WorldWideScience

Sample records for generators vapor

  1. Boiler for generating high quality vapor

    Science.gov (United States)

    Gray, V. H.; Marto, P. J.; Joslyn, A. W.

    1972-01-01

    Boiler supplies vapor for use in turbines by imparting a high angular velocity to the liquid annulus in heated rotating drum. Drum boiler provides a sharp interface between boiling liquid and vapor, thereby, inhibiting the formation of unwanted liquid droplets.

  2. Dynamic headspace generation and quantitation of triacetone triperoxide vapor.

    Science.gov (United States)

    Giordano, Braden C; Lubrano, Adam L; Field, Christopher R; Collins, Greg E

    2014-02-28

    Two methods for quantitation of triacetone triperoxide (TATP) vapor using a programmable temperature vaporization (PTV) inlet coupled to a gas chromatography/mass spectrometer (GC/MS) have been demonstrated. The dynamic headspace of bulk TATP was mixed with clean humid air to produce a TATP vapor stream. Sampling via a heated transfer line to a PTV inlet with a Tenax-TA™ filled liner allowed for direct injection of the vapor stream to a GC/MS for vapor quantitation. TATP was extracted from the vapor stream and subsequently desorbed from the PTV liner for splitless injection on the GC column. Calibration curves were prepared using solution standards with a standard split/splitless GC inlet for quantitation of the TATP vapor. Alternatively, vapor was sampled onto a Tenax-TA™ sample tube and placed into a thermal desorption system. In this instance, vapor was desorbed from the tube and subsequently trapped on a liquid nitrogen cooled PTV inlet. Calibration curves for this method were prepared from direct liquid injection of standards onto samples tube with the caveat that a vacuum is applied to the tube during deposition to ensure that the volatile TATP penetrates into the tube. Vapor concentration measurements, as determined by either GC/MS analysis or mass gravimetry of the bulk TATP, were statistically indistinguishable. Different approaches to broaden the TATP vapor dynamic range, including diluent air flow, sample chamber temperature, sample vial orifice size, and sample size are discussed. Vapor concentrations between 50 and 5400ngL(-1) are reported, with stable vapor generation observed for as long as 60 consecutive hours.

  3. Electrolysis cell functions as water vapor dehumidifier and oxygen generator

    Science.gov (United States)

    Clifford, J. E.

    1971-01-01

    Water vapor is absorbed in hygroscopic electrolyte, and oxygen generated by absorbed water electrolysis at anode is added simultaneously to air stream. Cell applications include on-board aircraft oxygen systems, portable oxygen generators, oxygen concentration requirements, and commercial air conditioning and dehumidifying systems.

  4. The fourth-generation Water Vapor Millimeter-Wave Spectrometer

    Science.gov (United States)

    Gomez, R. Michael; Nedoluha, Gerald E.; Neal, Helen L.; McDermid, I. Stuart

    2012-02-01

    For 20 years the Naval Research Laboratory has been making continuous water vapor profile measurements at 22.235 GHz with the Water Vapor Millimeter-Wave Spectrometer (WVMS) instruments, with the program expanding from one to three instruments in the first 6 years. Since the initial deployments there have been gradual improvements in the instrument design which have improved data quality and reduced maintenance requirements. Recent technological developments have made it possible to entirely redesign the instrument and improve not only the quality of the measurements but also the capability of the instrument. We present the fourth-generation instrument now operating at Table Mountain, California, which incorporates the most recent advances in microwave radiometry. This instrument represents the most significant extension of our measurement capability to date, enabling us to measure middle atmospheric water vapor from ˜26-80 km.

  5. Studies of interfaces and vapors with Optical Second Harmonic Generation

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, Christopher Shane [Lawrence Berkeley Lab., CA (United States); California Univ., Berkeley, CA (United States). Dept. of Physics

    1993-12-01

    Optical Second Harmonic Generation (SHG) has been applied to the study of soap-like molecules adsorbed to the water-air interface. By calibrating the signal from a soluble monolayer with that of an insoluble homolog, absolute measurements of the surface density could be obtained and related to the bulk concentration and surface tension. We could then demonstrate that the soluble surfactant forms a single monolayer at the interface. Furthermore, it deviates significantly from the ideal case in that its activity coefficients are far from 1, yet those coefficients remain constant over a broad range of surface pressures. We present evidence of a first-order phase transition taking place during the adsorption of this soluble monolayer. We consider the effects of the non-ideal behavior and the phase transition on the microscopic model of adsorption, and formulate an alternative to the Langmuir picture of adsorption which is just as simple, yet it can more easily allow for non-ideal behavior. The second half of this thesis considers the problem of SHG in bulk metal vapors. The symmetry of the vapor forbids SHG, yet it has been observed. We consider several models whereby the symmetry of the vapor is broken by the presence of the laser and compare their predictions to new observations we have made using a few-picosecond laser pulse. The two-lobed output beam profile shows that it is the vapor-plus-beam combination whose symmetry is important. The dependence on vapor pressure demonstrates the coherent nature of the radiation, while the dependence on buffer gas pressure hints at a change of the symmetry in time. The time-dependence is measured directly with a preliminary pump-probe measurement. The magnitude and intensity dependence of the signal are also measured. All but one of the models are eliminated by this comparison.

  6. Versatile thin-film reactor for photochemical vapor generation.

    Science.gov (United States)

    Zheng, Chengbin; Sturgeon, Ralph E; Brophy, Christine; Hou, Xiandeng

    2010-04-01

    A novel thin-film reactor is described and evaluated for its analytical performance with photochemical vapor generation (TF-PVG). The device, comprising both the generator and a gas-liquid separator, utilizes a vertical central quartz rod onto which the sample is pumped to yield a thin liquid film conducive to the rapid escape of generated hydrophobic species. The rod is housed within a concentric quartz tube through which a flow of argon carrier/stripping gas is passed to remove and transport the generated species to a detector, which in this study is an inductively coupled argon plasma optical emission spectrometer (ICP-OES). The concentric quartz tube is itself surrounded by a 78-turn 0.5 m long quartz coil low-pressure mercury discharge lamp operating at 20 W. The performance of this thin-film photoreactor was evaluated through comparison of analytical figures of merit for detection of a number of elements undergoing PVG in the presence of formic or acetic acid with those arising from conventional solution nebulization under optimized conditions. The TF-PVG reactor provided sensitivity enhancements, of 110-, 120-, 130-, 250-, 120-, 230-, 78-, 1.3-, 16-, and 32-fold for As, Sb, Bi, Se, Te, Hg, Ni, Co, Fe, and I, respectively, and detection limit enhancements of 110-, 140-, 170-, 270-, 200-, 300-, 160-, 2.7-, 50-, and 44-fold for these same elements. Vapor generation efficiencies ranged from 20-100% for this suite of analytes. The utility of this technique was demonstrated by the determination of Fe and Ni in Certified Reference Materials DORM-3 (fish protein) and DOLT-4 (dogfish liver tissue).

  7. Nonequilibrium vapor-generation model for flashing flows

    Energy Technology Data Exchange (ETDEWEB)

    Saha, P.; Abuaf, N.; Wu, B. J.C.

    1981-01-01

    A nonequilibrium vapor generation model for flashing flows is presented. The model consists of a flashing inception point, a bubbly flow regime followed by a bubbly-slug regime, an annular or annular-mist regime, and finally a dispersed-droplet regime. Existence of superheated liquid at the inception point and beyond is recognized. The vapor generation rate in each flow regime is calculated from the estimates for interfacial area density and net interfacial heat flux. However, the bubble number density at the flashing inception point was varied to obtain optimum fits with the void fraction data taken in a vertical converging-diverging nozzle. The interfacial area density at the inception point, thus determined, showed a rapid increase with the decrease in the liquid superheat at that point. This trend is correct since in the limit of thermal equilibrium flow where the liquid superheat approaches zero, the interfacial area for heat and mass transfer should approach infinity. 32 refs., 7 figs., 1 tab.

  8. Systems and methods for generation of hydrogen peroxide vapor

    Science.gov (United States)

    Love, Adam H; Eckels, Joel Del; Vu, Alexander K; Alcaraz, Armando; Reynolds, John G

    2014-12-02

    A system according to one embodiment includes a moisture trap for drying air; at least one of a first container and a second container; and a mechanism for at least one of: bubbling dried air from the moisture trap through a hydrogen peroxide solution in the first container for producing a hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above a hydrogen peroxide solution in the second container for producing a hydrogen peroxide vapor. A method according one embodiment includes at least one of bubbling dried air through a hydrogen peroxide solution in a container for producing a first hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above the hydrogen peroxide solution in a container for producing a second hydrogen peroxide vapor. Additional systems and methods are also presented.

  9. Continuous generation of Rubidium vapor in hollow-core photonic band-gap fibers

    CERN Document Server

    Donvalkar, Prathamesh S; Clemmen, Stephane; Gaeta, Alexander L

    2015-01-01

    We demonstrate high optical depths (50+/-5), lasting for hours in Rubidium-filled hollow-core photonic band-gap fibers, which represents a 1000X improvement over operation times previously reported. We investigate the vapor generation mechanism using both a continuous-wave and a pulsed light source and find that the mechanism for generating the Rubidium atoms is primarily due to thermal vaporization. Continuous generation of large vapor densities should enable measurements at the single-photon level by averaging over longer time scales.

  10. Testing and Results of Human Metabolic Simulation Utilizing Ultrasonic Nebulizer Technology for Water Vapor Generation

    Science.gov (United States)

    Stubbe, Matthew; Curley, Su

    2010-01-01

    Life support technology must be evaluated thoroughly before ever being implemented into a functioning design. A major concern during that evaluation is safety. The ability to mimic human metabolic loads allows test engineers to evaluate the effectiveness of new technologies without risking injury to any actual humans. The main function of most life support technologies is the removal of carbon dioxide (CO2) and water (H2O) vapor. As such any good human metabolic simulator (HMS) will mimic the human body s ability to produce these items. Introducing CO2 into a test chamber is a very straightforward process with few unknowns so the focus of this particular new HMS design was on the much more complicated process of introducing known quantities of H2O vapor on command. Past iterations of the HMS have utilized steam which is very hard to keep in vapor phase while transporting and injecting into a test chamber. Also steam adds large quantities of heat to any test chamber, well beyond what an actual human does. For the new HMS an alternative approach to water vapor generation was designed utilizing ultrasonic nebulizers as a method for creating water vapor. Ultrasonic technology allows water to be vibrated into extremely tiny pieces (2-5 microns) and evaporate without requiring additional heating. Doing this process inside the test chamber itself allows H2O vapor generation without the unwanted heat and the challenging process of transporting water vapor. This paper presents the design details as well as results of all initial and final acceptance system testing. Testing of the system was performed at a range of known human metabolic rates in both sea-level and reduced pressure environments. This multitude of test points fully defines the systems capabilities as they relate to actual environmental systems testing.

  11. Vapor generation – atomic spectrometric techniques. Expanding frontiers through specific-species preconcentration. A review

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Raúl A.; Pacheco, Pablo H.; Cerutti, Soledad [Área de Química Analítica, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Instituto de Química de San Luis, INQUISAL, Centro Científico-Tecnológico de San Luis (CCT-San Luis), Consejo Nacional de Investigaciones Científicas y Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Martinez, Luis D., E-mail: ldm@unsl.edu.ar [Área de Química Analítica, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Instituto de Química de San Luis, INQUISAL, Centro Científico-Tecnológico de San Luis (CCT-San Luis), Consejo Nacional de Investigaciones Científicas y Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina)

    2015-05-22

    This article reviews 120 articles found in SCOPUS and specific Journal cites corresponding to the terms ‘preconcentration’; ‘speciation’; ‘vapor generation techniques’ and ‘atomic spectrometry techniques’ in the last 5 years. - Highlights: • Recent advances in vapor generation and atomic spectrometry were reviewed. • Species-specific preconcentration strategies after and before VG were discussed. • New preconcentration and speciation analysis were evaluated within this framework. - Abstract: We review recent progress in preconcentration strategies associated to vapor generation techniques coupled to atomic spectrometric (VGT-AS) for specific chemical species detection. This discussion focuses on the central role of different preconcentration approaches, both before and after VG process. The former was based on the classical solid phase and liquid–liquid extraction procedures which, aided by automation and miniaturization strategies, have strengthened the role of VGT-AS in several research fields including environmental, clinical, and others. We then examine some of the new vapor trapping strategies (atom-trapping, hydride trapping, cryotrapping) that entail improvements in selectivity through interference elimination, but also they allow reaching ultra-low detection limits for a large number of chemical species generated in conventional VG systems, including complete separation of several species of the same element. This review covers more than 100 bibliographic references from 2009 up to date, found in SCOPUS database and in individual searches in specific journals. We finally conclude by giving some outlook on future directions of this field.

  12. Semi-continuous high speed gas analysis of generated vapors of chemical warfare agents

    NARCIS (Netherlands)

    Trap, H.C.; Langenberg, J.P.

    1999-01-01

    A method is presented for the continuous analysis of generated vapors of the nerve agents soman and satin and the blistering agent sulfur mustard. By using a gas sampling valve and a very short (15 cm) column connected to an on-column injector with a 'standard length' column, the system can either

  13. Advancements in oxygen generation and humidity control by water vapor electrolysis

    Science.gov (United States)

    Heppner, D. B.; Sudar, M.; Lee, M. C.

    1988-01-01

    Regenerative processes for the revitalization of manned spacecraft atmospheres or other manned habitats are essential for realization of long-term space missions. These processes include oxygen generation through water electrolysis. One promising technique of water electrolysis is the direct conversion of the water vapor contained in the cabin air to oxygen. This technique is the subject of the present program on water vapor electrolysis development. The objectives were to incorporate technology improvements developed under other similar electrochemical programs and add new ones; design and fabricate a mutli-cell electrochemical module and a testing facility; and demonstrate through testing the improvements. Each aspect of the water vapor electrolysis cell was reviewed. The materials of construction and sizing of each element were investigated analytically and sometime experimentally. In addition, operational considerations such as temperature control in response to inlet conditions were investigated. Three specific quantitative goals were established.

  14. A geração química de vapor em espectrometria atômica Chemical vapor generation in atomic spectrometry

    Directory of Open Access Journals (Sweden)

    Iracema Takase

    2002-12-01

    Full Text Available The historical development of atomic spectrometry techniques based on chemical vapor generation by both batch and flow injection sampling formats is presented. Detection via atomic absorption spectrometry (AAS, microwave induced plasma optical emission spectrometry (MIP-OES, inductively coupled plasma optical emission spectrometry (ICP-OES , inductively coupled plasma mass spectrometry (ICP-MS and furnace atomic nonthermal excitation spectrometry (FANES are considered. Hydride generation is separately considered in contrast to other methods of generation of volatile derivatives. Hg ¾ CVAAS (cold vapor atomic absorption spectrometry is not considered here. The current state-of-the-art, including extension, advantages and limitations of this approach is discussed.

  15. Health assessment of gasoline and fuel oxygenate vapors: generation and characterization of test materials.

    Science.gov (United States)

    Henley, Michael; Letinski, Daniel J; Carr, John; Caro, Mario L; Daughtrey, Wayne; White, Russell

    2014-11-01

    In compliance with the Clean Air Act regulations for fuel and fuel additive registration, the petroleum industry, additive manufacturers, and oxygenate manufacturers have conducted comparative toxicology testing on evaporative emissions of gasoline alone and gasoline containing fuel oxygenates. To mimic real world exposures, a generation method was developed that produced test material similar in composition to the re-fueling vapor from an automotive fuel tank at near maximum in-use temperatures. Gasoline vapor was generated by a single-step distillation from a 1000-gallon glass-lined kettle wherein approximately 15-23% of the starting material was slowly vaporized, separated, condensed and recovered as test article. This fraction was termed vapor condensate (VC) and was prepared for each of the seven test materials, namely: baseline gasoline alone (BGVC), or gasoline plus an ether (G/MTBE, G/ETBE, G/TAME, or G/DIPE), or gasoline plus an alcohol (G/EtOH or G/TBA). The VC test articles were used for the inhalation toxicology studies described in the accompanying series of papers in this journal. These studies included evaluations of subchronic toxicity, neurotoxicity, immunotoxicity, genotoxicity, reproductive and developmental toxicity. Results of these studies will be used for comparative risk assessments of gasoline and gasoline/oxygenate blends by the US Environmental Protection Agency.

  16. Chemistry of Impact-Generated Silicate Melt-Vapor Debris Disks

    CERN Document Server

    Visscher, Channon

    2013-01-01

    In the giant impact theory for lunar origin, the Moon forms from material ejected by the impact into an Earth-orbiting disk. Here we report the initial results from a silicate melt-vapor equilibrium chemistry model for such impact-generated planetary debris disks. In order to simulate the chemical behavior of a two-phase (melt+vapor) disk, we calculate the temperature-dependent pressure and chemical composition of vapor in equilibrium with molten silicate from 2000 to 4000 K. We consider the elements O, Na, K, Fe, Si, Mg, Ca, Al, Ti, and Zn for a range of bulk silicate compositions (Earth, Moon, Mars, eucrite parent body, angrites, and ureilites). In general, the disk atmosphere is dominated by Na, Zn, and O2 at lower temperatures (< 3000 K) and SiO, O2, and O at higher temperatures. The high-temperature chemistry is consistent for any silicate melt composition, and we thus expect abundant SiO, O2, and O to be a common feature of hot, impact-generated debris disks. In addition, the saturated silicate vapor...

  17. Studies on Aspirin Crystals Generated by a Modified Vapor Diffusion Method.

    Science.gov (United States)

    Mittal, Amit; Malhotra, Deepak; Jain, Preeti; Kalia, Anupama; Shunmugaperumal, Tamilvanan

    2016-08-01

    The objectives of the current investigation were (1) to study the influence of selected two different non-solvents (diethylether and dichloromethane) on the drug crystal formation of a model drug, aspirin (ASP-I) by the modified vapor diffusion method and (2) to characterize and compare the generated crystals (ASP-II and ASP-III) using different analytical techniques with that of unprocessed ASP-I. When compared to the classical vapor diffusion method which consumes about 15 days to generate drug crystals, the modified method needs only 12 h to get the same. Fourier transform-infrared spectroscopy (FT-IR) reveals that the internal structures of ASP-II and ASP-III crystals were identical when compared with ASP-I. Although the drug crystals showed a close similarity in X-ray diffraction patterns, the difference in the relative intensities of some of the diffraction peaks (especially at 2θ values of around 7.7 and 15.5) could be attributed to the crystal habit or crystal size modification. Similarly, the differential scanning calorimetry (DSC) study speculates that only the crystal habit modifications might occur but without involving any change in internal structure of the generated drug polymorphic form I. This is further substantiated from the scanning electron microscopy (SEM) pictures that indicated the formation of platy shape for the ASP-II crystals and needle shape for the ASP-III crystals. In addition, the observed slow dissolution of ASP crystals should indicate polymorph form I formation. Thus, the modified vapor diffusion method could routinely be used to screen and legally secure all possible forms of other drug entities too.

  18. Entropy and Exergy Analysis of a Heat Recovery Vapor Generator for Ammonia-Water Mixtures

    Directory of Open Access Journals (Sweden)

    Kyoung Hoon Kim

    2014-04-01

    Full Text Available Recently power generation systems using ammonia-water binary mixtures as a working fluid have been attracting much attention for their efficient conversion of low-grade heat sources into useful energy forms. This paper presents the First and Second Law thermodynamic analysis for a heat recovery vapor generator (HRVG of ammonia-water mixtures when the heat source is low-temperature energy in the form of sensible heat. In the analysis, key parameters such as ammonia mass concentration and pressure of the binary mixture are studied to investigate their effects on the system performance, including the effectiveness of heat transfer, entropy generation, and exergy efficiency. The results show that the ammonia concentration and the pressure of the mixture have significant effects on the system performance of the HRVG.

  19. Iodine Determination by Microwave Plasma Torch Atomic Emission Spectrometer Coupled with Online Preconcentration Vapor Generation Technique

    Institute of Scientific and Technical Information of China (English)

    FEI Yan-qun; LUO Gui-min; FENG Guo-dong; CHEN Huan-wen; FEI Qiang; HUAN Yan-fu; JIN Qin-han

    2008-01-01

    This article focuses on iodine determination by microwave plasma torch atomic emission spectrometry (MPT-AES) coupled with online preconcentration vapor generation method.A new desolvation device,multistrand Nation dryer,was used as the substitute for condenser desolvation system.Some experimental conditions,such as preconcentration time,acidity of sample solution,rinsing solution acidity and dynamic linear range were investigated and optimized.The new desolvation system eliminates the problem of decreasing emission intensity of I(I) 206.238 nm line with the increase of working time on a conventional condenser desolvation system,thus greatly improving the reproducibility.

  20. Demand management in steam generation?; Administracion de la demanda en la generacion de vapor?

    Energy Technology Data Exchange (ETDEWEB)

    Plauchu L., A.; Plauchu A., J. A. [Ingenieros consultores (Mexico)

    1997-12-31

    Energy management has acquired capital importance in all the branches of the industrial activity and services either private o public and it has been, from years behind, more familiar the technology for the demand control in the electric power distribution systems, with excellent results in the energy conservation and economy. The rate of consumption for the different forms of energy shows the prevalence of the thermal energy in a variety of end uses. Not much or almost nothing has been said of the term Demand Management or Control in Steam Generation although 12% of the total energy supply is used for this purpose. Steam demand management and control can avoid unnecessary investments that bring along the increment of operational and maintenance problems and it is for sure that it will always give raise to a more rational and economical utilization of the real capacity of steam generation. A real case is commented. [Espanol] La administracion de la energia ha cobrado importancia capital en todos los giros de actividad industrial y de servicios, privados y publicos y es de varios anos atras cada vez mas familiar la tecnologia en el control de demanda en los sistemas de distribucion de energia electrica, con magnificos resultados en el ahorro, energetico y economico. La relacion de consumos para las diferentes formas de energia muestra el predominio de la energia termica en una variedad de usos finales. Poco o nada oimos del termino Administracion o Control de Demanda en la Generacion de Vapor aun cuando el 12% de la oferta total de energia tiene como destino esta aplicacion. La administracion y control de la demanda de vapor puede evitar inversiones innecesarias e incremento de problemas de operacion y mantenimiento y con seguridad reportaran siempre una utilizacion mas racional y economica de la capacidad real de generacion de vapor, se comenta un caso real.

  1. Collimated Blue and Infrared Beams Generated by Two-Photon Excitation in Rb Vapor

    CERN Document Server

    Sell, J F; DePaola, B D; Knize, R J

    2013-01-01

    Utilizing two-photon excitation in hot Rb vapor we demonstrate the generation of collimated optical fields at 420 nm and 1324 nm. Input laser beams at 780 nm and 776 nm enter a heated Rb vapor cell collinear and circularly polarized, driving Rb atoms to the $5D_{5/2}$ state. Under phase-matching conditions coherence among the $5S_{1/2}\\rightarrow 5P_{3/2}\\rightarrow 5D_{5/2} \\rightarrow 6P_{3/2}$ transitions produces a blue (420 nm) beam by four-wave mixing. We also observe a forward and backward propagating IR (1324 nm) beam, due to cascading decays through the $6S_{1/2}\\rightarrow 5P_{1/2}$ states. Power saturation of the generated beams is investigated by scaling the input powers to greater than 200 mW, resulting in a coherent blue beam of 9.1 mW power, almost an order of magnitude larger than previously achieved. We measure the dependences of both beams in relation to the Rb density, the frequency detuning between Rb ground state hyperfine levels, and the input laser intensities.

  2. Multipass configuration for improved squeezed vacuum generation in hot Rb vapor

    Science.gov (United States)

    Zhang, Mi; Guidry, Melissa A.; Lanning, R. Nicholas; Xiao, Zhihao; Dowling, Jonathan P.; Novikova, Irina; Mikhailov, Eugeniy E.

    2017-07-01

    We study a squeezed vacuum field generated in hot Rb vapor via the polarization self-rotation effect. Our previous experiments showed that the amount of observed squeezing may be limited by the contamination of the squeezed vacuum output with higher-order spatial modes, also generated inside the cell. Here, we demonstrate that the squeezing can be improved by making the light interact several times with a less dense atomic ensemble. With optimization of some parameters we can achieve up to -2.6 dB of squeezing in the multipass case, which is a 0.6 dB improvement compared to the single-pass experimental configuration. Our results show that, other than the optical depth of the medium, the spatial mode structure and the cell configuration also affect the squeezing level.

  3. Generation of continuous-wave and pulsed squeezed light with $^{87}$Rb vapor

    CERN Document Server

    Agha, Imad H; Grangier, Philippe

    2009-01-01

    We present experimental studies on the generation of squeezed vacuum via nonlinear ellipse rotation in a $^{87}$Rb vapor. Squeezing is observed for a wide range of input powers and pump detunings on the D1 line, while only excess noise is present on the D2 line. The maximum squeezing observed is -1.4 $\\pm$0.1 dB (-2.0 dB corrected for loss). We measure -1.1 dB squeezing at the resonance frequency of the $^{85}$Rb $F=2 \\to F'=3$ transition, which may allow the storage of squeezed light generated by $^{87}$Rb in a $^{85}$Rb quantum memory. We also demonstrate a proof of principle pulsed squeezed light experiment, with -1 dB of squeezing for 200 ns pulse width.

  4. Generation of pulsed and continuous-wave squeezed light with 87Rb vapor.

    Science.gov (United States)

    Agha, Imad H; Messin, Gaétan; Grangier, Philippe

    2010-03-01

    We present experimental studies on the generation of pulsed and continuous-wave squeezed vacuum via nonlinear rotation of the polarization ellipse in a (87)Rb vapor. Squeezing is observed for a wide range of input powers and pump detunings on the D1 line, while only excess noise is present on the D2 line. The maximum continuous-wave squeezing observed is -1.4 +/- 0.1 dB (-2.0 dB corrected for losses). We measure -1.1 dB squeezing at the resonance frequency of the (85)Rb F = 3 --> F' transition, which may allow the storage of squeezed light generated by (87)Rb in a (85)Rb quantum memory. Using a pulsed pump, pulsed squeezed light with -1 dB of squeezing for 200 ns pulse widths is observed at 1 MHz repetition rate.

  5. Studies on photochemical vapor generation of selenium with germicidal low power ultraviolet mercury lamp

    Science.gov (United States)

    Campanella, B.; Menciassi, A.; Onor, M.; Ferrari, C.; Bramanti, E.; D'Ulivo, A.

    2016-12-01

    Photochemical vapor generation (photo-CVG) with flow injection - atomic fluorescence spectrometry was investigated for the determination of selenium, using formic and acetic acids as photochemical reagents. Using a germicidal low power ultraviolet mercury-based lamp, emitting both the 185 and 254 nm Hg lines, mild reaction conditions can be achieved in formic acid medium, where optimal sensitivity was obtained at 0.3-0.5% w/w acid concentrations, whereas the optimal sensitivity could be attained with acetic acid in the range from 12 to 35% w/w. The only volatile Se product identified by gas chromatography-mass spectrometry from formic acid-based photo-CVG was selenium carbonyl. A series of dedicated experiments were performed using photo-CVG and pure dimethylselenide in order to identify reaction pathways contributing to the formation of non-volatile selenium species or to the degradation of volatile selenium species. Under the optimized conditions in formic acid, using 250 μL sample volume, the limits of detection and quantification were 0.10 and 0.35 μg L- 1, respectively. The effect of several interfering species was investigated and the method was tested in the analysis of certified reference materials.

