Diffusion Of Mass In Evaporating Multicomponent Drops  

NASA Technical Reports Server (NTRS)

Report summarizes study of diffusion of mass and related phenomena occurring in evaporation of dense and dilute clusters of drops of multicomponent liquids intended to represent fuels as oil, kerosene, and gasoline. Cluster represented by simplified mathematical model, including global conservation equations for entire cluster and conditions on boundary between cluster and ambient gas. Differential equations of model integrated numerically. One of series of reports by same authors discussing evaporation and combustion of sprayed liquid fuels.

Bellan, Josette; Harstad, Kenneth G.

1992-01-01

227

Floating-roof tank evaporation  

SciTech Connect

The book describes an improved method for estimating the total evaporative losses of the equivalent atmospheric hydrocarbon emissions from external floating-roof tanks that contain multicomponent hydrocarbon mixtures (such as gasolines and crude oils) or single-component stocks (such as petro-chemicals).

Not Available

1989-01-01

228

Information preservation methods for modeling micro-scale gas flows  

NASA Astrophysics Data System (ADS)

Micro-scale gas flow is a rapidly growing research field driven by microsystems technology. Experiments have shown that fluid mechanics of these flows are not the same as those experienced in the macroscopic world. However, theoretical analysis is difficult because those flows are generally in the slip or transitional flow regime, and it is hard to investigate the detailed flow fields experimentally due to the small physical dimensions of microsystems. There are several numerical approaches that can model some micro-scale gas flows. Generally, continuum-based methods are numerically efficient, but physically limited; kinetic-based methods are physically accurate, but numerically expensive. Hence, it is necessary to develop a general-purpose numerical approach to understand micro-scale gas flows. This dissertation is devoted to developing a numerical approach for modeling general micro-scale gas flows with reasonable efficiency and accuracy. In the first stage, a particle method called the information preservation (IP) method, proposed by Fan and Shen based on the direct simulation Monte Carlo (DSMC) method, is developed to simulate general micro-scale gas flows. The IP method greatly reduces the statistical scatter associated with particle methods by using macroscopic information preserved in microscopic particles to sample the flow field. Thus low-speed micro-scale gas flows can be simulated using the IP method with reasonable numerical cost. In the second stage, a hybrid approach is designed by coupling the IP method and a Navier-Stokes solver for modeling micro-scale gas flows with better numerical efficiency. The IP method and the Navier-Stokes solver are strongly coupled using an adaptive continuum/particle interface. Using the hybrid approach, we investigate gas flows over micro-scale flat plates. We find that the normalized drag coefficient CDM on a flat plate having zero thickness depends on Re/M0.8 when 1

Sun, Quanhua

229

Determination of the Origin of Crystal Orientation for Nanocrystalline Bismuth Telluride-Based Thin Films Prepared by Use of the Flash Evaporation Method  

NASA Astrophysics Data System (ADS)

We have investigated the origin of crystal orientation for nanocrystalline bismuth telluride-based thin films. Thin films of p-type bismuth telluride antimony (Bi-Te-Sb) and n-type bismuth telluride selenide (Bi-Te-Se) were fabricated by a flash evaporation method, with exactly the same deposition conditions except for the elemental composition of the starting powders. For p-type Bi-Te-Sb thin films the main x-ray diffraction (XRD) peaks were from the c-axis (?{00l}/?{ hkl} = 0.88) whereas n-type Bi-Te-Se thin films were randomly oriented (?{00l}/?{ hkl} = 0.40). Crystal orientation, crystallinity, and crystallite size were improved for both types of thin film by sintering. For p-type Bi-Te-Sb thin films, especially, high-quality structures were obtained compared with those of n-type Bi-Te-Se thin films. We also estimated the thermoelectric properties of the as-grown and sintered thin films. The power factor was enhanced by sintering; maximum values were 34.9 ?W/cm K2 for p-type Bi-Te-Sb thin films at a sintering temperature of 300°C and 23.9 ?W/cm K2 for n-type Bi-Te-Se thin films at a sintering temperature of 350°C. The exact mechanisms of film growth are not yet clear but we deduce the crystal orientation originates from the size of nano-clusters generated on the tungsten boat during flash evaporation.

Takashiri, M.; Tanaka, S.; Miyazaki, K.

2014-06-01

230

Evaporated Silicon Thin-Film Transistors.  

National Technical Information Service (NTIS)

The method of fabrication, the theory and properties of evaporated silicon thin-film transistors are discussed. The device consists of a p-type silicon film (0.5-2 microns thick) on a sapphire substrate, with aluminum source-drain electrodes evaporated on...

C. A. T. Salama L. Young

1966-01-01

231

The growth of benzophenone crystals by Sankaranarayanan-Ramasamy (SR) method and slow evaporation solution technique (SEST): A comparative investigation  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Benzophenone single crystal was grown by Sankaranarayanan-Ramasamy method which has the sizes of 1060 mm length and 55 mm diameter for the first time. Black-Right-Pointing-Pointer The conventional and SR-grown benzophenone crystals were characterized and compared using HRXRD, etching, laser damage threshold, microhardness, UV-transmittance, birefringence and dielectric analysis. Black-Right-Pointing-Pointer The SR-grown benzophenone crystal has higher LDT, microhardness, transparency, dielectric permittivity, birefringence and lower FWHM, EPD, dielectric loss than the crystal grown by conventional method. Black-Right-Pointing-Pointer The probable reason for higher crystalline perfection in SR-grown crystal was discussed. -- Abstract: Longest unidirectional Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket benzophenone (BP) crystal having dimension of 1060 mm length and 55 mm diameter was grown by Sankaranarayanan-Ramasamy method. The growth rate was measured by monitoring the elevation of the crystal-solution interface at different temperatures. The high resolution X-ray diffraction and etching measurements indicate that the unidirectional grown benzophenone crystal has good crystalline perfection and less density of defects. The optical damage threshold of SEST and SR grown BP crystals has been investigated and found that the SR grown benzophenone crystal has higher laser damage threshold value than the conventional method grown crystal. Microhardness measurement shows that crystals grown by SR method have a higher mechanical stability than the crystals grown by SEST method. Dielectric permittivity and birefringence are high in SR grown crystal compared to SEST grown BP crystal. The UV-vis-NIR results show that SR method grown crystal exhibits 7% higher transmittance as against crystals grown by conventional method.

Senthil Pandian, M.; Boopathi, K. [Centre for Crystal Growth, SSN College of Engineering, Kalavakkam 603 110, Tamilnadu (India)] [Centre for Crystal Growth, SSN College of Engineering, Kalavakkam 603 110, Tamilnadu (India); Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [Centre for Crystal Growth, SSN College of Engineering, Kalavakkam 603 110, Tamilnadu (India); Bhagavannarayana, G. [Materials Characterization Division, National Physical Laboratory, New Delhi 110 012 (India)] [Materials Characterization Division, National Physical Laboratory, New Delhi 110 012 (India)

2012-03-15

232

Electrical-modulation method for molecular-gas absorption spectra  

SciTech Connect

The authors describe a method of modulating the vibrational-rotational absorption spectra of polar molecules by means of an electric field, which is based on filtering the nonmonochromatic radiation from the source with the gas, which is in a special cell. A model of the method is presented. The apparatus for recording the spectra was based on an IKS-31 infrared spectrometer. Radiator power oscillations clearly occur in the absence of the monochromator in this elecrooptic modulation method. The estimates show that this method is comparible with existing nondispersive optical methods of measuring gas concentrations as regards threshold sensitivity, although it is applicable only to detecting polar molecules. As there are differences in the Stark effect for molecules of different types, this method has high selectivity, and also has comparatively fast response with photoelectric recording, 10/sup -4/-10/sup -3/sec.

Mukhtarov, R.I.; Petrosyan, E.R.

1986-05-01

233

Numerical Simulation of Evaporating Capillary Jets.  

National Technical Information Service (NTIS)

A detailed numerical study of evaporating capillary jets is presented. The analysis is performed through use of a Galerkin finite element method with penalty formulation for solving the equations of motion and a flux method for tracking the free surface. ...

J. D. Zeda

1999-01-01

234

Simple and rapid assay method for simultaneous quantification of urinary nicotine and cotinine using micro-extraction by packed sorbent and gas chromatography-mass spectrometry.  

PubMed

A simple and rapid method for determination of nicotine and cotinine levels in urine was developed using samples prepared by micro-extraction by packed sorbent (MEPS) and subjected to gas chromatography-mass spectrometry (GC-MS) analysis. This method provided good reproducibility, as well as good linearity of calibration curves in the range of 1-100 and 50-1000 ng/mL for quality control samples spiked with nicotine and cotinine, respectively. The detection limit of nicotine and cotinine was as low as 0.25 and 20 ng/mL, respectively. An evaporation procedure is not suitable for nicotine determination, thus an advantage of the present MEPS assay method is direct testing with GC-MS without the need for evaporation to a dry solvent. Our findings show that it may be useful for determining nicotine levels in various types of research studies. PMID:24640182

Iwai, Masae; Ogawa, Tadashi; Hattori, Hideki; Zaitsu, Kei; Ishii, Akira; Suzuki, Osamu; Seno, Hiroshi

2013-08-01

235

Direct simulation methods for compressible inviscid ideal-gas flow  

Microsoft Academic Search

Two novel schemes are proposed for the calculation of compressible flow of an ideal fluid. One method is the equilibrium analog of the well-known discrete-particle direct simulation Monte Carlo method for the treatment of nonequilibrium ideal-gas flows. The second follows from an analytical treatment of the model inertial-transport mechanisms inherent in the first scheme. Accounts of the methods are presented

D. I. Pullin

1980-01-01

236

Synthesis Methods, Microscopy Characterization and Device Integration of Nanoscale Metal Oxide Semiconductors for Gas Sensing in Aerospace Applications  

NASA Technical Reports Server (NTRS)

A comparison is made between SnO2, ZnO, and TiO2 single-crystal nanowires and SnO2 polycrystalline nanofibers for gas sensing. Both nanostructures possess a one-dimensional morphology. Different synthesis methods are used to produce these materials: thermal evaporation-condensation (TEC), controlled oxidation, and electrospinning. Advantages and limitations of each technique are listed. Practical issues associated with harvesting, purification, and integration of these materials into sensing devices are detailed. For comparison to the nascent form, these sensing materials are surface coated with Pd and Pt nanoparticles. Gas sensing tests, with respect to H2, are conducted at ambient and elevated temperatures. Comparative normalized responses and time constants for the catalyst and noncatalyst systems provide a basis for identification of the superior metal-oxide nanostructure and catalyst combination. With temperature-dependent data, Arrhenius analyses are made to determine an activation energy for the catalyst-assisted systems.

VanderWal, Randy L.; Berger, Gordon M.; Kulis, Michael J.; Hunter, Gary W.; Xu, Jennifer C.; Evans, Laura J.

2009-01-01

237

Method for eliminating gas blocking in electrokinetic pumping systems  

DOEpatents

A method for eliminating gas bubble blockage of current flow during operation of an electrokinetic pump. By making use of the ability to modify the surface charge on the porous dielectric medium used in electrokinetic pumps, it becomes possible to place electrodes away from the pressurized region of the electrokinetic pump. While gas is still generated at the electrodes they are situated such that the generated gas can escape into a larger buffer reservoir and not into the high pressure region of the pump where the gas bubbles can interrupt current flow. Various combinations of porous dielectric materials and ionic conductors can be used to create pumps that have desirable electrical, material handling, and flow attributes.

Arnold, Don W. (Livermore, CA) [Livermore, CA; Paul, Phillip H. (Livermore, CA) [Livermore, CA; Schoeniger, Joseph S. (Oakland, CA) [Oakland, CA

2001-09-11

238

Comparison of ultraviolet detection, evaporative light scattering detection and charged aerosol detection methods for liquid-chromatographic determination of anti-diabetic drugs.  

PubMed

Recently, charged aerosol detection (CAD), a new kind of universal detection method, has been widely employed in the HPLC system. In the present study, four kinds of anti-diabetic drug standards, glipizide, gliclazide, glibenclamide and glimepiride were determined by ultraviolet (UV) detection, evaporative light scattering detection (ELSD) and the aforementioned CAD. The results were compared with reference to linearity, accuracy, precision and limit of detection (LOD). All of the experiments were performed on a reverse phase column with water and acetonitrile as the mobile phase. Separations were achieved under the same chromatographic conditions for each detection method. As a result, CAD generated nearly uniform responses compared with UV detection and ELSD. It showed the best accuracy and LOD among 3 detectors and had similar precision with UV detection at higher concentrations while UV detection showed a better precision at lower concentrations than did CAD or ELSD. The LOD of CAD, in fact, can be up to two times higher than that of ELSD. The UV and ELSD linearity was satisfactory at R(2)>0.99, though in the case of CAD, a log-log transformation was needed. The proposed methods were also applied to the real anti-diabetic drugs and diabetes-related dietary supplements. PMID:20004074

Shaodong, Jia; Lee, Won Jun; Ee, Ji Won; Park, Jeong Hill; Kwon, Sung Won; Lee, Jeongmi

2010-03-11

239

Size exclusion chromatography with evaporative light scattering detection as a method for speciation analysis of polydimethylsiloxanes. III. Identification and determination of dimeticone and simeticone in pharmaceutical formulations.  

PubMed

The pharmaceutical industry is one of the more important sectors for the use of polydimethylsiloxanes (PDMS), which belong to the organosilicon polymers. In drugs for internal use, they are used as an active pharmaceutical ingredient (API) called dimeticone or simeticone. Due to their specific chemical nature, PDMS can have different degrees of polymerization, which determine the molecular weight and viscosity. The Pharmacopoeial monographs for dimeticone and simeticone, only give the permitted polymerization and viscosity range. It is, however, essential to know also the degree of polymerization or the specific molecular weight of PDMS that are present in pharmaceutical formulations. In the literature there is information about the impact of particle size, and thus molecular weight, on the toxicity, absorption and migration in living organisms. This study focused on the use of a developed method - the exclusion chromatography with evaporative light scattering detector (SEC-ELSD) - for identification and determination of dimeticone and simeticone in various pharmaceutical formulations. The method had a high degree of specificity and was suitable for speciation analysis of these polymers. So far the developed method has not been used in the control of medicinal products containing dimeticone or simeticone. PMID:21962761

Mojsiewicz-Pie?kowska, Krystyna

2012-01-25

240

Method for treating a nuclear process off-gas stream  

DOEpatents

Disclosed is a method for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is adaptable and useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels whereby to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. Briefly, the method sequentially comprises treating the off-gas stream to preliminarily remove NO.sub.x, hydrogen and carbon-containing organic compounds, and semivolatile fission product metal oxide components therefrom; adsorbing iodine components on silver-exchanged mordenite; removing water vapor carried by said stream by means of a molecular sieve; selectively removing the carbon dioxide components of said off-gas stream by means of a molecular sieve; selectively removing xenon in gas phase by passing said stream through a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from oxygen by means of a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from the bulk nitrogen stream using a molecular sieve comprising silver-exchanged mordenite cooled to about -140.degree. to -160.degree. C.; concentrating the desorbed krypton upon a molecular sieve comprising silver-exchange mordenite cooled to about -140.degree. to -160.degree. C.; and further cryogenically concentrating, and the recovering for storage, the desorbed krypton.

Pence, Dallas T. (San Diego, CA); Chou, Chun-Chao (San Diego, CA)

1984-01-01

241

Evaporative Precooler Retrofit for Air Cooled Condensers. Small Scale Appropriate Technology Grant Program.  

National Technical Information Service (NTIS)

Three methods of evaporative cooling were evaluated; direct evaporative cooling of the condenser coil (spray directly on condenser coil), wetted media acting as evaporator and eliminator, and a spray type with eliminator. The direct spray achieved the low...

J. R. Campbell

1984-01-01

242

Analysis of a resistance-energy balance method for estimating daily evaporation from wheat plots using one-time-of-day infrared temperature observations  

NASA Technical Reports Server (NTRS)

Accurate estimates of evaporation over field-scale or larger areas are needed in hydrologic studies, irrigation scheduling, and meteorology. Remotely sensed surface temperature might be used in a model to calculate evaporation. A resistance-energy balance model, which combines an energy balance equation, the Penman-Monteith (1981) evaporation equation, and van den Honert's (1948) equation for water extraction by plant roots, is analyzed for estimating daily evaporation from wheat using postnoon canopy temperature measurements. Additional data requirements are half-hourly averages of solar radiation, air and dew point temperatures, and wind speed, along with reasonable estimates of canopy emissivity, albedo, height, and leaf area index. Evaporation fluxes were measured in the field by precision weighing lysimeters for well-watered and water-stressed wheat. Errors in computed daily evaporation were generally less than 10 percent, while errors in cumulative evaporation for 10 clear sky days were less than 5 percent for both well-watered and water-stressed wheat. Some results from sensitivity analysis of the model are also given.

Choudhury, B. J.; Idso, S. B.; Reginato, R. J.

1986-01-01

243

Methods for gas detection using stationary hyperspectral imaging sensors  

DOEpatents

According to one embodiment, a method comprises producing a first hyperspectral imaging (HSI) data cube of a location at a first time using data from a HSI sensor; producing a second HSI data cube of the same location at a second time using data from the HSI sensor; subtracting on a pixel-by-pixel basis the second HSI data cube from the first HSI data cube to produce a raw difference cube; calibrating the raw difference cube to produce a calibrated raw difference cube; selecting at least one desired spectral band based on a gas of interest; producing a detection image based on the at least one selected spectral band and the calibrated raw difference cube; examining the detection image to determine presence of the gas of interest; and outputting a result of the examination. Other methods, systems, and computer program products for detecting the presence of a gas are also described.

Conger, James L. (San Ramon, CA); Henderson, John R. (Castro Valley, CA)

2012-04-24

244

Evaporation from or condensation onto a sphere: Numerical analysis of the Boltzmann equation for hard-sphere molecules  

Microsoft Academic Search

A steady weak evaporation from or condensation onto a spherical condensed phase in its vapor gas is investigated, mainly numerically, on the basis of the Boltzmann equation for hard-sphere molecules. The numerical method is the combination of the hybrid-difference-scheme method, which can describe the discontinuity of the velocity distribution function in the gas, and the numerical kernel method [1]. The

M. Wakabayashi

1998-01-01

245

Field investigation of evaporation from freshwater tailings  

SciTech Connect

Safe and economical storage of tailings is now a major consideration in the operation of many mining operations. Tailings in slurried form, particularly if they have a significant clay content, can take a very long time to consolidate under the action of self-weight consolidation alone. However, if the operation is located in an area of high potential evaporation, this can be used to accelerate the rate of tailings densification. This paper presents a study of the evaporation behavior of a clayey tailings slurry deposited into an evaporation pond in the southwest of Western Australia. Over a six-month period, the rate of evaporation from the tailings surface was monitored using the Bowen Ratio method and the microlysimeter method. This was compared with the evaporation from a Class A pan located nearby. The tailings underwent very significant cracking as drying proceeded, and it was found that these cracks had a significant influence on the overall rate of evaporation once the top surface of the deposit started to desaturate. A large strain consolidation model was used to model the behavior, and the algorithm used in this model to include the effects of evaporation is shown to provide a reasonable prediction of the observed evaporation behavior.

Fujiyasu, Yoshimasa; Fahey, M.; Newson, T.

2000-06-01

246

Control method for mixed refrigerant based natural gas liquefier  

DOEpatents

In a natural gas liquefaction system having a refrigerant storage circuit, a refrigerant circulation circuit in fluid communication with the refrigerant storage circuit, and a natural gas liquefaction circuit in thermal communication with the refrigerant circulation circuit, a method for liquefaction of natural gas in which pressure in the refrigerant circulation circuit is adjusted to below about 175 psig by exchange of refrigerant with the refrigerant storage circuit. A variable speed motor is started whereby operation of a compressor is initiated. The compressor is operated at full discharge capacity. Operation of an expansion valve is initiated whereby suction pressure at the suction pressure port of the compressor is maintained below about 30 psig and discharge pressure at the discharge pressure port of the compressor is maintained below about 350 psig. Refrigerant vapor is introduced from the refrigerant holding tank into the refrigerant circulation circuit until the suction pressure is reduced to below about 15 psig, after which flow of the refrigerant vapor from the refrigerant holding tank is terminated. Natural gas is then introduced into a natural gas liquefier, resulting in liquefaction of the natural gas.

Kountz, Kenneth J. (Palatine, IL); Bishop, Patrick M. (Chicago, IL)

2003-01-01

247

Particle-gas Dynamics with Athena: Method and Convergence  

NASA Astrophysics Data System (ADS)

The Athena magnetohydrodynamics code has been extended to integrate the motion of particles coupled with the gas via aerodynamic drag in order to study the dynamics of gas and solids in protoplanetary disks (PPDs) and the formation of planetesimals. Our particle-gas hybrid scheme is based on a second-order predictor-corrector method. Careful treatment of the momentum feedback on the gas guarantees exact conservation. The hybrid scheme is stable and convergent in most regimes relevant to PPDs. We describe a semi-implicit integrator generalized from the leap-frog approach. In the absence of drag force, it preserves the geometric properties of a particle orbit. We also present a fully implicit integrator that is unconditionally stable for all regimes of particle-gas coupling. Using our hybrid code, we study the numerical convergence of the nonlinear saturated state of the streaming instability. We find that gas flow properties are well converged with modest grid resolution (128 cells per pressure length ?r for dimensionless stopping time ? s = 0.1) and an equal number of particles and grid cells. On the other hand, particle clumping properties converge only at higher resolutions, and finer resolution leads to stronger clumping before convergence is reached. Finally, we find that the measurement of particle transport properties resulted from the streaming instability may be subject to error of about ±20%.