  6. Characterization of acoustic droplet vaporization for control of bubble generation under flow conditions.

    Science.gov (United States)

    Kang, Shih-Tsung; Huang, Yi-Luan; Yeh, Chih-Kuang

    2014-03-01

    This study investigated the manipulation of bubbles generated by acoustic droplet vaporization (ADV) under clinically relevant flow conditions. Optical microscopy and high-frequency ultrasound imaging were used to observe bubbles generated by 2-MHz ultrasound pulses at different time points after the onset of ADV. The dependence of the bubble population on droplet concentration, flow velocity, fluid viscosity and acoustic parameters, including acoustic pressure, pulse duration and pulse repetition frequency, was investigated. The results indicated that post-ADV bubble growth spontaneously driven by air permeation markedly affected the bubble population after insonation. The bubbles can grow to a stable equilibrium diameter as great as twice the original diameter in 0.5-1 s, as predicted by the theoretical calculation. The growth trend is independent of flow velocity, but dependent on fluid viscosity and droplet concentration, which directly influence the rate of gas uptake by bubbles and the rate of gas exchange across the wall of the semipermeable tube containing the bubbles and, hence, the gas content of the host medium. Varying the acoustic pressure does not markedly change the formation of bubbles as long as the ADV thresholds of most droplets are reached. Varying pulse duration and pulse repetition frequency markedly reduces the number of bubbles. Lengthening pulse duration favors the production of large bubbles, but reduces the total number of bubbles. Increasing the PRF interestingly provides superior performance in bubble disruption. These results also suggest that an ADV bubble population cannot be assessed simply on the basis of initial droplet size or enhancement of imaging contrast by the bubbles. Determining the optimal acoustic parameters requires careful consideration of their impact on the bubble population produced for different application scenarios.

  7. Photochemical vapor generation of lead for inductively coupled plasma mass spectrometric detection

    Science.gov (United States)

    Duan, Hualing; Zhang, Ningning; Gong, Zhenbin; Li, Weifeng; Hang, Wei

    2016-06-01

    Photochemical vapor generation (PCVG) of lead was successfully achieved with a simplified and convenient system, in which only low molecular weight organic acid and a high-efficiency photochemical reactor were needed. The reactor was used to generate lead volatile species when a solution of lead containing a small amount of low molecular weight organic acid was pumped through. Several factors, including the concentration of acetic acid, the concentration of hydrochloride acid, and the irradiation time of UV light were optimized. Under the optimal conditions, including the addition of 0.90% (v/v) acetic acid and 0.03% (v/v) hydrochloride acid, and irradiation time of 28 s, intense and repeatable signal of lead volatile species was successfully obtained and identified with inductively coupled plasma mass spectrometry (ICPMS). In addition, the effects from inorganic anions and transition metal ions, including Cl-, NO3-, SO42 -, Cu2 +, Fe3 +, Co2 + and Ni2 +, were investigated, which suggests that their suppression to the PCVG of lead was in the order of Cl- anions and Ni2 +, Co2 + < Fe3 + < Cu2 + for transition metal ions. Under optimized conditions, relative standard derivation (RSD) of 4.4% was achieved from replicate measurements (n = 5) of a standard solution of 0.1 μg L- 1 lead. And, the limit of quantitation (LOQ, 10σ) of 0.012 μg L- 1 lead was obtained using this method and the method blank could be easily controlled down to 0.023 μg L- 1. To validate applicability of this method, it was also employed for the determination of lead in tap water, rain water and lake water.

  8. Determination of ultratrace cadmium in food and environmental samples by ETAAS after vapor generation and in situ preconcentration

    Institute of Scientific and Technical Information of China (English)

    Ran SUO; Weijuan AN; Na LI

    2009-01-01

    A method is described for the determination of ultratrace cadmium by coupling a continuous flow vapor generation system with in situ preconcentration technique and electrothermal atomic absorption spectrometry (ETAAS). A graphite tube coated with Ir as permanent chemical modifier was used for trapping cadmium vapor species. The effects of the flow rates of carrier gas and sample injection in vapor generation systems on the trapping measurement for cadmium were respectively investigated. Graphite tubes with different characteristic surfaces were comparatively studied for trapping cadmium vapor. The experimental results showed that the permanent chemical modifier of Ir is an alternative to the thermolabile modifier of Pd for simplifying the trapping measurement. The trapping efficiency of cadmium on the graphite tube coated with Ir was estimated. The trapping temperature and time were also investigated. A detection limit (3σ) of 0.005 μg·g-1 was obtained for this proposed method. The relative standard deviation (RSD) was 1.4% for 0.5 μg·g-1 of Cd (n=ll). This method can be applied to the determination of ultratrace cadmium in food and environmental samples with good agreement between the certified and found values.

  9. Quantitative calibration of vapor levels of TNT, RDX, and PETN using a diffusion generator with gravimetry and ion mobility spectrometry.

    Science.gov (United States)

    Eiceman, G A; Preston, D; Tiano, G; Rodriguez, J; Parmeter, J E

    1997-12-12

    A prototype generator for creating a continuous stream of explosive vapor was referenced quantitatively both to a standard weight from the National Institute of Standards and Technology (NIST) and to the response of an ion mobility spectrometer. Vapors from solid explosive, in a precision bore glass tube at constant temperature, diffuse into an inert gas flow. Mass output rates were determined by (1) sample temperature, and (2) sample tube dimensions (length and cross-sectional area). A reference to NIST was achieved gravimetrically though a microbalance calibrated with a reference weight; mass output rates were obtained for 2,4,6-trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX) and pentaerythritol tetranitrate (PETN) at three or more oven temperatures between 79 degrees C and 150 degrees C. The mass output rate was stable over hundreds of hours of continuous operation and the output was adjustable from a few picograms per second to several nanograms per second through variation of the oven temperature. An independent calibration of the vapor generator for TNT at 79 degrees C using an ion mobility spectrometer matched exactly the gravimetric-based findings. In most instances, measured mass output rates compared favorably with theoretically calculated mass output rates, with discrepancies in a few cases resulting primarily from uncertainties in terms (vapor pressures and diffusion coefficients) used to perform the calculations. Agreement is generally not good for PETN, where molecular decomposition contributed to higher than expected measured mass outputs.

  10. On-site measurement of trace-level sulfide in natural waters by vapor generation and microchannel collection.

    Science.gov (United States)

    Toda, Kei; Kuwahara, Haruka; Ohira, Shin-Ichi

    2011-07-01

    Aqueous sulfide plays an important role in the environment even at low concentrations. However, it is unstable, which means field samples cannot be transported to the laboratory for analysis without fixation. In this work, a novel method was developed to determine trace levels of sulfide on site. This method is based on vapor generation and collection in a special microchannel device followed by fluorescence measurement (VG-μGAS). The microchannel scrubber gave a high enrichment factor, and a high sensitivity was achieved, which allowed measurement of nanomolar (nM) levels of sulfide. The theoretical approach to vapor generation for several compounds is discussed to evaluate the applicability of the method to these analytes, and compounds having a low Henry's law constant (Ariake Sea and Lake Baikal.

  11. Safety assessment of in-vessel vapor explosion loads in next generation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Kwang Hyun; Cho, Jong Rae; Choi, Byung Uk; Kim, Ki Yong; Lee, Kyung Jung [Korea Maritime University, Busan (Korea); Park, Ik Kyu [Seoul National University, Seoul (Korea)

    1998-12-01

    A safety assessment of the reactor vessel lower head integrity under in-vessel vapor explosion loads has been performed. The premixing and explosion calculations were performed using TRACER-II code. Using the calculated explosion pressures imposed on the lower head inner wall, strain calculations were performed using ANSYS code. The explosion analyses show that the explosion impulses are not altered significantly by the uncertain parameters of triggering location and time, fuel and vapor volume fractions in uniform premixture bounding calculations within the conservative ranges. Strain analyses using the calculated pressure loads on the lower head inner wall show that the vapor explosion-induced lower head failure is physically unreasonable. The static analysis using the conservative explosion-end pressure of 7,246 psia shows that the maximum equivalent strain is 4.3% at the bottom of lower head, which is less than the allowable threshold value of 11%. (author). 24 refs., 40 figs., 3 tabs.

  12. Speciation analysis of mercury in cereals by liquid chromatography chemical vapor generation inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Lin, Liang-Yen; Chang, Lan-Fang; Jiang, Shiuh-Jen

    2008-08-27

    A simple and rapid procedure for the separation and determination of inorganic, methyl, and ethyl mercury compounds was described using liquid chromatography (LC) followed by vapor generation inductively coupled plasma-mass spectrometry (VG-ICP-MS). Well resolved chromatograms were obtained within 5 min by reversed-phase liquid chromatography with a C8 column as the stationary phase and a pH 4.7 solution containing 0.5% v/v 2-mercaptoethanol and 5% v/v methanol as the mobile phase. The separated mercury compounds were converted to mercury vapors by an in situ nebulizer/vapor generation system for their introduction into ICP. The concentrations of NaBH4 and HNO3 required for vapor generation were also optimized. The method was applied for the speciation of mercury in reference materials NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour and also rice flour and wheat flour samples purchased locally. The accuracy of the procedure was verified by analyzing the certified reference material NRCC DOLT-3 Dogfish Liver for methyl mercury. Precision between sample replicates was better than 13% for all the determinations. The detection limits of the mercury compounds studied were in the range 0.003-0.006 ng Hg mL(-1) in the injected solutions, which correspond to 0.02-0.06 ng g(-1) in original flour samples. A microwave-assisted extraction procedure was adopted for the extraction of mercury compounds from rice flour, wheat flour, and fish samples using a mobile phase solution.

  13. Hg speciation by differential photochemical vapor generation at UV-B and UV-C wavelengths

    Science.gov (United States)

    Mercury speciation was accomplished by differential photochemical reduction at two UV wavelengths; the resulting Hg(O) vapor was quantified by atomic fluorescence spectrometry. After microwave digestion and centrifugation, analyte solutions were mixed with 20% (v/v) formic acid in a reactor coil, an...

  14. Highly vibrationally excited CO generated in a low-temperature chemical reaction between carbon vapor and molecular oxygen

    Science.gov (United States)

    Jans, E.; Frederickson, K.; Yurkovich, M.; Musci, B.; Rich, J. W.; Adamovich, I. V.

    2016-08-01

    A chemical flow reactor is used to study the vibrational population distribution of CO produced by a reaction between carbon vapor generated in an arc discharge and molecular oxygen. The results demonstrate formation of highly vibrationally excited CO, up to vibrational level v = 14, at low temperatures, T = 400-450 K, with population inversion at v = 4-7, in a collision-dominated environment, 15-20 Torr. The average vibrational energy per CO molecule formed by the reaction is 0.6-1.2 eV/molecule, which corresponds to 10-20% of reaction enthalpy. The results show feasibility of development of a new CO chemical laser using carbon vapor and oxygen as reactants.

  15. Evaluation of vapor generation for the determination of nickel by inductively coupled plasma-atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Julieta [Comision Nacional de Energia Atomica, Unidad de Actividad Quimica, Centro Atomico Constituyentes, Av. Gral. Paz 1499, 1650-San Martin, Pcia. de Buenos Aires (Argentina); Smichowski, Patricia [Comision Nacional de Energia Atomica, Unidad Proyectos Especiales de Suministros Nucleares, Av. Libertador 8250, 1429-Buenos Aires (Argentina)

    2002-09-01

    Volatile species of Ni were generated by merging acidified aqueous samples and sodium tetrahydroborate(III) in a continuous flow system. The gaseous analyte was subsequently introduced via a stream of Ar carrier into the inlet tube of the plasma torch. Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for detection. The operating conditions (chemical and physical parameters) and the concentrations of different acids were evaluated for the efficient generation of Ni vapor. The detection limit (3 {sigma}{sub blank}) was 1.8 ng mL{sup -1}. The precision (RSD) of the determination was 4.2% at a level of 500 ng mL{sup -1} and 7.3% for 20 ng mL{sup -1} (n=10). The efficiency of the generation process was estimated to be 51%. The possible interfering effect of transition metals (Cd, Co, Cu, Cr, Fe, Mn, Zn), hydride forming elements (As, Ge, Pb, Sb, Se, Sn, Te), and Hg on Ni signal was examined. This study has demonstrated that Ni vapor generation is markedly free of interferences. (orig.)

  16. Flow injection-chemical vapor generation atomic fluorescence spectrometry hyphenated system for organic mercury determination: A step forward

    Energy Technology Data Exchange (ETDEWEB)

    Angeli, Valeria [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici - ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Biagi, Simona [National Research Council of Italy, C.N.R., Istituto per i Processi Chimico-Fisici - IPCF-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Ghimenti, Silvia [University of Pisa, Department of Chemistry and Industrial Chemistry, Via Risorgimento 35, 56126 Pisa (Italy); Onor, Massimo; D' Ulivo, Alessandro [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici - ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Bramanti, Emilia, E-mail: bramanti@pi.iccom.cnr.it [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici - ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy)

    2011-11-15

    Monomethylmercury and ethylmercury were determined on line using flow injection-chemical vapor generation atomic fluorescence spectrometry without neither requiring a pre-treatment with chemical oxidants, nor UV/MW additional post column interface, nor organic solvents, nor complexing agents, such as cysteine. Inorganic mercury, monomethylmercury and ethylmercury were detected by atomic fluorescence spectrometry in an Ar/H{sub 2} miniaturized flame after sodium borohydride reduction to Hg{sup 0}, monomethylmercury hydride and ethylmercury hydride, respectively. The effect of mercury complexing agent such as cysteine, ethylendiaminotetracetic acid and HCl with respect to water and Ar/H{sub 2} microflame was investigated. The behavior of inorganic mercury, monomethylmercury and ethylmercury and their cysteine-complexes was also studied by continuous flow-chemical vapor generation atomic fluorescence spectrometry in order to characterize the reduction reaction with tetrahydroborate. When complexed with cysteine, inorganic mercury, monomethylmercury and ethylmercury cannot be separately quantified varying tetrahydroborate concentration due to a lack of selectivity, and their speciation requires a pre-separation stage (e.g. a chromatographic separation). If not complexed with cysteine, monomethylmercury and ethylmercury cannot be separated, as well, but their sum can be quantified separately with respect to inorganic mercury choosing a suitable concentration of tetrahydroborate (e.g. 10{sup -5} mol L{sup -1}), thus allowing the organic/inorganic mercury speciation. The detection limits of the flow injection-chemical vapor generation atomic fluorescence spectrometry method were about 45 nmol L{sup -1} (as mercury) for all the species considered, a relative standard deviation ranging between 1.8 and 2.9% and a linear dynamic range between 0.1 and 5 {mu}mol L{sup -1} were obtained. Recoveries of monomethylmercury and ethylmercury with respect to inorganic mercury were

  17. Flow injection-chemical vapor generation atomic fluorescence spectrometry hyphenated system for organic mercury determination: A step forward

    Science.gov (United States)

    Angeli, Valeria; Biagi, Simona; Ghimenti, Silvia; Onor, Massimo; D'Ulivo, Alessandro; Bramanti, Emilia

    2011-11-01

    Monomethylmercury and ethylmercury were determined on line using flow injection-chemical vapor generation atomic fluorescence spectrometry without neither requiring a pre-treatment with chemical oxidants, nor UV/MW additional post column interface, nor organic solvents, nor complexing agents, such as cysteine. Inorganic mercury, monomethylmercury and ethylmercury were detected by atomic fluorescence spectrometry in an Ar/H 2 miniaturized flame after sodium borohydride reduction to Hg 0, monomethylmercury hydride and ethylmercury hydride, respectively. The effect of mercury complexing agent such as cysteine, ethylendiaminotetracetic acid and HCl with respect to water and Ar/H 2 microflame was investigated. The behavior of inorganic mercury, monomethylmercury and ethylmercury and their cysteine-complexes was also studied by continuous flow-chemical vapor generation atomic fluorescence spectrometry in order to characterize the reduction reaction with tetrahydroborate. When complexed with cysteine, inorganic mercury, monomethylmercury and ethylmercury cannot be separately quantified varying tetrahydroborate concentration due to a lack of selectivity, and their speciation requires a pre-separation stage (e.g. a chromatographic separation). If not complexed with cysteine, monomethylmercury and ethylmercury cannot be separated, as well, but their sum can be quantified separately with respect to inorganic mercury choosing a suitable concentration of tetrahydroborate (e.g. 10 - 5 mol L - 1 ), thus allowing the organic/inorganic mercury speciation. The detection limits of the flow injection-chemical vapor generation atomic fluorescence spectrometry method were about 45 nmol L - 1 (as mercury) for all the species considered, a relative standard deviation ranging between 1.8 and 2.9% and a linear dynamic range between 0.1 and 5 μmol L - 1 were obtained. Recoveries of monomethylmercury and ethylmercury with respect to inorganic mercury were never less than 91%. Flow injection

  18. Very large optical rotation generated by Rb vapor in a multi-pass cell

    CERN Document Server

    Li, S; Sheng, D; Dural, N; Romalis, M V

    2011-01-01

    Paramagnetic Faraday rotation is a powerful technique for atom sensing widely used in quantum non-demolition measurements, fundamental symmetry tests, and other precision measurements. We demonstrate the use of a multi-pass optical cell for Faraday rotation spectroscopy and observe polarization rotation in excess of 100 radians from spin-polarized Rb vapor. Unlike optical cavities, multi-pass cells have a deterministic number of light passes and can be used to measure large optical rotations. We also observe a 10-fold suppression of transverse spin relaxation when Rb atoms are placed in a coherent superposition state immune to spin-exchange collisions.

  19. Remote plasma enhanced chemical vapor deposition of GaP with in situ generation of phosphine precursors

    Science.gov (United States)

    Choi, S. W.; Lucovsky, G.; Bachmann, K. J.

    1992-01-01

    Thin homoepitaxial films of gallium phosphide (GaP) have been grown by remote plasma enhanced chemical vapor deposition utilizing in situ-generated phosphine precursors. The GaP forming reaction is kinetically controlled with an activation energy of 0.65 eV. The increase of the growth rate with increasing radio frequency (RF) power between 20 and 100 W is due to the combined effects of increasingly complete excitation and the spatial extension of the glow discharge toward the substrate; however, the saturation of the growth rate at even higher RF power indicates the saturation of the generation rate of phosphine precursors at this condition. Slight interdiffusion of P into Si and Si into GaP is indicated from GaP/Si heterostructures grown under similar conditions as the GaP homojunctions.

  20. Remote plasma enhanced chemical vapor deposition of GaP with in situ generation of phosphine precursors

    Science.gov (United States)

    Choi, S. W.; Lucovsky, G.; Bachmann, Klaus J.

    1993-01-01

    Thin homoepitaxial films of gallium phosphide (GaP) were grown by remote plasma enhanced chemical vapor deposition utilizing in situ generated phosphine precursors. The GaP forming reaction is kinetically controlled with an activation energy of 0.65 eV. The increase of the growth rate with increasing radio frequency (rf) power between 20 and 100 W is due to the combined effects of increasingly complete excitation and the spatial extension of the glow discharge toward the substrate, however, the saturation of the growth rate at even higher rf power indicates the saturation of the generation rate of phosphine precursors at this condition. Slight interdiffusion of P into Si and Si into GaP is indicated from GaP/Si heterostructures grown under similar conditions as the GaP homojunctions.

  1. Evaluation of Five Phase Digitally Controlled Rotating Field Plasma Source for Photochemical Mercury Vapor Generation Optical Emission Spectrometry.

    Science.gov (United States)

    Matusiewicz, Henryk; Ślachciński, Mariusz; Pawłowski, Paweł; Portalski, Marek

    2015-01-01

    A new sensitive method for total mercury determination in reference materials using a 5-phase digitally controlled rotating field plasma source (RFP) for optical emission spectrometry (OES) was developed. A novel synergic effect of ultrasonic nebulization (USN) and ultraviolet-visible light (UV-Vis) irradiation when used in combination was exploited for efficient Hg vapor generation. UV- and Vis-based irradiation systems were studied. It was found that the most advantageous design was an ultrasonic nebulizer fitted with a 6 W mercury lamp supplying a microliter sample to a quartz oscillator, converting liquid into aerosol at the entrance of the UV spray chamber. Optimal conditions involved using a 20% v/v solution of acetic acid as the generation medium. The mercury cold vapor, favorably generated from Hg(2+) solutions by UV irradiation, was rapidly transported into a plasma source with rotating field generated within the five electrodes and detected by digitally controlled rotating field plasma optical emission spectrometry (RFP-OES). Under optimal conditions, the experimental concentration detection limit for the determination, calculated as the concentration giving a signal equal to three times the standard deviation of the blank (LOD, 3σblank criterion, peak height), was 4.1 ng mL(-1). The relative standard deviation for samples was equal to or better than 5% for liquid analysis and microsampling capability. The methodology was validated through determination of mercury in three certified reference materials (corresponding to biological and environmental samples) (NRCC DOLT-2, NRCC PACS-1, NIST 2710) using the external aqueous standard calibration techniques in acetic acid media, with satisfactory recoveries. Mercury serves as an example element to validate the capability of this approach. This is a simple, reagent-saving, cost-effective and green analytical method for mercury determination.

  2. Factors which determine the utilization of urban solid residue in vapor and electric power generation; Fatores que condicionam o aproveitamento dos residuos solidos urbanos nas geracoes eletricas e de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Flavio B.; Sanchez, Wladimyr [Companhia Energetica de Sao Paulo, SP (Brazil)

    1991-12-31

    this work describes the main aspects concerning the utilization of urban solid residues in electric power and vapor generation such as: the transportation of the solid residues; the strategic factors which should be considered for the success of the plant; economic and financial analysis; and environmental impacts 5 refs., 2 figs.

  3. Generation and delayed retrieval of spatially multimode Raman scattering in warm rubidium vapors

    CERN Document Server

    Chrapkiewicz, Radoslaw

    2014-01-01

    We apply collective Raman scattering to create, store and retrieve spatially multimode light in warm rubidium-87 vapors. The light is created in a spontaneous Stokes scattering process. This is accompanied by the creation of counterpart collective excitations in the atomic ensemble -- the spin waves. After a certain storage time we coherently convert the spin waves into the light in deterministic anti-Stokes scattering. The whole process can be regarded as a delayed four-wave mixing which produces pairs of correlated, delayed random images. Storage of higher order spatial modes up to microseconds is possible owing to usage of a buffer gas. We study the performance of the Raman scattering, storage and retrieval of collective excitations focusing on spatial effects and the influence of decoherence caused by diffusion of rubidium atoms in different buffer gases. We quantify the number of modes created and retrieved by analyzing statistical correlations of intensity fluctuations between portions of the light scat...

  4. Generation and delayed retrieval of spatially multimode Raman scattering in warm rubidium vapors.

    Science.gov (United States)

    Chrapkiewicz, Radosław; Wasilewski, Wojciech

    2012-12-31

    We apply collective Raman scattering to create, store and retrieve spatially multimode light in warm rubidium-87 vapors. The light is created in a spontaneous Stokes scattering process. This is accompanied by the creation of counterpart collective excitations in the atomic ensemble - the spin waves. After a certain storage time we coherently convert the spin waves into the light in deterministic anti-Stokes scattering. The whole process can be regarded as a delayed four-wave mixing which produces pairs of correlated, delayed random images. Storage of higher order spatial modes up to microseconds is possible owing to usage of a buffer gas. We study the performance of the Raman scattering, storage and retrieval of collective excitations focusing on spatial effects and the influence of decoherence caused by diffusion of rubidium atoms in different buffer gases. We quantify the number of modes created and retrieved by analyzing statistical correlations of intensity fluctuations between portions of the light scattered in the far field.

  5. Organic, inorganic and total mercury determination in fish by chemical vapor generation with collection on a gold gauze and electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Duarte, Fábio Andrei; Bizzi, Cezar Augusto; Antes, Fabiane Goldschmidt; Dressler, Valderi Luiz; Flores, Érico Marlon de Moraes

    2009-06-01

    A method for organic, inorganic and total mercury determination in fish tissue has been developed using chemical vapor generation and collection of mercury vapor on a gold gauze inside a graphite tube and further atomization by electrothermal atomic absorption spectrometry. After drying and cryogenic grinding, potassium bromide and hydrochloric acid solution (1 mol L - 1 KBr in 6 mol L - 1 HCl) was added to the samples. After centrifugation, total mercury was determined in the supernatant. Organomercury compounds were selectively extracted from KBr solution using chloroform and the resultant solution was back extracted with 1% m/v L-cysteine. This solution was used for organic Hg determination. Inorganic Hg remaining in KBr solution was directly determined by chemical vapor generation electrothermal atomic absorption spectrometry. Mercury vapor generation from extracts was performed using 1 mol L - 1 HCl and 2.5% m/v NaBH 4 solutions and a batch chemical vapor generation system. Mercury vapor was collected on the gold gauze heated resistively at 80 °C and the atomization temperature was set at 650 °C. The selectivity of extraction was evaluated using liquid chromatography coupled to chemical vapor generation and determination by inductively coupled plasma mass spectrometry. The proposed method was applied for mercury analysis in shark, croaker and tuna fish tissues. Certified reference materials were used to check accuracy and the agreement was better than 95%. The characteristic mass was 60 pg and method limits of detection were 5, 1 and 1 ng g - 1 for organic, inorganic and total mercury, respectively. With the proposed method it was possible to analyze up to 2, 2 and 6 samples per hour for organic, inorganic and total Hg determination, respectively.

  6. Organic, inorganic and total mercury determination in fish by chemical vapor generation with collection on a gold gauze and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Fabio Andrei; Bizzi, Cezar Augusto; Goldschmidt Antes, Fabiane; Dressler, Valderi Luiz [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil); Flores, Erico Marlon de Moraes [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil)], E-mail: flores@quimica.ufsm.br

    2009-06-15

    A method for organic, inorganic and total mercury determination in fish tissue has been developed using chemical vapor generation and collection of mercury vapor on a gold gauze inside a graphite tube and further atomization by electrothermal atomic absorption spectrometry. After drying and cryogenic grinding, potassium bromide and hydrochloric acid solution (1 mol L{sup - 1} KBr in 6 mol L{sup - 1} HCl) was added to the samples. After centrifugation, total mercury was determined in the supernatant. Organomercury compounds were selectively extracted from KBr solution using chloroform and the resultant solution was back extracted with 1% m/v L-cysteine. This solution was used for organic Hg determination. Inorganic Hg remaining in KBr solution was directly determined by chemical vapor generation electrothermal atomic absorption spectrometry. Mercury vapor generation from extracts was performed using 1 mol L{sup - 1} HCl and 2.5% m/v NaBH{sub 4} solutions and a batch chemical vapor generation system. Mercury vapor was collected on the gold gauze heated resistively at 80 deg. C and the atomization temperature was set at 650 deg. C. The selectivity of extraction was evaluated using liquid chromatography coupled to chemical vapor generation and determination by inductively coupled plasma mass spectrometry. The proposed method was applied for mercury analysis in shark, croaker and tuna fish tissues. Certified reference materials were used to check accuracy and the agreement was better than 95%. The characteristic mass was 60 pg and method limits of detection were 5, 1 and 1 ng g{sup - 1} for organic, inorganic and total mercury, respectively. With the proposed method it was possible to analyze up to 2, 2 and 6 samples per hour for organic, inorganic and total Hg determination, respectively.

  7. Dual-mode chemical vapor generation for simultaneous determination of hydride-forming and non-hydride-forming elements by atomic fluorescence spectrometry.