Bai, Xue-Ning; Stone, James M.

2010-10-01

248

PARTICLE-GAS DYNAMICS WITH ATHENA: METHOD AND CONVERGENCE  

SciTech Connect

The Athena magnetohydrodynamics code has been extended to integrate the motion of particles coupled with the gas via aerodynamic drag in order to study the dynamics of gas and solids in protoplanetary disks (PPDs) and the formation of planetesimals. Our particle-gas hybrid scheme is based on a second-order predictor-corrector method. Careful treatment of the momentum feedback on the gas guarantees exact conservation. The hybrid scheme is stable and convergent in most regimes relevant to PPDs. We describe a semi-implicit integrator generalized from the leap-frog approach. In the absence of drag force, it preserves the geometric properties of a particle orbit. We also present a fully implicit integrator that is unconditionally stable for all regimes of particle-gas coupling. Using our hybrid code, we study the numerical convergence of the nonlinear saturated state of the streaming instability. We find that gas flow properties are well converged with modest grid resolution (128 cells per pressure length {eta}r for dimensionless stopping time {tau} {sub s} = 0.1) and an equal number of particles and grid cells. On the other hand, particle clumping properties converge only at higher resolutions, and finer resolution leads to stronger clumping before convergence is reached. Finally, we find that the measurement of particle transport properties resulted from the streaming instability may be subject to error of about {+-}20%.

Bai Xuening; Stone, James M., E-mail: xbai@astro.princeton.ed, E-mail: jstone@astro.princeton.ed [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2010-10-15

249

Methods for improving the gas barrier properties of polymeric containers  

SciTech Connect

Methods are disclosed for the treatment of food, beverage, and medicine containers and the like, which are made of organic polymeric resins, to greatly increase the gas barrier properties thereof. The containers are ion-plated with a very thin flexible layer of an inorganic oxide.

Hahn, G.J.

1984-10-23

250

Convergence of the viscosity method for isentropic gas dynamics  

Microsoft Academic Search

A convergence theorem for the method of artificial viscosity applied to the isentropic equations of gas dynamics is established. Convergence of a subsequence in the strong topology is proved without uniform estimates on the derivatives using the theory of compensated compactness and an analysis of progressing entropy waves.

Ronald J. DiPerna

1983-01-01

251

Flue gas desulfurization (FGD) chemistry and analytical methods handbook  

Microsoft Academic Search

The purpose of this handbook is to provide a comprehensive guide to sampling, analytical, and physical test methods essential to the operation, maintenance, and understanding of flue gas desulfurization (FGD) system chemistry. EPRI sponsored the first edition of this three-volume report in response to the needs of electric utility personnel responsible for establishing and operating commercial FGD analytical laboratories. The

J. G. Noblett; J. M. Burke

1990-01-01

252

Gas Turbine Engine and Method of Assembling Same.  

National Technical Information Service (NTIS)

A method of assembling a gas turbine engine that includes rotatably coupling a first low-pressure turbine rotor to a high-pressure turbine, rotatably coupling a second low pressure turbine rotor to the first low-pressure turbine rotor, and rotatably coupl...

J. L. Henry

2004-01-01

253

A novel method of measuring electrophoretic mobility of gas bubbles  

Microsoft Academic Search

Accurate measurement of electrophoretic mobility for gas bubbles is a challenging task as it requires the creation of a desired number of very small air bubbles to ensure negligible rise velocities during the course of the measurement. Here, we report a simple and reliable method for generating stable dispersions of “nano-bubbles.” Preparation of such dispersions relies on the nucleation of

Aref Seyyed Najafi; Jaroslaw Drelich; Anthony Yeung; Zhenghe Xu; Jacob Masliyah

2007-01-01

254

Multiphysics methods development for high temperature gas reactor analysis  

Microsoft Academic Search

Multiphysics computational methods were developed to perform design and safety analysis of the next generation Pebble Bed High Temperature Gas Cooled Reactors. A suite of code modules was developed to solve the coupled thermal-hydraulics and neutronics field equations. The thermal-hydraulics module is based on the three dimensional solution of the mass, momentum and energy equations in cylindrical coordinates within the

Volkan Seker; Thomas J. Downar

2007-01-01

255

Evaporation, Boiling and Bubbles  

ERIC Educational Resources Information Center

Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

Goodwin, Alan

2012-01-01

256

The effective encapsulation of a hydrophobic lipid-insoluble drug in solid lipid nanoparticles using a modified double emulsion solvent evaporation method.  

PubMed

Raloxifene HCl (RH), a selective estrogen receptor modulator (SERM), is indicated for the prophylaxis or treatment of postmenopausal osteoporosis. RH shows extremely poor bioavailability due to limited solubility and an extensive intestinal/hepatic first-pass metabolism. Solid lipid nanoparticles (SLNs) are valuable carriers that can enhance drug bioavailability. However, in the case of RH, the encapsulation of the drug in SLNs remains a challenge because of its poor solubility in both water and lipids. In this study, a series of RH-containing SLNs (RH-SLNs) were generated using a modified double emulsion solvent evaporation (DESE) method. Briefly, RH with various drug/lipid ratios was solubilized in the inner core of a double emulsion using different water/organic solvent mixtures. Our best formulation was achieved with the formation of negatively charged nanoparticles, 180nm in diameter, with an encapsulation and loading efficiency of 85% and 4.5%, respectively. It also showed a Fickian mechanism of the drug release in the basic dissolution media. Thermal analysis revealed a distinct decrease in the crystallinity of lipids and RH in comparison with the unprocessed materials. The results of a cell viability assay also showed a better antiproliferative effect of the drug-loaded SLNs versus the free drug solution. Thus, these results indicated that the modified DESE method could be proposed for the effective encapsulation of RH in SLNs with appropriate physicochemical and biological properties. PMID:24036624

Nabi-Meibodi, Mohsen; Vatanara, Alireza; Najafabadi, Abdolhossein Rouholamini; Rouini, Mohammad Reza; Ramezani, Vahid; Gilani, Kambiz; Etemadzadeh, Seyed Mohammad Hossein; Azadmanesh, Kayhan

2013-12-01

257

The Effect of Nitrogen Gas Flow Rate on the Properties of TiN-COATED High-Speed Steel (hss) Using Cathodic Arc Evaporation Physical Vapor Deposition (pvd) Technique  

NASA Astrophysics Data System (ADS)

Cathodic arc evaporation (CAE) is a widely-used technique for generating highly ionized plasma from which hard and wear resistant physical vapor deposition (PVD) coatings can be deposited. A major drawback of this technique is the emission of micrometer-sized droplets of cathode material from the arc spot, which are commonly referred to as "macroparticles." In present study, titanium nitride (TiN) coatings on high-speed steel (HSS) coupons were produced with a cathodic arc evaporation technique. We studied and discussed the effect of various nitrogen gas flow rates on microstructural and mechanical properties of TiN-coated HSS coupons. The coating properties investigated in this work included the surface morphology, thickness of deposited coating, adhesion between the coating and substrate, coating composition, coating crystallography, hardness and surface characterization using a field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), X-ray diffraction (XRD) with glazing incidence angle (GIA) technique, scratch tester, hardness testing machine, surface roughness tester, and atomic force microscope (AFM). An increase in the nitrogen gas flow rate showed decrease in the formation of macro-droplets in CAE PVD technique. During XRD-GIA studies, it was observed that by increasing the nitrogen gas flow rate, the main peak [1,1,1] shifted toward the lower angular position. Surface roughness decreased with an increase in nitrogen gas flow rate but was higher than the uncoated polished sample. Microhardness of TiN-coated HSS coupons showed more than two times increase in hardness than the uncoated one. Scratch tester results showed good adhesion between the coating material and substrate. Considerable improvement in the properties of TiN-deposited thin films was achieved by the strict control of all operational steps.

Mubarak, Ali; Hamzah, Esah Binti; Mohd Toff, Mohd Radzi Hj.; Hashim, Abdul Hakim Bin

258

Aircraft Engine Gas Path Diagnostic Methods: Public Benchmarking Results  

NASA Technical Reports Server (NTRS)

Recent technology reviews have identified the need for objective assessments of aircraft engine health management (EHM) technologies. To help address this issue, a gas path diagnostic benchmark problem has been created and made publicly available. This software tool, referred to as the Propulsion Diagnostic Method Evaluation Strategy (ProDiMES), has been constructed based on feedback provided by the aircraft EHM community. It provides a standard benchmark problem enabling users to develop, evaluate and compare diagnostic methods. This paper will present an overview of ProDiMES along with a description of four gas path diagnostic methods developed and applied to the problem. These methods, which include analytical and empirical diagnostic techniques, will be described and associated blind-test-case metric results will be presented and compared. Lessons learned along with recommendations for improving the public benchmarking processes will also be presented and discussed.

Simon, Donald L.; Borguet, Sebastien; Leonard, Olivier; Zhang, Xiaodong (Frank)

2013-01-01

259

78 FR 19605 - Greenhouse Gas Reporting Rule: Revision to Best Available Monitoring Method Request Submission...  

Federal Register 2010, 2011, 2012, 2013

...Method Request Submission Deadline for Petroleum and Natural Gas Systems Source Category...Method Request Submission Deadline for Petroleum and Natural Gas Systems Source Category...operators of facilities subject to the petroleum and natural gas systems source...

2013-04-02

260

Method of making gas diffusion layers for electrochemical cells  

DOEpatents

A method is provided for making a gas diffusion layer for an electrochemical cell comprising the steps of: a) combining carbon particles and one or more surfactants in a typically aqueous vehicle to make a preliminary composition, typically by high shear mixing; b) adding one or more highly fluorinated polymers to said preliminary composition by low shear mixing to make a coating composition; and c) applying the coating composition to an electrically conductive porous substrate, typically by a low shear coating method.

Frisk, Joseph William (Oakdale, MN); Boand, Wayne Meredith (Lino Lakes, MN); Larson, James Michael (Saint Paul, MN)

2002-01-01

261

Evaporative Cooling Membrane Device  

NASA Technical Reports Server (NTRS)

An evaporative cooling membrane device is disclosed having a flat or pleated plate housing with an enclosed bottom and an exposed top that is covered with at least one sheet of hydrophobic porous material having a thin thickness so as to serve as a membrane. The hydrophobic porous material has pores with predetermined dimensions so as to resist any fluid in its liquid state from passing therethrough but to allow passage of the fluid in its vapor state, thereby, causing the evaporation of the fluid and the cooling of the remaining fluid. The fluid has a predetermined flow rate. The evaporative cooling membrane device has a channel which is sized in cooperation with the predetermined flow rate of the fluid so as to produce laminar flow therein. The evaporative cooling membrane device provides for the convenient control of the evaporation rates of the circulating fluid by adjusting the flow rates of the laminar flowing fluid.

Lomax, Curtis (Inventor); Moskito, John (Inventor)

1999-01-01

262

Segmented inlet nozzle for gas turbine, and methods of installation  

DOEpatents

A gas turbine nozzle guide vane assembly is formed of individual arcuate nozzle segments. The arcuate nozzle segments are elastically joined to each other to form a complete ring, with edges abutted to prevent leakage. The resultant nozzle ring is included within the overall gas turbine stationary structure and secured by a mounting arrangement which permits relative radial movement at both the inner and outer mountings. A spline-type outer mounting provides circumferential retention. A complete rigid nozzle ring with freedom to "float" radially results. Specific structures are disclosed for the inner and outer mounting arrangements. A specific tie-rod structure is also disclosed for elastically joining the individual nozzle segments. Also disclosed is a method of assembling the nozzle ring subassembly-by-subassembly into a gas turbine employing temporary jacks.

Klompas, Nicholas (Scotia, NY)

1985-01-01

263

Turbulence effects during evaporation of drops in clusters  

NASA Astrophysics Data System (ADS)

The present modeling of droplet cluster evaporation, which encompasses the exchange processes between the cluster and the gas phase that surrounds it and is intended for application as a subscale model in calculations of spray evaporation and combustion, gives attention to two alternative turbulence models: (1) cluster evaporation in an evironment initially without turbulence, which then experiences a gradual buildup of turbulence, and (2) evaporation in an environment in which turbulence is initially present. Results obtained indicate that turbulence enhances evaporation, and is a controlling factor in the evaporation of very dense clusters; it is shown that evaporation time decreases with an initial increase in either turbulence level or relative velocity. Practical implications of these results are discussed.

Bellan, J.; Harstad, K.

1988-08-01

264

Turbulence effects during evaporation of drops in clusters  

NASA Technical Reports Server (NTRS)

The present modeling of droplet cluster evaporation, which encompasses the exchange processes between the cluster and the gas phase that surrounds it and is intended for application as a subscale model in calculations of spray evaporation and combustion, gives attention to two alternative turbulence models: (1) cluster evaporation in an evironment initially without turbulence, which then experiences a gradual buildup of turbulence, and (2) evaporation in an environment in which turbulence is initially present. Results obtained indicate that turbulence enhances evaporation, and is a controlling factor in the evaporation of very dense clusters; it is shown that evaporation time decreases with an initial increase in either turbulence level or relative velocity. Practical implications of these results are discussed.

Bellan, J.; Harstad, K.

1988-01-01

265

PREDICTING EVAPORATION RATES AND TIMES FOR SPILLS OF CHEMICAL MIXTURES  

EPA Science Inventory

Spreadsheet and short-cut methods have been developed for predicting evaporation rates and evaporation times for spills (and constrained baths) of chemical mixtures. Steady-state and time-varying predictions of evaporation rates can be made for six-component mixtures, includ...

266

Effect of selenium doping on structural and optical properties of SnS:Se thin films by electron beam evaporation method  

NASA Astrophysics Data System (ADS)

SnS nanoparticle has been synthesized initially using SnCl2 · 2H2O and Na2S · XH2O, in the presence of TEA by precipitation method and XRD and FTIR techniques have been used for characterization of the sample. Powder X-ray diffraction studies revealed the particle size to be 48 nm and the pattern represents polycrystalline herzenbergite orthorhombic crystal structure of SnS. The FTIR result also confirmed the SnS at 2354 cm-1. Secondly SnS:Se thin films have been deposited on glass substrates by electron beam evaporation technique and the films were annealed at 100 °C and 200 °C for 1 h. The unannealed films are amorphous in nature and the annealed film shows that a sharp crystalline peak is due to SnS. Also a peak is shown at 2? = 14.39°, which is due to characteristic peak of SnSe2, established by their XRD patterns. The band gap energy (Eg) was determined from transmission spectra and an optical band gap of Eg varies from 1.6 eV to 1.79 eV.

Henry, Johnson; Mohanraj, Kannusamy; Kannan, Selvaraj; Barathan, Seshathri; Sivakumar, Ganesan

2013-01-01

267

Influence of Preparation Conditions on Structural Stability of Ordered Mesoporous Carbons Synthesized by Evaporation-induced Triconstituent Co-assembly Method  

NASA Astrophysics Data System (ADS)

Various ordered mesoporous carbons (OMCs) have been prepared by evaporation-induced triconstituent co-assembly method. Their mesostructural stability under different carbon content, aging time and acidity were conveniently monitored by X-ray diffraction, transmission electron microscopy, and N2 sorption isotherms techniques. The results show mesostructural stability of OMCs is enhanced as the carbon content increases from 36% to 46%, further increasing carbon content deteriorates the mesostructural stability. Increasing aging time from 0.5 h to 5.0 h make the mesostructural stability go through an optimum (2.0 h) and gradually reduce framework shrinkage of the OMCs. Highly OMCs can only be obtained in the acidity range of 0.2-1.2 mol/L HCl, when the acidity is near the isoelectric point of silica, the resulting OMCs have the best mesostructure stability. Under the optimum condition, the carbon content of 46%, aging time of 2.0 h, and 0.2 mol/L HCl, the resulting OMCs have the best mesostructure stability and the highest BET surface areas of 2281 m2/g.

You, Bo; Yang, Jun; Yong, Guo-ping; Liu, Shao-min; Xie, Wei; Su, Qing-de

2011-06-01

268

Improvement in Thermal-Ionization Mass Spectrometry (TIMS) using Total Flash Evaporation (TFE) method for lanthanides isotope ratio measurements in transmutation targets  

SciTech Connect

The experiments involved in the PHENIX french nuclear reactor to obtain precise and accurate data on the total capture cross sections of the heavy isotopes and fission products require isotopic ratios measurements with uncertainty of a few per mil. These accurate isotopic ratio measurements are performed with mass spectrometer equipped with multi-collector system. The major difficulty for the analyses of these actinides and fission products is the low quantity of the initial powder enclosed in steel container (3 to 5 mg) and the very low quantities of products formed (several {mu}g) after irradiation. Specific analytical developments are performed by Thermal Ionization Mass Spectrometry (TIMS) to be able to analyse several nanograms of elements with this technique. A specific method of acquisition named Total Flash Evaporation was adapted in this study in the case of lanthanide measurements for quantity deposited on the filament in the order of 2 ng and applied on irradiated fuel. To validate the analytical approach and discuss about the accuracy of the data, the isotopic ratios obtained by TIMS are compared with other mass spectrometric techniques such as Multiple-Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS). (authors)

Mialle, S.; Gourgiotis, A.; Aubert, M.; Stadelmann, G.; Gautier, C.; Isnard, H. [Commissariat a l'Energie Atomique, CEA Saclay, DEN/DPC/SECR/LANIE, 91191 Gif sur Yvette (France); Chartier, F. [Commissariat a l'Energie Atomique, CEA Saclay, DEN/DPC, 91191 Gif sur Yvette (France)

2011-07-01

269

New gas-liquid equilibration method: syringe tonometer.  

PubMed

This new apparatus for gas-liquid equilibration (tonometry) in a transportable vessel is designed for tonometry of blood or buffer solution in a specially designed syringe. Gas enters the syringe chamber through small holes in the tip of the syringe plunger and bubbles upward through the sample. The syringe plunger is a second chamber, which is used for warming and humidifying the gas before it enters the tonometer chamber. The entire syringe is housed in a transparent, temperature-controlled environment during equilibration. After equilibration, the sample is easily entered into a blood-gas analyzer. At most, gas-liquid O2/CO2 equilibration for 2.5 mL of buffer or blood requires less than 13 min. Comparisons with a standard thin-film tonometer show good agreement for pO2 and pCO2 over the range 0-93 kPa (0-700 mmHg) and 2-20 kPa (14-150 mmHg), respectively. The syringe tonometer eliminates contamination of the sample during transfer and transport to the analyzer, thus making tonometry more technique-independent. The apparatus is simple and easy to use, with definite advantages over existing methods of tonometry. PMID:6784964

Wallace, W D; Cutler, C A; Clark, J S

1981-05-01

270

Chemical potential jump during evaporation of Bose gases  

NASA Astrophysics Data System (ADS)

The dependence of the chemical potential jump coefficient on the evaporation coefficient of a binary mixture is studied in the case where the evaporating component is a Bose gas with a concentration assumed to be much lower than that of the carrier gas. An analytical solution of the problem yields an expression for the chemical potential jump for the case of a constant collision frequency of the Bose gas molecules.

Bedrikova, E. A.; Latyshev, A. V.

2014-03-01

271

Evaporation from soybeans  

NASA Astrophysics Data System (ADS)

During the 1974 growing season, a micrometeorological measurement program was conducted at Simcoe, Ontario, Canada to study atmospheric and surface control on hourly and daytime evaporation from soybeans. For days when leaf area index exceeded unity, daytime evaporation varied linearly with volumetric soil moisture content when the latter was less than 0.12. At larger volumetric soil moisture contents, evaporation proceeded at a potential rate. The data confirm the usefulness of the Priestley and Taylor model with a proportionality constant of 1.26.

Bailey, W. G.; Davies, J. A.

1981-06-01

272

Flash evaporator systems test  

NASA Technical Reports Server (NTRS)

A flash evaporator heat rejection system representative of that proposed for the space shuttle orbiter underwent extensive system testing at the NASA Johnson Space Center (JSC) to determine its operational suitability and to establish system performance/operational characteristics for use in the shuttle system. During the tests the evaporator system demonstrated its suitability to meet the shuttle requirements by: (1) efficient operation with 90 to 95% water evaporation efficiency, (2) control of outlet temperature to 40 + or - 2 F for partial heat load operation, (3) stability of control system for rapid changes in Freon inlet temperature, and (4) repeated dormant-to-active device operation without any startup procedures.

Dietz, J. B.

1976-01-01

273

Urban Signatures: Evaporation (WMS)  

NSDL National Science Digital Library

Big cities influence the environment around them. For example, urban areas are typically warmer than their surroundings. Cities are strikingly visible in computer models that simulate the Earths land surface. This visualization shows evaporation rates predicted by the Land Information System (LIS) for a day in June 2001. Evaporation is lower in the cities because water tends to run off pavement and into drains, rather than being absorbed by soil and plants from which it later evaporates. Only part of the global computation is shown, focusing on the highly urbanized northeast corridor in the United States, including the cities of Boston, New York, Philadelphia, Baltimore, and Washington.