    Science.gov (United States)

    Wang, Yu; Xu, Kailai; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin

    2014-05-21

    A dual-mode chemical vapor generation integrating hydride generation and photochemical vapor generation was developed for simultaneous multi-element analysis of hydride-forming and non-hydride-forming elements by atomic fluorescence spectrometry. Four elements were selected as model elements of hydride-forming (As, Cd) and non-hydride-forming (Ni, Fe) elements to validate this proposed method. Standard or sample solutions were separately pumped to mix with tetrahydroborate, and concentrated formic acid and ammonia, and then directed to a hydride generator and a photochemical reactor to realize simultaneous hydride generation and photochemical vapor generation, respectively. Optimum conditions for dual-mode chemical vapor generation were carefully investigated. Under the optimized conditions, limits of detection of 0.05, 0.008, 0.8 and 0.1 μg L(-1) were obtained for As, Cd, Fe and Ni, respectively. The precisions were 5.0, 5.5, 4.3 and 4.5% (n = 6, RSDs) for 2 μg L(-1) of As, 1 μg L(-1) of Cd, 50 μg L(-1) of Fe and 10 μg L(-1) of Ni, respectively. This method was validated for accuracy with three certified reference water samples and applied to the simultaneous determination of these elements in a tap water sample with spike recoveries in the range of 95-99%.

  8. Failure problems in superheater spacers of steam generators; Problematica de fallas en espaciadores de sobrecalentadores de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Chacon Nava, Jose G.; Martinez Villafane, Alberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Fuentes Samaniego, Raul [Universidad Autonoma de Nuevo Leon (Mexico); Mojica Calderon, Cecilio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    In this article the general aspects of the steam generator superheater fixed spacers failures are analyzed, emphasis is made on the influence several aspects such as the operation of the unit have, the appropriate execution of welds and the selection of binding materials. Likewise several recommendations are made to bring the failures to a minimum. [Espanol] En este articulo se analizan aspectos generales de fallas en espaciadores fijos de sobrecalentadores de generadores de vapor, y se hace hincapie en la influencia que tienen diversos aspectos tales como la operacion de la unidad, la adecuada ejecucion de soldaduras y la seleccion del material de aporte. Asimismo, se proponen algunas recomendaciones para reducir al minimo las fallas.

  9. Simple field device for measurement of dimethyl sulfide and dimethylsulfoniopropionate in natural waters, based on vapor generation and chemiluminescence detection.

    Science.gov (United States)

    Nagahata, Takanori; Kajiwara, Hidetaka; Ohira, Shin-Ichi; Toda, Kei

    2013-05-07

    A small, simple device was developed for trace analysis of dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) in natural waters. These compounds are known to be the major sources of cloud condensation nuclei in the oceanic atmosphere and ideally should be measured onsite because of their volatility and instability. First, chemical and physical vapor generations were examined, and simple pressurizing by injection of 30 mL of air using a syringe was adopted. Pressurized headspace air above a 10 mL water sample was introduced to a detection cell as a result of the pressure differential and mixed with ozone to induce chemiluminescence. Although the measurement procedure was simple, the method was very sensitive: sharp peaks appeared within seconds for nanomolar levels of DMS, and the limit of detection was 0.02 nmol L(-1) (1 ng L(-1)). Although interference from methanethiol was significant, this was successfully addressed by adding a small amount of Cd(2+) before DMS vapor generation. DMSP was also measured after hydrolysis to DMS, as previously reported. Pond water and seawater samples were analyzed, and DMS was found in both types of sample, whereas DMSP was observed only in seawater. The DMS/DMSP data obtained using the developed method were compared with data obtained by purge/trap and gas chromatography-mass spectrometry, and the data from the two methods agreed, with good correlation (R(2) = 0.9956). The developed device is inexpensive, light (5 kg), simple to use, can be applied in the field, and is sensitive enough for fresh- and seawater analysis.

  10. Steam generation process control and automation; Automacao e controle no processo de geracao de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Souza Junior, Jose Cleodon de; Silva, Walmy Andre C.M. da [PETROBRAS S.A., Natal, RN (Brazil)

    2004-07-01

    This paper describes the implementation of the Supervisory Control and Data Acquisition System (SCADA) in the steam generation process for injection in heavy oil fields of the Alto do Rodrigues Production Asset, developed by PETROBRAS/E and P/UN-RNCE. This Asset is located in the northeastern region of Brazil, in Rio Grande do Norte State. It addresses to the steam generators for injection in oil wells and the upgrade project that installed remote terminal units and a new panel controlled by PLC, changed all the pneumatic transmitters by electronic and incorporated the steam quality and oxygen control, providing the remote supervision of the process. It also discusses the improvements obtained in the steam generation after the changes in the conception of the control and safety systems. (author)

  11. Dynamics of vapor bubbles growth at boiling resulting from enthalpy excess of the surrounding superheated liquid and sound pulses generated by bubbles

    Science.gov (United States)

    Dorofeev, B. M.; Volkova, V. I.

    2016-01-01

    The results of experiments investigating the exponential dependence of the vapor bubble radius on time at saturated boiling are generalized. Three different methods to obtain this dependence are suggested: (1) by the application of the transient heat conduction equation, (2) by using the correlations of energy conservation, and (3) by solving a similar electrodynamic problem. Based on the known experimental data, the accuracy of the dependence up to one percent and a few percent accuracy of its description based on the sound pressure generated by a vapor bubble have been determined. A significant divergence of the power dependence of the vapor bubble radius on time (with an exponent of 1/2) with the experimental results and its inadequacy for the description of the sound pulse generated by the bubble have been demonstrated.

  12. UV-photochemical vapor generation of selenium for atomic absorption spectrometry: Optimization and 75Se radiotracer efficiency study

    Science.gov (United States)

    Rybínová, Marcela; Musil, Stanislav; Červený, Václav; Vobecký, Miloslav; Rychlovský, Petr

    2016-09-01

    Volatile selenium compounds were generated UV-photochemically in the continuous flow mode using four UV-photoreactors differing in the material of the reaction coil; Teflon tubing and quartz tubes with various inner diameters and wall thicknesses were tested. Atomic absorption spectrometry with an externally heated quartz furnace atomizer was employed as the detector. The relevant experimental generation parameters were optimized and the basic analytical characteristics were determined. Using formic acid as the photochemical agent, limits of detection achieved for selenium were in the range 46-102 ng L- 1 in dependence on the type of UV-photoreactor employed. When nitric acid was also added to the photochemical agent, the limits of detection were reduced to 27-44 ng L- 1. The repeatability did not exceed 2.4% (5 μg L- 1 Se(IV), n = 10). Experiments with 75Se radiotracer have been performed for the first time to quantify the efficiency of UV-photochemical vapor generation (UV-PVG) of selenium. The highest efficiency of 67 ± 1% was obtained for a UV-photoreactor containing a quartz reaction coil (2.0 mm i.d., 4.0 mm o.d.). The generation efficiency of 61 ± 1% was obtained for a Teflon reaction coil (1.0 mm i.d., 1.4 mm o.d.). Mapping of the radiotracer distribution in the individual parts of the apparatus did not reveal substantial transport losses of the analyte in the UV-PVG system.

  13. Mechanisms of chemical vapor generation by aqueous tetrahydridoborate. Recent developments toward the definition of a more general reaction model

    Science.gov (United States)

    D'Ulivo, Alessandro

    2016-05-01

    A reaction model describing the reactivity of metal and semimetal species with aqueous tetrahydridoborate (THB) has been drawn taking into account the mechanism of chemical vapor generation (CVG) of hydrides, recent evidences on the mechanism of interference and formation of byproducts in arsane generation, and other evidences in the field of the synthesis of nanoparticles and catalytic hydrolysis of THB by metal nanoparticles. The new "non-analytical" reaction model is of more general validity than the previously described "analytical" reaction model for CVG. The non-analytical model is valid for reaction of a single analyte with THB and for conditions approaching those typically encountered in the synthesis of nanoparticles and macroprecipitates. It reduces to the previously proposed analytical model under conditions typically employed in CVG for trace analysis (analyte below the μM level, borane/analyte ≫ 103 mol/mol, no interference). The non-analytical reaction model is not able to explain all the interference effects observed in CVG, which can be achieved only by assuming the interaction among the species of reaction pathways of different analytical substrates. The reunification of CVG, the synthesis of nanoparticles by aqueous THB and the catalytic hydrolysis of THB inside a common frame contribute to rationalization of the complex reactivity of aqueous THB with metal and semimetal species.

  14. The generation of HCl in the system CaCl2-H2O: Vapor-liquid relations from 380-500°C

    Science.gov (United States)

    Bischoff, James L.; Rosenbauer, Robert J.; Fournier, Robert O.

    1996-01-01

    We determined vapor-liquid relations (P-T-x) and derived critical parameters for the system CaCl2-H2O from 380-500??C. Results show that the two-phase region of this system is extremely large and occupies a significant portion of the P-T space to which circulation of fluids in the Earth's crust is constrained. Results also show the system generates significant amounts of HCl (as much as 0.1 mol/kg) in the vapor phase buffered by the liquid at surprisingly high pressures (???230 bars at 380??C, CaCl2: CaCl2 + 2H2O = Ca(OH)2 + 2HCl. We interpret the abundance of HCl in the vapor as due to its preference for the vapor phase, and by the preference of Ca(OH)2 for either the liquid phase or solid. The recent recognition of the abundance of CaCl2 in deep brines of the Earth's crust and their hydrothermal mobilization makes the hydrolysis of CaCl2 geologically important. The boiling of Ca-rich brines produces abundant HCl buffered by the presence of the liquid at moderate pressures. The resultant Ca(OH)2 generated by this process reacts with silicates to form a variety of alteration products, such as epidote, whereas the vapor produces acid-alteration of rocks through which it ascends.

  15. Large scale generation of micro-droplet array by vapor condensation on mesh screen piece

    Science.gov (United States)

    Xie, Jian; Xu, Jinliang; He, Xiaotian; Liu, Qi

    2017-01-01

    We developed a novel micro-droplet array system, which is based on the distinct three dimensional mesh screen structure and sintering and oxidation induced thermal-fluid performance. Mesh screen was sintered on a copper substrate by bonding the two components. Non-uniform residue stress is generated along weft wires, with larger stress on weft wire top location than elsewhere. Oxidation of the sintered package forms micro pits with few nanograsses on weft wire top location, due to the stress corrosion mechanism. Nanograsses grow elsewhere to show hydrophobic behavior. Thus, surface-energy-gradient weft wires are formed. Cooling the structure in a wet air environment nucleates water droplets on weft wire top location, which is more “hydrophilic” than elsewhere. Droplet size is well controlled by substrate temperature, air humidity and cooling time. Because warp wires do not contact copper substrate and there is a larger conductive thermal resistance between warp wire and weft wire, warp wires contribute less to condensation but function as supporting structure. The surface energy analysis of drops along weft wires explains why droplet array can be generated on the mesh screen piece. Because the commercial material is used, the droplet system is cost effective and can be used for large scale utilization.

  16. Direct generation of steam and electricity in a open cycle Rankine; Generacion directa de vapor y electricidad en un ciclo Rankine abierto

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, Alvaro; Almanza, Rafael; Flores, Vicente [UNAM, Mexico, D.F. (Mexico)

    2000-07-01

    In this work the results of the experimental tests about steam and electricity generation are presented. This work carried out in the solar thermal power plant of the Institute of Engineering with direct steam generation in parabolic through. The global efficiency of the system is studied as for the conversion solar-electricity. The efficiency is determined and it describes the obtaining process of the main plant components, like they are, the solar steam generator, the steam motor and the electric generator. [Spanish] En este trabajo se presentan los resultados de las pruebas experimentales de la generacion de vapor y electricidad realizadas en la planta solar del Instituto de Ingenieria con generacion directa de vapor en concentradores de canal parabolico. Se estudia la eficiencia global del sistema en cuanto a la conversion de energia solar-electricidad. Se determina la eficiencia y describe el proceso de obtencion de la misma y de los principales componentes de la planta como son, el generador de vapor solar, el motor de pistones de vapor y el alternador electrico.

  17. Description of a program for steam generators; Descripcion de un programa de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Campana, F. J.

    2014-10-01

    Steam Generators (SGs) are a key component of PWR nuclear power plants, maintaining their structural integrity throughout their life time is necessary to allow for long term operation (LTD) of PWR plants. NEI 97-06 provides the fundamental elements to be included in a SG Program. In addiction it describes performance criteria that SG tubes have to meet in order to provide reasonable assurance that the tubes are still able to maintain specific safety function. Hence, it is mandatory for plants with SGs to have defined a SG program consistent with NEI 97-06 and contains the elements which are described by it. This Program must contain some elements such as, Degradation Assessment, inspection and Integrity Assessment, among other. (Author)

  18. Development of Liquid-Vapor Core Reactors with MHD Generator for Space Power and Propulsion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Samim Anghaie

    2002-08-13

    Any reactor that utilizes fuel consisting of a fissile material in a gaseous state may be referred to as a gaseous core reactor (GCR). Studies on GCRs have primarily been limited to the conceptual phase, mostly due to budget cuts and program cancellations in the early 1970's. A few scientific experiments have been conducted on candidate concepts, primarily of static pressure fissile gas filling a cylindrical or spherical cavity surrounded by a moderating shell, such as beryllium, heavy water, or graphite. The main interest in this area of nuclear power generation is for space applications. The interest in space applications has developed due to the promise of significant enhancement in fuel utilization, safety, plant efficiency, special high-performance features, load-following capabilities, power conversion optimization, and other key aspects of nuclear power generation. The design of a successful GCR adapted for use in space is complicated. The fissile material studied in the pa st has been in a fluorine compound, either a tetrafluoride or a hexafluoride. Both of these molecules have an impact on the structural material used in the making of a GCR. Uranium hexafluoride as a fuel allows for a lower operating temperature, but at temperatures greater than 900K becomes essentially impossible to contain. This difficulty with the use of UF6 has caused engineers and scientists to use uranium tetrafluoride, which is a more stable molecule but has the disadvantage of requiring significantly higher operating temperatures. Gas core reactors have traditionally been studied in a steady state configuration. In this manner a fissile gas and working fluid are introduced into the core, called a cavity, that is surrounded by a reflector constructed of materials such as Be or BeO. These reactors have often been described as cavity reactors because the density of the fissile gas is low and criticality is achieved only by means of the reflector to reduce neutron leakage from the

  19. Use of water processed by reverse osmosis For vapor generation in tobacco industry

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Klimeck Gouvea

    2012-06-01

    Full Text Available This article presents a study due to the technical use of reverse osmosis to treat the boiler water for steam generation in a plant of tobacco processing in Santa Catarina, Brazil. The monitoring was conducted between the years 2006 to 2008, presenting the results concerning the improvement of water quality with emphasis on environmental and financial gains. Water quality can be observed by the reduction of 90% in silica content and 100% hardness, leading to a reduction of incrustation and corrosion of the system. Moreover, a reduction in the discharges water from the boiler volume reduced the water consumption by approximately 6,000 m3/year and also the consumption of chemicals used in wastewater treatment plant, with a reduction of 32.76 m3/day of effluents to treatment. The reducing of energy with natural gas for water heating replacement was almost 900,000 m3/year (19.45%, because of increased in heat exchange efficiency. The reducing in the CO2 emissions was in order of 1215,65 t/year. Finally, based on the achieved results obtained, can be possible to assume a reducing costs of production as a whole.

  20. Remedial actions to improve the availability in steam generators; Acciones correctivas para mejorar la disponibilidad en generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Torres Toledano, J. Gerardo; Porras Loaiza, G. Lizbeth; Sanchez Hernandez, Laura E.; Salinas B, Victor M.; Nebart G, Jesus [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    In this article the results of the analysis of recurrent faults of four Generating Units of Thermoelectric Power Plants (UGT) of the Commission Federal de Electricidad (CFE) are presented. In three of the four cases, the studies focused to identify and to correct the root causes of recurrent faults in steam generator tubes, the analyzed units are: U-2 of the Thermoelectric Complex Pdte. Adolfo Lopez Mateos (CTPALM) of Tuxpan, Veracruz; U-3 of the Salamanca Thermoelectric Power Plant (TPP), and U-1 and 2 of the Thermoelectric Power Plant (TPP) Felipe Carrillo Puerto of Valladolid, Yucatan. In the other case the combinations air insufficiency was analyzed as one of the causes of decrement of power of the Unit 1 of the TPP Gral. Manuel Alvarez Moreno of Manzanillo, Colima. The steam generators of Unit 2 of the CTPALM and Unit 3 of the TPP of Salamanca presented faults in the reheater (RH) bank. In this case the recommendations focused to the improvement in the operative conditions to attenuate the faults by corrosion at high temperature. Unlike the CTPALM, in the case of U-3 of Salamanca it was concluded that the redesign of the RH was necessary; for this purpose it was proposed to permute trajectories of hot tubes with the cold ones to make the steam temperature uniform at the RH outlet. In order to evaluate the problems that have appeared in the steam generator of Units 1 and 2 of the TPP Felipe Carrillo Puerto of Valladolid, Yucatan the faults of the tubes of water wall were analyzed and it was found that the main mechanism of overheat is due to the impact of the combustion flame. In the study of the Unit 1 of the TPP Gral. Manuel Alvarez Moreno of Manzanillo, Colima, a methodology was developed to quantify the contribution that the main equipment has in the decrement of the power of the unit; this methodology consists of applying a process of computational simulation based in the design conditions and of real operation. In agreement with the obtained results, it

  1. Remedial actions to improve the availability in steam generators; Acciones correctivas para mejorar la disponibilidad en generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Torres Toledano, J. Gerardo; Porras Loaiza, G. Lizbeth; Sanchez Hernandez, Laura E.; Salinas B, Victor M.; Nebart G, Jesus [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    In this article the results of the analysis of recurrent faults of four Generating Units of Thermoelectric Power Plants (UGT) of the Commission Federal de Electricidad (CFE) are presented. In three of the four cases, the studies focused to identify and to correct the root causes of recurrent faults in steam generator tubes, the analyzed units are: U-2 of the Thermoelectric Complex Pdte. Adolfo Lopez Mateos (CTPALM) of Tuxpan, Veracruz; U-3 of the Salamanca Thermoelectric Power Plant (TPP), and U-1 and 2 of the Thermoelectric Power Plant (TPP) Felipe Carrillo Puerto of Valladolid, Yucatan. In the other case the combinations air insufficiency was analyzed as one of the causes of decrement of power of the Unit 1 of the TPP Gral. Manuel Alvarez Moreno of Manzanillo, Colima. The steam generators of Unit 2 of the CTPALM and Unit 3 of the TPP of Salamanca presented faults in the reheater (RH) bank. In this case the recommendations focused to the improvement in the operative conditions to attenuate the faults by corrosion at high temperature. Unlike the CTPALM, in the case of U-3 of Salamanca it was concluded that the redesign of the RH was necessary; for this purpose it was proposed to permute trajectories of hot tubes with the cold ones to make the steam temperature uniform at the RH outlet. In order to evaluate the problems that have appeared in the steam generator of Units 1 and 2 of the TPP Felipe Carrillo Puerto of Valladolid, Yucatan the faults of the tubes of water wall were analyzed and it was found that the main mechanism of overheat is due to the impact of the combustion flame. In the study of the Unit 1 of the TPP Gral. Manuel Alvarez Moreno of Manzanillo, Colima, a methodology was developed to quantify the contribution that the main equipment has in the decrement of the power of the unit; this methodology consists of applying a process of computational simulation based in the design conditions and of real operation. In agreement with the obtained results, it

  2. Direct determination of mercury in white vinegar by matrix assisted photochemical vapor generation atomic fluorescence spectrometry detection

    Energy Technology Data Exchange (ETDEWEB)

    Liu Qingyang, E-mail: liuqingyang0807@yahoo.com.c [Beijing Center for Physical and Chemical Analysis, Beijing 100089 (China)

    2010-07-15

    This paper proposes the use of photochemical vapor generation with acetic acid as sample introduction for the direct determination of ultra-trace mercury in white vinegars by atomic fluorescence spectrometry. Under ultraviolet irradiation, the sample matrix (acetic acid) can reduce mercury ion to atomic mercury Hg{sup 0}, which is swept by argon gas into an atomic fluorescence spectrometer for subsequent analytical measurements. The effects of several factors such as the concentration of acetic acid, irradiation time, the flow rate of the carrier gas and matrix effects were discussed and optimized to give detection limits of 0.08 ng mL{sup -1} for mercury. Using the experimental conditions established during the optimization (3% v/v acetic acid, 30 s irradiation time and 20 W mercury lamp), the precision levels, expressed as relative standard deviation, were 4.6% (one day) and 7.8% (inter-day) for mercury (n = 9). Addition/recovery tests for evaluation of the accuracy were in the range of 92-98% for mercury. The method was also validated by analysis of vinegar samples without detectable amount of Hg spiked with aqueous standard reference materials (GBW(E) 080392 and GBW(E) 080393). The results were also compared with those obtained by acid digestion procedure and determination of mercury by ICP-MS. There was no significant difference between the results obtained by the two methods based on a t-test (at 95% confidence level).

  3. Direct determination of mercury in white vinegar by matrix assisted photochemical vapor generation atomic fluorescence spectrometry detection

    Science.gov (United States)

    Liu, Qingyang

    2010-07-01

    This paper proposes the use of photochemical vapor generation with acetic acid as sample introduction for the direct determination of ultra-trace mercury in white vinegars by atomic fluorescence spectrometry. Under ultraviolet irradiation, the sample matrix (acetic acid) can reduce mercury ion to atomic mercury Hg 0, which is swept by argon gas into an atomic fluorescence spectrometer for subsequent analytical measurements. The effects of several factors such as the concentration of acetic acid, irradiation time, the flow rate of the carrier gas and matrix effects were discussed and optimized to give detection limits of 0.08 ng mL -1 for mercury. Using the experimental conditions established during the optimization (3% v/v acetic acid, 30 s irradiation time and 20 W mercury lamp), the precision levels, expressed as relative standard deviation, were 4.6% (one day) and 7.8% (inter-day) for mercury ( n = 9). Addition/recovery tests for evaluation of the accuracy were in the range of 92-98% for mercury. The method was also validated by analysis of vinegar samples without detectable amount of Hg spiked with aqueous standard reference materials (GBW(E) 080392 and GBW(E) 080393). The results were also compared with those obtained by acid digestion procedure and determination of mercury by ICP-MS. There was no significant difference between the results obtained by the two methods based on a t-test (at 95% confidence level).

  4. Design, Modeling, Fabrication, and Evaluation of Thermoelectric Generators with Hot-Wire Chemical Vapor Deposited Polysilicon as Thermoelement Material

    Science.gov (United States)

    de Leon, Maria Theresa; Tarazona, Antulio; Chong, Harold; Kraft, Michael

    2014-11-01

    This paper presents the design, modeling, fabrication, and evaluation of thermoelectric generators (TEGs) with p-type polysilicon deposited by hot-wire chemical vapor deposition (HWCVD) as thermoelement material. A thermal model is developed based on energy balance and heat transfer equations using lumped thermal conductances. Several test structures were fabricated to allow characterization of the boron-doped polysilicon material deposited by HWCVD. The film was found to be electrically active without any post-deposition annealing. Based on the tests performed on the test structures, it is determined that the Seebeck coefficient, thermal conductivity, and electrical resistivity of the HWCVD polysilicon are 113 μV/K, 126 W/mK, and 3.58 × 10-5 Ω m, respectively. Results from laser tests performed on the fabricated TEG are in good agreement with the thermal model. The temperature values derived from the thermal model are within 2.8% of the measured temperature values. For a 1-W laser input, an open-circuit voltage and output power of 247 mV and 347 nW, respectively, were generated. This translates to a temperature difference of 63°C across the thermoelements. This paper demonstrates that HWCVD, which is a cost-effective way of producing solar cells, can also be applied in the production of TEGs. By establishing that HWCVD polysilicon can be an effective thermoelectric material, further work on developing photovoltaic-thermoelectric (PV-TE) hybrid microsystems that are cost-effective and better performing can be explored.

  5. Copper Vapor Generator

    Science.gov (United States)

    1974-09-01

    The relation between density and refractive index in a gas is described by the Pale- Gladstone Law 60 • i M where the summation is over the...ias Phase," J.Clietn. Phys. 5], 2757 ( 1969 ). 22. G.M. Grover. TP. Cotter, and G.F. Erickson, "Structures of Very High Thermal Conductance...34 J.Appl.Phys. 40. 3370 ( 1969 ). 24. PP. Sorokin and J.R. Lankard. "Infrared Lasers Resulting from Gitut Pulse Laser Excitation of Alkali Metal Molecules

  6. Determination of copper in airborne particulate matter using slurry sampling and chemical vapor generation atomic absorption spectrometry.

    Science.gov (United States)

    Silva, Laiana O B; Leao, Danilo J; dos Santos, Debora C; Matos, Geraldo D; de Andrade, Jailson B; Ferreira, Sergio L C

    2014-09-01

    The present paper describes the development of a method for the determination of copper in airborne particulate matter using slurry sampling and chemical vapor generation atomic absorption spectrometry (CVG AAS). Chemometric tools were employed to characterize the influence of several factors on the generation of volatile copper species. First, a two-level full factorial design was performed that included the following chemical variables: hydrochloric acid concentration, tetrahydroborate concentration, sulfanilamide concentration and tetrahydroborate volume, using absorbance as the response. Under the established experimental conditions, the hydrochloric acid concentration had the greatest influence on the generation of volatile copper species. Subsequently, a Box-Behnken design was performed to determine the optimum conditions for these parameters. A second chemometric study employing a two-level full factorial design was performed to evaluate the following physical factors: tetrahydroborate flow rate, flame composition, alcohol volume and sample volume. The results of this study demonstrated that the tetrahydroborate flow rate was critical for the process. The chemometric experiments determined the following experimental conditions for the method: hydrochloric acid concentration, 0.208 M; tetrahydroborate concentration, 4.59%; sulfanilamide concentration, 0.79%; tetrahydroborate volume, 2.50 mL; tetrahydroborate flow rate, 6.50 mL min(-1); alcohol volume, 200 µL; and sample volume, 7.0 mL. Thus, this method, using a slurry volume of 500 µL and a final dilution of 7 mL, allowed for the determination of copper with limits of detection and quantification of 0.30 and 0.99 µg L(-1), respectively. Precisions, expressed as RSD%, of 4.6 and 2.8% were obtained using copper solutions at concentrations of 5.0 and 50.0 µg L(-1), respectively. The accuracy was evaluated by the analysis of a certified reference material of urban particulate matter. The copper concentration

  7. Estimation of fouling factors in the design of steam generators; Estimacion de factores de ensuciamiento en el diseno de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Flores Archila, David Ivanhoe

    1997-12-31

    This thesis proposes an alternative to correct design problems the evaluation of fouling factors of thermal energy transfer components of a power station generator. That alternative involves the development of a subroutine to apply fundamental empirical thermal transfer correlations, written in FORTRAN language and extends a principal program for steam generator thermal analysis, developed by Instituto de Investigaciones Electricas. [Espanol] Esta tesis propone una alternativa, basada en el calculo de factores de ensuciamiento de elementos de transferencia de energia termica de un generador de vapor, como mecanismo para corregir el diseno deficiente de areas de calefaccion. Esta alternativa involucra el desarrollo de una subrutina, escrita en FORTRAN, la cual realiza el calculo de los factores de ensuciamiento empleando correlaciones fundamentadas en la teoria de los procesos de transferencia de calor y forma parte de un programa principal para el analisis termico de generadores de vapor desarrollado en el Instituto de Investigaciones Electricas.

  8. Algorithm for the calculation of a steam generator efficiency; Algoritmo para el calculo de la eficiencia de un generador de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Franco, David; Ambriz, Juan Jose; Romero Paredes, Hernando [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1994-12-31

    The efficiency calculation of steam generators is not always simple. The purpose of this paper is to propose an algorithm for the calculation of steam generators efficiency, easy to understand and carry out, in the form of a series of steps to be followed. It takes as starting point that the person in charge of applying these calculations has knowledge of the combustion processes and thermodynamic principles that rule such processes. [Espanol] El calculo de la eficiencia de los generadores de vapor no siempre es sencillo, el presente trabajo tiene como objetivo el de proponer un algoritmo de calculo de eficiencia de generadores de vapor, el cual sea facil de entender y de llevar a cabo, en forma de una serie de pasos a seguir. Se toma como punto de partida, que la persona encargada de aplicar estos calculos tenga el conocimiento de los procesos de combustion y principios termodinamicos que rigen tales procesos.

  9. On-line continuous generation of zinc chelates in the vapor phase by reaction with sodium dithiocarbamates and determination by atomic fluorescence spectrometry

    Science.gov (United States)

    Duan, Xuchuan; Sun, Rui; Fang, Jinliang

    2017-02-01

    The present study shows for the first time that a volatile zinc chelate species can be generated by the on-line continuous merging of an acidified sample solution with an aqueous sodium diethyldithiocarbamate solution followed by rapid separation using a frit-based bubble gas-liquid separator at room temperature. The operating conditions for the generation of the vaporous zinc chelate were preliminarily investigated by non-dispersive atomic fluorescence spectrometry. The possible mechanism of zinc vapor generation is discussed. The study shows that the volatile species is an intermediate species with very similar properties to diethyldithiocarbamic acid and a very short half-life in the acidic solution. Moreover, this species can only be generated by on-line mixing and rapid separation. The efficiency of generation was 33-85% depending on acidity. Under optimal conditions, the flow rates of the sample and Na-DDTC solution were 1.3 ml min- 1, the carrier argon flow rate was 225 ml min- 1, the acid concentration of the sample solution and the concentration of Na-DDTC were 0.05 M and 0.4% (m/v), respectively, the detection limit of zinc was 0.33 (3σ) ng ml- 1, and the relative standard deviation (RSD) was 1.3%. The accuracy of the method was verified by the determination of zinc in the plant reference materials GBW10015 (spinach) and GBW10045 (rice). The results were in good agreement with the certified reference values.

  10. Effect of the carrier gas flow rate on the microstructure evolution and the generation of the charged nanoparticles during silicon chemical vapor deposition.

    Science.gov (United States)

    Youn, Woong-Kyu; Kim, Chan-Soo; Hwang, Nong-Moon

    2013-10-01

    The generation of charged nanoparticles in the gas phase has been continually reported in many chemical vapor deposition processes. Charged silicon nanoparticles in the gas phase were measured using a differential mobility analyzer connected to an atmospheric-pressure chemical vapor deposition reactor at various nitrogen carrier gas flow rates (300-1000 standard cubic centimeter per minute) under typical conditions for silicon deposition at the reactor temperature of 900 degrees C. The carrier gas flow rate affected not only the growth behavior of nanostructures but also the number concentration and size distribution of both negatively and positively charged nanoparticles. As the carrier gas flow rate decreased, the growth behavior changed from films to nanowires, which grew without catalytic metal nanoparticles on a quartz substrate.

  11. Direct determination of arsenic in soil samples by fast pyrolysis–chemical vapor generation using sodium formate as a reductant followed by nondispersive atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Xuchuan; Zhang, Jingya; Bu, Fanlong

    2015-09-01

    This new study shows for the first time that sodium formate can react with trace arsenic to form volatile species via fast pyrolysis – chemical vapor generation. We found that the presence of thiourea greatly enhanced the generation efficiency and eliminated the interference of copper. We studied the reaction temperature, the volume of sodium formate, the reaction acidity, and the carried argon rate using nondispersive atomic fluorescence spectrometry. Under optimal conditions of T = 500 °C, the volumes of 30% sodium formate and 10% thiourea were 0.2 ml and 0.05 ml, respectively. The carrier argon rate was 300 ml min{sup −1} and the detection limit and precision of arsenic were 0.39 ng and 3.25%, respectively. The amount of arsenic in soil can be directly determined by adding trace amount of hydrochloric acid as a decomposition reagent without any sample pretreatment. The method was successfully applied to determine trace amount of arsenic in two soil-certified reference materials (GBW07453 and GBW07450), and the results were found to be in agreement with certified reference values. - Highlights: • Sodium formate can react with trace arsenic to form volatile species via pyrolysis–chemical vapor generation. • Thiourea can enhance the generation efficiency and eliminate the interference of copper. • Arsenic in soil Sample can be directly determined without sample pretreatment.

  12. Enhanced generation of vacuum-ultraviolet radiation by four-wave mixing in mercury using pulsed laser vaporization

    Science.gov (United States)

    Chénais, S.; Forget, S.; Philippet, L.; Castex, M.-C.

    2007-11-01

    The efficiency of a coherent vacuum ultraviolet (VUV) source at 125 nm, based on two-photon resonant four-wave mixing in mercury vapor, has been enhanced by up to two orders of magnitude. This enhancement was obtained by locally heating a liquid mercury surface with a pulsed excimer laser, resulting in a high-density vapor plume in which the nonlinear interaction occurred. Energies up to 5 μJ (1 kW peak power) have been achieved while keeping the overall mercury cell at room temperature, avoiding the use of a complex heat pipe. We have observed a strong saturation of the VUV yield when peak power densities of the fundamental beams exceeded the GW/cm2 range, as well as a large intensity-dependent broadening (up to ˜ 30 cm-1) of the two-photon resonance. The source has potential applications for high-resolution interference lithography and photochemistry.

  13. Vapor shielding effects on energy transfer from plasma-gun generated ELM-like transient loads to material surfaces

    Science.gov (United States)

    Kikuchi, Y.; Sakuma, I.; Asai, Y.; Onishi, K.; Isono, W.; Nakazono, T.; Nakane, M.; Fukumoto, N.; Nagata, M.

    2016-02-01

    Energy transfer processes from ELM-like pulsed helium (He) plasmas with a pulse duration of ˜0.1 ms to aluminum (Al) and tungsten (W) surfaces were experimentally investigated by the use of a magnetized coaxial plasma gun device. The surface absorbed energy density of the He pulsed plasma on the W surface measured with a calorimeter was ˜0.44 MJ m-2, whereas it was ˜0.15 MJ m-2 on the Al surface. A vapor layer in front of the Al surface exposed to the He pulsed plasma was clearly identified by Al neutral emission line (Al i) measured with a high time resolution spectrometer, and fast imaging with a high-speed visible camera filtered around the Al i emission line. On the other hand, no clear evaporation in front of the W surface exposed to the He pulsed plasma was observed in the present condition. Discussions on the reduction in the surface absorbed energy density on the Al surface are provided by considering the latent heat of vaporization and radiation cooling due to the Al vapor cloud.

  14. Studies of the composition and reactivity of carbon species generated through laser vaporization of graphite, tantalum carbide and tungsten carbide

    Energy Technology Data Exchange (ETDEWEB)

    Ortman, B.J.

    1987-01-01

    Vapor compositions above graphite, tantalum carbide, and tungsten carbide together with the chemical reactions of C/sub 1/, C/sub 2/ and C/sub 3/ were studied by the techniques of CW laser vaporization, matrix isolation, and FTIR spectroscopy. The carbon species were scavenged by cocondensing reactive gases (N/sub 2/, H/sub 2/, O/sub 2/, CO and H/sub 2/O) with the vapors of graphitic samples in argon or nitrogen matrices. Products were identified from their infrared spectra. Photolysis and annealing studies were also conducted to detect reaction intermediates, formation of carbon clusters, and metastable C/sub 1/, C/sub 2/, and C/sub 3/ adducts with the added reactants. From these experiments, CO was shown to be potentially the most useful scavenger molecule, since it reacted with both C/sub 1/ and C/sub 2/ to form C/sub 2/O and C/sub 3/O, respectively. CO also reacted with C/sub 3/ to form an adduct, which rearranges upon photolysis to form C/sub 4/O, a previously unknown molecule. Its identity was confirmed by isotopic studies and comparison of its vibrations to those of related molecules, C/sub 3/O, C/sub 2/O, and CO.

  15. Experimental verification of the vaporization's contribution to the shock waves generated by underwater electrical wire explosion under micro-second timescale pulsed discharge

    Science.gov (United States)

    Han, Ruoyu; Zhou, Haibin; Wu, Jiawei; Clayson, Thomas; Ren, Hang; Wu, Jian; Zhang, Yongmin; Qiu, Aici

    2017-06-01

    This paper studies pressure waves generated by exploding a copper wire in a water medium, demonstrating the significant contribution of the vaporization process to the formation of shock waves. A test platform including a pulsed current source, wire load, chamber, and diagnostic system was developed to study the shock wave and optical emission characteristics during the explosion process. In the experiment, a total of 500 J was discharged through a copper wire load 0.2 mm in diameter and 4 cm in length. A water gap was installed adjacent to the load so that the current was diverted away from the load after breakdown occurred across the water gap. This allows the electrical energy injection into the load to be interrupted at different times and at different stages of the wire explosion process. Experimental results indicate that when the load was bypassed before the beginning of the vaporization phase, the measured peak pressure was less than 2.5 MPa. By contrast, the peak pressure increased significantly to over 6.5 MPa when the water gap broke down after the beginning of the vaporization phase. It was also found that when bypassing the load after the voltage peak, similar shock waves were produced to those from a non-bypassed load. However, the total optical emission of these bypassed loads was at least an order of magnitude smaller. These results clearly demonstrate that the vaporization process is vital to the formation of shock waves and the energy deposited after the voltage collapse may only have a limited effect.

  16. Chemical Vapor Deposition of GeSbTe Thin Films for Next-Generation Phase Change Memory

    Science.gov (United States)

    Machida, Hideaki; Hamada, Seichi; Horiike, Takafumi; Ishikawa, Masato; Ogura, Atsushi; Ohshita, Yoshio; Ohba, Takayuki

    2010-05-01

    In this paper, we describe chemical vapor deposition (CVD) of GeSbTe (GST) films for fabricating phase change memory. A low-carbon-impurity GST film was deposited by CVD. Film composition and structure varied significantly depending on deposition temperature and pressure. The tendency of composition variation on a TiN substrate was the same as that on a SiO2 substrate. Finally, flat Ge2Sb2Te5 thin films were obtained below 300 °C using tert-butylgermanium, triisopropylantimony and diisopropyltellurium as precursors.

  17. Determination of Se in biological samples by axial view inductively coupled plasma optical emission spectrometry after digestion with aqua regia and on-line chemical vapor generation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Eder Jose dos [Instituto de Tecnologia do Parana (TECPAR), 81350-010 Curitiba, PR (Brazil)], E-mail: eder@tecpar.br; Herrmann, Amanda Beatriz; Kulik de Caires, Suzete [Instituto de Tecnologia do Parana (TECPAR), 81350-010 Curitiba, PR (Brazil); Azzolin Frescura, Vera Lucia; Curtius, Adilson Jose [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), 880400-900 Florianopolis, SC (Brazil)

    2009-06-15

    A simple and fast method for the determination of Se in biological samples, including food, by axial view inductively coupled plasma optical emission spectrometry using on-line chemical vapor generation (CVG-ICP OES) is proposed. The concentrations of HCl and NaBH{sub 4}, used in the chemical vapor generation were optimized by factorial analysis. Six certified materials (non-fat milk powder, lobster hepatopancreas, human hair, whole egg powder, oyster tissue, and lyophilised pig kidney) were treated with 10 mL of aqua regia in a microwave system under reflux for 15 min followed by additional 15 min in an ultrasonic bath. The solutions were transferred to a 100 mL volumetric flask and the final volume was made up with water. The Se was determined directly in these solutions by CVG-ICP OES, using the analytical line at 196.026 nm. Calibration against aqueous standards in 10% v/v aqua regia in the concentration range of 0.5-10.0 {mu}g L{sup -} {sup 1} Se(IV) was used for the analysis. The quantification limit, considering a 0.5 g sample weight in a final volume of 100 mL{sup -} {sup 1} was 0.10 {mu}g g{sup -} {sup 1}. The obtained concentration values were in agreement with the total certified concentrations, according to the t-test for a 95% confidence level.

  18. Determination of mercury compounds in fish by microwave-assisted extraction and liquid chromatography-vapor generation-inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Chiou, Chwei-Sheng; Jiang, Shiuh-Jen; Kumar Danadurai, K. Suresh

    2001-07-01

    A method employing a vapor generation system and LC combined with inductively coupled plasma mass spectrometry (LC-ICP-MS) is presented for the determination of mercury in biological tissues. An open vessel microwave digestion system was used to extract the mercury compounds from the sample matrix. The efficiency of the mobile phase, a mixture of L-cysteine and 2-mercaptoethanol, was evaluated for LC separation of inorganic mercury [Hg(II)], methylmercury (methyl-Hg) and ethylmercury (ethyl-Hg). The sensitivity, detection limits and repeatability of the liquid chromatography (LC) ICP-MS system with a vapor generator were comparable to, or better than, that of an LC-ICP-MS system with conventional pneumatic nebulization, or other sample introduction techniques. The experimental detection limits for various mercury species were in the range of 0.05-0.09 ng ml -1 Hg, based on peak height. The proposed method was successfully applied to the determination of mercury compounds in a swordfish sample purchased from the local market. The accuracy of the method was evaluated by analyzing a marine biological certified reference material (DORM-2, NRCC).

  19. Enhancing vapor generation at a liquid-solid interface using micro/nanoscale surface structures fabricated by femtosecond laser surface processing

    Science.gov (United States)

    Anderson, Troy P.; Wilson, Chris; Zuhlke, Craig A.; Kruse, Corey; Gogos, George; Ndao, Sidy; Alexander, Dennis

    2015-03-01

    Femtosecond Laser Surface Processing (FLSP) is a versatile technique for the fabrication of a wide variety of micro/nanostructured surfaces with tailored physical and chemical properties. Through control over processing conditions such as laser fluence, incident pulse count, polarization, and incident angle, the size and density of both micrometer and nanometer-scale surface features can be tailored. Furthermore, the composition and pressure of the environment both during and after laser processing have a substantial impact on the final surface chemistry of the target material. FLSP is therefore a powerful tool for optimizing interfacial phenomena such as wetting, wicking, and phasetransitions associated with a vapor/liquid/solid interface. In the present study, we utilize a series of multiscale FLSPgenerated surfaces to improve the efficiency of vapor generation on a structured surface. Specifically, we demonstrate that FLSP of stainless steel 316 electrode surfaces in an alkaline electrolysis cell results in increased efficiency of the water-splitting reaction used to generate hydrogen. The electrodes are fabricated to be superhydrophilic (the contact angle of a water droplet on the surface is less than 5 degrees). The overpotential of the hydrogen evolution reaction (HER) is measured using a 3-electrode configuration with a structured electrode as the working electrode. The enhancement is attributed to several factors including increased surface area, increased wettability, and the impact of micro/nanostructures on the bubble formation and release. Special emphasis is placed on identifying and isolating the relative impacts of the various contributions.

  20. Determination of mercury in coal by isotope dilution cold-vapor generation inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Long, Stephen E; Kelly, W Robert

    2002-04-01

    A method based on isotope dilution cold-vapor inductively coupled plasma mass spectrometry (ID-CV-ICPMS) has been developed for high-accuracy determinations of mercury in bituminous and sub-bituminous coals. A closed-system digestion process employing a Carius tube is used to completely oxidize the coal matrix and chemically equilibrate the mercury in the sample with a 201Hg isotopic spike. The digestates are diluted with high-purity quartz-distilled water, and the mercury is released as a vapor by reduction with tin(II) chloride. Measurements of 201Hg/202Hg isotope ratios are made using a quadrupole ICPMS system in time-resolved analysis mode. The new method has some significant advantages over existing methods. The instrument detection limit is less than 1 pg/mL. The average blank (n = 17) is 30 pg, which is roughly 1 order of magnitude lower than the equivalent microwave digestion procedure. The detection limit in coal is blank limited and is approximately 40 pg/g. Memory effects are very low. The relative reproducibility of the analytical measurements is approximately 0.5% for mercury concentrations in the range 10-150 ng/g. The method has been used to measure mercury concentrations in six coal reference materials, SRM 1632b (77.4 ng/g), SRM 1632c (94.3 ng/g), BCR 40 (433.2 ng/g), BCR 180 (125.0 ng/g), BCR 181 (135.8 ng/g), and SARM 20 (252.6 ng/g), as well as a coal fly ash, SRM 1633b (143.1 ng/g). The method is equally applicable to other types of fossil fuels including both crude and refined oils.

  1. Determination of mercury in coal by isotope dilution cold-vapor generation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.E.; Kelly, W.R.

    2002-04-01

    A method based on isotope dilution cold-vapor inductively coupled plasma mass spectrometry (ID-CV-ICPMS) has been developed for high-accuracy determinations of mercury in bituminous and sub-bituminous coals. A closed-system digestion process employing a Carius tube is used to completely oxidize the coal matrix and chemically equilibrate the mercury in the sample with a Hg-201 isotopic spike. The digestates are diluted with high-purity quartz-distilled water, and the mercury is released as a vapor by reduction with tin chloride. Measurements of Hg-201/Hg-202 isotope ratios are made using a quadrupole ICPMS system in time-resolved analysis mode. The new method has some significant advantages over existing methods. The instrument detection limit is less than 1 pg/mL. The average blank (n = 17) is 30 pg, which is roughly 1 order of magnitude lower than the equivalent microwave digestion procedure. The detection limit in coal is blank limited and is similar to 40 pg/g. Memory effects are very low. The relative reproducibility of the analytical measurements is similar to 0.5% for mercury concentrations in the range 10-150 ng/g. The method has been used to measure mercury concentrations in six coal reference materials, SRM 1632b (77.4 ng/g), SRM 1632c (94.3 ng/g), BCR 40 (433.2 ng/g), BCR 180 (125.0 ng/g), BCR 181 (135.8 ng/g), and SARM 20 (252.6 ng/g), as well as a coal fly ash, SRM 1633b (143.1 ng/g). The method is equally applicable to other types of fossil fuels including both crude and refined oils.

  2. ''Risk safety of high frequency fatigue rupture for the vapor generators tubes''; ''Prevention du risque de rupture par fatigue vibratoire des tubes de generateurs de vapeur''

    Energy Technology Data Exchange (ETDEWEB)

    Solgadi, E.; Le Duff, J.A. [FRAMATOME, 92 - Paris-La-Defense (France); Bussy, B. [Electricite de France, 75 - Paris (France). Service Etudes et Projets Thermiques et Nucleaires

    2001-07-01

    Among the different rupture ways identified since 1975 for the steam generators tubes, the fatigue damage occurred on four cases. Two of them are analyzed in this paper: the NORTH ANNA 1 and the MIHAMA 2. From these analysis, it appears that the fatigue crack happens with aggravating factors as the tube embedding, the anti-vibration bars or fretting corrosion. As a preventive, the number of anti-vibration bars has been increase for the vapor generators 1300 and a new system of damper has been developed and implemented on the vapor generator 900. (A.L.B.)

  3. Experimental generation of quadruple quantum-correlated beams from hot rubidium vapor by cascaded four-wave mixing using spatial multiplexing

    Science.gov (United States)

    Cao, Leiming; Qi, Jian; Du, Jinjian; Jing, Jietai

    2017-02-01

    Multimode quantum states, such as multipartite quantum entanglement or quantum correlations, are important for both fundamental science and the future development of quantum technologies. Here we theoretically propose and experimentally realize a scheme that can fully exploit the multi-spatial-mode nature of the four-wave-mixing (FWM) process, i.e., spatial multiplexing, and thus integrates multiple FWM processes into a single cell at each stage of the cascaded process. The number of generated quantum-correlated beams 2n is exponentially dependent on the number of vapor cells n . In addition, the quantum correlations between the multiple beams also increase as the number of vapor cell increases. For the case of n =2 , we experimentally show that the degree of intensity-difference squeezing between the four quantum-correlated beams in our scheme is enhanced to -8.2 ±0.2 dB from -5.6 ±0.3 and -6.5 ±0.2 dB of squeezing obtained with a single FWM process. Our system may find applications in quantum information and precision measurement.

  4. The automated multiwavelength Raman polarization and water-vapor lidar PollyXT: the neXT generation

    Science.gov (United States)

    Engelmann, Ronny; Kanitz, Thomas; Baars, Holger; Heese, Birgit; Althausen, Dietrich; Skupin, Annett; Wandinger, Ulla; Komppula, Mika; Stachlewska, Iwona S.; Amiridis, Vassilis; Marinou, Eleni; Mattis, Ina; Linné, Holger; Ansmann, Albert

    2016-04-01

    The atmospheric science community demands autonomous and quality-assured vertically resolved measurements of aerosol and cloud properties. For this purpose, a portable lidar called Polly was developed at TROPOS in 2003. The lidar system was continuously improved with gained experience from the EARLINET community, involvement in worldwide field campaigns, and international institute collaborations within the last 10 years. Here we present recent changes of the setup of the portable multiwavelength Raman and polarization lidar PollyXT and discuss the improved capabilities of the system by means of a case study. The latest system developments include an additional near-range receiver unit for Raman measurements of the backscatter and extinction coefficient down to 120 m above ground, a water-vapor channel, and channels for simultaneous measurements of the particle linear depolarization ratio at 355 and 532 nm. Quality improvements were achieved by systematically following the EARLINET guidelines and the international PollyNET quality assurance developments. A modified ship radar ensures measurements in agreement with air-traffic safety regulations and allows for 24/7 monitoring of the atmospheric state with PollyXT.

  5. Corrosion detection and monitoring in steam generators by means of ultrasound; Deteccion y monitoreo de corrosion por medio de ultrasonido en generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Chacon Nava, Jose G.; Calva, Mauricio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Fuentes Samaniego, Raul [Universidad Autonoma de Nuevo Leon (Mexico); Peraza Garcia, Alejandro [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    The tube and component failures in steam generators due to corrosion cause huge economical losses. In this article the internal corrosion processes (hydrogen attack) and high temperature corrosion are described, as well as the ultrasound techniques used for its detection. The importance of obtaining corrosion rates, which are fundamental parameters for the detection of the tube`s residual life. The purpose is to prevent possible failures that would diminish the power plant availability. [Espanol] Las fallas de tuberia en componentes de generadores de vapor debidas a corrosion ocasionan considerables perdidas economicas. En este articulo se describen los procesos de corrosion interna (ataque por hidrogeno) y corrosion en alta temperatura, asi como tecnicas de ultrasonido empleadas para su deteccion. Se destaca la importancia de obtener valores de velocidad de corrosion, que es un parametro fundamental para la determinacion de la vida residual de tuberias. El proposito es poder prevenir posibles fallas que disminuyan la disponibilidad de centrales termoelectricas.

  6. ASME power test code ptc 4.1 for steam generators; Codigo de pruebas de potencia ASME ptc 4.1 para generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Plauchu Alcantara, Jorge Alberto [Plauchu Consultores, Morelia, Michoacan (Mexico)

    2001-07-01

    This presentation is oriented towards those who in this subject have experience in the design and equipment specification, plant projects, factory and field testing, operation or result analyses. An important fraction of the national energy supply, approximately 13%, is applied to the steam generation in the different aspects of the industrial activity, in the electrical industry of public service and in the commercial and services sector. The development of the national programs of energy efficiency verifies this when dedicating to this use of the energy important projects, some of them with support of the USAID. The measurement of the energy utilization or the efficiency of steam generators (or boilers) is made applying some procedure agreed by the parts and the one of greater acceptance and best known in Mexico and internationally is the ASME Power Test Code PTC 4.1 for Steam Generators. The purpose and formality in the determination of efficiency and of steam generation capacity behavior, thermal basic regime or fulfillment of guarantees, radically changes the exigencies of strict attachment to the PTC 4.1 This definition will determine the importance of the test method selected, the deviations and convened exceptions, the influence of the precision and the measurement errors, the consideration of auxiliary equipment, etc. An interpretation or incorrect application of the Test Code has lead and will lead to results and nonreliable decisions. [Spanish] Esta exposicion se orienta a quienes en este tema cuenta con experiencia en diseno y especificacion de equipo, proyecto de planta, pruebas en fabrica y campo, operacion o analisis de resultados. Una fraccion importante de la oferta nacional de energia, 13% aproximadamente, se aplica a la generacion de vapor en diferentes giros de actividad industrial, en la industria electrica, de servicio publico y en el sector de servicios y comercial. El desarrollo de los programas nacionales de eficiencia energetica comprueba

  7. Design and construction of a steam generator with feedback; Projeto e construcao de um gerador de vapor com realimentacao

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Camila C., E-mail: camilacamargo@outlook.com [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil); Placco, Guilherme M., E-mail: placco@ieav.cta.br [Instituto de Tecnologia Aeronautica (ITA/CTA), Sao Jose dos Campos, SP (Brazil); Guimaraes, Lamartine N.F., E-mail: guimarae@ieav.cta.br [Instituto de Estudos Avancado (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil). Departamento ENU

    2013-07-01

    The EARTH project aims to develop technologies to design and build systems that generate electricity in space, using microreactors. One of the activities within the TERRA project aims to build a closed thermal cycle Rankine type in order to test a Tesla turbine type. The objective of this work is to design and build a steam generator with feedback, which should ensure a satisfactory range of steam supply, security system, feedback system and heating system.

  8. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of trace Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Ni [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Jiang, Shiuh-Jen, E-mail: sjjiang@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Chen, Yen-Ling [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Sahayam, A.C. [National Centre for Compositional Characterisation of Materials (CCCM), Hyderabad (India)

    2015-02-20

    Highlights: • Determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions in a single run. • Accurate analysis using isotope dilution and standard addition methods. • Vapor generation ICP-MS yielded superior detection limits compared to ETV-ICP-MS. • No sample dissolution increased sample through put. • Analysis of GBW09305 Cosmetic (Cream) reference material for accuracy. - Abstract: A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions using flow injection (FI) vapor generation (VG) as the sample introduction system. A slurry containing 2% m/v lotion, 2% m/v thiourea, 0.05% m/v L-cysteine, 0.5 μg mL{sup −1} Co(II), 0.1% m/v Triton X-100 and 1.2% v/v HCl was injected into a VG-ICP-MS system for the determination of Ge, As, Cd, Sb, Hg and Bi without dissolution and mineralization. Because the sensitivities of the analytes in the slurry and that of aqueous solution were quite different, an isotope dilution method and a standard addition method were used for the determination. This method has been validated by the determination of Ge, As, Cd, Sb, Hg and Bi in GBW09305 Cosmetic (Cream) reference material. The method was also applied for the determination of Ge, As, Cd, Sb, Hg and Bi in three cosmetic lotion samples obtained locally. The analysis results of the reference material agreed with the certified value and/or ETV-ICP-MS results. The detection limit estimated from the standard addition curve was 0.025, 0.1, 0.2, 0.1, 0.15, and 0.03 ng g{sup −1} for Ge, As, Cd, Sb, Hg and Bi, respectively, in original cosmetic lotion sample.

  9. Trace determination of Hg together with As, Sb, Se by miniaturized optical emission spectrometry integrated with chemical vapor generation and capacitively coupled argon microwave miniplasma discharge

    Science.gov (United States)

    Matusiewicz, Henryk; Ślachciński, Mariusz

    2017-07-01

    A miniaturized optical emission spectrometer (OES) with capacitively coupled argon microwave microplasma (μCMP) as and excitation source and chemical vapor generation (CVG) for sample introduction was constructed for the determination of trace Hg, As, Sb and Se. The applied method enabled simultaneous determination of hydride-forming elements (As, Sb, Se) and volatile Hg. Mercury cold vapor and the hydride volatile species of As, Sb and Se were generated when standard or sample solutions were separated from the liquid phase for transport to the capacitively coupled microwave microplasma and detection of their atomic emission. A univariate approach and the simplex optimization procedure were used to achieve optimized conditions and derive analytical figures of merit. The experimental concentration detection limits (LODs) for simultaneous determination, calculated as the concentration giving a signal equal to three times of the standard deviation of the blank (LOD, 3σblank criterion, peak height) were 3.0, 1.4, 1.5 and 3.8 ng mL- 1 for Hg, As, Sb and Se, respectively. The method was validated by the analysis of three Certified Reference Materials (NIST 2711, NRCC DOLT-2, NIST 1643e) of different matrix composition and by the standard addition technique. The method offers relatively good precision (RSD ranged from 5% to 8%) for microsampling (200 μL) analysis. The measured of contents of elements in certified reference materials were in good agreement with the certified values (Hg 1.99-6.25 μg g- 1, As 16.6-105 μg g- 1, Sb 19.4-56.88 μg g- 1, Se 1.52-11.68 μg g- 1), according to the Student t-test, for a confidence level of 95%.