Delabeaujardiere, Jeff

2005-05-27

274

Selecting the optimal method to calculate daily global reference potential evaporation from CFSR reanalysis data for application in a hydrological model study  

NASA Astrophysics Data System (ADS)

Potential evaporation (PET) is one of the main inputs of hydrological models. Yet, there is limited consensus on which PET equation is most applicable in hydrological climate impact assessments. In this study six different methods to derive global scale reference PET daily time series from Climate Forecast System Reanalysis (CFSR) data are compared: Penman-Monteith, Priestley-Taylor and original and re-calibrated versions of the Hargreaves and Blaney-Criddle method. The calculated PET time series are (1) evaluated against global monthly Penman-Monteith PET time series calculated from CRU data and (2) tested on their usability for modeling of global discharge cycles. A major finding is that for part of the investigated basins the selection of a PET method may have only a minor influence on the resulting river flow. Within the hydrological model used in this study the bias related to the PET method tends to decrease while going from PET, AET and runoff to discharge calculations. However, the performance of individual PET methods appears to be spatially variable, which stresses the necessity to select the most accurate and spatially stable PET method. The lowest root mean squared differences and the least significant deviations (95% significance level) between monthly CFSR derived PET time series and CRU derived PET were obtained for a cell-specific re-calibrated Blaney-Criddle equation. However, results show that this re-calibrated form is likely to be unstable under changing climate conditions and less reliable for the calculation of daily time series. Although often recommended, the Penman-Monteith equation applied to the CFSR data did not outperform the other methods in a evaluation against PET derived with the Penman-Monteith equation from CRU data. In arid regions (e.g. Sahara, central Australia, US deserts), the equation resulted in relatively low PET values and, consequently, led to relatively high discharge values for dry basins (e.g. Orange, Murray and Zambezi). Furthermore, the Penman-Monteith equation has a high data demand and the equation is sensitive to input data inaccuracy. Therefore, we recommend the re-calibrated form of the Hargreaves equation which globally gave reference PET values comparable to CRU derived values for multiple climate conditions. The resulting gridded daily PET time series provide a new reference dataset that can be used for future hydrological impact assessments in further research, or more specifically, for the statistical downscaling of daily PET derived from raw GCM data. The dataset can be downloaded from http://opendap.deltares.nl/thredds/dodsC/opendap/deltares/FEWS-IPCC.

Sperna Weiland, F. C.; Tisseuil, C.; Dürr, H. H.; Vrac, M.; van Beek, L. P. H.

2012-03-01

275

Mergers, cooling flows, and evaporation  

NASA Technical Reports Server (NTRS)

Mergers (the capture of cold gas, especially) can have a profound influence on the hot coronal gas of early-type galaxies and clusters, potentially inducing symptoms hitherto attributed to a cooling flow, if thermal conduction is operative in the coronal plasma. Heat can be conducted from the hot phase into the cold phase, simultaneously ionizing the cold gas to make optical filaments, while locally cooling the coronal gas to mimic a cooling-flow. If there is heat conduction, though, there is no standard cooling-flow since radiative losses are balanced by conduction and not mass deposition. Amongst the strongest observational support for the existence of cooling-flows is the presence of intermediate temperature gas with x-ray emission-line strengths in agreement with cooling-flow models. Here, x-ray line strengths are calculated for this alternative model, in which mergers are responsible for the observed optical and x-ray properties. Since gas around 10(exp 4) K is thermally stable, the cold cloud need not necessarily evaporate and hydrostatic solutions exist. Good agreement with the x-ray data is obtained. The relative strengths of intermediate temperature x-ray emission lines are in significantly better agreement with a simple conduction model than with published cooling-flow models. The good agreement of the conduction model with optical, infrared and x-ray data indicates that significantly more theoretical effort into this type of solution would be profitable.

Sparks, W. B.

1993-01-01

276

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

277

An evaluation of models of bare soil evaporation formulated with different land surface boundary conditions and assumptions  

NASA Astrophysics Data System (ADS)

Bare soil evaporation is a key process for water exchange between the land and the atmosphere and an important component of the water balance. However, there is no agreement on the best modeling methodology to determine evaporation under different atmospheric boundary conditions. Also, there is a lack of directly measured soil evaporation data for model validation to compare these methods to establish the validity of their mathematical formulations. Thus, a need exists to systematically compare evaporation estimates using existing methods to experimental observations. The goal of this work is to test different conceptual and mathematical formulations that are used to estimate evaporation from bare soils to critically investigate various formulations and surface boundary conditions. Such a comparison required the development of a numerical model that has the ability to incorporate these boundary conditions. For this model, we modified a previously developed theory that allows nonequilibrium liquid/gas phase change with gas phase vapor diffusion to better account for dry soil conditions. Precision data under well-controlled transient heat and wind boundary conditions were generated, and results from numerical simulations were compared with experimental data. Results demonstrate that the approaches based on different boundary conditions varied in their ability to capture different stages of evaporation. All approaches have benefits and limitations, and no one approach can be deemed most appropriate for every scenario. Comparisons of different formulations of the surface boundary condition validate the need for further research on heat and vapor transport processes in soil for better modeling accuracy.

Smits, Kathleen M.; Ngo, Viet V.; Cihan, Abdullah; Sakaki, Toshihiro; Illangasekare, Tissa H.

2012-12-01

278

Quantifying nonisothermal subsurface soil water evaporation  

NASA Astrophysics Data System (ADS)

Accurate quantification of energy and mass transfer during soil water evaporation is critical for improving understanding of the hydrologic cycle and for many environmental, agricultural, and engineering applications. Drying of soil under radiation boundary conditions results in formation of a dry surface layer (DSL), which is accompanied by a shift in the position of the latent heat sink from the surface to the subsurface. Detailed investigation of evaporative dynamics within this active near-surface zone has mostly been limited to modeling, with few measurements available to test models. Soil column studies were conducted to quantify nonisothermal subsurface evaporation profiles using a sensible heat balance (SHB) approach. Eleven-needle heat pulse probes were used to measure soil temperature and thermal property distributions at the millimeter scale in the near-surface soil. Depth-integrated SHB evaporation rates were compared with mass balance evaporation estimates under controlled laboratory conditions. The results show that the SHB method effectively measured total subsurface evaporation rates with only 0.01-0.03 mm h-1difference from mass balance estimates. The SHB approach also quantified millimeter-scale nonisothermal subsurface evaporation profiles over a drying event, which has not been previously possible. Thickness of the DSL was also examined using measured soil thermal conductivity distributions near the drying surface. Estimates of the DSL thickness were consistent with observed evaporation profile distributions from SHB. Estimated thickness of the DSL was further used to compute diffusive vapor flux. The diffusive vapor flux also closely matched both mass balance evaporation rates and subsurface evaporation rates estimated from SHB.

Deol, Pukhraj; Heitman, Josh; Amoozegar, Aziz; Ren, Tusheng; Horton, Robert

2012-11-01

279

Method for reduced temperature operation of flue gas collectors  

SciTech Connect

A method for reduced temperature operation of flue gas collectors is disclosed wherein the benefits of low temperature operation are made possible by avoidance of the acid dewpoint limit. The process increases the specific collecting area of the collector, results in lower pressure drop through the collector and, where the collector is an electrostatic precipitator, allows improved collection efficiency through higher electric field strength and reduced particulate resistivity.

Feldman, P. L.; Gleason, R. J.

1985-12-17

280

Improved micro-flame detection method for gas chromatography  

Microsoft Academic Search

A previously developed micro-counter-current flame method is modified to provide both sensitive photometric and ionization detection for gas chromatography (GC). A stainless steel capillary (0.254mm i.d.) supplying oxygen functions as a burner, which supports a compact flame that burns in a counter-flowing excess of hydrogen. In the “micro-flame photometric detector” (?FPD) response mode, the background emission level is reduced by

Kevin B Thurbide; Taylor C Hayward

2004-01-01

281

Method and apparatus for controlling gas evolution from chemical reactions  

DOEpatents

The present invention is directed toward monitoring a thermally driven gas evolving chemical reaction with an acoustic apparatus. Signals from the acoustic apparatus are used to control a heater to prevent a run-away condition. A digestion module in combination with a robotic arm further automate physical handling of sample material reaction vessels. The invention is especially useful for carrying out sample procedures defined in EPA Methods SW-846. 8 figs.

Skorpik, J.R.; Dodson, M.G.

1999-05-25

282

Method and apparatus for controlling gas evolution from chemical reactions  

DOEpatents

The present invention is directed toward monitoring a thermally driven gas evolving chemical reaction with an acoustic apparatus. Signals from the acoustic apparatus are used to control a heater to prevent a run-away condition. A digestion module in combination with a robotic arm further automate physical handling of sample material reaction vessels. The invention is especially useful for carrying out sample procedures defined in EPA Methods SW-846.

Skorpik, James R. (Kennewick, WA); Dodson, Michael G. (Richland, WA)

1999-01-01

283

Gas phase fractionation method using porous ceramic membrane  

DOEpatents

Flaw-free porous ceramic membranes fabricated from metal sols and coated onto a porous support are advantageously used in gas phase fractionation methods. Mean pore diameters of less than 40 .ANG., preferably 5-20 .ANG. and most preferably about 15 .ANG., are permeable at lower pressures than existing membranes. Condensation of gases in small pores and non-Knudsen membrane transport mechanisms are employed to facilitate and increase membrane permeability and permselectivity.

Peterson, Reid A. (Madison, WI); Hill, Jr., Charles G. (Madison, WI); Anderson, Marc A. (Madison, WI)

1996-01-01

284

Method for removing hydrogen sulfide from gas streams  

Microsoft Academic Search

A hydrogen sulfide removal and conversion method is disclosed in which a hydrogen sulfide-containing gas stream is contacted with a substantially quinone-free aqueous washing solution containing, inter alia, solubilized vanadium, thiocyanate ions, and one or more water-soluble nonquinone aromatic compounds capable of solubilizing tetravalent vanadium. The absorbed hydrogen sulfide is converted to elemental sulfur which, after oxidative regeneration of the

D. M. Fenton; H. W. Gowdy

1981-01-01

285

Method for removing hydrogen sulfide from gas streams  

Microsoft Academic Search

A hydrogen sulfide removal and conversion method in which a hydrogen sulfide-containing gas stream is contacted with a regenerable washing solution having a pH between about 5 and about 10 and containing solubilized vanadium, thiocyanate ions, a carboxylate complexing agent, one or more water-soluble quinones and one or more water-soluble nonquinone aromatic compounds capable of solubilizing tetravalent vanadium. The absorbed

H. W. Gowdy; D. M. Fenton

1984-01-01

286

Method for removing hydrogen sulfide from gas streams  

Microsoft Academic Search

A hydrogen sulfide removal and conversion method in which a hydrogen sulfide-containing gas stream is contacted with a regenerable washing solution containing solubilized vanadium thiocyanate ions, a carboxylate complexing agent and one or more water-soluble quinones capable of solubilizing tetravalent vanadium. The molar ratio of vanadium to quinone(S) in the washing solution is selected to substantially reduce or eliminate the

D. M. Fenton; H. W. Gowdy

1982-01-01

287

CAPSULE REPORT: EVAPORATION PROCESS  

EPA Science Inventory

Evaporation has been an established technology in the metal finishing industry for many years. In this process, wastewaters containing reusable materials, such as copper, nickel, or chromium compounds are heated, producing a water vapor that is continuously removed and condensed....

288

Mixed feed evaporator  

DOEpatents

In the preparation of the gaseous reactant feed to undergo a chemical reaction requiring the presence of steam, the efficiency of overall power utilization is improved by premixing the gaseous reactant feed with water and then heating to evaporate the water in the presence of the gaseous reactant feed, the heating fluid utilized being at a temperature below the boiling point of water at the pressure in the volume where the evaporation occurs.

Vakil, Himanshu B. (Schenectady, NY) [Schenectady, NY; Kosky, Philip G. (Ballston Lake, NY) [Ballston Lake, NY

1982-01-01

289

Method of fabricating an integral gas seal for fuel cell gas distribution assemblies  

SciTech Connect

A method of producing a bipolar assembly for use in a fuel cellstack wherein contiguous plates are provided to distribute oxidant and reactant gas respectively to adjacent cells of the stack is described comprising the steps of providing at least two electrically conductive distribution plates having a foraminous structure suitable for transporting gas therethrough; disposing a layer of thermally sensitive, insulative sealant material between the plates; applying pressure and elevated temperature to the plates and layer of thermally sensitive sealant material sufficient to render the layer deformable and bond the plates together upon redistribution of the sealant within the pores of the plates; the layer of insulative sealant material being present in such amount to impregnate the pores of the plates and form a substantially gas-impermeable barrier at the interface between the plates, the plates being bonded so that they are in contact with one another in electroconductive registry.

Dettling, C.J.; Terry, P.L.

1988-03-22

290

Statistical Methods Handbook for Advanced Gas Reactor Fuel Materials  

SciTech Connect

Fuel materials such as kernels, coated particles, and compacts are being manufactured for experiments simulating service in the next generation of high temperature gas reactors. These must meet predefined acceptance specifications. Many tests are performed for quality assurance, and many of these correspond to criteria that must be met with specified confidence, based on random samples. This report describes the statistical methods to be used. The properties of the tests are discussed, including the risk of false acceptance, the risk of false rejection, and the assumption of normality. Methods for calculating sample sizes are also described.

J. J. Einerson

2005-05-01

291

Sheet Membrane Spacesuit Water Membrane Evaporator  

NASA Technical Reports Server (NTRS)

A document describes a sheet membrane spacesuit water membrane evaporator (SWME), which allows for the use of one common water tank that can supply cooling water to the astronaut and to the evaporator. Test data showed that heat rejection performance dropped only 6 percent after being subjected to highly contaminated water. It also exhibited robustness with respect to freezing and Martian atmospheric simulation testing. Water was allowed to freeze in the water channels during testing that simulated a water loop failure and vapor backpressure valve failure. Upon closing the backpressure valve and energizing the pump, the ice eventually thawed and water began to flow with no apparent damage to the sheet membrane. The membrane evaporator also serves to de-gas the water loop from entrained gases, thereby eliminating the need for special degassing equipment such as is needed by the current spacesuit system. As water flows through the three annular water channels, water evaporates with the vapor flowing across the hydrophobic, porous sheet membrane to the vacuum side of the membrane. The rate at which water evaporates, and therefore, the rate at which the flowing water is cooled, is a function of the difference between the water saturation pressure on the water side of the membrane, and the pressure on the vacuum side of the membrane. The primary theory is that the hydrophobic sheet membrane retains water, but permits vapor pass-through when the vapor side pressure is less than the water saturation pressure. This results in evaporative cooling of the remaining water.

Bue, Grant; Trevino, Luis; Zapata, Felipe; Dillion, Paul; Castillo, Juan; Vonau, Walter; Wilkes, Robert; Vogel, Matthew; Frodge, Curtis

2013-01-01

292

78 FR 11619 - Greenhouse Gas Reporting Rule: Revision to Best Available Monitoring Method Request Submission...  

Federal Register 2010, 2011, 2012, 2013

...Method Request Submission Deadline for Petroleum and Natural Gas Systems Source Category...operators of facilities subject to the petroleum and natural gas systems source category...operators of facilities subject to the petroleum and natural gas systems source...

2013-02-19

293

78 FR 25392 - Greenhouse Gas Reporting Rule: Revision to Best Available Monitoring Method Request Submission...  

Federal Register 2010, 2011, 2012, 2013

...Method Request Submission Deadline for Petroleum and Natural Gas Systems Source Category...operators of facilities subject to the petroleum and natural gas systems source category...final rule affects owners or operators of petroleum and natural gas systems. Regulated...

2013-05-01

294

78 FR 11585 - Greenhouse Gas Reporting Rule: Revision to Best Available Monitoring Method Request Submission...  

Federal Register 2010, 2011, 2012, 2013

...Method Request Submission Deadline for Petroleum and Natural Gas Systems Source Category...operators of facilities subject to the petroleum and natural gas systems source category...regulations could affect owners or operators of petroleum and natural gas systems. Regulated...

2013-02-19

295

Effect of the dispersion of Eudragit S100 powder on the properties of cellulose acetate butyrate microspheres containing theophylline made by the emulsion-solvent evaporation method.  

PubMed

The dispersion/incorporation of Eudragit S100 powder as a filler in cellulose acetate butyrate (CAB-551-0.01) microsphere containing theophylline was investigated as a means of controlling drug release. Microspheres of CAB-551-0.01 of different polymer solution concentrations/viscosities were prepared (preparations Z(0), Z(A), Z(B) and Z(C)) and evaluated and compared to microspheres of a constant concentration of CAB-551-0.01 containing different amounts of Eudragit S100 powder as a filler (preparations X(A), X(B) and X(C)). The organic solvent acetonitrile used was capable of dissolving the matrix former CAB-551-0.01 only but not Eudragit S100 powder in the emulsion-solvent evaporation method. The CAB-551-0.01 concentration in Z(A), Z(B) and Z(C) was equal to the total polymer concentration (CAB-551-0.01 and Eudragit S100 powder) in X(A), X(B) and X(C), respectively. Scanning electron microscopy (SEM) was used to identify microspheres shape and morphology. In vitro dissolution studies were carried out on the microspheres at 37 degrees C (+/-0.5 degrees C) at two successive different pH media (1.2 +/- 0.2 for 2 h and 6.5 +/- 0.2 for 10 h). Z preparations exhibited low rates of drug release in the acidic and the slightly neutral media. On the other hand, X preparations showed an initial rapid release in the acidic medium followed by a decrease in the release rate at the early stage of dissolution in the slightly neutral pH which could be due to some relaxation and gelation of Eudragit S100 powder to form a gel network before it dissolves completely allowing the remained drug to be released. PMID:17454437

Obeidat, Wasfy M; Obaidat, Ihab M

2007-05-01

296

Usability of calcium carbide gas pressure method in hydrological sciences  

NASA Astrophysics Data System (ADS)

Soil moisture is a key engineering variable with major influence on ecological and hydrological processes as well as in climate, weather, agricultural, civil and geotechnical applications. Methods for quantification of the soil moisture are classified into three main groups: (i) measurement with remote sensing, (ii) estimation via (soil water balance) simulation models, and (iii) measurement in the field (ground based). Remote sensing and simulation modeling require rapid ground truthing with one of the ground based methods. Calcium carbide gas pressure (CCGP) method is a rapid measurement procedure for obtaining soil moisture and relies on the chemical reaction of the calcium carbide reagent with the water in soil pores. However, the method is overlooked in hydrological science applications. Therefore, the purpose of this study is to evaluate the usability of the CCGP method in comparison with standard oven-drying and dielectric methods in terms of accuracy, time efficiency, operational ease, cost effectiveness and safety for quantification of the soil moisture over a wide range of soil types. The research involved over 250 tests that were carried out on 15 different soil types. It was found that the accuracy of the method is mostly within ±1% of soil moisture deviation range in comparison to oven-drying, and that CCGP method has significant advantages over dielectric methods in terms of accuracy, cost, operational ease and time efficiency for the purpose of ground truthing.

Arsoy, S.; Ozgur, M.; Keskin, E.; Yilmaz, C.

2013-10-01

297

Estimating soil water evaporation using radar measurements  

NASA Technical Reports Server (NTRS)

Field studies were conducted to evaluate the application of radar reflectivity as compared with the shortwave reflectivity (albedo) used in the Idso-Jackson equation for the estimation of daily evaporation under overcast sky and subhumid climatic conditions. Soil water content, water potential, shortwave and radar reflectivity, and soil and air temperatures were monitored during three soil drying cycles. The data from each cycle were used to calculate daily evaporation from the Idso-Jackson equation and from two other standard methods, the modified Penman and plane of zero-flux. All three methods resulted in similar estimates of evaporation under clear sky conditions; however, under overcast sky conditions, evaporation fluxes computed from the Idso-Jackson equation were consistently lower than the other two methods. The shortwave albedo values in the Idso-Jackson equation were then replaced with radar reflectivities and a new set of total daily evaporation fluxes were calculated. This resulted in a significant improvement in computed soil evaporation fluxes from the Idso-Jackson equation, and a better agreement between the three methods under overcast sky conditions.

Sadeghi, Ali M.; Scott, H. D.; Waite, W. P.; Asrar, G.

1988-01-01

298

Self-contained cryogenic gas sampling apparatus and method  

DOEpatents

Apparatus for obtaining a whole gas sample, is composed of: a sample vessel having an inlet for receiving a gas sample; a controllable valve mounted for controllably opening and closing the inlet; a valve control coupled to the valve for opening and closing the valve at selected times; a portable power source connected for supplying operating power to the valve control; and a cryogenic coolant in thermal communication with the vessel for cooling the interior of the vessel to cryogenic temperatures. A method is described for obtaining an air sample using the apparatus described above, by: placing the apparatus at a location at which the sample is to be obtained; operating the valve control to open the valve at a selected time and close the valve at a selected subsequent time; and between the selected times maintaining the vessel at a cryogenic temperature by heat exchange with the coolant. 3 figs.

McManus, G.J.; Motes, B.G.; Bird, S.K.; Kotter, D.K.

1996-03-26

299

Self-contained cryogenic gas sampling apparatus and method  

DOEpatents

Apparatus for obtaining a whole gas sample, composed of: a sample vessel having an inlet for receiving a gas sample; a controllable valve mounted for controllably opening and closing the inlet; a valve control coupled to the valve for opening and closing the valve at selected times; a portable power source connected for supplying operating power to the valve control; and a cryogenic coolant in thermal communication with the vessel for cooling the interior of the vessel to cryogenic temperatures. A method of obtaining an air sample using the apparatus described above, by: placing the apparatus at a location at which the sample is to be obtained; operating the valve control to open the valve at a selected time and close the valve at a selected subsequent time; and between the selected times maintaining the vessel at a cryogenic temperature by heat exchange with the coolant.

McManus, Gary J. (Idaho Falls, ID); Motes, Billy G. (Idaho Falls, ID); Bird, Susan K. (Idaho Falls, ID); Kotter, Dale K. (Shelley, ID)

1996-01-01

300

Computation of Pressurized Gas Bearings Using CE/SE Method  

NASA Technical Reports Server (NTRS)

The space-time conservation element and solution element (CE/SE) method is extended to compute compressible viscous flows in pressurized thin fluid films. This numerical scheme has previously been used successfully to solve a wide variety of compressible flow problems, including flows with large and small discontinuities. In this paper, the method is applied to calculate the pressure distribution in a hybrid gas journal bearing. The formulation of the problem is presented, including the modeling of the feeding system. the numerical results obtained are compared with experimental data. Good agreement between the computed results and the test data were obtained, and thus validate the CE/SE method to solve such problems.

Cioc, Sorin; Dimofte, Florin; Keith, Theo G., Jr.; Fleming, David P.

2003-01-01

301

Numerical study of impact of evaporation on liquid jet in cross-flow  

NASA Astrophysics Data System (ADS)

Atomization of a liquid fuel jet by a high speed cross-flowing gas plays a critical role in many propulsion devices. High fidelity simulation offers the potential of a better understanding and enhancement of this atomization process. In this work, a computationally efficient hybrid Eulerian-Lagrangian approach is coupled with a droplet evaporation model and is used to probe the impact of evaporation on the spray development. The Coupled Level Set and Volume of Fluid (CLSVOF) method is used to directly calculate the breakup and coalescence of the liquid-gas interface. Adaptive Mesh Refinement (AMR) is adopted to achieve high resolution at the interface. Small fuel droplets in dilute regions are removed from the Eulerian description, transformed into Lagrangian particles and tracked by a discrete phase transport model. The coupling of the spray evaporation to the gas phase is examined with respect to jet blockage, spray penetration, and overall far-field spray dispersion. The calculation is validated with flow rate, spray size distribution and velocity data acquired in a spray rig at high-Weber, high-Reynolds number injection conditions. The effect of evaporation on spray distribution is also discussed.

Soteriou, Marios; Li, Xiaoyi; Arienti, Marco

2010-11-01

302

Asymptotic Behavior of Rotating Rarefied Gases with Evaporation and Condensation.  

National Technical Information Service (NTIS)

The asymptotic behavior of the cylindrical Couette flow problem for a rarefied rotating gas with evaporation and condensation is studied when the state of equilibrium is perturbed by the following small thermodynamic forces: (i) the pressure difference of...

L. M. Cumin G. M. Kremer F. Sharipov

2000-01-01

303

Applications of Electromagnetic Measurement Methods in Oil and Gas Industry  

NASA Astrophysics Data System (ADS)

When hydrocarbons accumulate in reservoirs, the reservoir rocks and a large volume of rock associated with the reservoirs undergo resistance changes. This method relates generally to the field of geophysical prospecting for the purposes of hydrocarbon exploration, development, and production. This method includes measuring magnetic field gradient in at least two orthogonal directions in response to the induced electromagnetic field and determining an electric field response. Specifically, this method is a method for determining the difference between the electrical resistance of a reservoir at an initial time and its electrical resistance at one or more later times, and relating that difference to production of hydrocarbons from the reservoir during the interim period. Electromagnetic methods are now being used to provide images of subsurface resistance on the reservoir scale. These images provide for the first time observation of the distribution of porosity and fluid content on the same scale as the reservoir. They are being used to identify bypassed oil, monitor sweep efficiency, identify unanticipated breakthrough, and map features. All such information could previously only be inferred from measurements within the well or from production data from the well. For monitoring production and enhanced recovery processes, when it can be assumed that the porosity is essentially constant and when there is a resistivity contrast in the different fluids or phases involved, the imaged resistivity is a direct mapping of the changes in saturation. In this paper we discuss about the methods for electromagnetic measurement methods and its application in oil and gas industry.

Dehghani, Maryam

2011-12-01

304

Method For Enhanced Gas Monitoring In High Density Flow Streams  

DOEpatents

A method for conducting laser absorption measurements in high temperature process streams having high levels of particulate matter is disclosed. An impinger is positioned substantially parallel to a laser beam propagation path and at upstream position relative to the laser beam. Beam shielding pipes shield the beam from the surrounding environment. Measurement is conducted only in the gap between the two shielding pipes where the beam propagates through the process gas. The impinger facilitates reduced particle presence in the measurement beam, resulting in improved SNR (signal-to-noise) and improved sensitivity and dynamic range of the measurement.

Von Drasek, William A. (Oak Forest, IL); Mulderink, Kenneth A. (Countryside, IL); Marin, Ovidiu (Lisle, IL)

2005-09-13

305

Hot air drum evaporator  

DOEpatents

An evaporation system for aqueous radioactive waste uses standard 30 and 55 gallon drums. Waste solutions form cascading water sprays as they pass over a number of trays arranged in a vertical stack within a drum. Hot dry air is circulated radially of the drum through the water sprays thereby removing water vapor. The system is encased in concrete to prevent exposure to radioactivity. The use of standard 30 and 55 gallon drums permits an inexpensive compact modular design that is readily disposable, thus eliminating maintenance and radiation build-up problems encountered with conventional evaporation systems.

Black, Roger L. (Idaho Falls, ID)

1981-01-01

306

Evaporator Development for an Evaporative Heat Pipe System  

NASA Technical Reports Server (NTRS)

As fossil fuel resources continue to deplete, research for alternate power sources continues to develop. One of these alternate technologies is fuel cells. They are a practical fuel source able to provide significant amounts of power for applications from laptops to automobiles and their only byproduct is water. However, although this technology is over a century old and NASA has been working with it since the early 1960 s there is still room for improvement. The research I am involved in at NASA's Glenn Research Center is focusing on what is called a regenerative fuel cell system. The unique characteristic of this type of system is that it used an outside power source to create electrolysis of the water it produces and it then reuses the hydrogen and oxygen to continue producing power. The advantage of this type of system is that, for example, on space missions it can use solar power to recharge its gas supplies between periods when the object being orbited blocks out the sun. This particular system however is far from completion. This is because of the many components that are required to make up a fuel cell that need to be tested individually. The specific part of the system that is being worked on this summer of 2004 is the cooling system. The fuel cell stack, that is the part that actually creates the power, also produces a lot of heat. When not properly cooled, it has been known to cause fires which, needless to say are not conducive to the type of power that is trying to be created. In order to cool the fuel cell stack in this system we are developing a heat pipe cooling system. One of the main components of a heat pipe cooling system is what is known as the evaporator, and that is what happens to be the part of the system we are developing this summer. In most heat pipe systems the evaporator is a tube in which the working fluid is cooled and then re-circulated through the system to absorb more heat energy from the fuel cell stack. For this system, instead of a tube, the evaporator is made up of a stack-up of screen material and absorbent membranes inside a stainless steel shell and held together by a film adhesive and epoxy. There is an initial design for this flat plate evaporator, however is has not yet been made. The components of the stack-up are known, so all testing is focused on how it will all go together. This includes finding an appropriate epoxy to make the evaporator conductive all the way through and finding a way to hold the required tight tolerances as the stainless steel outer shell is put together. By doing the tests on smaller samples of the stack-ups and then testing the fill size component, the final flat plate evaporator will reach its final design so that research can continue on other parts of the regenerative fue1 cell system, and another step in the improvement of fue1 cell technology can be made.

Peters, Leigh C.

2004-01-01

307

Exploration soil gas methods that reduce site characterization costs  

SciTech Connect

Initial site characterization of impacted or suspected sites is the most important portion of an integrated environmental remediation program. By use of passive soil gas (PSG) characterization methods, the author has saved his clients significant sums of money by expediting the characterization phase of a project, thus eliminating unnecessary drilling and sampling. He has also been able to advance remedial response by allowing better design of the characterization program. Several commercial products are available which incorporate the principals of the PSG methodology described herein. Using a decidedly low tech approach, the PSG methodology described herein can be used to identify impacted areas on a given site prior to installation of soil borings and monitorings wells. The method is low impact and does not attract unwanted attention to a potentially impacted site. Given the passive nature of the method; it allows a more accurate evaluation of subsurface soil gas conditions, and allows placement of subsequent subsurface tests (whether soil borings or monitoring wells) in optium positions for accurate characterization. This approach minimizes the number of wells needed to characterize a site, eliminates over-characterization and unnecessary drilling, and provides lateral data which in turn allows a client to determine the extent of any liability on a select property. By identifying the extent of his problem, the client can more realistically evaluate his liability and project a budget for completion of remediation. It also allows him to more easily identify the most effective remediation approach. The PSG method allows rapid characterization and priortization of multiple sites, thus allowing a more effective use of environmental budgets.

Pyron, A.J. [Pyron Consulting, Pottstown, PA (United States)

1995-09-01

308

Evaporation loss measurement from storage tanks  

Microsoft Academic Search

Evaporation loss measurement from storage tanks is explored here. The paper concentrates only on external and internal floating-roof tanks. Specifically, it covers: parameters affecting tank losses, loss estimation methods, and several sample problems for assuring proper utilization of these methods. The main goal is to understand the application of the loss estimation methods using specific examples.

1984-01-01

309

Evaporation loss measurement from storage tanks  

SciTech Connect

Evaporation loss measurement from storage tanks is explored here. The paper concentrates only on external and internal floating-roof tanks. Specifically, it covers: parameters affecting tank losses, loss estimation methods, and several sample problems for assuring proper utilization of these methods. The main goal is to understand the application of the loss estimation methods using specific examples.

Connors, K.A.

1984-04-01

310

Apparatus and method for monitoring of gas having stable isotopes  

DOEpatents

Gas having stable isotopes is monitored continuously by using a system that sends a modulated laser beam to the gas and collects and transmits the light not absorbed by the gas to a detector. Gas from geological storage, or from the atmosphere can be monitored continuously without collecting samples and transporting them to a lab.

Clegg, Samuel M; Fessenden-Rahn, Julianna E

2013-03-05

311

Effect of various inlet air cooling methods on gas turbine performance  

Microsoft Academic Search

Turbine air inlet cooling is one of many available commercial methods to improve the efficiency of an existing gas turbine. The method has various configurations which could be utilized for almost all installed gas turbines. This paper presents a comparison between two commons and one novel inlet air cooling method using turbo-expanders to improve performance of a gas turbine located

Mahmood Farzaneh-Gord; Mahdi Deymi-Dashtebayaz

2011-01-01

312

High Vacuum Evaporation System.  

National Technical Information Service (NTIS)

The primary objective of the electron beam evaporator is to apply high quality optical coatings for lasers operating in the midinfrared region (2-5 micron) band, as well as lasers emitting in the range of 0.7 - 1.0 micron wavelength. The electron beam eva...

M. Razeghi

1996-01-01

313

Incorporated evaporative condenser  

Microsoft Academic Search

The incorporated evaporative condenser developed in this work comprises of a system of fins, basin of water condensates, circuit pump and system of drop cloud via spraying. In the whole provision a system of drop collector is also included for the minimisation of water escapes now essential for the operation of system. Actually, the present work aims on the development

Michalis Gr. Vrachopoulos; Andronikos E. Filios; Georgios T. Kotsiovelos; Eleftherios D. Kravvaritis

2007-01-01

314

Evaporative roof cooling system  

Microsoft Academic Search

An evaporative roof cooling system is described for placement upon a roof surface exposed to relatively high levels of solar radiation causing high under roof temperatures and comprising: (a) water distribution mist\\/spray nozzles positioned on the roof surface for supplying substantially uniform mist\\/sprays of water to lay down a substantially uniform thin film of water on the roof surface; (b)

Viner

1988-01-01

315

Water Evaporation Test  

NSDL National Science Digital Library

In this activity, learners conduct an experiment to measure the temperature of a dry cotton ball versus a wet one. Explore water evaporation and investigate why swimming and drinking water keeps your body cool. This activity guide includes a step-by-step instructional video.

Center, Saint L.

2013-01-17

316

Evaporation of extrasolar planets  

Microsoft Academic Search

This article presents a review on the observations and theoretical modeling of the evaporation of extrasolar planets. The observations and the resulting constraints on the upper atmosphere (thermosphere and exosphere) of the ``hot-Jupiters'' are described. The early observations of the first discovered transiting extrasolar planet, HD209458b, allowed the discovery that this planet has an extended atmosphere of escaping hydrogen. Subsequent

A. Lecavelier Des Etangs

2010-01-01

317

Theoretical analysis of evaporative losses of adsorbed or absorbed species during atmospheric aerosol sampling  

Microsoft Academic Search

Evaporative losses of adsorbed or absorbed species from particle deposits during sampling is discussed. The theory that is developed focuses on evaporative losses that occur as a result of the pressure drop within the sampling device. The theory assumes that temperature and gas and particle concentrations remain constant during sampling. When the atmospheric aerosol is in equilibrium, the evaporative losses

Zhang Xinqiu; Peter H. McMurry

1991-01-01

318

Analytical resource assessment method for continuous (unconventional) oil and gas accumulations - The "ACCESS" Method  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) periodically assesses petroleum resources of areas within the United States and the world. The purpose of this report is to explain the development of an analytic probabilistic method and spreadsheet software system called Analytic Cell-Based Continuous Energy Spreadsheet System (ACCESS). The ACCESS method is based upon mathematical equations derived from probability theory. The ACCESS spreadsheet can be used to calculate estimates of the undeveloped oil, gas, and NGL (natural gas liquids) resources in a continuous-type assessment unit. An assessment unit is a mappable volume of rock in a total petroleum system. In this report, the geologic assessment model is defined first, the analytic probabilistic method is described second, and the spreadsheet ACCESS is described third. In this revised version of Open-File Report 00-044 , the text has been updated to reflect modifications that were made to the ACCESS program. Two versions of the program are added as appendixes.

Crovelli, Robert A.; revised by Charpentier, Ronald R.

2012-01-01

319

Vacuum Evaporation of Pure Metals  

NASA Astrophysics Data System (ADS)

Theories on the evaporation of pure substances are reviewed and applied to study vacuum evaporation of pure metals. It is shown that there is good agreement between different theories for weak evaporation, whereas there are differences under intensive evaporation conditions. For weak evaporation, the evaporation coefficient in Hertz-Knudsen equation is 1.66. Vapor velocity as a function of the pressure is calculated applying several theories. If a condensing surface is less than one collision length from the evaporating surface, the Hertz-Knudsen equation applies. For a case where the condensing surface is not close to the evaporating surface, a pressure criterion for intensive evaporation is introduced, called the effective vacuum pressure, p eff. It is a fraction of the vapor pressure of the pure metal. The vacuum evaporation rate should not be affected by pressure changes below p eff, so that in lower pressures below p eff, the evaporation flux is constant and equal to a fraction of the maximum evaporation flux given by Hertz-Knudsen equation as 0.844 dot{n}_{Max } . Experimental data on the evaporation of liquid and solid metals are included.

Safarian, Jafar; Engh, Thorvald A.

2013-02-01

320

Apparatus for the liquefaction of natural gas and methods relating to same  

Microsoft Academic Search

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating

Bruce M. Wilding; Dennis N. Bingham; Michael G. McKellar; Terry D. Turner; Kevin T. Raterman; Gary L. Palmer; Kerry M. Klingler; John J. Vranicar

2007-01-01

321

Apparatus For The Liquefaaction Of Natural Gas And Methods Relating To Same  

Microsoft Academic Search

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating

Bruce M. Wilding; Dennis N. Bingham; Michael G. McKellar; Terry D. Turner; Kevin T. Rateman; Gary L. Palmer; Kerry M. Klinger; John J. Vranicar

2005-01-01

322

Apparatus For The Liquefaaction Of Natural Gas And Methods Relating To Same  

Microsoft Academic Search

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating

Bruce M. Wilding; Dennis N. Bingham; Michael G. McKellar; Terry D. Turner; Kevin T. Raterman; Gary L. Palmer; Kerry M. Klingler; John J. Vranicar

2003-01-01

323

Apparatus for the liquefaction of natural gas and methods relating to same  

Microsoft Academic Search

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work

Terry D. Turner; Bruce M. Wilding; Michael G. McKellar

2009-01-01

324

An optimum design method for high pressure natural gas trunk-lines  

Microsoft Academic Search

Natural gas is rapidly growing in global importance both as a primary energy source and a feedstock for downstream industry. Therefore, needs for natural gas transportation from production zones to consuming areas are ever increasing. Natural Gas transmission through pipelines is the oldest and most common method for high capacities gas transmission. These transmission systems are very capital intensive, therefore,

S. Hesam Najibi; N. Taghavi

2010-01-01

325

Method of treating natural gas to remove ethane and higher hydrocarbons  

Microsoft Academic Search

This patent describes a method of treating a high pressure stream of natural gas to remove ethane and higher boiling point hydrocarbons therefrom and to produce a low pressure stream of pipeline gas and a high pressure stream of plant residue gas. It comprises: splitting the high pressure stream of natural gas into a first process stream, a second process

D. L. Summers; D. A. Martin

1990-01-01

326

Method for directly recovering fluorine from gas streams  

DOEpatents

This invention is a process for the direct recovery of gaseous fluorine from waste-gas streams or the like. The process comprises passing the gas stream through a bed of anhydrous K.sub.3 NiF.sub.6 pellets to fluorinate the same to K.sub.3 NiF.sub.7 and subsequently desorbing the fluorine by heating the K.sub.3 NiF.sub.7 pellets to a temperature re-converting them to K.sub.3 NiF.sub.6. The efficiency of the fluorine-absorption step is maximized by operating in a selected and conveniently low temperature. The desorbed fluorine is highly pure and is at a pressure of several atmospheres. Preferably, the K.sub.3 NiF.sub.6 pellets are prepared by a method including the steps of forming agglomerates of hydrated K.sub.3 NiF.sub.5, sintering the agglomerates to form K.sub.3 NiF.sub.5 pellets of enhanced reactivity with respect to fluorine, and fluorinating the sintered pellets to K.sub.3 NiF.sub.6.

Orlett, Michael J. (Portsmouth, OH); Saraceno, Anthony J. (Waverly, OH)

1981-01-01

327

Localization of shallow gas deposits and uncontrolled gas flows in young and unconsolidated sediments by geophysical methods  

SciTech Connect

The great mass of Neogene sediments in the Hungarian basin, where several hydrocarbon accumulations are known, is affected by Pliocene strike-slip movements, resulting in many [open quotes]flower structures.[close quotes] The gas may migrate from the reservoirs upward to the surface along the faults. Thus, shallow gas deposits can be located in the young, unconsolidated sands. There are also several shallow gas deposits derived from uncontrolled gas flows. In Hungary, the shallow gas reservoirs, which are small but increasingly important, have not yet been explored properly. However, the depleting gas may pollute the water in the soil as well as cause explosions. Our purpose is to develop inexpensive, complete, and highly sophisticated field- and data-processing techniques and an integrated complex of geophysical methods in order to define the limits of shallow gas deposits. To avoid anomalous behavior on seismic sections of the depleting gas, we started from uncontrolled gas flows which require special velocity and amplitude vs. offset analyses. In addition, natural and controlled source electromagnetic/electric surveys with various parameters were applied. An industrial-scale seismic section over an uncontrolled gas flow, special sections over flower structures and geoelectric sections, and a magnetic map are presented. The integrated complex of geophysical methods outlined above is being developed in order to establish the conditions for the exploration of gas reservoirs which have been used close to their locality and which could be recovered inexpensively.

Csoergei, J.; Kummer, I.; Papa, A.; Sipos, J.; Solyom, I.; Takacs, E.; Timar, Z. (Eotvos Lorand Geophysical Institute of Hungary, Budapest (Hungary)); Keresztes, T. (MOL RT, Budapest (Hungary))

1993-09-01

328

[Determination of natural gas by gas chromatography with external standard-area normalization method].  

PubMed

A GC method for determination of natural gas by external standard-normalization has been established. O2, N2, CH4, CO2, and C2H4 were separated by 13X molecular sieves (1 m x 3 mm i.d., 50 degrees C) connected with PORAPAK T columns (2 m x 3 mm i.d.) in series and detected by TCD and the hydrocarbons of C3 and higher were separated by an SE-30 column (50 m x 0.32 mm i.d.) at 50 degrees C and detected by FID at first. Then O2 + N2 + CH4, CO2 and C2-C5 hydrocarbons were separated on a column (6 m x 3 mm i.d.) with mixed phases of beta, beta'-oxydipropionitrile and dibutyl phthalate at ambient temperature, and detected by TCD. Peak areas from SE-30 column and mixed phase column were correlated with C5, and area normalization was used for quantitative analysis; then normalization correction factors of each component in sample on 13X molecular sieves, PORAPAK T and SE-30 columns were calculated. In analysis, only the first step, area normalization was used for quantitative analysis. The method achieved calibration by SP-6000 Natural Gas Analyzer itself. It is economic, convenient, rapid and accurate. PMID:12683016

Zhao, Shu-yun

2002-11-01

329

Apparatus and method for gas turbine active combustion control system  

NASA Technical Reports Server (NTRS)

An Active Combustion Control System and method provides for monitoring combustor pressure and modulating fuel to a gas turbine combustor to prevent combustion dynamics and/or flame extinguishments. The system includes an actuator, wherein the actuator periodically injects pulsed fuel into the combustor. The apparatus also includes a sensor connected to the combustion chamber down stream from an inlet, where the sensor generates a signal detecting the pressure oscillations in the combustor. The apparatus controls the actuator in response to the sensor. The apparatus prompts the actuator to periodically inject pulsed fuel into the combustor at a predetermined sympathetic frequency and magnitude, thereby controlling the amplitude of the pressure oscillations in the combustor by modulating the natural oscillations.