  10. Additional generation capacity or steam demand administration?; Capacidad adicional de generacion o administracion de demanda de vapor?

    Energy Technology Data Exchange (ETDEWEB)

    Plauchu Lima, Alberto; Plauchu Alcantara, Jorge Alberto [Plauchu Consultores, Morelia, Michoacan (Mexico)

    1999-07-01

    The authors have presented in seminars XVIII and XIX of ATPAE papers on subjects on Demand in Steam Systems and on the Supply of Consulting Services, respectively, and this paper is a contribution that retaking both subjects, tries to motivate the interest in generally underestimated areas of opportunity in energy programs. It is intention of this paper to invite the spokesmen to this Seminar and of the futures ones to deepen and to offer continuity and pursuit of an event to the nest one, on subjects of permanent interest and to incorporate contributions of new experiences, criteria and technologies. One exhorts to professionals and technicians interested in the rational and economic administration of the energy to deepen into the real conditions, abilities and capacities of the equipment in the steam power plants and to the study of better options of its use, adaptation and operation. In order to exemplify the previous matter two cases of industrial plants in which real and satisfactorily and economically solved problems, were very different from the ones that the proprietors of those facilities originally raised when soliciting the support of consulting services. Notice is made that in both cases capacity problems were contemplated, after the study and recommended actions it was demonstrated they handle their demands without augmenting the installed capacity, with avoided investments and increased efficiency. Finally the determinant is emphasized that can be the function of the consultant in the approach of his services and the direction towards orientation to right solutions. [Spanish] Los autores han expuesto en los seminarios XVIII y XIX de ATPAE trabajos sobre temas de Demanda en Sistemas de Vapor y Prestacion de Servicios de Consultoria, respectivamente y la presente es una contribucion que retomando ambos temas, pretende motivar el interes en areas de oportunidad generalmente subestimadas en programas de energia. Es intencion de este trabajo invitar a los

  11. System of aid for the starting of the steam generator of a thermoelectric unit; Sistema de ayuda para el arranque del generador de vapor de una unidad termoelectrica

    Energy Technology Data Exchange (ETDEWEB)

    Quintero R, Agustin; Suarez C, Dionisio A; Aquino E, Juan C; Diaz H, Carlos A; Cruz T, Jorge A; Sanchez L, Jose A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2002-07-01

    This article presents the development of an on line aid system, whose objective is to aid the operator of a thermoelectric unit, providing the information that is required to carry out the heating and pressurization of the steam generator in the shortest possible time. The former takes place respecting the operation limits determined by the manufacturer and the conditions of security established to carry out the maneuvers of operation of the equipment. The system incorporates a scheme of predictive control, based on a neuronal model that estimates the optimal position of two final elements of control to fulfill with the curves of reference for the temperature and pressure of the main steam. The system is based on an architecture client-server and uses technology Web for the access of the information through a navigator of the Internet. [Spanish] Este articulo presenta el desarrollo de un sistema de ayuda en linea, cuyo objetivo es asistir al operador de una unidad termoelectrica, proporcionando la informacion que requiere para llevar a cabo el calentamiento y presurizacion del generador de vapor en el menor tiempo posible. Lo anterior se efectua respetando los limites de operacion determinados por el fabricante y las condiciones de seguridad establecidas para efectuar las maniobras de operacion de los equipos. El sistema incorpora un esquema de control predictivo, basado en un modelo neuronal, que estima la posicion optima de dos elementos finales de control para cumplir con las curvas de referencia para la temperatura y presion del vapor principal. El sistema esta basado en una arquitectura cliente-servidor y utiliza tecnologia Web para el acceso a la informacion a traves de un navegador del Internet.

  12. Vapor Bubbles

    Science.gov (United States)

    Prosperetti, Andrea

    2017-01-01

    This article reviews the fundamental physics of vapor bubbles in liquids. Work on bubble growth and condensation for stationary and translating bubbles is summarized and the differences with bubbles containing a permanent gas stressed. In particular, it is shown that the natural frequency of a vapor bubble is proportional not to the inverse radius, as for a gas bubble, but to the inverse radius raised to the power 2/3. Permanent gas dissolved in the liquid diffuses into the bubble with strong effects on its dynamics. The effects of the diffusion of heat and mass on the propagation of pressure waves in a vaporous bubbly liquid are discussed. Other topics briefly touched on include thermocapillary flow, plasmonic nanobubbles, and vapor bubbles in an immiscible liquid.

  13. Ultraviolet vapor generation atomic fluorescence spectrometric determination of mercury in natural water with enrichment by on-line solid phase extraction

    Science.gov (United States)

    Qin, Deyuan; Gao, Feng; Zhang, Zhaohui; Zhao, Liqian; Liu, Jixin; Ye, Jianping; Li, Junwei; Zheng, Fengxi

    2013-10-01

    A novel method, which coupled an on-line solid phase extraction (SPE) enrichment with ultraviolet vapor generation (UVG) atomic fluorescence spectrometry (AFS), was developed to improve the sensitivity of mercury determination and to remove the interference of some anion and organics to UVG of mercury. A high mercury retention efficiency and maximum exclusion of inorganic and organic matrix in water samples were achieved by using C18 SPE mini cartridge modified with sodium diethyldithiocarbamate (DDTC). Fast and efficient elution from the cartridge was found by using L-cysteine mixing solution. Furthermore, through the investigation of different UV reactor designs, the most important factor was the structure of the reactor (which corresponded roughly to the photon flux) wherein the tubing was sintered into the UV lamp to give the highest UV generation efficiency. The second factor was the materials of the tubing (which roughly corresponded to the working wavelength). Synthetic quartz, characterized by the highest transparency at 185 nm, attained the highest UVG efficiency, suggesting that the most favorable wavelength for UVG was 185 nm. Under optimum conditions, the achievable detection limit (3σ) with sample loadings of 10.0 mL was 0.03 ng L- 1 and 0.08 ng L- 1 with different manifolds, respectively. The method was successfully applied to the determination of Hg in tap water, river water and lake water samples.

  14. Direct determination of arsenic in soil samples by fast pyrolysis-chemical vapor generation using sodium formate as a reductant followed by nondispersive atomic fluorescence spectrometry

    Science.gov (United States)

    Duan, Xuchuan; Zhang, Jingya; Bu, Fanlong

    2015-09-01

    This new study shows for the first time that sodium formate can react with trace arsenic to form volatile species via fast pyrolysis - chemical vapor generation. We found that the presence of thiourea greatly enhanced the generation efficiency and eliminated the interference of copper. We studied the reaction temperature, the volume of sodium formate, the reaction acidity, and the carried argon rate using nondispersive atomic fluorescence spectrometry. Under optimal conditions of T = 500 °C, the volumes of 30% sodium formate and 10% thiourea were 0.2 ml and 0.05 ml, respectively. The carrier argon rate was 300 ml min- 1 and the detection limit and precision of arsenic were 0.39 ng and 3.25%, respectively. The amount of arsenic in soil can be directly determined by adding trace amount of hydrochloric acid as a decomposition reagent without any sample pretreatment. The method was successfully applied to determine trace amount of arsenic in two soil-certified reference materials (GBW07453 and GBW07450), and the results were found to be in agreement with certified reference values.

  15. Organotin speciation in environmental matrices by automated on-line hydride generation-programmed temperature vaporization-capillary gas chromatography-mass spectrometry detection.

    Science.gov (United States)

    Serra, H; Nogueira, J M F

    2005-11-11

    In the present contribution, a new automated on-line hydride generation methodology was developed for dibutyltin and tributyltin speciation at the trace level, using a programmable temperature-vaporizing inlet followed by capillary gas chromatography coupled to mass spectrometry in the selected ion-monitoring mode acquisition (PTV-GC/MS(SIM)). The methodology involves a sequence defined by two running methods, the first one configured for hydride generation with sodium tetrahydroborate as derivatising agent and the second configured for speciation purposes, using a conventional autosampler and data acquisition controlled by the instrument's software. From the method-development experiments, it had been established that injector configuration has a great effect on the speciation of the actual methodology, particularly, the initial inlet temperature (-20 degrees C; He: 150 ml/min), injection volume (2 microl) and solvent characteristics using the solvent venting mode. Under optimized conditions, a remarkable instrumental performance including very good precision (RSD CRM 462, Nr. 330 dibutyltin: 68+/-12 ng/g; tributyltin: 54+/-15 ng/g on dry mass basis), using liquid-liquid extraction (LLE) and solid-phase extraction (SPE) sample enrichment and multiple injections (2 x 5 microl) for sensitivity enhancement. The methodology evidenced high reproducibility, is easy to work-up, sensitive and showed to be a suitable alternative to replace the currently dedicated analytical systems for organotin speciation in environmental matrices at the trace level.

  16. Statistical mechanics of sum frequency generation spectroscopy for the liquid-vapor interface of dilute aqueous salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Noah-Vanhoucke, Joyce; Smith, Jared D.; Geissler, Phillip L.

    2009-01-02

    We demonstrate a theoretical description of vibrational sum frequency generation (SFG) at the boundary of aqueous electrolyte solutions. This approach identifies and exploits a simple relationship between SFG lineshapes and the statistics of molecular orientation and electric field. Our computer simulations indicate that orientational averages governing SFG susceptibility do not manifest ion-specific shifts in local electric field, but instead, ion-induced polarization of subsurface layers. Counterbalancing effects are obtained for monovalent anions and cations at the same depth. Ions held at different depths induce an imbalanced polarization, suggesting that ion-specific effects can arise from weak, long ranged influence on solvent organization.

  17. Statistical mechanics of sum frequency generation spectroscopy for the liquid-vapor interface of dilute aqueous salt solutions

    Science.gov (United States)

    Noah-Vanhoucke, Joyce; Smith, Jared D.; Geissler, Phillip L.

    2009-02-01

    We demonstrate a theoretical description of vibrational sum frequency generation (SFG) at the boundary of aqueous electrolyte solutions. This approach identifies and exploits a simple relationship between SFG lineshapes and the statistics of molecular orientation and electric field. Our computer simulations indicate that orientational averages governing SFG susceptibility do not manifest ion-specific shifts in local electric field, but instead, ion-induced polarization of subsurface layers. Counterbalancing effects are obtained for monovalent anions and cations at the same depth. Ions held at different depths induce an imbalanced polarization, suggesting that ion-specific effects can arise from weak, long-ranged influence on solvent organization.

  18. Flow speed of the ablation vapors generated during laser drilling of CFRP with a continuous-wave laser beam

    Science.gov (United States)

    Faas, S.; Freitag, C.; Boley, S.; Berger, P.; Weber, R.; Graf, T.

    2017-03-01

    The hot plume of ablation products generated during the laser drilling process of carbon fiber reinforced plastics (CFRP) with a continuous-wave laser beam was analyzed by means of high-speed imaging. The formation of compression shocks was observed within the flow of the evaporated material, which is an indication of flow speeds well above the local speed of sound. The flow speed of the hot ablation products can be estimated by analyzing the position of these compression shocks. We investigated the temporal evolution of the flow speed during the drilling process and the influence of the average laser power on the flow speed. The flow speed increases with increasing average laser powers. The moment of drilling through the material changes the conditions for the drilling process and was confirmed to influence the flow speed of the ablated material. Compression shocks can also be observed during laser cutting of CFRP with a moving laser beam.

  19. Numerical study of the dielectric liquid around an electrical discharge generated vapor bubble in ultrasonic assisted EDM.

    Science.gov (United States)

    Shervani-Tabar, Mohammad T; Mobadersany, Nima

    2013-07-01

    In electrical discharge machining due to the electrical current, very small bubbles are created in the dielectric fluid between the tool and the workpiece. Increase of the number of bubbles and their growth in size generate a single bubble. The bubble has an important role in electrical discharge machining. In this paper the effect of ultrasonic vibration of the tool and the velocity fields and pressure distribution in the dielectric fluid around the bubble in the process of electrical discharge machining are studied numerically. The boundary integral equation method is applied for the numerical solution of the problem. It is shown that ultrasonic vibration of the tool has great influence on the evolution of the bubble, fluid behavior and the efficiency of the machining in EDM. At the last stages of the collapse phase of the bubble, a liquid jet develops on the bubble which has different shapes. Due to the different cases, and a high pressure region appears just near the jet of the bubble. Also the fluid particles have the highest relative velocity just near the liquid jet of the bubble.

  20. Recyclable decoration of amine-functionalized magnetic nanoparticles with Ni(2+) for determination of histidine by photochemical vapor generation atomic spectrometry.

    Science.gov (United States)

    Hu, Yuan; Wang, Qi; Zheng, Chengbin; Wu, Li; Hou, Xiandeng; Lv, Yi

    2014-01-07

    It is critically important to accurately determine histidine since it is an indicator for many diseases when at an abnormal level. Here, an inexpensive and simple method using an amine-functionalized magnetic nanoparticle-based Ni(2+)-histidine affinity pair system was developed for highly sensitive and selective detection of histidine in human urine by photochemical vapor generation atomic spectrometry. Ni(2+) was first bound to the amine groups of the amine-functionalized magnetic nanoparticles and then liberated to solution via the highly specific interaction between the histidine and Ni(2+) in the presence of histidine. The liberated histidine-Ni(2+) complex was exposed to UV irradiation in the presence of formic acid to form gaseous nickel tetracarbonyl, which was separated from the sample matrix and determined by atomic absorption/fluorescence spectrometry. Compared to other methods, this approach promises high sensitivity, simplicity in design, and convenient operation. The need for organic solvents, enzymatic reactions, separation processes, chemical modification, expensive instrumentations, and sophisticated and complicated pretreatment is minimized with this strategy. A limit of detection of 1 nM was obtained and provided tens-to-hundreds of fold improvements over that achieved with conventional methods. The protocol was evaluated by analysis of several urine samples with good recoveries and showed great potential for practical application.

  1. Detection and evaluation of corrosion zones at high temperature in steam generators; Deteccion y evaluacion de zonas de corrosion en alta temperatura de generadoras de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Villafane, Alberto; Chacon Nava, Jose G.; Huerta Espino, Mario; Mojica Calderon, Cecilio; Castillo Viveros, Antonio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    This paper presents the methodology for the detection and evaluation of high corrosion zones at high temperature. The results found up to now, show a critical zone in the Babcock Hitachi design, specifically in the high temperature reheater in the zone nearby the outlet header. In the normalized design CE (Mitsubishi) of 300 MW and CE (Canada) of 300 MW, the results found in recent years show small thickness reduction, therefore a good operation of these steam generators is recognized. [Espanol] En este trabajo se presenta la metodologia para la deteccion y evaluacion de zonas de corrosion en alta temperatura. Los resultados encontrados hasta el momento muestran una zona critica en el diseno Babcock Hitachi, especificamente en el recalentador de alta temperatura en la zona cercana al cabezal de salida. En el diseno normalizado CE (Mitsubishi) de 300 MW y CE (Canada) de 300 MW, los resultados encontrados en anos recientes muestran poca disminucion de espesor, por lo que se considera una buena operacion de estos generadores de vapor.

  2. AMTEC vapor-vapor series connected cells

    Science.gov (United States)

    Underwood, Mark L.; Williams, Roger M.; Ryan, Margaret A.; Nakamura, Barbara J.; Oconnor, Dennis E.

    1995-08-01

    An alkali metal thermoelectric converter (AMTEC) having a plurality of cells structurally connected in series to form a septum dividing a plenum into two chambers, and electrically connected in series, is provided with porous metal anodes and porous metal cathodes in the cells. The cells may be planar or annular, and in either case a metal alkali vapor at a high temperature is provided to the plenum through one chamber on one side of the wall and returned to a vapor boiler after condensation at a chamber on the other side of the wall in the plenum. If the cells are annular, a heating core may be placed along the axis of the stacked cells. This arrangement of series-connected cells allows efficient generation of power at high voltage and low current.

  3. 过冷沸腾起始点和净蒸汽产生点的实验研究%EXPERIMENTAL STUDY ON ONSET OF SUBCOOLED BOILING AND POINT OF NET VAPOR GENERATION

    Institute of Scientific and Technical Information of China (English)

    杨瑞昌; 王彦武; 唐虹; 司徒荣

    2001-01-01

    This paper reports the experimental study of onset of subcooled boiling and point of net vapor generation in a natural circulation system with subcooled boiling. Freon-12 was used as the working medium. In the experiments the onset of subcooled boiling and the point of net vapor generation were determined byvisual observation. The influence of the system pressure, inlet subcooling of the working medium and the input power to the heated section on the onset of subcooled boiling and the point of net vapor generation were investigated in the experiments. Based on the data reduction, the calculation methods of the onset of subcooled boiling and the net vapor generation in the natural circulation system have been presented respectively.%本文报告了使用R-12作工质进行的自然循环过冷沸腾起始点和净蒸汽产生点的实验结果。实验过程中使用可视化方法观察确定过冷沸腾起始点和净蒸汽产生点. 在相当宽广的工质压力、入口过冷度及加热功率范围内研究了上述参数对过冷沸腾起始点和净蒸汽产生点的影响, 在此基础上提出了计算自然循环过冷沸腾起始点和净蒸汽产生点的计算方法。

  4. Development of a System to Generate Near Real Time Tropospheric Delay and Precipitable Water Vapor in situ at Geodetic GPS Stations, to Improve Forecasting of Severe Weather Events

    Science.gov (United States)

    Moore, A. W.; Bock, Y.; Geng, J.; Gutman, S. I.; Laber, J. L.; Morris, T.; Offield, D. G.; Small, I.; Squibb, M. B.

    2012-12-01

    We describe a system under development for generating ultra-low latency tropospheric delay and precipitable water vapor (PWV) estimates in situ at a prototype network of geodetic GPS sites in southern California, and demonstrating their utility in forecasting severe storms commonly associated with flooding and debris flow events along the west coast of North America through infusion of this meteorological data at NOAA National Weather Service (NWS) Forecast Offices and the NOAA Earth System Research Laboratory (ESRL). The first continuous geodetic GPS network was established in southern California in the early 1990s and much of it was converted to real-time (latency tropospheric zenith delays, which can be converted into mm-accuracy PWV using collocated pressure and temperature measurements, the basis for GPS meteorology (Bevis et al. 1992, 1994; Duan et al. 1996) as implemented by NOAA with a nationwide distribution of about 300 GPS-Met stations providing PW estimates at subhourly resolution currently used in operational weather forecasting in the U.S. We improve upon the current paradigm of transmitting large quantities of raw data back to a central facility for processing into higher-order products. By operating semi-autonomously, each station will provide low-latency, high-fidelity and compact data products within the constraints of the narrow communications bandwidth that often occurs in the aftermath of natural disasters. The onsite ambiguity-resolved precise point positioning solutions are enabled by a power-efficient, low-cost, plug-in Geodetic Module for fusion of data from in situ sensors including GPS and a low-cost MEMS meteorological sensor package. The decreased latency (~5 minutes) PW estimates will provide the detailed knowledge of the distribution and magnitude of PW that NWS forecasters require to monitor and predict severe winter storms, landfalling atmospheric rivers, and summer thunderstorms associated with the North American monsoon. On the

  5. Petroleum Vapor Intrusion

    Science.gov (United States)

    One type of vapor intrusion is PVI, in which vapors from petroleum hydrocarbons such as gasoline, diesel, or jet fuel enter a building. Intrusion of contaminant vapors into indoor spaces is of concern.

  6. Long Term Field Development of a Surfactant Modified Zeolite/Vapor Phase Bioreactor System for Treatment of Produced Waters for Power Generation

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-31

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

  7. Insights in the laser-induced breakdown spectroscopy signal generation underwater using dual pulse excitation — Part I: Vapor bubble, shockwaves and plasma

    Energy Technology Data Exchange (ETDEWEB)

    Lazic, V., E-mail: violeta.lazic@enea.it [ENEA (UTAPRAD-DIM), Via. E. Fermi 45, 00044 Frascati (RM) (Italy); Laserna, J.J. [Dept. of Analytical Chemistry, Faculty of Sciences, University of Málaga, Málaga (Spain); Jovicevic, S. [Institute of Physics, University of Belgrade, Belgrade (Serbia)

    2013-04-01

    Plasma and vapor bubble formation and evolution after a nanosecond laser pulse delivered to aluminum targets inside water were studied by fast photography. This technique was also applied to monitor the plasma produced by a second laser pulse and for different interpulse delays. The bubble growth was evident only after 3 μs from the first laser pulse and the bubble shape changed during expansion and collapse cycles. The evolution and propagation of the initial shockwave and its reflections both from the back sample surface and cell walls were detected by Schlieren photography. The primary plasma develops in two phases: violent particle expulsion and ionization during the first μs, followed by slow plasma growth from the ablation crater into the evolving vapor bubble. The shape of the secondary plasma strongly depends on the inner bubble pressure whereas the particle expulsion into the expanded bubble is much less evident. Both the primary and secondary plasma have similar duration of about 30 μs. Detection efficiency of the secondary plasma is much reduced by light refraction at the curved bubble–water interface, which behaves as a negative lens; this leads to an apparent reduction of the plasma dimensions. Defocusing power of the bubble lens increases with its expansion due to the lowering of the vapor's refraction index with respect to that of the surrounding liquid (Lazic et al., 2012 [1]). Smell's reflections of secondary plasma radiation at the expanded bubble wall redistribute the detected intensity on a wavelength-dependent way and allow gathering of the emission also from the external plasma layer that otherwise, would not enter into the optical system. - Highlights: ► Primary plasma during the first μs is irregular due to particle expulsion. ► Later the plasma grows into the evolving bubble, its emission lasts more than 30 μs. ► The initial shockwave and its echoes alter locally the refraction index. ► Defocusing by the bubble

  8. Modelling the flow and the two-phase science of heat inside a cross-section tube of a `once through` vapor generator overheated with sodium; Modelisation de l`ecoulement et de la thermique double phase a l`interieur d`un tube droit de generateur de vapeur `once-through` a surchauffe chauffe au sodium

    Energy Technology Data Exchange (ETDEWEB)

    Mutelle, H

    1997-11-28

    Concerning the future fast neutrons reactors, studied in the frame of the European Fast Reactor (E.F.R.) project, several innovations have been proposed particularly in the field of vapor generators. These vapor generators have the particularity to use two different exchange fluids which can react violently one with the other. The thermodynamic fluid or secondary fluid is water under high pressure (18.5 MPa) which comes under saturated in the inlet of the device, warms and vaporizes inside the nest of boiler-tubes. At the outlet, vapor is overheated. The primary fluid is a liquid metal (sodium for French reactors) which flows outside the nest of boiler-tubes in the opposite direction of the secondary fluid. Several vapor generators models have been carried out. Concerning the European Fast Reactor project, the tubes have a cross-section and are in ferritic steel. Inside the boiler-tubes, the water-vapor flow can be divided into three areas. The first one is the liquid monophasic rate. It ends by the start of the boiling which is nucleated in the shell. Downstream, the two-phase flow passes from a bubbles flow to an annular flow. The liquid is then on the form of shell film and on the form of droplets carried along by the vapor flux. The dryout of the annular film is the start of the third area where there is vapor forced convection. At the present time, there is still no thermohydraulic code in the conditions of the E.F.R. vapor generator. In order to have a reliable size tool, the members of the E.F.R. project have then decided to do a two-phase flow model and have experimented a mono tubular scale model called ``ATLAS`` which represents well the real component for size, fluids and running conditions. The aim of the present work is then, in the frame of this experimental program, to 1)qualify the heat exchange and friction laws which will be later introduced in the thermohydraulic codes of cross-sections vapor generators 2)characterize the dryout phenomenon 3

  9. Temperature control of a steam generator by means of an hybrid system PID-RLC; Control de las temperaturas de un generador de vapor mediante un sistema hibrido PID-RLC

    Energy Technology Data Exchange (ETDEWEB)

    Palomares Gonzalez, Daniel; Garcia Mendoza, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    A description is made of the design and evaluation of an hybrid control system, formed by a quadratic gaussian linear regulator (QLR) and proportional integral derivative (PID) type regulators. This scheme is used to control the reheater and secondary superheater steam temperatures of a steam generator model with a maximum capacity of 2,150,000 pounds per hour. Once applied to the model of a 300 MW steam power plant, this system showed better results than the traditional schemes and inclusively better than some modern control schemes. This fact characterizes it as a high potential system to be applied to steam power plants. [Espanol] Se describe el diseno y la evaluacion de un sistema de control hibrido, formado por un regulador lineal cuadratico gaussiano (RLC) y reguladores tipo proporcional integral derivativo (PID). Este esquema se utiliza para controlar las temperaturas de vapor del recalentador y sobrecalentador secundario del modelo de un generador de vapor con capacidad maxima de 2,150,000 libras por hora. Una vez aplicado al modelo de una unidad termoelectrica de 300 MW, este sistema produjo mejores resultados que los esquemas tradicionales e incluso mejores que algunos esquemas de control moderno. Esto lo caracteriza como un sistema con un alto potencial para aplicarse a unidades termoelectricas.

  10. Simulación del sistema de generación de vapor y procesos de depuración de SO2 y NOX. // Simulation of the steam generation system and scrubbing processes of SO2 and NOx.

    Directory of Open Access Journals (Sweden)

    P. Clavelo Robinson

    2003-09-01

    Full Text Available El presente trabajo propone el empleo del simulador SIMCOMB en el cálculo de la eficiencia de un sistema de generaciónde vapor con diferentes alternativas, como el tipo de combustible a emplear. Además, el mismo brinda diferentes variantesde sistemas de depuración de SO2 y NOX, contaminantes primarios que son causantes de problemas atmosféricos como lalluvia ácida.Palabras claves: Simulación, generación de vapor, depuración, dióxido de azufre, óxidos de nitrógeno,contaminación atmosférica._______________________________________________________________________________Abstract.The present work proposes the employment of the simulator SIMCOMB in the calculation of the efficiency of the steamgeneration system with different alternative, as the type of fuel to use. Also, the same one offers different variants ofscrubbing processes of SO2 and NOX, primary pollutants that are causing of atmospheric problems as the acid rainKey words: simulation, . steam generation, scrubbing, sulfur dioxide, nitrogen oxides, air pollution.

  11. Co-generation on steam industrial systems with disks turbines; Co-geracao em sistemas industriais de vapor com turbinas de discos

    Energy Technology Data Exchange (ETDEWEB)

    Lezsovits, Ferenc [Universidad de Tecnologia y Economia de Budapest (Hungary)

    2010-03-15

    The disk turbine, also called Tesla turbine, being of simple construction and low cost, can be used as steam pressure reduction on industrial systems, generating simultaneously electric power, becoming the co-generation even at lower levels. Can be used for various operational parameters and mass flux ratios.This paper analyses the advantages and disadvantages of the turbines under various operation conditions.