Umeh, Chukwueloka (Inventor); Kammer, Leonardo C. (Inventor); Shah, Minesh (Inventor); Fortin, Jeffrey B. (Inventor); Knobloch, Aaron (Inventor); Myers, William J. (Inventor); Mancini, Alfred Albert (Inventor)

2011-01-01

330

Some methods of oil and gas reserve estimation in Azerbaijan  

SciTech Connect

This article deals with the scientific and practical problems related to estimating oil and gas reserves in terrigenous reservoirs of the Productive Series of middle Pliocene and in Upper Cretaceous volcanic and sedimentary rocks. The deposits in question are spread over onshore Azerbaijan and adjacent offshore areas in the Caspian Sea and are approximately 6.5 km deep. This article presents lithologic, stratigraphic, and petrophysical criteria used for selecting prospects for reserve estimation. Also presented are information on structure of rocks and estimation of their lithologic and physical properties. New methods for the interpretation and application of petrophysical and logging data, as well as statistical estimation of reserves, in complex volcaniclastic reservoir rocks, are also discussed.

Abasov, M.T.; Buryakovsky, L.A.; Kondrushkin, Y.M.; Dzhevanshir, R.D.; Bagarov, T.Y. [Azerbaijan Academy of Sciences, Baku (Azerbaijan); Chilingar, G.V. [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Civil and Environmental Engineering

1997-08-01

331

Thermal clearance control method for gas turbine engine  

SciTech Connect

This patent describes a method for controlling blade tip to shroud clearance at a steady state, part load operating conditions in a gas turbine engine having an output power level responsive to the position of an engine power level and further having an active clearance control system delivering a scheduled flow of cooling air to an engine case supporting the shroud radially with respect to the rotating blade tips. It comprises determining the occurrence of a change in position of the engine power lever; reducing the flow of cooling air to the engine case responsive to the determined occurrence of the lever position change; restoring the scheduled flow of cooling air to the engine case after a predetermined elapse of time.

Schwarz, F.M.; Crawley, C.J. Jr.

1991-12-31

332

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

333

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

334

Method for controlling exhaust gas heat recovery systems in vehicles  

DOEpatents

A method of operating a vehicle including an engine, a transmission, an exhaust gas heat recovery (EGHR) heat exchanger, and an oil-to-water heat exchanger providing selective heat-exchange communication between the engine and transmission. The method includes controlling a two-way valve, which is configured to be set to one of an engine position and a transmission position. The engine position allows heat-exchange communication between the EGHR heat exchanger and the engine, but does not allow heat-exchange communication between the EGHR heat exchanger and the oil-to-water heat exchanger. The transmission position allows heat-exchange communication between the EGHR heat exchanger, the oil-to-water heat exchanger, and the engine. The method also includes monitoring an ambient air temperature and comparing the monitored ambient air temperature to a predetermined cold ambient temperature. If the monitored ambient air temperature is greater than the predetermined cold ambient temperature, the two-way valve is set to the transmission position.

Spohn, Brian L.; Claypole, George M.; Starr, Richard D

2013-06-11

335

Flue gas desulfurization (FGD) chemistry and analytical methods handbook  

SciTech Connect

The purpose of this handbook is to provide a comprehensive guide to sampling, analytical, and physical test methods essential to the operation, maintenance, and understanding of flue gas desulfurization (FGD) system chemistry. EPRI sponsored the first edition of this three-volume report in response to the needs of electric utility personnel responsible for establishing and operating commercial FGD analytical laboratories. The second, revised editions of Volumes 1 and 2 were prompted by the results of research into various non-standard aspects of FGD system chemistry. Volume 1 of the handbook explains FGD system chemistry in the detail necessary to understand how the processes operate and how process performance indicators can be used to optimize system operation. Volume 2 includes 63 physical-testing and chemical-analysis methods for reagents, slurries, and solids, and information on the applicability of individual methods to specific FGD systems. Volume 3 contains instructions for FGD solution chemistry computer program designated by EPRI as FGDLIQEQ. Executable on IBM-compatible personal computers, this program calculates the concentrations (activities) of chemical species (ions) in scrubber liquor and can calculate driving forces for important chemical reactions such as S0{sub 2} absorption and calcium sulfite and sulfate precipitation. This program and selected chemical analyses will help an FGD system operator optimize system performance, prevent many potential process problems, and define solutions to existing problems. 22 refs., 17 figs., 28 tabs.

Noblett, J.G.; Burke, J.M.

1990-08-01

336

Method for removal of sulfur compounds from a gas  

SciTech Connect

This invention relates to a process for the removal of sulfur compounds from a gas stream which consists of contacting said gas stream with alkali metal salts of sulfonamides or resins containing sulfonamide functionalities.

Frech, K.J.; Tazuma, J.J.

1981-08-11

337

Method for removal of sulfur compounds from a gas  

Microsoft Academic Search

This invention relates to a process for the removal of sulfur compounds from a gas stream which consists of contacting said gas stream with alkali metal salts of sulfonamides or resins containing sulfonamide functionalities.

K. J. Frech; J. J. Tazuma

1981-01-01

338

Improved gas chromatography methods for micro-volume analysis of haloacetic acids in water and biological matrices.  

PubMed

A fast headspace solid-phase microextraction gas chromatography method for micro-volume (0.1 mL) samples was optimized for the analysis of haloacetic acids (HAAs) in aqueous and biological samples. It includes liquid-liquid microextraction (LLME), derivatization of the acids to their methyl esters using sulfuric acid and methanol after evaporation, followed by headspace solid-phase microextraction with gas chromatography and electron capture detection (SPME-GC-ECD). The derivatization procedure was optimized to achieve maximum sensitivity using the following conditions: esterification for 20 min at 80 degrees C in 10 microL methanol, 10 microL sulfuric acid and 0.1 g anhydrous sodium sulfate. Multi-point standard addition method was used to determine the effect of the sample matrix by comparing with internal standard method. It was shown that the effect of the matrix for urine and blood samples in this method is insignificant. The method detection limits are in the range of 1 microg L(-1) for most of the HAAs, except for monobromoacetic acid (MBAA) (3 microg L(-1)) and for monochloroacetic acid (MCAA) (16 microg L(-1)). The optimized procedure was applied to the analysis of HAAs in water, urine and blood samples. All nine HAAs can be separated in < 13 min for biological samples and < 7 min for drinking water samples, with total sample preparation and analysis time < 50 min. Analytical uncertainty can increase dramatically as the sample volume decreases; however, similar precision was observed with our method using 0.1 mL samples as with a standard method using 40 mL samples. PMID:12430602

Wu, Fengwu; Gabryelski, Wojciech; Froese, Kenneth

2002-10-01

339

Gas-liquid separator and method of operation  

DOEpatents

A system for gas-liquid separation in electrolysis processes is provided. The system includes a first compartment having a liquid carrier including a first gas therein and a second compartment having the liquid carrier including a second gas therein. The system also includes a gas-liquid separator fluidically coupled to the first and second compartments for separating the liquid carrier from the first and second gases.

Soloveichik, Grigorii Lev (Latham, NY) [Latham, NY; Whitt, David Brandon (Albany, NY) [Albany, NY

2009-07-14

340

Method for treatment of tar-bearing fuel gas  

Microsoft Academic Search

A process is described of producing a fuel gas which contains condensable tar vapor when it leaves a gasifier, the improvement wherein the tar-bearing gases are treated to remove tar therefrom. The process consists of: (a) continuously conducting hot fuel gas from a gasifier to and discharging it into a spray chamber where the hot tar-bearing gas is contacted with

L. L. Frauen; S. Kasper

1986-01-01

341

Method for filtering atomic or molecular contaminants from a gas  

Microsoft Academic Search

Tubular or rod-shaped pieces of a metal having a holding-back capability, with respect to the principal atomic or molecular contaminant in a gas, are arranged in the interior of a containing cylinder through which the gas flows, so as to provide passages for gas flow along the surface of the filter material pieces, the latter being typically disposed with their

Iniotakis

1983-01-01

342

Method for removing particulate matter from a gas stream  

DOEpatents

Particulate matter is removed from a stream of pressurized gas by directing the stream of gas upwardly through a bed of porous material, the porous bed being held in an open ended container and at least partially submerged in liquid. The passage of the gas through the porous bed sets up a circulation in the liquid which cleans the particulate matter from the bed.

Postma, Arlin K. (Benton City, WA)

1984-01-01

343

Dispersive optical parameters of evaporated nickel films  

Microsoft Academic Search

Dispersion of refractive index and extinction coefficient of nickel film and nickel crystal surface (100) has been determined with spectroscopic ellipsometry over spectral range ? ~ 250-1030 nm. Nickel film has been prepared by thermal evaporation method. Nickel crystal has been grown by horizontal Bridgman method. The crystal surface (100) at a first stage was mechanically polished and then treated

Victor V. Atuchin; Tatiana I. Grigorieva; Vladimir N. Kruchinin; Dmitry V. Lychagin; L. D. Pokrovsky

2010-01-01

344

An indirect evaporative chiller  

Microsoft Academic Search

A novel indirect evaporative chiller driven by outdoor dry air to produce cold water as the cooling source for air conditioning\\u000a systems is introduced, and the principle and the structure of the chiller is presented. The cold water can be produced almost\\u000a reversibly under ideal working conditions, with its temperature infinitely close to the dew point temperature of the inlet

Xiaoyun Xie; Yi Jiang

2010-01-01

345

Quality control of vacuum insulation panels: Methods of measuring gas pressure  

Microsoft Academic Search

Presented here are different methods of measuring gas pressure, suitable for vacuum insulation panels. They are essential for reliable quality control of these products. New methods for measuring gas pressure in vacuum panels enable fast and efficient quality control after production. The gas and water vapour transmission of high barrier films used as vacuum tight envelopes for the panels can

Roland Caps; Hermann Beyrichen; Daniel Kraus; Stephan Weismann

2008-01-01

346

An integrated quantitative risk analysis method for natural gas pipeline network  

Microsoft Academic Search

Natural gas industry is developing rapidly, and its accidents are threatening the urban safety. Risk management through quantitative assessment has become an important way to improve the safety performance of the natural gas supply system. In this paper, an integrated quantitative risk analysis method for natural gas pipeline network is proposed. This method is composed of the probability assessment of

Z. Y. Han; W. G. Weng

2010-01-01

347

Water Membrane Evaporator  

NASA Technical Reports Server (NTRS)

A water membrane evaporator (WME) has been conceived and tested as an alternative to the contamination-sensitive and corrosion-prone evaporators currently used for dissipating heat from space vehicles. The WME consists mainly of the following components: An outer stainless-steel screen that provides structural support for the components mentioned next; Inside and in contact with the stainless-steel screen, a hydrophobic membrane that is permeable to water vapor; Inside and in contact with the hydrophobic membrane, a hydrophilic membrane that transports the liquid feedwater to the inner surface of the hydrophobic membrane; Inside and in contact with the hydrophilic membrane, an annular array of tubes through which flows the spacecraft coolant carrying the heat to be dissipated; and An inner exclusion tube that limits the volume of feedwater in the WME. In operation, a pressurized feedwater reservoir is connected to the volume between the exclusion tube and the coolant tubes. Feedwater fills the volume, saturates the hydrophilic membrane, and is retained by the hydrophobic membrane. The outside of the WME is exposed to space vacuum. Heat from the spacecraft coolant is conducted through the tube walls and the water-saturated hydrophilic membrane to the liquid/vapor interface at the hydrophobic membrane, causing water to evaporate to space. Makeup water flows into the hydrophilic membrane through gaps between the coolant tubes.

Ungar, Eugene K.; Almlie, Jay C.

2010-01-01

348

Evaporation of extrasolar planets  

NASA Astrophysics Data System (ADS)

This article presents a review on the observations and theoretical modeling of the evaporation of extrasolar planets. The observations and the resulting constraints on the upper atmosphere (thermosphere and exosphere) of the ``hot-Jupiters'' are described. The early observations of the first discovered transiting extrasolar planet, HD209458b, allowed the discovery that this planet has an extended atmosphere of escaping hydrogen. Subsequent observations showed the presence of oxygen and carbon at very high altitude. These observations give unique constraints on the escape rate and mechanism in the atmosphere of hot-Jupiters. The most recent Lyman-alpha HST observations of HD189733b and MgII observations of Wasp-12b allow for the first time a comparison of the evaporation from different planets in different environments. Models to quantify the escape rate from the measured occultation depths, and an energy diagram to describe the evaporation state of hot-Jupiters are presented. Using this diagram, it is shown that few already known planets like GJ876d or CoRot-7b could be remnants of formerly giant planets.

Lecavelier Des Etangs, A.

2010-12-01

349

A Simpler Way to Tame Multiple-Effect Evaporators.  

ERIC Educational Resources Information Center

Presents a new method to teach the subject of evaporators which is both simple enough to use in the classroom and accurate and flexible enough to be used as a design tool in practice. Gives an example using a triple evaporator series. Analyzes the effect of this method. (CW)

Joye, Donald D.; Koko, F. William Jr.

1988-01-01

350

Method for removing undesired particles from gas streams  

DOEpatents

The present invention discloses a process for removing undesired particles from a gas stream including the steps of contacting a composition containing an adhesive with the gas stream; collecting the undesired particles and adhesive on a collection surface to form an aggregate comprising the adhesive and undesired particles on the collection surface; and removing the agglomerate from the collection zone. The composition may then be atomized and injected into the gas stream. The composition may include a liquid that vaporizes in the gas stream. After the liquid vaporizes, adhesive particles are entrained in the gas stream. The process may be applied to electrostatic precipitators and filtration systems to improve undesired particle collection efficiency.

Durham, Michael Dean (Castle Rock, CO) [Castle Rock, CO; Schlager, Richard John (Aurora, CO) [Aurora, CO; Ebner, Timothy George (Westminster, CO) [Westminster, CO; Stewart, Robin Michele (Arvada, CO) [Arvada, CO; Hyatt, David E. (Denver, CO) [Denver, CO; Bustard, Cynthia Jean (Littleton, CO) [Littleton, CO; Sjostrom, Sharon (Denver, CO) [Denver, CO

1998-01-01

351

Method and apparatus for producing gas-filled hollow spheres  

NASA Astrophysics Data System (ADS)

A system for forming hollow spheres containing pressured gas is described which includes a cylinder device containing a molten solid material with a nozzle at its end. A second gas nozzle, lying slightly upstream from the tip of the first nozzle, is connected to a source that applies pressured filler gas that is to fill the hollow spheres. High pressure is applied to the molten metal, as by moving a piston within the cylinder device, to force the molten material out of the first nozzle. At the same time, pressured gas fills the center of the extruded hollow liquid pipe that breaks into hollow spheres. The environment outside the nozzles contains gas at a high pressure such as 100 atmospheres. Gas is supplied to the gas nozzle at a slightly higher pressure such as 101 atmospheres. The pressure applied to the molten material is at a still higher pressure such as 110 atmospheres.

Wang, T. G.; Elleman, D. D.

1982-08-01

352

DWPF Recycle Evaporator Shielded Cells Testing  

SciTech Connect

Testing was performed to determine the feasibility and processing characteristics of evaporation of actual Defense Waste Processing Facility (DWPF) recycle material. Samples of the Off Gas Condensate Tank (OGCT) and Slurry Mix Evaporator Condensate Tank (SMECT) were transferred from DWPF to the Savannah River National Lab (SRNL) Shielded Cells and blended with De-Ionized (DI) water and a small amount of Slurry Mix Evaporator (SME) product. A total of 3000 mL of this feed was concentrated to approximately 90 mL during a semi-batch evaporation test of approximately 17 hours. One interruption occurred during the run when the feed tube developed a split and was replaced. Samples of the resulting condensate and concentrate were collected and analyzed. The resulting analysis of the condensate was compared to the Waste Acceptance Criteria (WAC) limits for the F/H Effluent Treatment Plant (ETP). Results from the test were compared to previous testing using simulants and OLI modeling. Conclusions from this work included the following: (1) The evaporation of DWPF recycle to achieve a 30X concentration factor was successfully demonstrated. The feed blend of OGCT and SMECT material was concentrated from 3000 mL to approximately 90 mL during testing, a concentration of approximately 33X. (2) Foaming was observed during the run. Dow Corning 2210 antifoam was added seven times throughout the run at 100 parts per million (ppm) per addition. The addition of this antifoam was very effective in reducing the foam level, but the impact diminished over time and additional antifoam was required every 2 to 3 hours during the run. (3) No scale or solids formed on the evaporator vessel, but splatter was observed in the headspace of the evaporator vessel. No scaling formed on the stainless steel thermocouple. (4) The majority of the analytes met the F/H ETP WAC. However, the detection limits for selected species (Sr-90, Pu-238, Pu-240, Am-243, and Cm-244) exceeded the ETP WAC limits. (5) I-129 was calculated to have exceeded the ETP WAC limits based on an assumed Decontamination Factor (DF) of 1 during evaporation. (6) The DF for most species was limited by the detection limits of the sample analysis. Based on iron, manganese, total alpha, total beta, and other species, very low entrainment was noted and evaporator DF was >10,000 for non-volatile species. (7) Very low DF's were obtained for selected species, especially mercury and formate. These species are present as volatile compounds and will exceed ETP WAC limits if sufficient concentrations are in the evaporator feed. (8) The evaporator DF's for the radioactive test were in good agreement with simulant test results. Differences noted in the DF of selected species, such as Hg, were more likely attributed to analytical issues than differences in the performance of the two evaporators. (9) The simulant appeared to be conservative in terms of foaming and scaling characteristics of the evaporator. The initial spike in foaming that occurred during all simulant runs did not occur during the Shielded Cells run and overall foaminess after the start of the test was controlled by antifoam additions. The splatter that was deposited during the radioactive test was less than the simulant runs and was more easily removed. (10) The OLI model results were overly conservative due to the manner that entrainment of solids was incorporated into the model.

Fellinger, T. L.; Herman, D. T.; Stone, M.E

2005-07-01

353

The effect of carrier gas flow rate and source cell temperature on low pressure organic vapor phase deposition simulation by direct simulation Monte Carlo method.  

PubMed

The process of low pressure organic vapor phase deposition (LP-OVPD) controls the growth of amorphous organic thin films, where the source gases (Alq3 molecule, etc.) are introduced into a hot wall reactor via an injection barrel using an inert carrier gas (N2 molecule). It is possible to control well the following substrate properties such as dopant concentration, deposition rate, and thickness uniformity of the thin film. In this paper, we present LP-OVPD simulation results using direct simulation Monte Carlo-Neutrals (Particle-PLUS neutral module) which is commercial software adopting direct simulation Monte Carlo method. By estimating properly the evaporation rate with experimental vaporization enthalpies, the calculated deposition rates on the substrate agree well with the experimental results that depend on carrier gas flow rate and source cell temperature. PMID:23674843

Wada, Takao; Ueda, Noriaki

2013-04-21

354

The effect of carrier gas flow rate and source cell temperature on low pressure organic vapor phase deposition simulation by direct simulation Monte Carlo method  

NASA Astrophysics Data System (ADS)

The process of low pressure organic vapor phase deposition (LP-OVPD) controls the growth of amorphous organic thin films, where the source gases (Alq3 molecule, etc.) are introduced into a hot wall reactor via an injection barrel using an inert carrier gas (N2 molecule). It is possible to control well the following substrate properties such as dopant concentration, deposition rate, and thickness uniformity of the thin film. In this paper, we present LP-OVPD simulation results using direct simulation Monte Carlo-Neutrals (Particle-PLUS neutral module) which is commercial software adopting direct simulation Monte Carlo method. By estimating properly the evaporation rate with experimental vaporization enthalpies, the calculated deposition rates on the substrate agree well with the experimental results that depend on carrier gas flow rate and source cell temperature.

Wada, Takao; Ueda, Noriaki

2013-04-01

355

The effect of carrier gas flow rate and source cell temperature on low pressure organic vapor phase deposition simulation by direct simulation Monte Carlo method  

PubMed Central

The process of low pressure organic vapor phase deposition (LP-OVPD) controls the growth of amorphous organic thin films, where the source gases (Alq3 molecule, etc.) are introduced into a hot wall reactor via an injection barrel using an inert carrier gas (N2 molecule). It is possible to control well the following substrate properties such as dopant concentration, deposition rate, and thickness uniformity of the thin film. In this paper, we present LP-OVPD simulation results using direct simulation Monte Carlo-Neutrals (Particle-PLUS neutral module) which is commercial software adopting direct simulation Monte Carlo method. By estimating properly the evaporation rate with experimental vaporization enthalpies, the calculated deposition rates on the substrate agree well with the experimental results that depend on carrier gas flow rate and source cell temperature.

Wada, Takao; Ueda, Noriaki

2013-01-01

356

Tried and True: Evaporating is cool  

NSDL National Science Digital Library

Many students hold misconceptions about evaporation. In this short exercise, students will apply the kinetic molecular theory to explain how cold water can evaporate and to observe the cooling effect of evaporation, and develop their own evaporation experiments.

Hand, Richard

2006-03-01

357

Method for high temperature mercury capture from gas streams  

DOEpatents

A process to facilitate mercury extraction from high temperature flue/fuel gas via the use of metal sorbents which capture mercury at ambient and high temperatures. The spent sorbents can be regenerated after exposure to mercury. The metal sorbents can be used as pure metals (or combinations of metals) or dispersed on an inert support to increase surface area per gram of metal sorbent. Iridium and ruthenium are effective for mercury removal from flue and smelter gases. Palladium and platinum are effective for mercury removal from fuel gas (syngas). An iridium-platinum alloy is suitable for metal capture in many industrial effluent gas streams including highly corrosive gas streams.

Granite, E.J.; Pennline, H.W.

2006-04-25

358

Methods For Delivering Liquified Gas To An Engine  

DOEpatents

A liquified gas delivery system for a motorized platform includes a holding tank configured to receive liquified gas. A first conduit extends from a vapor holding portion of the tank to a valve device. A second conduit extends from a liquid holding portion of the tank to the valve device. Fluid coupled to the valve device is a vaporizer which is in communication with an engine. The valve device selectively withdraws either liquified gas or liquified gas vapor from the tank depending on the pressure within the vapor holding portion of the tank. Various configurations of the delivery system can be utilized for pressurizing the tank during operation.

Bingham, Dennis N. (Idaho Falls, ID); Wilding, Bruce M. (Idaho Falls, ID); O'Brien, James E. (Idaho Falls, ID); Siahpush, Ali S. (Idaho Falls, ID); Brown, Kevin B. (Idaho Falls, ID)

2003-09-16

359

Methods For Delivering Liquified Gas To An Engine  

DOEpatents

A liquified gas delivery system for a motorized platform includes a holding tank configured to receive liquified gas. A first conduit extends from a vapor holding portion of the tank to a valve device. A second conduit extends from a liquid holding portion of the tank to the valve device. Fluid coupled to the valve device is a vaporizer which is in communication with an engine. The valve device selectively withdraws either liquified gas or liquified gas vapor from the tank depending on the pressure within the vapor holding portion of the tank. Various configurations of the delivery system can be utilized for pressurizing the tank during operation.

Bingham, Dennis N. (Idaho Falls, ID); Wilding, Bruce M. (Idaho Falls, ID); O'Brien, James E. (Idaho Falls, ID); Siahpush, Ali S. (Idaho Falls, ID); Brown, Kevin B. (Idaho Falls, ID)

2005-10-11

360

Systems and method for delivering liquified gas to an engine  

DOEpatents

A liquified gas delivery system for a motorized platform includes a holding tank configured to receive liquified gas. A first conduit extends from a vapor holding portion of the tank to a valve device. A second conduit extends from a liquid holding portion of the tank to the valve device. Fluid coupled to the valve device is a vaporizer which is in communication with an engine. The valve device selectively withdraws either liquified gas or liquified gas vapor from the tank depending on the pressure within the vapor holding portion of the tank. Various configurations of the delivery system can be utilized for pressurizing the tank during operation.

Bingham, Dennis N. (Idaho Falls, ID); Wilding, Bruce M. (Idaho Falls, ID); O'Brien, James E. (Idaho Falls, ID); Siahpush, Ali S. (Idaho Falls, ID); Brown, Kevin B. (Idaho Falls, ID)

2002-01-01

361

Nitrogen isotopes determination in natural gas: analytical method and first results on magmatic, hydrothermal and soil gas samples  

Microsoft Academic Search

A continuous-flow GC\\/IRMS technique has been developed to analyse ?N values for molecular nitrogen in gas samples. This method provides reliable results with accuracy better than 0.15 ‰ and reproducibility (1?) within±0.1 ‰ for volumes of N2 between 1.35 (about 56 nmol) and 48.9 ?L (about 2 ?mol).The method was tested on magmatic and hydrothermal gases as well as on natural gas samples collected from

Fausto Grassa; Giorgio Capasso; Ygor Oliveri; Aldo Sollami; Paula Carreira; M. Rosário Carvalho; José M. Marques; João C. Nunes

2010-01-01

362

Apparatus for the liquefaction of a gas and methods relating to same  

DOEpatents

Apparatuses and methods are provided for producing liquefied gas, such as liquefied natural gas. In one embodiment, a liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream may be sequentially pass through a compressor and an expander. The process stream may also pass through a compressor. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. A portion of the liquid gas may be used for additional cooling. Gas produced within the system may be recompressed for reintroduction into a receiving line.

Turner, Terry D. (Idaho Falls, ID) [Idaho Falls, ID; Wilding, Bruce M. (Idaho Falls, ID) [Idaho Falls, ID; McKellar, Michael G. (Idaho Falls, ID) [Idaho Falls, ID

2009-12-29

363

EVAPORATION OF ICY PLANETESIMALS DUE TO BOW SHOCKS  

SciTech Connect

We present the novel concept of evaporation of planetesimals as a result of bow shocks associated with planetesimals orbiting with supersonic velocities relative to the gas in a protoplanetary disk. We evaluate the evaporation rates of the planetesimals based on a simple model describing planetesimal heating and evaporation by the bow shock. We find that icy planetesimals with radius {approx}>100 km evaporate efficiently even outside the snow line in the stage of planetary oligarchic growth, where strong bow shocks are produced by gravitational perturbations from protoplanets. The obtained results suggest that the formation of gas giant planets is suppressed owing to insufficient accretion of icy planetesimals onto the protoplanet within the {approx}<5 AU disk region.

Tanaka, Kyoko K.; Yamamoto, Tetsuo; Tanaka, Hidekazu [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan)] [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan); Miura, Hitoshi [Department of Earth Sciences, Tohoku University, Sendai 980-8578 (Japan)] [Department of Earth Sciences, Tohoku University, Sendai 980-8578 (Japan); Nagasawa, Makiko; Nakamoto, Taishi [Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551 (Japan)] [Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551 (Japan)

2013-02-20

364

Detection methods for atoms and radicals in the gas phase  

NASA Astrophysics Data System (ADS)

This report lists atoms and free radicals in the gas phase which are of interest for environmental and flame chemistry and have been detected directly. The detection methods which have been used are discussed with respect to their range of application, specificity and sensitivity. In table 1, detection methods for the five atoms of group IV (C, Si, Ge, Sn, Pb) and about 60 radicals containing at least one atom of group IV are summarized (CH, Cd, Cf, CC1, CBr, Cn, Cs, CSe, CH2, CD2, Chf, Cdf, CHC1, CHBr, CF2, CC12, CBr2, CFC1, CFBr, CH3, CD3, CF3, CH2F, CH2C1, CH2Br, CHF2, CHC12, CHBr2, Hco, Fco, CH30, CD30, CH2OH, CH3S, Nco, CH4N, CH302, CF302; C2, C2N, C2H, C20, C2HO, C2H3, C2F3, C2H5, C2HsO, C2H4OH, CH3CO, CD3CO, C2H3O, C2H502, CH3COO2, C2H4N, C2H6N, C3; Si, SiF, SiF2, SiO, SiC, Si2; Ge, GeC, GeO, GeF, GeF2, GeCl2, Sn, SnF, SnO, SnF2, Pb, PbF, PbF2, PbO, PbS). In table 2 detection methods for about 25 other atoms and 60 radicals are listed: (H, D, O, O2, Oh, Od, HO2, DO2, F, Ci, Br, I, Fo, Cio, BrO, Io, FO2, C1O2, Li, Na, K, Rb, Cs, N, N3, Nh, Nd, Nf, Nci, NBr, NH2, ND2, Nhd, Nhf, NF2, NC12, N2H3, No, NO2, NO3, Hno, Dno, P, Ph, Pd, Pf, Pci, PH2, PD2, PF2, Po, As, AsO, AsS, Sb, Bi, S, S2, Sh, Sd, Sf, SF2, So, Hso, Dso, Sn, Se, Te, Se2, SeH, SeD, SeF, SeO, SeS, SeN, TeH, TeO, Bh, BH2, Bo, Bn, B02, Cd, Hg, UF5). The tables also cite some recent kinetic applications of the various methods.

Hack, W.

365

Leachate evaporation demonstration project at Brookhaven Municipal Landfill. Final report  

SciTech Connect

A demonstration leachate evaporation project using landfill gas as the primary energy source was successfully conducted at the Brookhaven Municipal Landfill. A submerged flame evaporator was used for the process. Leachate generated at the landfill could be concentrated to greater than 25% total solids. At the highest level of solids achieved, the evaporation equipment continued to meet design capacity. Effluent produced in the process passed the United States Environmental Protection Agency`s Toxicity Characteristics Leaching Procedure (TCLP). In addition, effluent was virtually odor-free. Based on these results, according to applicable permits for the project, the effluent material could be returned directly to the landfill.

NONE

1998-09-01

366

Method for removing undesired particles from gas streams  

DOEpatents

The present invention discloses a process for removing undesired particles from a gas stream including the steps of contacting a composition containing an adhesive with the gas stream; collecting the undesired particles and adhesive on a collection surface to form an aggregate comprising the adhesive and undesired particles on the collection surface; and removing the agglomerate from the collection zone. The composition may then be atomized and injected into the gas stream. The composition may include a liquid that vaporizes in the gas stream. After the liquid vaporizes, adhesive particles are entrained in the gas stream. The process may be applied to electrostatic precipitators and filtration systems to improve undesired particle collection efficiency. 11 figs.

Durham, M.D.; Schlager, R.J.; Ebner, T.G.; Stewart, R.M.; Hyatt, D.E.; Bustard, C.J.; Sjostrom, S.

1998-11-10

367

New mathematical method for the solution of gas-gas equilibria with special application to HTGR primary-coolant environments  

SciTech Connect

A new mathematical method and corresponding computer program have been developed that provide a general method for the numerical solution of an equilibrium problem involving the chemical interactions of gaseous species. The method and computer code were developed to calculate the equilibrium concentrations of impurity gases, such as CO, CO/sub 2/, H/sub 2/, H/sub 2/O, CH/sub 4/, and O/sub 2/, which may be approached as the result of gaseous chemical reactions occurring within the hot primary coolant helium of a high-temperature gas-cooled reactor (HTGR). The method, however, can be applied to any gas mixture.

Bongartz, K.

1983-07-01

368

Evaporation loss control effectiveness for storage tanks  

Microsoft Academic Search

The American Petroleum Institute (API) recently revised Publications 2517 and 2519 on methods for estimating evaporation loss from external floating roof tanks and internal floating roof tanks, respectively. These revisions are based on an extensive testing program performed over the past 5 years. This paper gives an overview of the results of these efforts, including loss sources, loss mechanisms, loss

Laverman

1985-01-01

369

Behavior Of Evaporating Liquid Drops In Clusters  

NASA Technical Reports Server (NTRS)

Report presents critical analysis of methods, developed for calculating behavior of evaporating liquid drops in dense and dilute clusters. Essential to understanding variety of physical and chemical phenomena occurring in combustion of sprayed fuels and in sprays used in agriculture, food industry, and painting. Presents insights on important aspects of two-phase flow.

Bellan, Josette

1990-01-01

370

Thermodynamic Modeling of Savannah River Evaporators  

Microsoft Academic Search

A thermodynamic model based on the code SOLGASMIX is developed to calculate phase equilibrium in evaporators and related tank wastes at the Savannah River Site (SRS). This model uses the Pitzer method to calculate activity coefficients, and many of the required Pitzer parameters have been determined in the course of this work. Principal chemical species in standard SRS simulant solutions

2001-01-01

371

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

372

Evolution of highly-selective gas sensing methods using correlation spectroscopy  

Microsoft Academic Search

This review describes the recent history and latest developments in gas detection at Southampton University, using real-time correlation spectroscopy. The general approach has been to use a gas sample as a matched optical filter, to selectively detect similar absorption spectra of the same gas in a measurement region. All variations of the method exhibit excellent selectivity whenever the gases have

J. P. Dakin

373

Determination of gas phase adsorption isotherms—a simple constant volume method  

Microsoft Academic Search

Single and ternary solute gas phase adsorption isotherms were conducted in this study to evaluate the effectiveness of a simple constant volume method, which was utilized by using Tedlar gas sampling bags as a constant volume batch reactor. For this purpose, gas phase adsorption of toluene, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) on two types of activated

Daekeun Kim; Zhangli Cai; George A. Sorial

2006-01-01

374

Improving Model-Based Gas Turbine Fault Diagnosis Using Multi-Operating Point Method  

Microsoft Academic Search

A comprehensive gas turbine fault diagnosis system has been designed using a full nonlinear simulator developed in Turbotec company for the V94.2 industrial gas turbine manufactured by Siemens AG. The methods used for detection and isolation of faulty components are gas path analysis (GPA) and extended Kalman filter (EKF). In this paper, the main health parameter degradations namely efficiency and

Amin Salar; SeyedMehrdad Hosseini; Ali Khaki Sedigh; Behnam Rezaei Zangmolk

2010-01-01

375

Method for the removal of elemental mercury from a gas stream  

DOEpatents

A method is provided to remove elemental mercury from a gas stream by reacting the gas stream with an oxidizing solution to convert the elemental mercury to soluble mercury compounds. Other constituents are also oxidized. The gas stream is then passed through a wet scrubber to remove the mercuric compounds and oxidized constituents.

Mendelsohn, Marshall H. (Downers Grove, IL); Huang, Hann-Sheng (Darien, IL)

1999-01-01

376

Measuring and modelling soil evaporation in wheat crops  

Microsoft Academic Search

Soil evaporation is often an important component of the total water loss from plant canopies, but is poorly estimated in many SVAT models. This paper reports the use of micrometeorological and lysimetric methods to measure soil evaporation (Es) in the canopy of a wheat crop over a period of 7 weeks as the crop matured and green leaf area index

O. T. Denmead; F. X. Dunin; R. Leuning; M. R. Raupach

1996-01-01

377

PRODUCTION ENGINEERING AND MARKETING ANALYSIS OF THE ROTATING DISK EVAPORATOR  

EPA Science Inventory

Recent EPA-funded research into the onsite, mechanical evaporation of wastewater from single family homes revealed that a rotating disk evaporator (RDE) could function in a nondischarging mode. Such a device has potential use where site limitations preclude conventional methods o...

378

Apparatus for the liquefaction of natural gas and methods relating to same  

DOEpatents

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work output. A compressor may be driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates a vapor from the liquid natural gas. A portion of the liquid gas is used for additional cooling. Gas produced within the system may be recompressed for reintroduction into a receiving line or recirculation within the system for further processing.

Turner, Terry D. (Ammon, ID) [Ammon, ID; Wilding, Bruce M. (Idaho Falls, ID) [Idaho Falls, ID; McKellar, Michael G. (Idaho Falls, ID) [Idaho Falls, ID

2009-09-22

379

Determination of gamma- and alpha-tocopherols in human milk by a direct high-performance liquid chromatographic method with UV-vis detection and comparison with evaporative light scattering detection.  

PubMed

A rapid direct method (Method I) for measuring gamma- and alpha-tocopherols in human milk was developed and validated using reversed-phase high-performance liquid chromatography with ultraviolet/visible (UV-vis) detection. Human milk, with an internal standard (alpha-tocopherol acetate) added, was diluted in hexane. The chromatographic system consisted of a short column (50 mm x 2.1mm I.D., 3 microm particle size) that allowed the separation of the gamma- and alpha-tocopherols in less than 6 min. The new direct method (Method I) was compared with other methods. Method II (saponification with ultraviolet/visible detection) determined 24% and 22% less gamma- and alpha-tocopherols, respectively. Method III (saponification with evaporative light scattering detection) gave the same values for alpha-tocopherol content as Method II. However, the amount of sample used in the application of Method III was higher than that used in Method II. Furthermore, Method I uses smaller amounts of solvents, and it is simpler and faster than Methods II or III. Only a small volume of sample is needed, which is an additional advantage for biological assays. PMID:16574129

Romeu-Nadal, M; Morera-Pons, S; Castellote, A I; López-Sabater, M C

2006-05-01

380

Chemical characterization of Brickellia cavanillesii (Asteraceae) using gas chromatographic methods  

PubMed Central

A methanol extract of lyophilized Brickellia cavanillesii was quantitatively analyzed using gas chromatographic (GC) techniques. The chromatographic methods employed were (i) GC-flame ionization detector (GC-FID), (ii) GC-mass spectrometry (GC-MS), and (iii) purge and trap GC-MS (P&T GC-MS). Thirteen compounds were identified with a quality match of 90% and above using GC-MS. The compounds were (1) Cyclohexene, 6-ethenyl-6-methyl-1-(1-methylethyl)-3-(1-methylethylidene)-, (S)-; (2) Bicylo (2.2.1) heptan-2-one, 1, 7, 7-trimethyl-(1S, 4S)-; (3) Phenol, 2-methoxy-4-(1-propenyl)-; (4) Benzene, 1-(1, 5-dimethyl-4-hexenyl)-4-methyl-; (5) Naphthalene, 1, 2, 3, 5, 6, 8a-hexahydro4, 7-dimethyl-1-1-(1-methylethyl)-, (1S-cis)-; (6) Phenol, 2-methoxy-; (7) Benzaldehyde, 3-hydroxy-4-methoxy-; (8) 11, 13-Eicosadienoic acid, methyl ester; (9) 2-Furancarboxaldehyde, 5-methyl-; (10) Maltol; (11) Phenol; (12) Hydroquinone; (13) 1H-Indene, 1-ethylideneoctahydro-7a-methyl-, (1E, 3a.alpha, 7a.beta.). Other compounds (14) 3-methyl butanal; (15) (D)-Limonene; (16) 1-methyl-4-(1-methyl ethyl) benzene; (17) Butanoic acid methyl ester; (18) 2-methyl propanal; (19) 2-butanone; (20) 2-pentanone; and (21) 2-methyl butane were also identified when P&T GC-MS was performed. Of the 21 compounds identified, 12 were validated using chemical standards. The identified compounds were found to be terpenes, derivatives of terpenes, esters, ketones, aldehydes, and phenol-derived aromatic compounds; these are the primary constituents of the essential oils of many plants and flowers.

Eshiet, Etetor R; Zhu, Jinqiu; Anderson, Todd A; Smith, Ernest E

2014-01-01

381

Chemical characterization of Brickellia cavanillesii (Asteraceae) using gas chromatographic methods.  

PubMed

A methanol extract of lyophilized Brickellia cavanillesii was quantitatively analyzed using gas chromatographic (GC) techniques. The chromatographic methods employed were (i) GC-flame ionization detector (GC-FID), (ii) GC-mass spectrometry (GC-MS), and (iii) purge and trap GC-MS (P&T GC-MS). Thirteen compounds were identified with a quality match of 90% and above using GC-MS. The compounds were (1) Cyclohexene, 6-ethenyl-6-methyl-1-(1-methylethyl)-3-(1-methylethylidene)-, (S)-; (2) Bicylo (2.2.1) heptan-2-one, 1, 7, 7-trimethyl-(1S, 4S)-; (3) Phenol, 2-methoxy-4-(1-propenyl)-; (4) Benzene, 1-(1, 5-dimethyl-4-hexenyl)-4-methyl-; (5) Naphthalene, 1, 2, 3, 5, 6, 8a-hexahydro4, 7-dimethyl-1-1-(1-methylethyl)-, (1S-cis)-; (6) Phenol, 2-methoxy-; (7) Benzaldehyde, 3-hydroxy-4-methoxy-; (8) 11, 13-Eicosadienoic acid, methyl ester; (9) 2-Furancarboxaldehyde, 5-methyl-; (10) Maltol; (11) Phenol; (12) Hydroquinone; (13) 1H-Indene, 1-ethylideneoctahydro-7a-methyl-, (1E, 3a.alpha, 7a.beta.). Other compounds (14) 3-methyl butanal; (15) (D)-Limonene; (16) 1-methyl-4-(1-methyl ethyl) benzene; (17) Butanoic acid methyl ester; (18) 2-methyl propanal; (19) 2-butanone; (20) 2-pentanone; and (21) 2-methyl butane were also identified when P&T GC-MS was performed. Of the 21 compounds identified, 12 were validated using chemical standards. The identified compounds were found to be terpenes, derivatives of terpenes, esters, ketones, aldehydes, and phenol-derived aromatic compounds; these are the primary constituents of the essential oils of many plants and flowers. PMID:24804069

Eshiet, Etetor R; Zhu, Jinqiu; Anderson, Todd A; Smith, Ernest E

2014-03-01

382

Comparative Assessment of Advanced Gas Hydrate Production Methods.  

National Technical Information Service (NTIS)

Displacing natural gas and petroleum with carbon dioxide is a proven technology for producing conventional geologic hydrocarbon reservoirs, and producing additional yields from abandoned or partially produced petroleum reservoirs. Extending this concept t...