  12. Structure, Optical Properties, and Photocatalytic Activity towards H2 Generation and CO2 Reduction of GaN Nanowires via Vapor-Liquid-Solid Process

    Directory of Open Access Journals (Sweden)

    Hong Pang

    2014-01-01

    Full Text Available High quality single crystalline GaN nanowires with large aspect ratio (>100 are synthesized on n-type Si (111 substrate via Au-catalyzed vapor-liquid-solid process. Morphology, crystal structure, and optical property of the as-synthesized GaN nanowires are characterized by means of X-ray diffraction, scanning/transmission electron microscopy, UV-vis diffuse reflection spectroscopy, and room temperature photoluminescence. The results indicate that the as-prepared GaN nanowires with a large aspect ratio are well crystallized in the hexagonal wurtzite structure, and a slight blue shift appears in both the absorption edge and emission peak probably due to the quantization effect. Photocatalytic H2 evolution over the as-prepared GaN nanowires is performed with the incorporation of Pt or Rh as the cocatalyst, exhibiting greatly enhanced capability compared to the GaN powder tested under the same conditions. Moreover, photocatalytic CO2 reduction over the GaN nanowires is also successfully realized using Pt or Rh as the cocatalyst, depending on which the products show a strong selectivity inherently related to the reductive electrons transferred by cocatalyst.

  13. Evaluation of Mercury in Environmental Samples by a Supramolecular SolventBased Dispersive LiquidLiquid Microextraction Method Before Analysis by a Cold Vapor Generation Technique.

    Science.gov (United States)

    Ali, Jamshed; Tuzen, Mustafa; Kazi, Tasneem G

    2017-02-01

    Supramolecular solvent–based dispersive liquid–liquid microextraction was used as a preconcentration method for the determination of trace levels of Hg. This simple method accurately measured oxidized HgII content in claystone and sandstone samples obtained from the Thar Coalfield in Pakistan. Cold vapor atomic absorption spectrometry was used as the detection technique because it is reliable and accurate. The HgII in acidic media forms a complex with dithizone (DTz) in the presence of supramolecular solvent (tetrahydrofuran and 1-undecanol), forming reverse micelles. Formation of the Hg-DTz complex was achieved to increase the interactions with the supramolecular solvent phase at pH 2.5 under the optimized experimental conditions. After addition of the supramolecular solvent to the aqueous solution, the micelles were uniformly mixed using a vortex mixer. The cloudy solution was centrifuged, and the Hg-DTz complex was extracted into the supramolecular solvent phase. Under optimized experimental conditions, the LOD and enrichment factor were found to be 5.61 ng/L and 77.8, respectively. Accuracy of the developed method was checked with Certified Reference Materials. The developed method was successfully applied for the determination of HgII in claystone and sandstone samples from the Block VII and Block VIII areas of the Thar Coalfield on the basis of depth.

  14. Study of porogen removal by atomic hydrogen generated by hot wire chemical vapor deposition for the fabrication of advanced low-k thin films

    Energy Technology Data Exchange (ETDEWEB)

    Godavarthi, S., E-mail: srinivas@cinvestav.mx [Program of Nanoscience and Nanotechnology, Cinvestav-IPN (Mexico); Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Fisicas, Av. Universidad, Cuernavaca, Morelos (Mexico); Wang, C.; Verdonck, P. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Matsumoto, Y.; Koudriavtsev, I. [Program of Nanoscience and Nanotechnology, Cinvestav-IPN (Mexico); SEES, Electrical Engineering Department, Cinvestav-IPN (Mexico); Dutt, A. [SEES, Electrical Engineering Department, Cinvestav-IPN (Mexico); Tielens, H.; Baklanov, M.R. [imec, Kapeldreef 75, 3001 Leuven (Belgium)

    2015-01-30

    In order to obtain low-k dielectric films, a subtractive technique, which removes sacrificial porogens from a hydrogenated silicon oxycarbide (SiOC:H) film, has been used successfully by different groups in the past. In this paper, we report on the porogen removal from porogenated SiOC:H films, using a hot wire chemical vapor deposition (HWCVD) equipment. Molecular hydrogen is dissociated into atomic hydrogen by the hot wires and these atoms may successfully remove the hydrocarbon groups from the porogenated SiOC:H films. The temperature of the HWCVD filaments proved to be a determining factor. By Fourier transform infrared spectroscopy, X-ray reflectivity (XRR), secondary ion mass spectrometry (SIMS), ellipsometric porosimetry and capacitance-voltage analyses, it was possible to determine that for temperatures higher than 1700 °C, efficient porogen removal occurred. For temperatures higher than 1800 °C, the presence of OH groups was detected. The dielectric constant was the lowest, 2.28, for the samples processed at a filament temperature of 1800 °C, although porosity measurements showed higher porosity for the films deposited at the higher temperatures. XRR and SIMS analyses indicated densification and Tungsten (W) incorporation at the top few nanometers of the films.

  15. Iron bromide vapor laser

    Science.gov (United States)

    Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

    2016-03-01

    We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

  16. Analysis regarding steam generator furnace's incident heat, temperature and composition of combustion gases; Analisis de calor incidente, temperatura y composicion de gases de combustion en hornos de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Diego Marin, Antonio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2006-07-01

    In order to obtain more precise evaluations of the combustion process in the furnace of a steam generator a suction pyrometer has been integrated to measure the temperature of the combustion gases; an ellipsoidal radiometer to measure the incident heat by thermal radiation in the water walls; a water cooled probe to determine the particle concentration, as well as a water cooled probe to determine the composition of the combustion gases present. This document clarifies the form of use of these instruments and their engineering specifications, simultaneously presenting an analysis that considers, unlike others, the internal conditions of the furnace to obtain a more precise evaluation of the efficiency that the combustion process presents and bases for the taking of preventive actions in specific zones of the furnace. Thus, the present work exhibits instruments and techniques of analysis to study the phenomena occurring within a steam generator. [Spanish] Con el fin de obtener evaluaciones mas precisas del proceso de combustion en el horno de un generador de vapor, se ha integrado un pirometro de succion para medir la temperatura de los gases de combustion; un radiometro elipsoidal para medir el calor incidente por radiacion termica en las paredes del agua; una sonda enfriada con agua para determinar la concentracion de particulas, asi como una sonda refrigerada con agua para determinar la composicion de los gases de combustion presentes. Este documento aclara la forma de uso de estos instrumentos y sus especificaciones tecnicas, a la vez que presenta un analisis que considera, a diferencia de otros, las condiciones internas del horno para obtener una evaluacion mas precisa sobre la eficiencia del proceso de combustion y bases para la toma de acciones preventivas en zonas especificas del horno. Asi, el presente trabajo exhibe instrumentos y tecnicas de analisis para estudiar los fenomenos que ocurren dentro de un generador de vapor.

  17. Deposits on the secondary side of the steam generators: Causes and consequences; Depositos en el lado secundario de los generadores de vapor: causas y consecuencias

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Briceno, D.; Yague, C.; Fernandez Diaz, M.; Gomez Mancebo, B.; Fernandez Saavedra, R.

    2013-07-01

    Despite improvements in the control of the chemistry of the secondary circuit of the PWR type reactor, large amounts of corrosion products are incorporated in the steam generators and deposited on the surface of the tubes, on the flow holes the support plates and the tubes sheet. Magnetite accumulated on the tube sheet undergoes consolidation giving rise to what is known as hard sludge, which reduces heat transfer and induces a temperature rise in the tubes which will favor the possible processes degradation. Hard sludge accumulation has been identified as a necessary condition for degradation by denting of the tubes of steam generators found in Almaraz and Asco NPP: In this article, we discuss the causes of the accumulation of deposits and their effects on the degradation of the tubes of the steam generators. (Author)

  18. Generations.

    Science.gov (United States)

    Chambers, David W

    2005-01-01

    Groups naturally promote their strengths and prefer values and rules that give them an identity and an advantage. This shows up as generational tensions across cohorts who share common experiences, including common elders. Dramatic cultural events in America since 1925 can help create an understanding of the differing value structures of the Silents, the Boomers, Gen Xers, and the Millennials. Differences in how these generations see motivation and values, fundamental reality, relations with others, and work are presented, as are some applications of these differences to the dental profession.

  19. GRUVAL for ET inspection of the steam generator tubes; GRUVAL para la inspeccion ET de los tubos de los Generadores de Vapor

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Bueno, A.; Francia, L.; Jimenez Garcia, J. J.; Garcia, R.; Castelinou, M.; Torrens, J.

    2013-07-01

    The steam generators of the nuclear power plants, PWR type are one of the most important components from the point of view of safety and plant availability. Thousands of tubes that form, approximately 1 mm of thickness, required to be inspected in accordance with codes and standards, to ensure the integrity of the component during the operation of the plant.

  20. Devices for the contamination containment employees in the steam generator inspection; Dispositivo para confinamiento de la contaminacion empleados en la inspeccion de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Bueno, A.; Largo Izquierdo, P.; Calleja Rubio, J. A.

    2010-07-01

    The process of induced current inspection of the tubes of the steam generator is a typical programmed inspections at each refueling outages of pressurized water in nuclear power plants. components inspection being quite active, interested in the program of continuous improvement, further optimize the inspection system.

  1. Simulation and analysis of the tangential flow in the combustion chamber of a steam generator; Simulacion y analisis del flujo tangencial en la camara de combustion de un generador de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Ramirez, Isaias

    1997-06-01

    supplying ducts, were obtained, with a maximum discrepancy of 5.5 m/s between the data published by McKenty and Gravel (1997) and this analysis, for the case of combustion gases in the interior of the furnace. Temperature profiles were obtained, which were overestimated in the order of 417 Celsius degrees for the case of the temperature of gases in the center of the combustion chamber, when comparing them with the corresponding ones obtained by McKenty and Gravel (1997). It is speculated that this discrepancy must to be due to the omission of the connection of the radiation model to the global computational model and; the contours of concentration of species for the combustion products in the chamber were considered (carbon dioxide, oxygen and nitrogen), obtaining only the qualitative behavior of these. It is proposed as conclusion that the computational model developed in this thesis work can be used for the estimation of flow of fluids patterns, heat transference and transference of mass of a steam generator VU-60 of the tangential type and similar to the one taken as a base for this analysis. One improvement to the computational model developed could be achieved including the radiation effect, which requires a larger memory capacity of the computer hardware than the one available during the elaboration of this thesis. [Espanol] El presente trabajo de tesis describe la simulacion y analisis de la camara de combustion de un generador de vapor VU-60 del tipo tangencial, el cual esta basado en la solucion de la ecuacion generalizada de transporte, empleando modelos matematicos desarrollados para la caracterizacion de fenomenos fisicos para cerrar los sistemas de ecuaciones gobernantes. Para la solucion de los modelos matematicos y ecuaciones gobernantes se empleo el metodo de volumen finito, el cual se basa en el concepto de volumen de control. Se desarrollo un modelo computacional tridimensional por medio del cual se estimaron los perfiles de velocidad, presion, temperatura

  2. Permission of change of limits in the vapor generators of the Atucha I Nuclear Central; Permiso de cambio de limites en los GVs de la CNA-I

    Energy Technology Data Exchange (ETDEWEB)

    Ventura, M. [Autoridad Regulatoria Nuclear, Av. Libertador 8250 (1429), Capital Federal (Argentina)]. e-mail: mventura@sede.arn.gov.ar

    2006-07-01

    In the mark of the modification of the Atucha-I Nuclear Central Installation (CNA-I) as consequence of the Introduction of the System 'Second Drain of Heat' (SSC), the Entity Responsible for the CNA-I (NASA) requested authorization to the Nuclear Regulatory Authority (ARN) to modify the value of the minimum level of water in the secondary side in the Steam generators (GVs) to activate the signal 'shoot of the Cut of the Reactor' (RESA-LLV). As the level in the GVs is one of those parameters that are used to shoot the Emergency Feeding System (RX), component of the SSC System, also was analyzed the change in the activation of the shoot signal of the 'Second Drain of Heat' (2SSC-LLV). The ARN uses for the study of the nuclear safety of nuclear power plants, the series of prediction programs RELAP5/MOD3.X. It participates of the evaluation and maintenance activities of these codes through specific agreements with the U.S. Nuclear Regulatory Commission (US-NRC). It is necessary to account with programs of this type since the ARN it licenses the construction and operation of Nuclear Power Plants (NPPs) and other outstanding facilities and it inquires its operation according to its own standards. With these tools its are auditing the calculations that the Responsible Entities of the operation make to guarantee the operability of the NPPs assisting the mentioned standards. The analysis with computational codes is used as a tool to achieve the best understanding in the behavior of the plant in union with the engineering approach, the manual calculations, the data analysis and the experience in the operation of the machine. (Author)

  3. Starting of the steam generator of a fossil fuel power plant, using predictive control based in a neuronal model; Arranque del generador de vapor de una central termoelectrica, usando control predictivo basado en un modelo neuronal

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo Dominguez, Tonatiuh

    2004-09-15

    In this thesis work it is presented the design and implementation of a simulator of total scope of a predictive controller based in the neuronal model of the temperature in two stages of the heating of the steam generator of a fossil fuel power plant. An implemented control scheme is detailed, as well as the methodology for the identification of a neuronal model utilized for the control. Finally the results of the implementation in the simulator located at the Instituto de Investigaciones Electricas (IIE) are shown to be satisfactory. This control structure is not applied directly in closed circuit, but provides the value of the control actions to a human operator. [Spanish] En este trabajo de tesis se presenta el diseno e implementacion, en un simulador de alcance total, de un controlador predictivo basado en un modelo neuronal para el control de la temperatura en dos etapas del calentamiento del generador de vapor de una central termoelectrica. Se detalla el esquema de control implementado, asi como la metodologia de identificacion de un modelo neuronal utilizado para la sintesis del control. Finalmente se muestran los resultados de la implementacion en el simulador que se encuentra en el Instituto de Investigaciones Electricas (IIE); dichos resultados fueron satisfactorios. Esta estructura de control no se aplica directamente en lazo cerrado, sino que provee el valor de las acciones de control a un operador humano.

  4. Low-temperature operation of copper-vapor lasers by using vapor-complex reaction of metallic copper and metal halide

    OpenAIRE

    Saito, Hiroshi; Taniguchi, Hiroshi

    1985-01-01

    The first successful use of vapor-complex reactions for a laser is reported. Vapor-complex reactions between metallic copper and metal halides are found effective in reducing the operating temperature in copper-vapor lasers. By using a vapor-complex reaction of Cu+AlBr3, a laser oscillation starts at a reservoir temperature of about 25°C. The results obtained by the mass spectroscopic analysis support the presumption that the copper vapor is generated through a vapor-complex reaction process.

  5. Electrical properties of carbon nanotubes in flowing vapor

    Institute of Scientific and Technical Information of China (English)

    XIAO Peng; WANG Xin-qiang; ZHANG Yun-huai

    2006-01-01

    Electric potentials were generated from carbon nanotubes immersed in flowing vapors.The nanomaterials used in this study were multiwall carbon nanotubes(MWCNTs) and silver nanopowders.These nanomaterials were dispersed and densely packed on a substrate and immersed in flowing vapors generated from solution such as water,ethanol and KCl.The potentials generated from these samples were measured by a voltmeter.Experimental results showed that the electric potentials were produced at the surface of the MWCNT samlpes,and strongly dependent on the pretreatment of MWCNT and properties of the flowing vapors.The mechanism of vapor-flow induced potentials may be ascribed to ions in the flowing vapors.This property of MWCNTs can advantage their application to nanoscale sensors,detectors and power cells.

  6. Gasoline Vapor Recovery

    Science.gov (United States)

    1979-01-01

    Gasoline is volatile and some of it evaporates during storage, giving off hydrocarbon vapor. Formerly, the vapor was vented into the atmosphere but anti-pollution regulations have precluded that practice in many localities, so oil companies and storage terminals are installing systems to recover hydrocarbon vapor. Recovery provides an energy conservation bonus in that most of the vapor can be reconverted to gasoline. Two such recovery systems are shown in the accompanying photographs (mid-photo at right and in the foreground below). They are actually two models of the same system, although.configured differently because they are customized to users' needs. They were developed and are being manufactured by Edwards Engineering Corporation, Pompton Plains, New Jersey. NASA technological information proved useful in development of the equipment.

  7. Gasoline Reid Vapor Pressure

    Science.gov (United States)

    EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

  8. Vapor Control Layer Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-09-08

    This information sheet describes the level of vapor control required on the interior side of framed walls with typical fibrous cavity insulation (fibreglass, rockwool, or cellulose, based on DOE climate zone of construction.

  9. Single-Drop Solution Electrode Discharge-Induced Cold Vapor Generation Coupling to Matrix Solid-Phase Dispersion: A Robust Approach for Sensitive Quantification of Total Mercury Distribution in Fish.

    Science.gov (United States)

    Chen, Qian; Lin, Yao; Tian, Yunfei; Wu, Li; Yang, Lu; Hou, Xiandeng; Zheng, Chengbin

    2017-02-07

    Sensitive quantification of mercury distribution in fish is challenging because of insufficient sensitivities of conventional analytical methods, the limited mass of organs (tens of micrograms to several milligrams), and dilution of analyte concentration from sample digestion. In this work, a simple and robust approach coupling multiwall carbon nanotubes assisted matrix solid-phase dispersion (MWCNTs-MSPD) to single-drop solution electrode glow discharge-induced cold vapor generation (SD-SEGD-CVG) was developed for the sensitive determination of mercury in limited amount of sample. Mercury species contained in a limited amount of sample can be efficiently extracted into a 100 μL of eluent by MWCNTs-MSPD, which are conveniently converted to Hg(0) by SD-SEGD-CVG and further transported to atomic fluorescence spectrometry for their determination. Therefore, analyte dilution resulted from sample preparation is avoided and sensitivity is significantly improved. On the basis of consumption of 1 mg of sample, a limit of detection of 0.01 μg L(-1) (0.2 pg) was obtained with relative standard deviations (RSDs) of 5.2% and 4.6% for 2 and 20 μg L(-1), respectively. The accuracy of the proposed method was validated by analysis of three Certified Reference Materials with satisfying results. To confirm that SD-SEGD-CVG-AFS coupling to MWCNTs-MSPD is a promising method to quantify mercury distribution in fish, this method was successfully applied for the sensitive determination of mercury in seven organs of common carps (muscle, gill, intestine, liver, gallbladder, brain, and eye) after dietary of mercury species. The proposed method provides advantages of minimum sample dilution, low blank, high sample introduction efficiency, high sensitivity, and minimum toxic chemicals and sample consumption.

  10. Improvement in using steam for electric generation at the Los Azufres, Mich., geothermal field; Mejora en el aprovechamiento del vapor para generar energia electrica en el campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Torres Rodriguez, Marco A.; Flores Armenta, Magaly; Mendoza Covarrubias, Alfredo [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx

    2010-01-15

    Commercial exploitation in the Los Azufres geothermal field, Michoacan, Mexico, started in 1982 when the first five backpressure-power units of 5-MW each were commissioned. Nowadays the installed capacity is 188 MW from 14 units: five in the South Zone fed by steam produced from 18 production wells plus two binary-cycle power units fed by residual brines; and seven in the North Zone with steam supplied by 22 production wells. There are seven backpressure-power units with high specific consumption [between 14.5 and 13.6 tons per hour of steam (t/h) per MW]. Three operate in the South Zone and four in the North Zone. This paper shows a way to achieve more efficient use of the geothermal resource by replacing the seven backpressure units, which have completed their useful lifetime-or are close to do it-with two, new condensing power units with lower specific consumption: one unit of 50 MW to be located in the North Zone and the other of 25 MW to be placed in the South Zone. No new wells need be drilled. In this way, the average specific consumption would be reduced to 8.8-7.2 t/h per MW (saving 47% of the steam), the income for electric generation would be increased and the steam-extraction rate would remain the same. [Spanish] En 1982 empezo la explotacion comercial del campo geotermico de Los Azufres, Mich., Mexico, con la instalacion y puesta en servicio de las primeras cinco unidades turbogeneradoras a contrapresion de 5 MW cada una. Actualmente la capacidad instalada es de 188 MW, con catorce unidades: cinco en la zona sur, alimentadas por el vapor de 18 pozos productores, mas dos unidades de ciclo binario que utilizan salmuera residual, y siete unidades en la zona norte, alimentadas por 22 pozos. Hay siete unidades a contrapresion con un consumo especifico elevado [entre 14.5 y 13.6 toneladas por hora (t/h) de vapor por MW], tres de las cuales se localizan en la zona sur y cuatro en la zona norte. En este documento se presenta un proyecto para hacer mas

  11. Vapor pressures and enthalpies of vaporization of azides

    Energy Technology Data Exchange (ETDEWEB)

    Verevkin, Sergey P., E-mail: sergey.verevkin@uni-rostock.de [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059 Rostock (Germany); Emel' yanenko, Vladimir N. [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059 Rostock (Germany); Algarra, Manuel [Centro de Geologia do Porto, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Manuel Lopez-Romero, J. [Department of Organic Chemistry, University of Malaga. Campus de Teatinos s/n, 29071 Malaga (Spain); Aguiar, Fabio; Enrique Rodriguez-Borges, J.; Esteves da Silva, Joaquim C.G. [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2011-11-15

    Highlights: > We prepared and measured vapor pressures and vaporization enthalpies of 7 azides. > We examined consistency of new and available in the literature data. > Data for geminal azides and azido-alkanes selected for thermochemical calculations. - Abstract: Vapor pressures of some azides have been determined by the transpiration method. The molar enthalpies of vaporization {Delta}{sub l}{sup g}H{sub m} of these compounds were derived from the temperature dependencies of vapor pressures. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of similarly structured compounds.

  12. Vapor concentration monitor

    Science.gov (United States)

    Bayly, John G.; Booth, Ronald J.

    1977-01-01

    An apparatus for monitoring the concentration of a vapor, such as heavy water, having at least one narrow bandwidth in its absorption spectrum, in a sample gas such as air. The air is drawn into a chamber in which the vapor content is measured by means of its radiation absorption spectrum. High sensitivity is obtained by modulating the wavelength at a relatively high frequency without changing its optical path, while high stability against zero drift is obtained by the low frequency interchange of the sample gas to be monitored and of a reference sample. The variable HDO background due to natural humidity is automatically corrected.

  13. Water vapor: An extraordinary terahertz wave source under optical excitation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Keith [Massachusetts Institute of Technology, PO Box 380792, Cambridge, MA 02238-0792 (United States); HydroElectron Ventures Inc., 1303 Greene Avenue Suite 102, Westmount, QC, H3Z 2A7 (Canada)], E-mail: kjohnson@mit.edu; Price-Gallagher, Matthew [HydroElectron Ventures Inc., 1303 Greene Avenue Suite 102, Westmount, QC, H3Z 2A7 (Canada); Mamer, Orval; Lesimple, Alain [Mass Spectroscopy Unit, 740 Dr. Penfield, Suite 5300, McGill University, Montreal, QC, H3A 1A4 (Canada); Fletcher, Clark [HydroElectron Ventures Inc., 1303 Greene Avenue Suite 102, Westmount, QC, H3Z 2A7 (Canada); Chen Yunqing; Lu Xiaofei; Yamaguchi, Masashi; Zhang, X.-C. [W.M. Keck Laboratory for Terahertz Science, Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

    2008-09-15

    In modern terahertz (THz) sensing and imaging spectroscopy, water is considered a nemesis to be avoided due to strong absorption in the THz frequency range. Here we report the first experimental demonstration and theoretical implications of using femtosecond laser pulses to generate intense broadband THz emission from water vapor. When we focused an intense laser pulse in water vapor contained in a gas cell or injected from a gas jet nozzle, an extraordinarily strong THz field from optically excited water vapor is observed. Water vapor has more than 50% greater THz generation efficiency than dry nitrogen. It had previously been assumed that the nonlinear generation of THz waves in this manner primarily involves a free-electron plasma, but we show that the molecular structure plays an essential role in the process. In particular, we found that THz wave generation from H{sub 2}O vapor is significantly stronger than that from D{sub 2}O vapor. Vibronic activities of water cluster ions, occurring naturally in water vapor, may possibly contribute to the observed isotope effect along with rovibrational contributions from the predominant monomers.

  14. Passive Vaporizing Heat Sink

    Science.gov (United States)

    Knowles, TImothy R.; Ashford, Victor A.; Carpenter, Michael G.; Bier, Thomas M.

    2011-01-01

    A passive vaporizing heat sink has been developed as a relatively lightweight, compact alternative to related prior heat sinks based, variously, on evaporation of sprayed liquids or on sublimation of solids. This heat sink is designed for short-term dissipation of a large amount of heat and was originally intended for use in regulating the temperature of spacecraft equipment during launch or re-entry. It could also be useful in a terrestrial setting in which there is a requirement for a lightweight, compact means of short-term cooling. This heat sink includes a hermetic package closed with a pressure-relief valve and containing an expendable and rechargeable coolant liquid (e.g., water) and a conductive carbon-fiber wick. The vapor of the liquid escapes when the temperature exceeds the boiling point corresponding to the vapor pressure determined by the setting of the pressure-relief valve. The great advantage of this heat sink over a melting-paraffin or similar phase-change heat sink of equal capacity is that by virtue of the =10x greater latent heat of vaporization, a coolant-liquid volume equal to =1/10 of the paraffin volume can suffice.

  15. Study on the effect of subcooling on vapor film collapse on high temperature particle surface

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Yutaka; Tochio, Daisuke; Yanagida, Hiroshi [Department of Mechanical Systems Engineering, Yamagata Univ., Yonezawa, Yamagata (Japan)

    2000-11-01

    Thermal detonation model is proposed to describe vapor explosion. According to this model, vapor film on pre-mixed high temperature droplet surface is needed to be collapsed for the trigger of the vapor explosion. It is pointed out that the vapor film collapse behavior is significantly affected by the subcooling of low temperature liquid. However, the effect of subcooling on micro-mechanism of vapor film collapse behavior is not experimentally well identified. The objective of the present research is to experimentally investigate the effect of subcooling on micro-mechanism of film boiling collapse behavior. As the results, it is experimentally clarified that the vapor film collapse behavior in low subcooling condition is qualitatively different from the vapor film collapse behavior in high subcooling condition. In case of vapor film collapse by pressure pulse, homogeneous vapor generation occurred all over the surface of steel particle in low subcooling condition. On the other hand, heterogeneous vapor generation was observed for higher subcooling condition. In case of vapor film collapse spontaneously, fluctuation of the gas-liquid interface after quenching propagated from bottom to top of the steel particle heterogeneously in low subcooling condition. On the other hand, simultaneous vapor generation occurred for higher subcooling condition. And the time transient of pressure, particle surface temperature, water temperature and visual information were simultaneously measured in the vapor film collapse experiment by external pressure pulse. Film thickness was estimated by visual data processing technique with the pictures taken by the high-speed video camera. Temperature and heat flux at the vapor-liquid interface were estimated by solving the heat condition equation with the measured pressure, liquid temperature and vapor film thickness as boundary conditions. Movement of the vapor-liquid interface were estimated with the PIV technique with the visual observation

  16. Diagnóstico de fallos en un generador de vapor BKZ-340-140-29M utilizando herramientas de lógica difusa//Fault diagnosis in a BKZ-340-140-29M steam generator using tools of fuzzy logic

    Directory of Open Access Journals (Sweden)

    Adrián Rodríguez‐Ramos

    2014-05-01

    Full Text Available En este trabajo se presenta el diseño de un sistema de diagnóstico de fallos utilizando herramientas de lógica difusa para un generador de vapor BKZ-340-140-29M en una central termoeléctrica. La aplicación tiene como objetivo estudiar las ventajas que ofrece esta técnica en el desarrollo de un método de diagnóstico de fallos que sea robusto a perturbaciones externas y sensible ante fallos de pequeña magnitud. El diagnosticador se diseñó para el circuito agua – vapor del generador a partir de demostrarse su gran incidencia en la disponibilidad de los bloques de generación. Los resultados obtenidos indican la factibilidad de la propuesta.Palabras claves: diagnóstico de fallos, robustez, sensibilidad, lógica difusa, generador de vapor._______________________________________________________________________________AbstractIn this work the design of a fault diagnosis system using tools of fuzzy logic for a BKZ-340-140-29M steam generator in a thermoelectric power station is presented. The application aims to study the advantages of these techniques in the development of a fault diagnostic method with the characteristic to be robust to external disturbances and sensitive to small faults. The fault diagnosissystem was designed for the water – steam circuit of the steam generator by its great incidence in the correct functionality of the generation blocks. The obtained results indicate the feasibility of the proposal.Key words: fault diagnosis, robustness, sensibility, fuzzy logic, steam generator.

  17. Nitric acid vapor removal by activated, impregnated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Wood, G.O.

    1996-12-31

    Laboratory and industrial workers can be exposed to vapors of nitric acid, especially in accidents, such as spills. Nitric acid can also be a product of incineration for energy production or waste (e.g., CW agent) disposal. Activated carbons containing impregnants for enhancing vapor and gas removal have been tested for effectiveness in removing vapors of nitric acid from air. The nitric acid vapor was generated from concentrated acid solutions and detected by trapping in a water bubbler for pH measurements. Both low and moderate relative humidity conditions were used. All carbons were effective at vapor contact times representative of air-purifying respirator use. One surprising observation was the desorption of low levels of ammonia from impregnated carbons. This was apparently due to residual ammonia from the impregnation processes.

  18. Thermogravimetric study of vapor pressure of TATP synthesized without recrystallization.

    Science.gov (United States)

    Mbah, Jonathan; Knott, Debra; Steward, Scott

    2014-11-01

    This study aims at characterizing the vapor pressure signatures generated by triacetone triperoxide (TATP) that was synthesized without recrystallization by thermogravimmetric analysis (TGA) for exploitation by standoff detection technologies of explosive devices. The thermal behavior of the nonrecrystallized sample was compared with reported values. Any phase change, melting point and decomposition identification were studied by differential scanning calorimeter. Vapor pressures were estimated by the Langmuir method of evaporation from an open surface in a vacuum. Vapor pressures of TATP at different temperatures were calculated using the linear logarithmic relationship obtained from benzoic acid reference standard. Sublimation of TATP was found to follow apparent zero-order kinetics and sublimes at steady rates at 298 K and above. While the enthalpy of sublimation found, 71.7 kJ mol(-1), is in agreement with reported values the vapor pressures deviated significantly. The differences in the vapor pressures behavior are attributable to the synthesis pathway chosen in this study.

  19. Characterization of Bioeffects on Endothelial Cells under Acoustic Droplet Vaporization.

    Science.gov (United States)

    Seda, Robinson; Li, David S; Fowlkes, J Brian; Bull, Joseph L

    2015-12-01

    Gas embolotherapy is achieved by locally vaporizing microdroplets through acoustic droplet vaporization, which results in bubbles that are large enough to occlude blood flow directed to tumors. Endothelial cells, lining blood vessels, can be affected by these vaporization events, resulting in cell injury and cell death. An idealized monolayer of endothelial cells was subjected to acoustic droplet vaporization using a 3.5-MHz transducer and dodecafluoropentane droplets. Treatments included insonation pressures that varied from 2 to 8 MPa (rarefactional) and pulse lengths that varied from 4 to 16 input cycles. The bubble cloud generated was directly dependent on pressure, but not on pulse length. Cellular damage increased with increasing bubble cloud size, but was limited to the bubble cloud area. These results suggest that vaporization near the endothelium may impact the vessel wall, an effect that could be either deleterious or beneficial depending on the intended overall therapeutic application.

  20. Vapor-liquid equilibria from the triple point up to the critical point for the new generation of TIP4P-like models: TIP4P/Ew, TIP4P/2005, and TIP4P/ice.

    Science.gov (United States)

    Vega, C; Abascal, J L F; Nezbeda, I

    2006-07-21

    The vapor-liquid equilibria of three recently proposed water models have been computed using Gibbs-Duhem simulations. These models are TIP4P/Ew, TIP4P/2005, and TIP4P/ice and can be considered as modified versions of the TIP4P model. By design TIP4P reproduces the vaporization enthalpy of water at room temperature, whereas TIP4P/Ew and TIP4P/2005 match the temperature of maximum density and TIP4P/ice the melting temperature of water. Recently, the melting point for each of these models has been computed, making it possible for the first time to compute the complete vapor-liquid equilibria curve from the triple point to the critical point. From the coexistence results at high temperature, it is possible to estimate the critical properties of these models. None of them is capable of reproducing accurately the critical pressure or the vapor pressures and densities. Additionally, in the cases of TIP4P and TIP4P/ice the critical temperatures are too low and too high, respectively, compared to the experimental value. However, models accounting for the density maximum of water, such as TIP4P/Ew and TIP4P/2005 provide a better estimate of the critical temperature. In particular, TIP4P/2005 provides a critical temperature just 7 K below the experimental result as well as an extraordinarily good description of the liquid densities from the triple point to the critical point. All TIP4P-like models present a ratio of the triple point temperature to the critical point temperature of about 0.39, compared with the experimental value of 0.42. As is the case for any effective potential neglecting many body forces, TIP4P/2005 fails in describing simultaneously the vapor and the liquid phases of water. However, it can be considered as one of the best effective potentials of water for describing condensed phases, both liquid and solid. In fact, it provides a completely coherent view of the phase diagram of water including fluid-solid, solid-solid, and vapor-liquid equilibria.

  1. Fault diagnosis in the steam generator of a thermoelectric power plant using Petri networks; Diagnostico de fallas en el generador de vapor de una termoelectrica usando redes de Petri

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Cerda, Dionisio A; Sanchez Lopez, Alfredo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Martinez Prieto, Jose E; Garcia Beltran, Carlos D. [Centro Nacional de Investigacion y Desarrollo Tecnologico, Cuernavaca, Morelos (Mexico)

    2007-07-01

    With time, all physical systems show modifications in the dynamics of its operation. This can be attributed to different causes, for example, wear by friction, deterioration by overheating or natural aging, among others. These changes evolve gradually, until getting to become faults related to the reliability, availability, efficiency, safety and continuity of the operation, which seriously affect the performance indexes of the system. In this article a scheme of fault diagnosis is shown, applied to the steam generator of a thermoelectric power unit, based on techniques of modeling of dynamic systems by means of Petri networks. Against other methods, the scheme offers greater easiness for its implementation, rapidity of adaptation before changes of operation zone and good robustness. A way to reduce the effect of faults in a production system consists of two steps. The first one is to diagnose the fault as soon as it occurs and subsequently put into practice remedial actions. The concept of fault diagnosis is related to the first stage and encompasses the detection, as well as the location of this one. That is to say, besides determining that a fault is present, it is known in what component it has happened. In base to the former, it is clear that a diagnosis system requires supervising the variables that characterize the behavior of the faults, in order to detect them at the moment in which they occur and informing it to the operator. With this information, the operator will be able to realize the necessary remedial actions so that the plant continues operating as long as possible. [Spanish] Con el tiempo, todo sistema fisico manifiesta modificaciones en la dinamica de su funcionamiento. Esto puede atribuirse a diferentes causas, como por ejemplo, desgaste por friccion, deterioro por sobrecalentamiento o envejecimiento natural, entre otras. Estos cambios evolucionan gradualmente, hasta llegar a convertirse en fallas relacionadas con la confiabilidad

  2. Vapor Online Monitor Model of Vapor Power Station Based on UML

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We presents a vapor online monitor system model of vapor power station developed by visual tool rational rose2000. Use cases such as on line instrument (onlineinstr), control, query, report, real database (realdb) and alarm are generated according to the system requirements. Use case view and class view of the system are formed at the same time. As for all the UML models of the system, this paper focuses the discussion on the class view, the component diagram of the control class and the sequence diagram of the query class. Corresponding C++ codes are produced and finally transferred into the spot running software.

  3. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    Energy Technology Data Exchange (ETDEWEB)

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  4. Combined rankine and vapor compression cycles

    Science.gov (United States)

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  5. Improved waste water vapor compression distillation technology. [for Spacelab

    Science.gov (United States)

    Johnson, K. L.; Nuccio, P. P.; Reveley, W. F.

    1977-01-01

    The vapor compression distillation process is a method of recovering potable water from crewman urine in a manned spacecraft or space station. A description is presented of the research and development approach to the solution of the various problems encountered with previous vapor compression distillation units. The design solutions considered are incorporated in the preliminary design of a vapor compression distillation subsystem. The new design concepts are available for integration in the next generation of support systems and, particularly, the regenerative life support evaluation intended for project Spacelab.

  6. Criteria for the provision and assembly of the rotor blades of a 300 MW low pressure steam turbine for electrical generation; Criterios para el suministro y ensambles de la alabes de rotor de turbina de vapor de 300 MW baja presion para generacion electrica

    Energy Technology Data Exchange (ETDEWEB)

    Bertin, Galo; Felix, Jorge A.; Quijano, Octavio [Especialistas en Turbopartes, S.A. de C.V., Queretaro, Queretaro (Mexico)

    2007-11-15

    This paper presents some of the main criteria to consider from the inspection, disassembling and assembly of blades with different root types of a turbine rotor of steam turbines for power generation, having as an aim to count on a reliable rotor, fulfilling with the equipment original design and norms and international standards. [Spanish] Este trabajo presenta algunos de los criterios principales a considerar desde la inspeccion, desmontaje y montaje de alabes de diferentes tipos de raiz de un rotor de turbinas de vapor de generacion electrica, teniendo como finalidad contar con un rotor confiable, cumpliendo con el diseno original del equipo y con normas y estandares internacionales.

  7. The toxicity of inhaled methanol vapors

    Energy Technology Data Exchange (ETDEWEB)

    Kavet, R.; Nauss, K.M. (Environmental Research Information, Inc., Palo Alto, CA (USA))

    1990-01-01

    Methanol could become a major automotive fuel in the U.S., and its use may result in increased exposure of the public to methanol vapor. Nearly all of the available information on methanol toxicity in humans relates to the consequences of acute, rather than chronic, exposures. Acute methanol toxicity evolves in a well-understood pattern and consists of an uncompensated metabolic acidosis with superimposed toxicity to the visual system. The toxic properties of methanol are rooted in the factors that govern both the conversion of methanol to formic acid and the subsequent metabolism of formate to carbon dioxide in the folate pathway. In short, the toxic syndrome sets in if formate generation continues at a rate that exceeds its rate of metabolism. Current evidence indicates that formate accumulation will not challenge the metabolic capacity of the folate pathway at the anticipated levels of exposure to automotive methanol vapor.117 references.

  8. Water vapor retrieval from OMI visible spectra

    Directory of Open Access Journals (Sweden)

    H. Wang

    2014-01-01

    optimization of retrieval windows and parameters. The Air Mass Factor (AMF is calculated using look-up tables of scattering weights and monthly mean water vapor profiles from the GEOS-5 assimilation products. We convert from SCD to Vertical Column Density (VCD using the AMF and generate associated retrieval averaging kernels and shape factors. Our standard water vapor product has a median SCD of ~ 1.3 × 1023 molecule cm−2 and a median relative uncertainty of ~ 11% in the tropics, about a factor of 2 better than that from a similar OMI algorithm but using narrower retrieval window. The corresponding median VCD is ~ 1.2 × 1023 molecule cm−2. We have also explored the sensitivities to various parameters and compared our results with those from the Moderate-resolution Imaging Spectroradiometer (MODIS and the Aerosol Robotic NETwork (AERONET.

  9. Automatic control of plants of direct steam generation with cylinder-parabolic solar collectors; Control automatico de plantas de generacion directa de vapor con colectores solares cilindro-parabolicos

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela Gutierrez, L.

    2008-07-01

    The main objective of this dissertation has been the contributions to the operation in automatic mode of a new generation of direct steam generation solar plants with parabolic-trough collectors. The dissertation starts introducing the parabolic-trough collectors solar thermal technology for the generation of process steam or steam for a Rankine cycle in the case of power generation generation, which is currently the most developed and commercialized technology. Presently, the parabolic-trough collectors technology is based on the configuration known as heat-exchanger system, based in the use of a heat transfer fluid in the solar field which is heated during the recirculation through the absorber tubes of the solar collectors, transferring later on the that thermal energy to a heat-exchanger for steam generation. Direct steam generation in the absorber tubes has always been shown as an ideal pathway to reduce generation cost by 15% and increase conversion efficiency by 20% (DISS, 1999). (Author)

  10. Solvents and vapor intrusion pathways.

    Science.gov (United States)

    Phillips, Scott D; Krieger, Gary R; Palmer, Robert B; Waksman, Javier C

    2004-08-01

    Vapor intrusion must be recognized appropriately as a separate pathway of contamination. Although many issues resemble those of other forms of contamination (particularly its entryway, which is similar to that of radon seepage), vapor intrusion stands apart as a unique risk requiring case-specific action. This article addresses these issues and the current understanding of the most appropriate and successful remedial actions.

  11. Vapor phase heat transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Hedstrom, J.C.; Neeper, D.A.

    1985-09-01

    This report describes progress in theoretical and experimental investigations of various forms of a vapor transport system for solar space heating, which could also be applied to service water heating. Refrigerant is evaporated in a solar collector, which may be located on the external wall or roof of a building. The vapor is condensed in a passively discharged thermal storage unit located within the building. The condensed liquid can be returned to the collector either by a motor-driven pump or by a completely passive self-pumping mechanism in which the vapor pressure lifts the liquid from the condenser to the collector. The theoretical investigation analyzes this self-pumping scheme. Experiments in solar test cells compare the operation of both passive and active forms of the vapor system with the operation of a passive water wall. The vapor system operates as expected, with potential advantages over other passive systems in design flexibility and energy yield.

  12. 33 CFR 154.828 - Vapor recovery and vapor destruction units.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vapor recovery and vapor... SECURITY (CONTINUED) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154.828 Vapor recovery and vapor destruction units. (a) The inlet to a vapor recovery unit...

  13. Vapor pressure measured with inflatable plastic bag

    Science.gov (United States)

    1965-01-01

    Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

  14. A Citizen's Guide to Vapor Intrusion Mitigation

    Science.gov (United States)

    This guide describes how vapor intrusion is the movement of chemical vapors from contaminated soil and groundwater into nearby buildings.Vapors primarily enter through openings in the building foundation or basement walls.

  15. A Lithium Vapor Box similarity experiment employing water vapor

    Science.gov (United States)

    Schwartz, Ja; Jagoe, C.; Goldston, Rj; Jaworski, Ma

    2016-10-01

    Handling high power loads and heat flux in the divertor is a major challenge for fusion power plants. A detached plasma will likely be required. However, hydrogenic and impurity puffing experiments show that detached operation leads easily to X-point MARFEs, impure plasmas, degradation in confinement, and lower helium pressure at the exhaust. The concept of the Lithium Vapor Box Divertor is to use local evaporation and strong differential pumping through condensation to localize the gas-phase material that absorbs the plasma heat flux, and so avoid those difficulties. In order to design such a box first the vapor without plasma must be simulated. The density of vapor required can be estimated using the SOL power, major radius, poloidal box length, and cooling energy per lithium atom. For an NSTX-U-sized machine, the Knudsen number Kn spans 0.01 to 1, the transitional flow regime. This regime cannot handled by fluid codes or collisionless Monte Carlo codes, but can be handled by Direct Simulation Monte Carlo (DSMC) codes. To validate a DSMC model, we plan to build a vapor box test stand employing more-convenient water vapor instead of lithium vapor as the working fluid. Transport of vapor between the chambers at -50C will be measured and compared to the model. This work supported by DOE Contract No. DE-AC02-09CH11466.

  16. Collapsing criteria for vapor film around solid spheres as a fundamental stage leading to vapor explosion

    Energy Technology Data Exchange (ETDEWEB)

    Freud, Roy [Nuclear Research Center - Negev, Beer-Sheva (Israel)], E-mail: freud@bgu.ac.il; Harari, Ronen [Nuclear Research Center - Negev, Beer-Sheva (Israel); Sher, Eran [Pearlstone Center for Aeronautical Studies, Department of Mechanical Engineering, Ben-Gurion University, Beer-Sheva (Israel)

    2009-04-15

    during the cooling process-from values typical for film boiling to much higher values typical for nucleate boiling. Correlations for the minimum temperature and the minimum heat flux necessary to maintain film boiling were established in terms of the subcooling level, the size of the spheres and their material. The minimum temperature to maintain film boiling was used as the principle criteria for the occurrence of vapor explosion. Other criteria, for the intensity of the vapor film collapse was derived from the maximum heat flux following the vapor film collapse, and the audible sound (which is generated by the shock wave). It is assumed that a high intensity of the vapor film collapse will result in a more efficient propagation stage and enhancement of the vapor explosion.

  17. Introduction of Novel UVHg-1000 UV Vapor Generation based Mercury Analyzer and Trace Level Mercury Determination in Water%新型UVHg-1000紫外光化学发生测汞仪简介及其对水中超痕量汞的检测

    Institute of Scientific and Technical Information of China (English)

    曹小丹; 秦德元

    2012-01-01

    研发了一种型号为UVHg-1000的紫外光化学发生测汞仪,用于自来水、地表水、地下水中痕量汞的检测。水中的痕量汞经C18固相萃取小柱(SPE)富集,洗脱进入紫外发生装置产生汞原子,汞原子被导入原子荧光检测器进行检测。本方法首次将固相萃取富集-光化学发生法串联系统应用到测汞领域,提高了检测灵敏度,同时也便于野外采样,样品保存以及样品运输。可通过增加进样环的方式实现自动配制标准曲线;可不经消解,直接测量水样中的有机汞。本方法对水中汞总量的检出限为0.0005μg/L,线性范围0.5~1000 ng/L,相对标准偏差(RSD)为5%以内,线性相关系数(R)〉0.995,实际样品回收率为85%-110%。%Mercury Analyzer(Model UVHg-1000) based on UV vapor generation was developed for trace level mercury determination in tap water,surface water and underground water.C18 solid phase extraction(SPE) column was used for water sample accumulation,and then the eluent was introduced into UV vapor generation system.The mercury atom produced from the UV vapor generation system was detected through atomic fluorescence detector.It is the first time for UV vapor generation technique being employed in the field of mercury determination.In-field sample collection,sample storage and transportation were facilitated through the high efficient SPE accumulation column with an improved sensitivity.The sample loops were added for standard curve generation.Organic mercury could be determined without sample digestion.Under the optimistic condition,the robust system has achieved a detection limit(DL) of 0.0005μg /L with RSD less than 5%,a linear range of 0.5-1000 ng/L with the linear correlation coefficient larger than 0.995,and matrix spiked recovery in the range of 85%-110% for mercury determination.

  18. Multiwavelength Strontium Vapor Lasers

    Science.gov (United States)

    Soldatov, A. N.; Yudin, N. A.

    2016-08-01

    Based on an analysis of experimental and theoretical works, modern notion on conditions of forming of population density inversion on self-terminating IR transitions of alkali-earth metals is given. It is demonstrated that there is a significant difference in the inversion formation in lasers on self-terminating transitions in the visible and near-IR ranges and lasers on self-terminating transitions of alkali-earth metals lasing IR lines in the mid-IR range. It is shown that in the discharge circuit of lasers on self-terminating metal atom transitions (LSMT) there are processes strengthening the influence of the known mechanism limiting the frequency and energy characteristics (FEC) of radiation caused by the presence of prepulse electron concentration. The mechanism of influence of these processes on FEC of the LSMT and technical methods of their neutralization are considered. The possibility of obtaining average lasing power of ~200 W from one liter volume of the active medium of the strontium vapor laser is demonstrated under conditions of neutralization of these processes.

  19. Archimedes Mass Filter Vaporizer

    Science.gov (United States)

    Putvinski, S.; Agnew, A. F.; Cluggish, B. P.; Ohkawa, T.; Sevier, L.; Umstadter, K. R.; Dresvin, S. V.; Kuteev, B. V.; Feygenson, O. N.; Ivanov, D. V.; Zverev, S. G.; Miroshnikov, I. V.; Egorov, S. M.; Kiesewetter, D. V.; Maliugin, V. I.

    2001-10-01

    Archimedes Technology Group, Inc., is developing a plasma mass separator called the Archimedes Filter that separates waste oxide mixtures ion by ion into two mass groups: light and heavy. Since high-level waste at Hanford has 99.9its radioactivity associated with heavy elements, the Archimedes Filter can effectively decontaminate over three-quarters of that waste. The Filter process involves some preprocessing followed by volatilization and separation by the magnetic and electric fields of the main plasma. This presentation describes the approach to volatilization of the waste oxy-hydroxide mixture by means of a very high heat flux (q > 10 MW/m2). Such a high heat flux is required to ensure congruent evaporation of the complex oxy-hydroxide mixture and is achieved by injection of small droplets of molten waste into an inductively coupled plasma (ICP) torch. This presentation further addresses different issues related to evaporation of the waste including modeling of droplet evaporation, estimates of parameters of plasma torch, and 2D modeling of the plasma. The experimental test bed for oxide vaporization and results of the initial experiments on oxide evaporation in 60 kW ICP torch will also be described.

  20. Electricity generation using electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

    2017-08-22

    In general, in one aspect, the invention relates to a system to create vapor for generating electric power. The system includes a vessel comprising a fluid and a complex and a turbine. The vessel of the system is configured to concentrate EM radiation received from an EM radiation source. The vessel of the system is further configured to apply the EM radiation to the complex, where the complex absorbs the EM radiation to generate heat. The vessel of the system is also configured to transform, using the heat generated by the complex, the fluid to vapor. The vessel of the system is further configured to sending the vapor to a turbine. The turbine of the system is configured to receive, from the vessel, the vapor used to generate the electric power.

  1. Transient analysis with high percentages steam generator tube plugging of Angra 1 nuclear power plant; Analise de transientes com altos percentuais de tamponamento dos tubos dos geradores de vapor de Angra 1

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Marcio Poubel; Martins Junior, Laercio Lucena; Vanni, Enio Antonio; Machado, Marcio Dornellas; Moreira, Francisco Jose [ELETRONUCLEAR, Rio de Janeiro, RJ (Brazil); Alvim, Antonio Carlos M. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    1999-11-01

    The present work is part of several analyses under development in ELETRONUCLEAR/ COPPE-UFRJ to evaluate impacts on licensing bases and operating conditions of an increase in steam generator tube plugging for Angra 1 NPP. Total loss of reactor coolant flow uncontrolled boron dilution transients were initially analysed. The final results indicated that were no impacts on FSAR established margins, in case of 24% steam generator tube plugging. (author) 3 refs., 4 figs., 4 tabs.

  2. Vapor Intrusion Facilities - South Bay

    Data.gov (United States)

    U.S. Environmental Protection Agency — POINT locations for the South Bay Vapor Instrusion Sites were derived from the NPL data for Region 9. One site, Philips Semiconductor, was extracted from the...

  3. Understanding Latent Heat of Vaporization.

    Science.gov (United States)

    Linz, Ed

    1995-01-01

    Presents a simple exercise for students to do in the kitchen at home to determine the latent heat of vaporization of water using typical household materials. Designed to stress understanding by sacrificing precision for simplicity. (JRH)

  4. Modeling vapor dominated geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Marconcini, R.; McEdwards, D.; Neri, G.; Ruffilli, C.; Schroeder, R.; Weres, O.; Witherspoon, P.

    1977-09-12

    The unresolved questions with regard to vapor-dominated reservoir production and longevity are reviewed. The simulation of reservoir behavior and the LBL computer program are discussed. The geology of Serrazzano geothermal field and its reservoir simulation are described. (MHR)

  5. Modeling the effect of ethanol vapor on the germination time of Penicillium chrysogenum

    NARCIS (Netherlands)

    Dantigny, P.; Tchobanov, I.; Bensoussan, M.; Zwietering, M.H.

    2005-01-01

    The influence of ethanol vapor on germination of Penicillium chrysogenum was determined on yeast nitrogen base plus glucose agar medium at 25°C. Ethanol vapors were generated by 0 to 6% (wt/wt) ethanol solutions at the bottom of hermetically closed petri dishes. The logistic equation was used to des

  6. Modeling the effect of ethanol vapor on the germination time of Penicillium chrysogenum

    NARCIS (Netherlands)

    Dantigny, P.; Tchobanov, I.; Bensoussan, M.; Zwietering, M.H.

    2005-01-01

    The influence of ethanol vapor on germination of Penicillium chrysogenum was determined on yeast nitrogen base plus glucose agar medium at 25°C. Ethanol vapors were generated by 0 to 6% (wt/wt) ethanol solutions at the bottom of hermetically closed petri dishes. The logistic equation was used to

  7. Numerical simulation of vapor-liquid two-phase flow and boiling in steam generator based on population balance%基于群体平衡原理的蒸汽发生器汽液两相流动与沸腾数值模拟

    Institute of Scientific and Technical Information of China (English)

    杨元龙; 孙宝芝; 杨柳; 郑陆松

    2014-01-01

    Based on similarity principle, a three-dimensional“unit pipe”physical model is built for a steam generator coupled with quatrefoil tube support plates. A multiple size group model considering breakup and coalescence of bubbles is used to describe bubble size distribution and hydraulic characteristic in the secondary side. The process of local vapor-liquid two-phase boiling with phase change is calculated through a thermal phase change model. Numerical investigation is carried out on vapor-liquid two-phase flow and boiling of steam generator at Daya Bay Nuclear Power Plant. Simulation results show that vapor and liquid velocities rapidly increase in the support plate and jet flow appears, and when the flow leaves the support plate orifice, reflow forms rapidly. The periodic distribution from small to large bubble size occurs obviously within adjacent tube support plates and the maximum bubble diameter decreases slowly in the direction of hot and cold legs. In addition, the averaged heat transfer coefficient of secondary side agrees well with the results calculated using Rohsenow’s correlation.%基于相似原理建立了耦合四叶梅花形支撑板的蒸汽发生器“单元管”三维物理模型。采用考虑汽泡聚合与破碎效应的MUSIG (multiple-size-group)模型描述二次侧汽泡尺度分布和水力特性,热相变模型计算二次侧汽液两相沸腾相变过程,对大亚湾蒸汽发生器汽液两相流动与沸腾过程进行数值研究。模拟结果表明,支撑板位置处汽、液相流速均急剧升高,产生射流,在离开支撑板孔口时迅速形成回流。两相邻支撑板间出现明显的汽泡由小到大的周期性变化过程,冷、热端沿程汽泡最大直径缓慢减小。二次侧平均传热系数与 Rohsenow 经验关联式的计算结果吻合较好。

  8. Dispensing fuel with aspiration of condensed vapors

    Energy Technology Data Exchange (ETDEWEB)

    Butkovich, M.S.; Strock, D.J.

    1993-08-10

    A vapor recovery process is described, comprising the steps of: fueling a motor vehicle with gasoline by discharging gasoline into a fill opening or filler pipe of a tank of said vehicle through a fuel outlet conduit of a nozzle; emitting gasoline vapors from said tank during said fueling; substantially collecting said vapors during said fueling with a vapor return conduit of said nozzle and passing said vapors through said vapor return conduit in counter current flow relationship to said discharging gasoline in said fuel conduit; conveying said vapors from said vapor return conduit to a vapor return hose; at least some of said vapors condensing to form condensate in said vapor return hose; substantially removing said condensate from said vapor return hose during said fueling with a condensate pickup tube from said nozzle by passing said condensate through said condensate pickup tube in counter current flow relationship to said conveying vapors in said vapor return hose; sensing the presence of gasoline with a liquid sensing tube in said vapor return conduit of said nozzle between inner and outer spouts of said nozzle to detect when said tank of said vehicle is filled with said fuel conduit being within the inner spout of said nozzle; and automatically shutting off said fueling and condensate removing when said liquid sensing tube detects when said tank of said vehicle is filled and fuel enters said vapor return conduit.