B. P. McGrail M. D. White S. K. Wurstner

2009-01-01

383

Two-dimensional MHD simulations of accretion disk evaporation  

NASA Astrophysics Data System (ADS)

We simulate the accretion disk evaporation to study the nature of spectral transitions in the black hole binaries. We perform 2 dimensional magnetohydrodynamical simulations with heat conduction by electrons. We assume axisymmetric accretion disks. We put cold gas torus in hot hydrostatic halo. Weak magnetic fields are initially threaded vertically. Self-gravity and magnetic resistivity are neglected. We use the numerical codes set "CANS "(Coordinated Astronomical Numerical Software). Heat conduction equation and MHD equations are solved separately according to time splitting method. We adopt Lax-Wendroff method for the MHD part and BiCG stabilized method for heat conduction part. We set an absorbing inner boundary condition. We obtain the result that the hot gas emanates from the disk, since there is the heat flow from hot halo to cool accretion disk. Near central objects, the mass flow rate is large. In inner region the corona gas falls to black hole, otherwise in outer region that goes to far from black hole.

Nakamura, Kenji E.

2007-04-01

384

Method and apparatus for processing exhaust gas with corona discharge  

DOEpatents

The present invention is placing a catalyst coating upon surfaces surrounding a volume containing corona discharge. In addition, the electrodes are coated with a robust dielectric material. Further, the electrodes are arranged so that at least a surface portion of each electrode extends into a flow path of the exhaust gas to be treated and there is only exhaust gas in the volume between each pair of electrodes. 12 figs.

Barlow, S.E.; Orlando, T.M.; Tonkyn, R.G.

1999-06-22

385

Calculation notes that support accident scenario and consequence of the evaporator dump  

SciTech Connect

The purpose of this calculation note is to provide the basis for evaporator dump consequence for the Tank Farm Safety Analysis Report (FSAR). Evaporator Dump scenario is developed and details and description of the analysis methods are provided.

Crowe, R.D.

1996-09-27

386

Calculation notes that support accident scenario and consequence of the evaporator dump  

SciTech Connect

The purpose of this calculation note is to provide the basis for evaporator dump consequence for the Tank Farm Safety Analysis Report (FSAR). Evaporator Dump scenario is developed and details and description of the analysis methods are provided.

Crowe, R.D., Westinghouse Hanford

1996-09-09

387

Temperature dependence of the evaporation coefficient of water in air and nitrogen under atmospheric pressure: study in water droplets.  

PubMed

The evaporation coefficients of water in air and nitrogen were found as a function of temperature by studying the evaporation of a pure water droplet. The droplet was levitated in an electrodynamic trap placed in a climatic chamber maintaining atmospheric pressure. Droplet radius evolution and evaporation dynamics were studied with high precision by analyzing the angle-resolved light scattering Mie interference patterns. A model of quasi-stationary droplet evolution accounting for the kinetic effects near the droplet surface was applied. In particular, the effect of thermal effusion (a short-range analogue of thermal diffusion) was discussed and accounted for. The evaporation coefficient alpha in air and in nitrogen were found to be equal. The alpha was found to decrease from approximately 0.18 to approximately 0.13 for the temperature range from 273.1 to 293.1 K and follow the trend given by the Arrhenius formula. The agreement with condensation coefficient values obtained with an essentially different method by Li et al. [Li, Y.; Davidovits, P.; Shi, Q.; Jayne, J.; Kolb, C.; Worsnop, D. J. Phys. Chem. A. 2001, 105, 10627] was found to be excellent. The comparison of experimental conditions used in both methods revealed no dependence of the evaporation/condensation coefficient on the droplet charge nor the ambient gas pressure within the experimental parameters range. The average value of the thermal accommodation coefficient over the same temperature range was found to be 1 +/- 0.05. PMID:18491849

Zientara, M; Jakubczyk, D; Kolwas, K; Kolwas, M

2008-06-12

388

Indirect evaporative cooling of air to a sub-wet bulb temperature  

Microsoft Academic Search

Indirect evaporative cooling is a sustainable method for cooling of air. The main constraint that limits the wide use of evaporative coolers is the ultimate temperature of the process, which is the wet bulb temperature of ambient air. In this paper, a method is presented to produce air at a sub-wet bulb temperature by indirect evaporative cooling, without using a

Ala Hasan

2010-01-01

389

A transient method for measuring the gas volume fraction in a mixed gas-liquid flow using acoustic resonance spectroscopy  

Microsoft Academic Search

In this paper, the feasibility of measuring the gas volume fraction in a mixed gas-liquid flow by using an acoustic resonant\\u000a spectroscopy (ARS) method in a transient way is studied theoretically and experimentally. Firstly, the effects of sizes and\\u000a locations of a single air bubble in a cylindrical cavity with two open ends on resonant frequencies are investigated numerically.\\u000a Then,

Dehua Chen; Xiuming Wang; Chengxuan Che; Jiansheng Cong; Delong Xu; Xiaomin Wang

2010-01-01

390

A simple method for determining brine-gas interfacial tensions  

NASA Astrophysics Data System (ADS)

It is well known that most inorganic electrolytes dissolved in water have the effect to raise the interfacial tension (IFT), whereas all compressed gases but helium have the opposite effect, which corresponds respectively to negative adsorption (depletion) of the salt and to gas adsorption on the two opposite sides of the interface. By using Gibbs' adsorption equation and reasonable assumptions, we show that those two effects are independent: the presence of inorganic electrolytes in the aqueous phase has a negligible impact on the gas-related IFT decrement, and the compressed gas does not in turn alter the IFT increment due to the salt dissolved in the aqueous phase. As a consequence the IFT at a given pressure and temperature can be approximated by the brine surface tension at the same temperature, minus the gas-related IFT decrement of pure water surface tension at those pressure and temperature. The two latter quantities are easier to determine experimentally, and have been the subject of numerous experimental and theoretical investigations. The proposed approximation is consistent with the available experimental data, including when the 'gas' is a supercritical fluid or a compressible condensate (liquid) made up of compounds sparingly soluble in water, such as CO2 at respectively supercritical or subcritical temperatures.

Duchateau, C.; Broseta, D.

2012-06-01

391

17Oexcess in evaporated desert waters and vapor from evaporation experiments  

NASA Astrophysics Data System (ADS)

Oxygen and hydrogen isotopes are classical proxies for the investigation of climatic effects in hydrological processes. The combination of the isotopic ratios 17O/16O and 18O/16O in water allowed the determination of mass dependent processes and enabled differentiation between equilibrium and kinetic fractionation (Barkan and Luz, 2007). In analogy to d-excess, deviation in ?17O from the global average trend of meteoric water is defined as: 17Oexcess = ?'17O - 0.528 × ?'18O 17Oexcess depends on the impact of diffusive evaporation into air and thus reflects relative humidity conditions. The isotope ratios of water ?17O and ?18O were determined by isotope ratio gas mass spectrometry in dual inlet mode on a ThermoFinnigan MAT 253. The oxygen was extracted by water fluorination with CoF3. Our average measurement precision for ?17O is ×0.03 ‰, for ?18O ×0.05 ‰ and for 17Oexcess approximately ×7 per meg (1?). We compared 17Oexcess in natural waters from the highly arid deserts of Sistan (East Iran) and Atacama (Chile) with data obtained from evaporation experiments. In these experiments, water was evaporated into a stream of dry nitrogen and vapor collected cryogenically. The data show a systematic depletion of 17Oexcess in water with increasing degree of evaporation in the residual water body. Most negative 17Oexcess were determined for samples from ponds (Sistan) and salars (Atacama). These strongly evaporated samples indicate an evaporation development, following a fractionation trend (?) of approximately 0.523. The evaporation experiment shows a ? of 0.525 and is in agreement with water data from an experiment by Barkan and Luz (2007). The difference between natural and experimental evaporation suggests either different evaporation kinetics in the natural environment, variable proportion of kinetic and equilibrium fractionation, or additional diffusive processes during ground water seepage. References: Barkan, E. and Luz, L. (2007). Diffusivity fractionations of H216O/H217O and H216O/H218O in air and their implications for isotope hydrology. Rapid Commun. Mass Spectrom., Vol. 21, pp. 2999-3005.

Surma, J.; Assonov, S.; Staubwasser, M.

2013-12-01

392

Method of heat recovery from thermally decomposed high temperature hydrocarbon gas  

Microsoft Academic Search

The invention discloses a method for recovering sensible heat from a thermally decomposed high temperature hydrocarbon gas product in the form of high pressure steam of from 40 to 100 kg\\/cm². The method comprises pre-cooling at first the thermally decomposed gas product of high temperature by mixing the gas product with sprayed low temperature hydrocarbon oil as a quenching oil

K. Ozaki; A. Fukuhara; T. Hosoi; Y. Sagi

1979-01-01

393

Contribution to the Knowledge of the Evaporation Regimen in the Republic of Argentina . Contribucion al Conocimiento Del Regimen de Evaporacion en la Republica Argentina.  

National Technical Information Service (NTIS)

The evaporation pattern for Argentina was studied, together with the relationship existing between evaporation, and lakes and ponds. Indirect calculation methods are considered. An analysis is included for the formulas used to calculate evaporation, as we...

R. M. Quintela

1970-01-01

394

Dynamics of Water Absorption and Evaporation During Methanol Droplet Combustion in Microgravity  

NASA Technical Reports Server (NTRS)

The combustion of methanol droplets is profoundly influenced by the absorption and evaporation of water, generated in the gas phase as a part of the combustion products. Initially there is a water-absorption period of combustion during which the latent heat of condensation of water vapor, released into the droplet, enhances its burning rate, whereas later there is a water-evaporation period, during which the water vapor reduces the flame temperature suffciently to extinguish the flame. Recent methanol droplet-combustion experiments in ambient environments diluted with carbon dioxide, conducted in the Combustion Integrated Rack on the International Space Station (ISS), as a part of the FLEX project, provided a method to delineate the water-absorption period from the water-evaporation period using video images of flame intensity. These were obtained using an ultra-violet camera that captures the OH* radical emission at 310 nm wavelength and a color camera that captures visible flame emission. These results are compared with results of ground-based tests in the Zero Gravity Facility at the NASA Glenn Research Center which employed smaller droplets in argon-diluted environments. A simplified theoretical model developed earlier correlates the transition time at which water absorption ends and evaporation starts. The model results are shown to agree reasonably well with experiment.

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

2012-01-01

395

Down-hole concentric chamber gas separator and method  

SciTech Connect

A down-hole separator is described, comprising: a first tube; a second tube, having a smaller diameter than the first tube and being disposed within the first tube, the second tube having an inlet end and an outlet end, the outlet end being turned at an angle relative to a longitudinal axis of the second tube and passing through a side wall of the first tube, and the inlet end passing sealingly through the second end of the first tube whereby the second end of the first tube is closed, the first tube having perforations at a point below the outlet end of the second tube wherein the first tube further includes an upper joint member having an aperture in which the outlet end of the second tube is mounted, a central tubular section attached to the upper joint member, and a lower joint member, attached to the central tubular section, the lower joint member having a reduced inside diameter whereby sealing connection with the inlet end of the second tube is provided, the perforations of the first tube being located in the lower joint member. A method is also described for separating a down-hole flow of oil and gas, comprising the steps of: disposing a down-hole separator at a bottom end of a tubing string at a desired distance from a pump contained in the tubing string, the separator comprising a first tube, having a first end and a second end, a second tube, having a smaller diameter than the first tube and being disposed within the first tube, the second tube having an inlet end and an outlet end, the outlet end being turned at an angle relative to a longitudinal axis of the second tube and passing through a side wall of the first tube, and the inlet end passing sealingly through the second end of the first tube, the first tube having perforations at a point below the outlet end of the second tube; selecting the desired distance to provide a desired pressure differential at the perforations of the first tube; and passing the flow through the down-hole separator.

Bustamante, A.; Gonzalez, J.R.

1993-08-31

396

Method for combined removal of mercury and nitrogen oxides from off-gas streams  

DOEpatents

A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

Mendelsohn, Marshall H. (Downers Grove, IL); Livengood, C. David (Lockport, IL)

2006-10-10

397

Improved gas chromatographic electron-capture analysis using a pulse frequency method  

Microsoft Academic Search

A method was developed to extend the dynamic output range of the Varian 3700 Gas Chromatograph (GC) and to improve its ability to analyze samples that simultaneously exhibit high and low quantities of gas tracers. A series of tests were run, using three different tracers, to compare the results obtained by this pulse frequency method to those using the normal

N. Latner; R. J. Lagomarsino

1991-01-01

398

Defrosting method adopting dual hot gas bypass for an air-to-air heat pump  

Microsoft Academic Search

A novel dual hot gas bypass defrosting (DHBD) method is developed to remove frost from the outside heat exchanger (HEX) of an air-to-air heat pump. The proposed method adopts two bypass lines of hot gas from the compressor: one is connected to the inlet of the outdoor HEX, and the other is connected to the outlet of the exchanger. We

Hwan-Jong Choi; Byung-Soon Kim; Donghoon Kang; Kyung Chun Kim

2011-01-01

399

A method for the analysis of gas trapped in EBW (exploding bridgewire) detonators  

Microsoft Academic Search

A method for sampling and determination of permanent gases, oxids of carbon and nitrogen, and light hdyrocarbon species in sealed explosive devices is described. The method uses a gas chromatograph equipped with a thermal conductivity detector and mass spectrometer to obtain qualitative and quantitative data. The apparatus used to sample the gas consists of a stainless steel bellows valve modified

Andrzejewski

1988-01-01

400

A transient method for measuring the gas volume fraction in a mixed gas-liquid flow using acoustic resonance spectroscopy  

NASA Astrophysics Data System (ADS)

In this paper, the feasibility of measuring the gas volume fraction in a mixed gas-liquid flow by using an acoustic resonant spectroscopy (ARS) method in a transient way is studied theoretically and experimentally. Firstly, the effects of sizes and locations of a single air bubble in a cylindrical cavity with two open ends on resonant frequencies are investigated numerically. Then, a transient measurement system for ARS is established, and the trends of the resonant frequencies (RFs) and resonant amplitudes (RAs) in the cylindrical cavity with gas flux inside are investigated experimentally. The measurement results by the proposed transient method are compared with those by steady-state ones and numerical ones. The numerical results show that the RFs of the cavity are highly sensitive to the volume of the single air bubble. A tiny bubble volume perturbation may cause a prominent RF shift even though the volume of the air bubble is smaller than 0.1% of that of the cavity. When the small air bubble moves, the RF shift will change and reach its maximum value as it is located at the middle of the cavity. As the gas volume fraction of the two-phase flow is low, both the RFs and RAs from the measurement results decrease dramatically with the increasing gas volume, and this decreasing trend gradually becomes even as the gas volume fraction increases further. These experimental results agree with the theoretical ones qualitatively. In addition, the transient method for ARS is more suitable for measuring the gas volume fraction with randomness and instantaneity than the steady-state one, because the latter could not reflect the random and instant characteristics of the mixed fluid due to the time consumption for frequency sweeping. This study will play a very important role in the quantitative measurement of the gas volume fraction of multiphase flows.

Chen, Dehua; Wang, Xiuming; Che, Chengxuan; Cong, Jiansheng; Xu, Delong; Wang, Xiaomin

2010-08-01

401

Experimental Investigations of the Internal Energy of Molecules Evaporated via Laser-induced Acoustic Desorption into a Fourier-transform Ion Cyclotron Resonance Mass Spectrometer (LIAD/FT-ICR)  

PubMed Central

The internal energy of neutral gas-phase organic and biomolecules, evaporated by means of laser-induced acoustic desorption (LIAD) into a Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR), was investigated through several experimental approaches. The desorbed molecules were demonstrated not to undergo degradation during the desorption process by collecting LIAD-evaporated molecules and subjecting them to analysis by electrospray ionization/quadrupole ion trap mass spectrometry. Previously established gas-phase basicity (GB) values were remeasured for LIAD-evaporated organic molecules and biomolecules with the use of the bracketing method. No endothermic reactions were observed. The remeasured basicity values are in close agreement with the values reported in the literature. The amount of internal energy deposited during LIAD is concluded to be less than a few kcal/mol. Chemical ionization with a series of proton transfer reagents was employed to obtain a breakdown curve for a protonated dipeptide, val-pro, evaporated by LIAD. Comparison of this breakdown curve with a previously published analogous curve obtained by using substrate-assisted laser desorption (SALD) to evaporate the peptide suggests that the molecules evaporated via LIAD have less internal energy than those evaporated via SALD.

Shea, Ryan C.; Petzold, Christopher J.; Liu, Ji-ang; Kenttamaa, Hilkka I.

2008-01-01

402

Evaporative Cooling of Sodium Atoms  

Microsoft Academic Search

Results of experiments on evaporative cooling of sodium atoms are presented. Atoms are loaded into a spherical quadrupole magnetic trap and are cooled by a novel technique, rf induced evaporation. The elastic collision cross section for cold sodium atoms is measured to be 6 10^{-12} cm^2 . These initial experiments result in an increase of phase space density of 190.

Kendall Bruce Davis

1995-01-01

403

Flash evaporation of liquid monomer particle mixture  

DOEpatents

The present invention is a method of making a first solid composite polymer layer. The method has the steps of (a) mixing a liquid monomer with particles substantially insoluble in the liquid monomer forming a monomer particle mixture; (b) flash evaporating the particle mixture and forming a composite vapor; and (c) continuously cryocondensing said composite vapor on a cool substrate and cross-linking the cryocondensed film thereby forming the polymer layer.

Affinito, John D. (Kennewick, WA); Darab, John G. (Richland, WA); Gross, Mark E. (Pasco, WA)

1999-01-01

404

A method for observing gas evolution during plastic laminate cure  

NASA Technical Reports Server (NTRS)

Polyimide, phenolic, and other resins which develop volatiles during laminating or molding cure are studied using optimum cure cycles. The specimen is placed on a platen and sealed in a plastic bag, then heated and observed for gas evolution using a binocular microscope. A cover plate is added to sumulate an autoclave.

Nicholls, A. H.

1969-01-01

405

Investigation of Possible Methods for Testing Gas Filters.  

National Technical Information Service (NTIS)

An investigation and literature search was made of activated charcoal, mercaptans and the use of odors in testing gas penetration of carbon filters. Tests were performed on the detection of mercaptans, especially N-amyl mercaptan. This work was done in co...

J. R. Gilder

1964-01-01

406

Modelling gas hydrate thermodynamic behaviour: theoretical basis and computational methods  

Microsoft Academic Search

The thermodynamic theory of van der Waals and Platteeuw has served up to now and for many decades as the principal basis for the development of tools for predicting the equilibrium conditions of various gas hydrate systems. Several of these developments are briefly presented in the present paper, with the aim of revealing associated difficulties and possible inherent limitations. After

Dimitrios Avlonitis; Nikos Varotsis

1996-01-01

407

High Sensitive Formaldehyde Gas Sensor Prepared by R.F. Induction Plasma Deposition Method  

NASA Astrophysics Data System (ADS)

The present work is concerned on developing high sensitive and high performance SnO2-based gas sensors for detecting indoor air pollutant formaldehyde gas. The film was deposited on an alumina substrate using R.F. Induction Plasma Deposition technique. Physical properties of sensing films were examined by SEM, XRD method. The sensors showed high sensitivity to typical HCHO gas at an extremely low gas concentration of 20 parts-per-billion (ppb) with quick response and recovery time at several minutes. The effect of the doping of various metallic additives on the gas-sensing properties and operating temperature dependency were also investigated in the work.

Shi, Liqin; Gao, Wei; Hasegawa, Yuki; Katsube, Teruaki; Nakano, Mamoru; Nakamura, Kiyozumi

408

Method and apparatus for measuring the gas permeability of a solid sample  

DOEpatents

The disclosure is directed to an apparatus and method for measuring the permeability of a gas in a sample. The gas is allowed to reach a steady flow rate through the sample. A measurable amount of the gas is collected during a given time period and then delivered to a sensitive quadrupole. The quadrupole signal, adjusted for background, is proportional to the amount of gas collected during the time period. The quadrupole can be calibrated with a standard helium leak. The gas can be deuterium and the sample can be polyvinyl alcohol.

Carstens, D.H.W.

1984-01-27

409

Experimental Investigation of Microstructured Evaporators  

NASA Astrophysics Data System (ADS)

Microfluidic devices have become more and more popular over the last decades [1]. Cooling is a topic where microstructures offer significant advantages compared to conventional techniques due the much higher possible surface to volume ratios and short heat transfer lengths. By evaporating of a fluid in microchannels, compact, fast and powerful cooling devices become possible [2]. Experimental results for different designs of microstructured evaporators are presented here. They have been obtained either using water as evaporating coolant or the refrigerant R134a (Tetrafluoroethane). A new microstructured evaporator design consisting of bended microchannels instead of straight channels for a better performance is shown and compared to previous results [2] for the evaporation of R134a in straight microchannels.

Wibel, W.; Westermann, S.; Maikowske, S.; Brandner, J. J.

2012-11-01

410

Mathematical simulation for non-equilibrium droplet evaporation  

NASA Astrophysics Data System (ADS)

Investigations of acute problems of phase transitions in continua mechanics need adequate modeling of evaporation, which is extremely important for the curved surfaces in the presence of strong heat and mass diffusion fluxes. Working cycle of heat pipes is governed by the active fluid evaporation rate. Combustion of most widely spread hydrocarbon fuels takes place in a gas-phase regime. Thus, evaporation of fuel from the surface of droplets turns to be one of the limiting factors of the process as well. In the present paper processes of non-equilibrium evaporation of small droplets in a quiescent air and in streaming gas flows were investigated theoretically. The rate of droplet evaporation is characterized by a dimensionless Peclet number ( Pe). A new dimensionless parameter I characterizing the deviation of phase transition from the equilibrium was introduced, which made it possible to investigate its influence on variations of the Peclet number and to determine the range of applicability for the quasi-equilibrium model. As it follows from the present investigations accounting for non-equilibrium effects in evaporation for many types of widely used liquids is crucial for droplets diameters less than 100?m, while the surface tension effects essentially manifest only for droplets below 0.1?m. The effects of velocity non-equilibrium and droplet atomization were taken into account.

Dushin, V. R.; Kulchitskiy, A. V.; Nerchenko, V. A.; Nikitin, V. F.; Osadchaya, E. S.; Phylippov, Yu. G.; Smirnov, N. N.

2008-12-01

411

Comparative Evaluation of Two Methods to Estimate Natural Gas Production in Texas  

EIA Publications

This report describes an evaluation conducted by the Energy Information Administration (EIA) in August 2003 of two methods that estimate natural gas production in Texas. The first method (parametric method) was used by EIA from February through August 2003 and the second method (multinomial method) replaced it starting in September 2003, based on the results of this evaluation.

Information Center

2003-12-23

412

Evaporation and condensation on a plane condensed phase - Numerical analysis of the linearized Boltzmann equation for hard-sphere molecules  

Microsoft Academic Search

The behavior of a semi-infinite expanse of a gas bounded by its plane condensed phase, where evaporation or condensation is taking place, is considered on the basis of the linearized Boltzmann equation for hard-sphere molecules. The half-space boundary-value problem of the linearized Boltzmann equation for hard-sphere molecules is solved numerically by the finite difference method introduced in the temperature jump

Yoshio Sone; Taku Ohwada; Kazuo Aoki

1989-01-01

413

Evaporative Depolarization and Deformation of 3D Imbalanced Fermi Gases  

NASA Astrophysics Data System (ADS)

We previously observed phase separation of a spin-imbalanced 3D Fermi gas, with a spatially deformed paired core surrounded by a shell of polarized atoms.ootnotetextG. B. Partridge et al., Science 311, 503 (2006); G. B. Partridge et al., PRL 97, 190407 (2006). By studying the dynamics of evaporation, we find that trap depth anisotropy and fast evaporation produces the deformation. The deformed state is remarkably metastable, with a superfluid-normal transition which is extended to a much higher polarization than observed in the MIT and ENS experiments.ootnotetextM. Zwierlein et al., Science 311, 492 (2006); S. Nascimbene et al., PRL 103, 170402 (2009). Our findings confirm the evaporative depolarization mechanism suggested previously,ootnotetextM. M. Parish et al., PRA 80, 063605 (2009) in which preferential evaporation from the center of an elongated trap reduces the chemical potential difference in the central core relative to the surrounding polarized phases.

Liao, Y. A.; Rittner, A. S.; Revelle, M.; Hulet, R. G.

2011-06-01

414

Synthesis and electrochemical properties of Sb2Se3 nanowires prepared by a gas induced reduction method.  

PubMed

Sb2Se3 nanowires have been prepared by a novel gas induced reduction (GIR) method. The precursor solution prepared by dissolving Sb2(OCH2CH2O)3 and SeO2 in a certain solvent was initially separated from the reductant, hydrazine hydrate. The reductant evaporated during the heating process, dissolved into the precursor solution and reacted with Sb3+ and SeO2 and finally Sb2Se3 nanostructures formed. Different solvents including diethanolamine, glycerol, ethylene glycol, deionized water, absolute ethanol and isopropyl alcohol were respectively used for comparison. It was found that when ethylene glycol was used as a solvent, pure, relatively homogeneous, and high aspect-ratio Sb2Se3 nanowires (40-120 nm in diameter and -100 microm in length) were prepared. Growth mechanism of the Sb2Se3 nanowires was proposed. The electrochemistry character of the nanowires was investigated via assembling into lithium ion batteries. The discharge capacity of Sb2Se3/Li cell cycled between 0.3 and 2.5 V was performed in the range of 142-1036 mA x h x g(-1) during the first 30 cycles, with the charge/discharge efficiency increasing from 89.4% to 97.5%. PMID:23646581

Wang, Xin; Cai, Kefeng; Chen, Song

2013-02-01

415

Gas sensing response of nanostructured CoSb2O6 prepared by non-aqueous solution methods  

NASA Astrophysics Data System (ADS)

Nanostructured CoSb2O6, with trirutile type structure, was prepared by a non-aqueous solution-polymerization method, using antimony chloride, cobalt nitrate, polyvinyl pyrrolidone and ethyl alcohol. The evaporation, by microwave radiation, of the precipitate obtained in the initial stage of the synthesis, produced an amorphous solid precursor. Further calcination at 700^oC yielded the target composition. X-ray powder diffraction was used to identify the crystal structure, which corresponds to tetragonal with cell parameters a = 4.6544 å and c = 9.2823 å, and space group P42/nmn. SEM and TEM were used to analyze particle size and shape; by TEM, nanostructured particles with shape of filaments with 20 nm diameter and length up to 600 nm were observed. Their local crystallinity was confirmed by selected area electron diffraction. To test CoSb2O6 as a gas sensor material, the powder was deposited on alumina substrates using the screen-printing technique. DC electrical characterization was performed in air, O2 and CO2 from room temperature to 600^oC. The dynamic response of resistance characterization displayed a variation of about 1k? when detecting CO2; whereas for O2 a change in the order of 10^2 ? was measured.

Michel, Carlos; Moran, Juan; Guillen, Hector; Martinez, Alma

2008-10-01

416

An efficient numerical method for intergranular fission gas evolution under transient with piecewise boundary resolution  

NASA Astrophysics Data System (ADS)

It is theoretically found that the boundary gas concentration could decline under transient due to the intergranular resolution. An efficient numerical method is first developed for the case before saturation. After the saturation of the grain boundary, a rate-release equation is applied not only to ensure no return of the gas released, but also ensure the gas conservation in the grain boundary. Accordingly, an efficient predict-correct algorithm for the intergranular gas concentration is invented for arbitrary power transient. Our numerical method has been validated by the analytical solution and the finite element solution. It demonstrates both high efficiency as well as high accuracy.

Cui, Yi; Ding, Shurong; Huo, Yongzhong; Wang, Canglong; Yang, Lei

2013-11-01

417

Comparison of different evaporation estimates over the African continent  

NASA Astrophysics Data System (ADS)

Evaporation is a key process in the water cycle with implications ranging, inter alia, from water management to weather forecast and climate change assessments. The estimation of continental evaporation fluxes is complex and typically relies on continental-scale hydrological models or land-surface models. However, it appears that most global or continental-scale hydrological models underestimate evaporative fluxes in some regions of Africa, and as a result overestimate stream flow. Other studies suggest that land-surface models may overestimate evaporative fluxes. In this study, we computed actual evaporation for the African continent using a continental version of the global hydrological model PCR-GLOBWB, which is based on a water balance approach. Results are compared with other independently computed evaporation products: the evaporation results from the ECMWF reanalysis ERA-Interim and ERA-Land (both based on the energy balance approach), the MOD16 evaporation product, and the GLEAM product. Three other alternative versions of the PCR-GLOBWB hydrological model were also considered. This resulted in eight products of actual evaporation, which were compared in distinct regions of the African continent spanning different climatic regimes. Annual totals, spatial patterns and seasonality were studied and compared through visual inspection and statistical methods. The comparison shows that the representation of irrigation areas has an insignificant contribution to the actual evaporation at a continental scale with a 0.5° spatial resolution when averaged over the defined regions. The choice of meteorological forcing data has a larger effect on the evaporation results, especially in the case of the precipitation input as different precipitation input resulted in significantly different evaporation in some of the studied regions. ERA-Interim evaporation is generally the highest of the selected products followed by ERA-Land evaporation. In some regions, the satellite-based products (GLEAM and MOD16) show a different seasonal behaviour compared to the other products. The results from this study contribute to a better understanding of the suitability and the differences between products in each climatic region. Through an improved understanding of the causes of differences between these products and their uncertainty, this study provides information to improve the quality of evaporation products for the African continent and, consequently, leads to improved water resources assessments at regional scale.

Trambauer, P.; Dutra, E.; Maskey, S.; Werner, M.; Pappenberger, F.; van Beek, L. P. H.; Uhlenbrook, S.

2014-01-01

418

Highly transparent and conductive ZnO:Al thin films prepared by vacuum arc plasma evaporation  

NASA Astrophysics Data System (ADS)

A vacuum arc plasma evaporation (VAPE) method using both oxide fragments and gas sources as the source materials is demonstrated to be very effective for the preparation of multicomponent oxide thin films. Highly transparent and conductive Al-doped ZnO (AZO) thin films were prepared by the VAPE method using a ZnO fragment target and a gas source Al dopant, aluminum acethylacetonate (Al(C5H7O2)3) contained in a stainless steel vessel. The Al content in the AZO films was altered by controlling the partial pressure (or flow rate) of the Al dopant gas. High deposition rates as well as uniform distributions of resistivity and thickness on the substrate surface were obtained on large area glass substrates. A low resistivity on the order of 10-4 ? cm and an average transmittance above 80% in the visible range were obtained in AZO thin films deposited on glass substrates. .

Miyata, Toshihiro; Minamino, Youhei; Ida, Satoshi; Minami, Tadatsugu

2004-07-01

419

Evaporative roof cooling system  

SciTech Connect

An evaporative roof cooling system is described for placement upon a roof surface exposed to relatively high levels of solar radiation causing high under roof temperatures and comprising: (a) water distribution mist/spray nozzles positioned on the roof surface for supplying substantially uniform mist/sprays of water to lay down a substantially uniform thin film of water on the roof surface; (b) conduit means on the one roof surface for supplying the nozzles with water; (c) solenoid-controlled valve means in water flow communication with the conduit means to supply controlled quantities of water to the nozzles through the conduit means over periods during which the temperature of the roof surface is measured to be within a predetermined temperature range; (d) temperature measurement means comprised of a thermistor encapsulated in an epoxy block in direct contact with the roof surface for monitoring and measuring the actual temperature of the surface substantially by thermal conductivity and developing an electrical resistance value in direct relationship with the temperature of the surface; and (e) cooling system control means in electric communication with the temperature measurement means for comparing the electric resistance value developed by the temperature measurement means and a range of current values related to the predetermined temperature range.

Viner, S.G.

1988-08-09

420

Long term measurement of lake evaporation using a pontoon mounted Eddy Covariance system  

NASA Astrophysics Data System (ADS)

Accurate quantification of evaporation from water storages is essential for design of water management and allocation policy that aims to balance demands for water without compromising the sustainability of future water resources, particularly during periods of prolonged and severe drought. Precise measurement of evaporation from lakes and dams however, presents significant research challenges. These include design and installation of measurement platforms that can withstand a range of wind and wave conditions; accurate determination of the evaporation measurement footprint and the influence of changing water levels. In this paper we present results from a two year long deployment of a pontoon mounted Eddy Covariance (EC) system on a 17.2ha irrigation reservoir in southeast Queensland, Australia. The EC unit included a CSAT-3 sonic anemometer (Campbell Scientific, Utah, United States) and a Li-Cor CS7500 open-path H2O/CO2 infrared gas analyzer (LiCor, Nebraska, United States) at a height of 2.2m, a net radiometer (CNR1, Kipp & Zonen, Netherlands) at a height of 1.2m and a humidity and temperature probe (HMP45C,Vaisala, Finland) at 2.3m. The EC unit was controlled by a Campbell Scientific CR3000 data logger with flux measurements made at 10 Hz and block averaged values logged every 15 minutes. Power to the EC system was from mounted solar panels that charged deep cycle lead-acid batteries while communication was via a cellphone data link. The pontoon was fitted with a weighted central beam and gimbal ring system that allowed self-levelling of the instrumentation and minimized dynamic influences on measurements (McGowan et al 2010; Wiebe et al 2011). EC measurements were corrected for tilt errors using the double rotation method for coordinate rotation described by Wilczak et al. (2001). High and low frequency attenuation of the measured co-spectrum was corrected using Massman's (2000) method for estimating frequency response corrections, while measurements were corrected for density fluctuations using the method of Webb-Pearman-Leuning (Webb et al. 1980). The evaporation measurement footprint over the reservoir was determined using the SCADIS one and a half order turbulence closure footprint model (Sogachev and Lloyd, 2004). Comparison of EC measured evaporation rates show excellent agreement with independent measurement of evaporation by scintillometer under a wide range of conditions (McJannet et al 2011). They confirm that pontoon mounted EC systems offer a robust, highly portable and reliable cost effective approach for accurate quantification of evaporation from reservoirs.

McGowan, H. A.; McGloin, R.; McJannet, D.; Burn, S.

2011-12-01

421

Method of generating hydrogen gas from sodium borohydride  

DOEpatents

A compact solid source of hydrogen gas, where the gas is generated by contacting water with micro-disperse particles of sodium borohydride in the presence of a catalyst, such as cobalt or ruthenium. The micro-disperse particles can have a substantially uniform diameter of 1-10 microns, and preferably about 3-5 microns. Ruthenium or cobalt catalytic nanoparticles can be incorporated in the micro-disperse particles of sodium borohydride, which allows a rapid and complete reaction to occur without the problems associated with caking and scaling of the surface by the reactant product sodium metaborate. A closed loop water management system can be used to recycle wastewater from a PEM fuel cell to supply water for reacting with the micro-disperse particles of sodium borohydride in a compact hydrogen gas generator. Capillary forces can wick water from a water reservoir into a packed bed of micro-disperse fuel particles, eliminating the need for using an active pump.

Kravitz, Stanley H. (Placitas, NM); Hecht, Andrew M. (Sandia Park, NM); Sylwester, Alan P. (Albuquerque, NM); Bell, Nelson S. (Albuquerque, NM)

2007-12-11

422

Benchmarking Gas Path Diagnostic Methods: A Public Approach  

NASA Technical Reports Server (NTRS)

Recent technology reviews have identified the need for objective assessments of engine health management (EHM) technology. The need is two-fold: technology developers require relevant data and problems to design and validate new algorithms and techniques while engine system integrators and operators need practical tools to direct development and then evaluate the effectiveness of proposed solutions. This paper presents a publicly available gas path diagnostic benchmark problem that has been developed by the Propulsion and Power Systems Panel of The Technical Cooperation Program (TTCP) to help address these needs. The problem is coded in MATLAB (The MathWorks, Inc.) and coupled with a non-linear turbofan engine simulation to produce "snap-shot" measurements, with relevant noise levels, as if collected from a fleet of engines over their lifetime of use. Each engine within the fleet will experience unique operating and deterioration profiles, and may encounter randomly occurring relevant gas path faults including sensor, actuator and component faults. The challenge to the EHM community is to develop gas path diagnostic algorithms to reliably perform fault detection and isolation. An example solution to the benchmark problem is provided along with associated evaluation metrics. A plan is presented to disseminate this benchmark problem to the engine health management technical community and invite technology solutions.

Simon, Donald L.; Bird, Jeff; Davison, Craig; Volponi, Al; Iverson, R. Eugene

2008-01-01

423

Advances in Sensible Heat Balance Characterization of Soil Water Evaporation  

NASA Astrophysics Data System (ADS)

Soil water evaporation intimately couples the hydrological cycle with the land-surface energy balance, making it an important driver for a wide range of terrestrial processes. To date, few methods have been available characterize soil water evaporation in detail, which has, in turn, limited capability to predict soil water evaporation processes in local and large scale models. Recent work has developed a measurement-based soil sensible heat balance (SHB) approach, capable of quantifying evaporation time and depth dynamics at a vertical scale of millimeters, near the soil surface. The SHB approach does not require detailed characterization or estimation of soil hydraulic properties, which has been a limitation in previous work. Rather it utilizes detailed measurements of the soil temperature profile and soil thermal properties from heat-pulse sensors in order to derive evaporation front dynamics. Laboratory experiments indicate that the SHB approach is precise to within <10% of independent mass balance measurements. Field tests indicate that the SHB is well correlated to lysimeter and Bowen ratio measurement approaches for bare surface conditions. Using SHB, laboratory and field experiments have characterized migration of the soil water evaporation front during multi-day drying events, and linked the shift between potential evaporation and falling rate evaporation to changes in soil surface albedo and soil moisture.

Heitman, J.; Xiao, X.; Deol, P. K.; Horton, R.; Ren, T.

2013-05-01

424

Small Scale Evaporation Kinetics of a Binary Fluid Mixture  

NASA Astrophysics Data System (ADS)

Evaporation induces a concentrating effect in liquid mixtures. The transient process has significant influence on the dynamic behaviors of a complex fluid. To simultaneously investigate the fluid properties and small-scale evaporation kinetics during the transient process, the quartz crystal microbalance is applied to a binary mixture droplet of light alcohols including both a single volatile component (a fast evaporation followed by a slow evaporation) and a mixture of two volatile components with comparable evaporation rates. The density and viscosity stratification are evaluated by the shear wave, and the evaporation kinetics is measured by the resonant signature of the acoustic p-wave. The evaporation flux can be precisely determined by the resonant frequency spikes and the complex impedance. To predict the concentration field, the moving interface, and the precision evaporation kinetics of the mixture, a multiphase model is developed to interpret the complex impedance signals based on the underlying mass and momentum transport phenomena. The experimental method and theoretical model are developed for better characterizing and understanding of the drying process involving liquid mixtures of protein pharmaceuticals.

Basdeo, Carl; Ye, Dezhuang; Kalonia, Devendra; Fan, Tai-Hsi

2013-03-01

425

Contaminated Water Evaporation System Design for the Tailing Facility  

NASA Astrophysics Data System (ADS)

The treatment and disposal of contaminated water is a major issue for the mining industry. A common approach to this issue is through the process of evaporation and evapotranspiration. This process is commonly done simply by spreading the contaminated water over a given area and exposing it to the sun. This causes the water to evaporate and be returned into the hydrological cycle as clean water, leaving the contaminants behind. Evaporation systems are based on the continuity principle for conservation of mass, so that the rate of evaporation is greater than the inflow. Evaporation systems are by no means a new method, but the design criteria, procedures, and methodology have not been documented. Without design criteria there are no guidelines to creating a successful evaporation system for water treatment. This paper describes the methodology of designing a water evaporation system based on the continuity principle and conservation of mass. This paper also presents how incorporating a time series model can utilize historical data to predict future requirements for the evaporation area and contaminated water storage. With this methodology, the mining industry can have guidelines and design standards to follow for a sustainable alternative for the treatment of contaminated water.; ;

Langer, J. M.; Cheng, J.

2012-12-01

426

Evaporation of tiny water aggregation on solid surfaces with different wetting properties.  

PubMed

The evaporation of a tiny amount of water on the solid surface with different wettabilities has been studied by molecular dynamics simulations. From nonequilibrium MD simulations, we found that, as the surface changed from hydrophobic to hydrophilic, the evaporation speed did not show a monotonic decrease as intuitively expected, but increased first, and then decreased after it reached a maximum value. The analysis of the simulation trajectory and calculation of the surface water interaction illustrate that the competition between the number of water molecules on the water-gas surface from where the water molecules can evaporate and the potential barrier to prevent those water molecules from evaporating results in the unexpected behavior of the evaporation. This finding is helpful in understanding the evaporation on biological surfaces, designing artificial surfaces of ultrafast water evaporating, or preserving water in soil. PMID:23051060

Wang, Shen; Tu, Yusong; Wan, Rongzheng; Fang, Haiping

2012-11-29

427

Influence of Refractance Window evaporation on quality of juices from small fruits  

Microsoft Academic Search

A new type of evaporator (Refractance Window® (RW) evaporator) has been developed that operates at atmospheric conditions and uses thermal energy from hot water to concentrate foods. The influence of product temperature and dissolved solids on vitamin C in blueberry juice and color of cranberry juice was evaluated in this new evaporation method in comparison with conventional falling film multi-effect

C. I. Nindo; J. R. Powers; J. Tang

2007-01-01

428

Apparatus for the liquefaction of natural gas and methods relating to same  

DOEpatents

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work output. A compressor may be driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream.

Wilding, Bruce M. (Idaho Falls, ID) [Idaho Falls, ID; McKellar, Michael G. (Idaho Falls, ID) [Idaho Falls, ID; Turner, Terry D. (Ammon, ID) [Ammon, ID; Carney, Francis H. (Idaho Falls, ID) [Idaho Falls, ID

2009-09-29

429

Objective Forecasting of Pan Evaporation - Two Contributions.  

National Technical Information Service (NTIS)

This memorandum consists of two articles on forecasting of pan evaporation. The first, An Aid to Agricultural Evaporation Forecasting, offers a linear equation which estimates 24-hour pan evaporation as a function of means of temperature, relative humidit...

N. P. Cimino J. B. Graham

1976-01-01

430

Noninvasive Cardiac Output Determination for Children by the Inert Gas-Rebreathing Method  

Microsoft Academic Search

Standard methods for determination of cardiac output (CO) are either invasive or technically demanding. Measurement of CO\\u000a by the inert gas–rebreathing (IGR) method, applied successfully in adults, uses a low-concentration mixture of an inert and\\u000a a blood-soluble gas, respectively. This study tested the feasibility of this method for determining CO during exercise for\\u000a pediatric patients with complete congenital atrioventricular block

Gesa Wiegand; Gunter Kerst; Winfried Baden; Michael Hofbeck

2010-01-01