  9. Efficient Nd Promoted Rh Catalysts for Vapor Phase Methanol Carbonylation

    Institute of Scientific and Technical Information of China (English)

    Shu Feng ZHANG; Qing Li QIAN; Ping Lai PAN; Yi CHEN; Guo Qing YUAN

    2005-01-01

    A Nd promoted-Rh catalysts supported on polymer-derived carbon beads for vapor-phase methanol carbonylation was developed. Rh-Nd bimetallic catalysts obviously have higher activity than that of supported Rh catalyst under similar reaction condition. The difference between the activity of above two catalyst systems is clearly caused by the intrinsic properties generated by the introduction of Nd.

  10. Vapor Phase Detection Using Chemi-Resistor Sensor Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Nathan S. Lewis

    1999-02-17

    This paper focuses on two main areas: understanding sensor response times so as to obtain improved time response in the field when needed for vapor tracking and classification, and improved theoretical understanding of the sensor response properties that generate the pattern on the array in response to a given analyte.

  11. Thermodynamic Analysis of Combined Vapor Compression and Vapor Absorption Refrigeration System

    Directory of Open Access Journals (Sweden)

    AAMIR SHAIKH

    2017-07-01

    Full Text Available Two of the popular refrigeration cycles, VC (Vapor Compression, and VA (Vapor Absorption are used extensively for refrigeration purposes. In this paper, a system is proposed that works using both cycles powered by an IC (Internal Combustion engine, where mechanical energy is used to run the VC cycle while exhaust gasses are used to operate the VA cycle. The VC cycle works on R12 refrigerant while LiBr-H2O combination is selected for operation of VA cycle. Firstly, the refrigeration system is modeled, followed by a parametric study to investigate the impacts of various operating parameters on the system performance. The results exhibit that for maximum chilling and overall performance, the condenser and evaporator pressures in the VC cycle are obtained as 710 and 340 kPa, respectively, whereas generator and absorber temperatures in VA cycle are 85 and 20oC, respectively

  12. Detection of the high vibration origin in the body of an electrical generator driven by steam turbine applying diagnostic techniques; Deteccion del origen de alta vibracion en el cuerpo de un generador electrico accionado por turbinas de vapor aplicando tecnicas de diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Bravo, Fernando (Mexico)

    2007-11-15

    One of the problems that electric generators present is the high vibration due to causes that can go from simple mechanical unbalance, misalignment, mechanical relaxation, resonance or some other interaction that can influence in the system. In this document is presented the vibration analysis of an electric generator with a capacity of 350 MW, driven by a steam turbine composed of three stages (high pressure, intermediate pressure and low pressure) connected to the electric generator through a rigid connection. [Spanish] Uno de los problemas que se presentan en los generadores electricos es la alta vibracion debida a causas que pueden ir desde un simple desbalance mecanico, desalineamiento, aflojamiento mecanico, resonancia o alguna otra interaccion que pueda influir en el sistema. Se presenta en este documento el analisis de vibracion de un generador electrico con una capacidad de 350 MW, impulsado por una turbina de vapor compuesta de tres etapas (alta presion, presion intermedia y baja presion) acopladas al generador electrico a traves de un acoplamiento rigido.

  13. Eddy-current tests on operational evaluation of steam generator tubes in nuclear power plants; Ensaios de Eddy-current na avaliacao do estado operacional de tubos de geradores de vapor de centrais nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Luiz Antonio Negro Martin [Faculdade de Engenharia Industrial (FEI), Sao Paulo, SP (Brazil). Dept. de Energetica]. E-mail: luizlope@cci.fei.br; Ting, Daniel Kao Sun [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil). Dept. Engenharia de Reatores]. E-mail: dksting@net.ipen.br

    2000-07-01

    This paper presents a worldwide research on the technical and economical impacts due to failure in tube bundles of nuclear power plant steam generators. An Eddy current non destructive test using Foucault currents for the inspection and failure detection on the tubes, and also the main type of defects. The paper also presents the signals generated by a Zetec MIZ-40 test equipment. This paper also presents a brief description of an automatic system for data analysis which is under development by using a fuzzy logic and artificial intelligence.

  14. Methanol reformer with water vapor and oxygen in catalysts of Cu/CeO{sub 2}-ZrO{sub 2} to generate H{sub 2}; Reformado de metanol con vapor de agua y oxigeno en catalizadores de Cu/CeO{sub 2}-ZrO{sub 2} para generar H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Aguila M, M.M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    The environmental pollution is one of the problems more important to solve in the present time because its affect the quality of the alive beings' life. For such a reason alternatives have been looked for to diminish the percentage of air pollution (NO{sub x}, CO{sub x}, SO{sub x}, etc.), for they have been developed it the well-known catalytic converters. Another possibility is the energy use through fuel cells in vehicles using H{sub 2} as fuel free of CO (smaller concentration to 10 ppm). Processes exist for the production of H{sub 2} starting from the methanol and in this work the one was used reformed of methanol with water vapor and oxygen (OSRM) as the main reaction of this work. The primordial objective of this work consists on studying the catalytic properties of the copper (Cu) supported in mixed oxides (ZrO{sub 2}-CeO{sub 2}) in the reaction of having reformed of methanol with water vapor and oxygen for the production of H{sub 2}. Zirconia is synthesized (ZrO{sub 2}) and mixed oxides ZrO{sub 2}-CeO{sub 2} (with different relationship Zr/Ce) for the sol-gel method and the one cerium oxide (CeO{sub 2}) by direct combustion of the cerium nitrate. The oxides were stabilized thermally at 600 C by 5h. The catalysts were prepared by classic impregnation using copper acetate, the nominal concentration was of 3% in weight. The catalysts were roasted at 350 C and later on reduced in flow from H{sub 2} to 350 C for 1h. The characterization of the catalytic materials is carried out through different techniques as: adsorption-desorption of nitrogen to determine the surface area BET, scanning electron microscopy (SEM) to determine the final morphology of the catalysts, X-ray diffraction (XRD) to identify the crystalline phases of the catalytic materials and reduction to programmed temperature (TPR) to evidence the interaction metal-support. The catalytic properties of the catalysts were studied in the reaction CH{sub 3}OH + H{sub 2}O + O{sub 2}, to determine the

  15. A Review of Vapor Intrusion Models

    OpenAIRE

    Yao, Yijun; Suuberg, Eric M.

    2013-01-01

    A complete vapor intrusion (VI) model, describing vapor entry of volatile organic chemicals (VOCs) into buildings located on contaminated sites, generally consists of two main parts-one describing vapor transport in the soil and the other its entry into the building. Modeling the soil vapor transport part involves either analytically or numerically solving the equations of vapor advection and diffusion in the subsurface. Contaminant biodegradation must often also be included in this simulatio...

  16. Recent advances in vapor intrusion site investigations.

    Science.gov (United States)

    McHugh, Thomas; Loll, Per; Eklund, Bart

    2017-02-22

    Our understanding of vapor intrusion has evolved rapidly since the discovery of the first high profile vapor intrusion sites in the late 1990s and early 2000s. Research efforts and field investigations have improved our understanding of vapor intrusion processes including the role of preferential pathways and natural barriers to vapor intrusion. This review paper addresses recent developments in the regulatory framework and conceptual model for vapor intrusion. In addition, a number of innovative investigation methods are discussed.

  17. Adequacy of the SPARC9O code for the simulation of the capture of aerosols by break in steam generator; Adecuacion del codigo sparc90 para la simulacion de la captura de aerosoles por rotura en el generador de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Escriva, A.; Munoz-Cobo, J. L.; Berna, C.; Herranz, L. E.

    2011-07-01

    The SPARC9O (Suppression Pool Aerosol Removal Code)is intended to perform the calculation in terms of discharge of aerosols in swimming pools, is for this reason that it is working to achieve an analytical model that suits the conditions of discharge in a steam generator the code.

  18. How do organic vapors contribute to new-particle formation?

    CERN Document Server

    Donahue, Neil M; Chuang, Wayne; Riipinen, Ilona; Riccobono, Francesco; Schobesberger, Siegfried; Dommen, Josef; Baltensperger, Urs; Kulmala, Markku; Worsnop, Douglas R; Vehkamaki, Hanna

    2013-01-01

    Highly oxidised organic vapors can effectively stabilize sulphuric acid in heteronuclear clusters and drive new-particle formation. We present quantum chemical calculations of cluster stability, showing that multifunctional species can stabilize sulphuric acid and also present additional polar functional groups for subsequent cluster growth. We also model the multi-generation oxidation of vapors associated with secondary organic aerosol formation using a two-dimensional volatility basis set. The steady-state saturation ratios and absolute concentrations of extremely low volatility products are sufficient to drive new-particle formation with sulphuric acid at atmospherically relevant rates.

  19. Stage 2 vapor recovery system

    Energy Technology Data Exchange (ETDEWEB)

    Koch, W.H.; Strock, D.J.; Butkovich, M.S.; Hartman, H.B.

    1993-05-25

    A vapor recovery system is described, comprising: a set of elongated underground storage tanks, each storage tank containing a different grade of gasoline; vent pipes; a series of dispensing units; fuel flow lines; vapor return lines; an array of fuel pumps for pumping gasoline from said storage tanks to said dispenser units; an elongated condensate liquid pickup tube; an elongated inner spout providing a fuel conduit and having an outer tip defining a fuel outlet for discharging gasoline into a filler pipe of a motor vehicle tank during fueling; an outer spout assembly; extending into and engaging said spout-receiving socket, said outer spout assembly comprising an outer spout providing a vapor return conduit and defining apertures providing a vapor inlet spaced from said fuel outlet for withdrawing, removing, and returning a substantial amount of gasoline vapors emitted during said fueling; an elongated liquid sensing tube; a manually operable level; a flow control valve assembly; an automatic shutoff valve assembly; and a venturi sleeve assembly positioned in said venturi sleeve receiving chamber.

  20. The Lithium Vapor Box Divertor

    Science.gov (United States)

    Goldston, Robert; Hakim, Ammar; Hammett, Gregory; Jaworski, Michael; Myers, Rachel; Schwartz, Jacob

    2015-11-01

    Projections of scrape-off layer width to a demonstration power plant suggest an immense parallel heat flux, of order 12 GW/m2, which will necessitate nearly fully detached operation. Building on earlier work by Nagayama et al. and by Ono et al., we propose to use a series of differentially pumped boxes filled with lithium vapor to isolate the buffering vapor from the main plasma chamber, allowing stable detachment. This powerful differential pumping is only available for condensable vapors, not conventional gases. We demonstrate the properties of such a system through conservation laws for vapor mass and enthalpy, and then include plasma entrainment and ultimately an estimate of radiated power. We find that full detachment should be achievable with little leakage of lithium to the main plasma chamber. We also present progress towards solving the Navier-Stokes equation numerically for the chain of vapor boxes, including self-consistent wall boundary conditions and fully-developed shocks, as well as concepts for an initial experimental demonstration-of-concept. This work supported by DOE Contract No. DE-AC02-09CH11466.

  1. Concept and operational experience of the Areva DMT process for preventive maintenance of steam generators; Concepto y experiencia operacional del proceso DMT de Areva para el mantenimiento preventivo de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, S.; Gaspar, J. D.; Potier, P.; Jones, D.

    2015-07-01

    The AREVAs DMT process is a preventive chemical cleaning of the steam generators (SG) that provides the required features to keep the SG in good operative conditions. -Very low carbon steel corrosion -Innocuous towards stainless steel and nickel base alloys -Inherently safe process -Efficient magnetite dissolution -No use of CMR (i.e Carcinogenic, Mutagenic and toxic to Reproduction) Chemicals (e. g. Hydrazine) -No ammonia emissions -Easy decomposition of waste Several applications have been performed world-wide over the last 5 years. The results were fully satisfying in all the above stated points. The removal of up to 800 kg of dry deposits per SG was realized. A positive effect on fouling factor was observed, showing that AREVAs DMT process is a safe, easy and successful way to maintain the steam generators in excellent operative conditions. (Author)

  2. Utilization of high CO2 content formation gas for steam and electricity generation; Aprovechamiento del gas de formacion con alto contenido de CO2 para generacion de vapor y electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Villagomez, Paul; Lamino, Marcelo; Jacome, Jose; Pastor, Santiago [EcuadorTLC, Quito (Ecuador). Grupo PETROBRAS

    2008-07-01

    Ecuador TLC SA, as part of the PETROBRAS Group, respecting its mission to act safe, cost-effectiveness, social and environmental responsibility, currently operates an oil production project in the Ecuatorian Amazon, known as Block 18. In Block 18, the process of gas burning is response for launch approximately 10 MMSCF of the gas associated with 77% CO2 in the environment. For this reason it was built a centralized power generation plants (PGE), of 17.38 MW, taking advantage of the gas with 77% CO2 from boilers to burn it, using it as a source of heat in a combined cycle steam turbines, generating electricity. This project is environmentally efficient with reduced emissions of CO2 and as reducing fuel costs to zero. The results of CO2 reduction is a corporate goal of PETROBRAS and this project will contribute to reducing CO2 emissions by approximately 400,000 Ton over the life of the project.

  3. Use of self-organizing maps for classification of defects in the tubes from the steam generator of nuclear power plants; Classificacao de defeitos em tubos de gerador de vapor de plantas nucleares utilizando mapas auto-organizaveis

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Roberto Navarro de

    2002-07-01

    This thesis obtains a new classification method for different steam generator tube defects in nuclear power plants using Eddy Current Test signals. The method uses self-organizing maps to compare different signal characteristics efficiency to identify and classify these defects. A multiple inference system is proposed which composes the different extracted characteristic trained maps classification to infer the final defect type. The feature extraction methods used are the Wavelet zero-crossings representation, the linear predictive coding (LPC), and other basic signal representations on time like module and phase. Many characteristic vectors are obtained with combinations of these extracted characteristics. These vectors are tested to classify the defects and the best ones are applied to the multiple inference system. A systematic study of pre-processing, calibration and analysis methods for the steam generator tube defect signals in nuclear power plants is done. The method efficiency is demonstrated and characteristic maps with the main prototypes are obtained for each steam generator tube defect type. (author)

  4. Thermodynamic analysis of a Rankine cycle powered vapor compression ice maker using solar energy

    National Research Council Canada - National Science Library

    Hu, Bing; Bu, Xianbiao; Ma, Weibin

    2014-01-01

    To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working...

  5. Thermodynamic Analysis of a Rankine Cycle Powered Vapor Compression Ice Maker Using Solar Energy

    National Research Council Canada - National Science Library

    Hu, Bing; Bu, Xianbiao; Ma, Weibin

    2014-01-01

      To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working...

  6. Optimization of metal vapor lasers

    Science.gov (United States)

    Buchanov, V. V.; Molodykh, E. I.; Tykotskii, V. V.

    1983-03-01

    The method proposed here for performing numerical calculations on a computer in order to predict and optimize the characteristics of metal vapor lasers is based on the use of a universal program for numerical experiments designed expressly for metal vapor lasers and on a simultaneous application of an algorithm for multifactor optimization of the output parameters. The latter, in turn, is based on the complex Boks method (Himmelblau, 1970) and on the Gel'fand-Tsetlin ravine method (Himmelblau, 1970). Calculations carried out for a metal with a copper vapor in neon reveal that for optimization with respect to the geometry of the active zone and the parameters of the electrical circuits (including the voltage pulses and excitation frequency) it is sufficient to use the Boks method. The objective function optimum regarding the concentration of the metal particles and the buffer gas found using this algorithm calls for further refinement; this can be performed efficiently with the Gel'fand-Tsetlin ravine method.

  7. Análisis de la redundancia en la generación de vapor con parámetros inferiores en un monobloque de 64 MW // Analysis of redundancy in the steam generation with inferior parameters in an unit of 64 MW.

    Directory of Open Access Journals (Sweden)

    A. Paneque Matos

    2000-10-01

    Full Text Available La necesidad del país de mantener la generación eléctrica a fin de evitar los cortes de servicio planificados e imprevistos,debido a la difícil situación económica actual, obliga a buscar soluciones que al menos sirvan de paliativo temporal a estadesagradable situación. En una central termoeléctrica ubicada en el perímetro de la ciudad, se presentó la situación de queproducto de un accidente, un bloque quedó sin turbogenerador, estando su generador de vapor en magníficas condicionesde explotación; y que otro bloque presentaba muchas salidas forzosas fuera de servicio producto de una insuficientereparación de su generador de vapor. La carencia de fondos para acometer una efectiva reparación, hizo pensar en elanálisis de la posibilidad de utilizar la caldera de una unidad para alimentar el turbogenerador de la otra. En el presentetrabajo se muestran los cálculos correspondientes para determinar aproximadamente el comportamiento de la turbina en lasnuevas condiciones impuestas, se realizó un análisis de fiabilidad del sistema propuesto y se utilizó la simulación comoherramienta para modelar el proceso.Palabras claves: centrales termoeléctricas, fiabilidad, eficiencia, turbina de gas, caldera._______________________________________________________________________Abstract:The necessity of Cuba to maintain the electric generation in order to avoid the interruption of service in planned oraccidental way, due to the difficult current economic situation, forces to solutions that at least serve for temporary palliativeto this unpleasant situation. In a thermoelectric power station located in the perimeter of the city, a situation was presenteddue to an accident, a block with fail in the turbogenerator and the steam generator in good conditions of exploitation; andthat another block, the No.7, presented many mandatory out of service product of an insufficient repair of its generator.This situation lead to analyze the possibility of

  8. Integration of direct steam generation with parabolic trough collector for electricity production. Project INDITEP 310; Integracion de la tecnologia de generacion directa de vapor con colectores cilindro-parabolicos para produccion de electricidad. Proyecto INDITEP 310

    Energy Technology Data Exchange (ETDEWEB)

    Leon, J.; Zarza, E.; Valenzuela, L.

    2004-07-01

    The Plataforma Solar de Almeria (PSA) held during the latest years the test campaign of a new concept of direct steam generation in a real size parabolic trough collector row using solar energy. It has been experimentally demonstrated the possibility of replacing thermal oil by water as heat transfer fluid and the process technical and technological viability. The INDITEP project applies the acquired acknowledge for improving the efficiency and to reduce costs, designing, developing, testing and assessing new components able of improving technologically the system, the operating procedures for solar power plants and, performing a social and economic study of the technology. (Author)

  9. A computational model for reliability calculation of steam generators from defects in its tubes; Um modelo computacional para o calculo da confiabilidade de geradores de vapor a partir de defeitos em seus tubos

    Energy Technology Data Exchange (ETDEWEB)

    Rivero, Paulo C.M.; Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2000-07-01

    Nowadays, probability approaches are employed for calculating the reliability of steam generators as a function of defects in their tubes without any deterministic association with warranty assurance. Unfortunately, probability models produce large failure values, as opposed to the recommendation of the U.S. Code of Federal Regulations, that is, failure probabilities must be as small as possible In this paper, we propose the association of the deterministic methodology with the probabilistic one. At first, the failure probability evaluation of steam generators follows a probabilistic methodology: to find the failure probability, critical cracks - obtained from Monte Carlo simulations - are limited to have length's in the interval defined by their lower value and the plugging limit one, so as to obtain a failure probability of at most 1%. The distribution employed for modeling the observed (measured) cracks considers the same interval. Any length outside the mentioned interval is not considered for the probability evaluation: it is approached by the deterministic model. The deterministic approach is to plug the tube when any anomalous crack is detected in it. Such a crack is an observed one placed in the third region on the plot of the logarithmic time derivative of crack lengths versus the mode I stress intensity factor, while for normal cracks the plugging of tubes occurs in the second region of that plot - if they are dangerous, of course, considering their random evolution. A methodology for identifying anomalous cracks is also presented. (author)

  10. Application of perturbation methods for sensitivity analysis for nuclear power plant steam generators; Aplicacao da teoria de perturbacao a analise de sensibilidade em geradores de vapor de usinas nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Gurjao, Emir Candeia

    1996-02-01

    The differential and GPT (Generalized Perturbation Theory) formalisms of the Perturbation Theory were applied in this work to a simplified U-tubes steam generator model to perform sensitivity analysis. The adjoint and importance equations, with the corresponding expressions for the sensitivity coefficients, were derived for this steam generator model. The system was numerically was numerically solved in a Fortran program, called GEVADJ, in order to calculate the sensitivity coefficients. A transient loss of forced primary coolant in the nuclear power plant Angra-1 was used as example case. The average and final values of functionals: secondary pressure and enthalpy were studied in relation to changes in the secondary feedwater flow, enthalpy and total volume in secondary circuit. Absolute variations in the above functionals were calculated using the perturbative methods, considering the variations in the feedwater flow and total secondary volume. Comparison with the same variations obtained via direct model showed in general good agreement, demonstrating the potentiality of perturbative methods for sensitivity analysis of nuclear systems. (author) 22 refs., 7 figs., 8 tabs.

  11. Water Vapor Products from Differential-InSAR with Auxiliary Calibration Data: Accuracy and Statistics

    Science.gov (United States)

    Gong, W.; Meyer, F. J.; Webley, P.

    2014-12-01

    calibration data set and their corresponding accuracy; and (3) Accuracy of the derived absolute water vapor products. Overall, we work on the strategy definition that bring the d-InSAR-derived water vapor products to be practically generated association with their accuracy information and available to wide research communities.

  12. Enhanced frequency up-conversion in Rb vapor

    CERN Document Server

    Vernier, A; Riis, E; Arnold, A S

    2009-01-01

    We demonstrate highly efficient generation of coherent 420 nm light via up-conversion of near-infrared lasers in a hot rubidium vapor cell. By optimizing pump polarizations and frequencies we achieve a single-pass conversion efficiency of 260%/W, significantly higher than in previous experiments. A full 2D exploration of the coherent light generation and fluorescence as a function of the pump frequencies reveals that coherent blue light is generated at 85Rb two-photon resonances, as predicted by theory, but at high vapor pressure it is suppressed in spectral regions that don't support phase matching or exhibit single-photon Kerr refraction. Favorable scaling of our current 1 mW blue beam power with additional pump power is predicted. Infrared pump polarization could be used for future intensity switching experiments.

  13. Estimated vapor pressure for WTP process streams

    Energy Technology Data Exchange (ETDEWEB)

    Pike, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-01-01

    Design assumptions during the vacuum refill phase of the Pulsed Jet Mixers (PJMs) in the Hanford Waste Treatment and Immobilization Plant (WTP) equate the vapor pressure of all process streams to that of water when calculating the temperature at which the vacuum refill is reduced or eliminated. WTP design authority asked the authors to assess this assumption by performing calculations on proposed feed slurries to calculate the vapor pressure as a function of temperature. The vapor pressure was estimated for each WTP waste group. The vapor pressure suppression caused by dissolved solids is much greater than the increase caused by organic components such that the vapor pressure for all of the waste group compositions is less than that of pure water. The vapor pressure for each group at 145°F ranges from 81% to 98% of the vapor pressure of water. If desired, the PJM could be operated at higher temperatures for waste groups with high dissolved solids that suppress vapor pressure. The SO4 group with the highest vapor pressure suppression could be operated up to 153°F before reaching the same vapor pressure of water at 145°F. However, most groups would reach equivalent vapor pressure at 147 to 148°F. If any of these waste streams are diluted, the vapor pressure can exceed the vapor pressure of water at mass dilution ratios greater than 10, but the overall effect is less than 0.5%.

  14. Final OSWER Vapor Intrusion Guidance

    Science.gov (United States)

    EPA is preparing to finalize its guidance on assessing and addressing vapor intrusion, which is defined as migration of volatile constituents from contaminated media in the subsurface (soil or groundwater) into the indoor environment. In November 2002, EPA issued draft guidance o...

  15. Simple Chemical Vapor Deposition Experiment

    Science.gov (United States)

    Pedersen, Henrik

    2014-01-01

    Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

  16. Hydrazine vapor inactivates Bacillus spores

    Science.gov (United States)

    Schubert, Wayne W.; Engler, Diane L.; Beaudet, Robert A.

    2016-05-01

    NASA policy restricts the total number of bacterial spores that can remain on a spacecraft traveling to any planetary body which might harbor life or have evidence of past life. Hydrazine, N2H4, is commonly used as a propellant on spacecraft. Hydrazine as a liquid is known to inactivate bacterial spores. We have now verified that hydrazine vapor also inactivates bacterial spores. After Bacillus atrophaeus ATCC 9372 spores deposited on stainless steel coupons were exposed to saturated hydrazine vapor in closed containers, the spores were recovered from the coupons, serially diluted, pour plated and the surviving bacterial colonies were counted. The exposure times required to reduce the spore population by a factor of ten, known as the D-value, were 4.70 ± 0.50 h at 25 °C and 2.85 ± 0.13 h at 35 °C. These inactivation rates are short enough to ensure that the bioburden of the surfaces and volumes would be negligible after prolonged exposure to hydrazine vapor. Thus, all the propellant tubing and internal tank surfaces exposed to hydrazine vapor do not contribute to the total spore count.

  17. Application o f shaft furnace vaporization cooling system transformation and saturated steam generation%球团竖炉汽化冷却改造及饱和蒸汽发电的应用

    Institute of Scientific and Technical Information of China (English)

    陈世然; 陆在洋

    2014-01-01

    An engineering application of using the saturated steam for generation which was obtained from shaft furnace cooling system was presented.The engineering belonged to Yonggang.The re-claimed steam was used in the steam turbine.It made production system simplify come true.It en-hanced thermal stability of the furnace and reduced consumption of water and electricity.The corpora-tion economized power, reduced consumed cost and improved enterprise's benefit.%介绍了在永钢集团竖炉生产球团过程中,将炉内水梁循环水冷改为汽化冷却,产生的低压饱和蒸汽用于发电的的工程实例。优化了生产冷却系统,提高了竖炉热稳定性,降低了用电量、耗水量,同时回收竖炉余热产生蒸汽用于发电,获得了良好的经济效益,提升了产品竞争力。

  18. The effect of thermal and vapor annealing treatments on the self-assembly of TiO{sub 2} /PS-b-PMMA nanocomposites generated via the sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, J; Tercjak, A; Garcia, I; Mondragon, I [' Materials-Technologies' Group, Departamento IngenierIa Quimica y Medio Ambiente, Escuela Politecnica, Universidad PaIs Vasco/Euskal Herriko Unibertsitatea, Plaza Europa 1, E-20018 Donostia-San Sebastian (Spain)], E-mail: inaki.mondragon@ehu.es

    2009-06-03

    Polystyrene-block-poly(methyl methacrylate) (SMMA) block copolymer has been used as a structure-directing agent for generating TiO{sub 2} /SMMA nanocomposites via the sol-gel process using a hydrophobic surfactant. The aim of the work has been focused on the preparation of well-defined nanostructured composites based on the self-assembling capability of the block copolymer using two different annealing methods: thermal- and solvent-induced microphase separation. The addition of different amounts of nanoparticles caused strong variations in the self-assembled morphology of the TiO{sub 2} /SMMA nanocomposites with respect to the block copolymer, as observed by atomic force microscopy (AFM). To verify the confinement of the nanoparticles in the PMMA block 3D AFM images and corresponding AFM profiles have also been reported. UV light irradiation of the nanocomposite films provoked the removal of the organic matrix and consequently led to an array of TiO{sub 2} nanoparticles on the substrate surface.

  19. Vapor Pressure Data Analysis and Statistics

    Science.gov (United States)

    2016-12-01

    VAPOR PRESSURE DATA ANALYSIS AND STATISTICS ECBC-TR-1422 Ann Brozena RESEARCH AND TECHNOLOGY DIRECTORATE...DATE XX-12-2016 2. REPORT TYPE Final 3. DATES COVERED (From - To) Nov 2015 – Apr 2016 4. TITLE Vapor Pressure Data Analysis and Statistics 5a...1 VAPOR PRESSURE DATA ANALYSIS AND STATISTICS 1. INTRODUCTION Knowledge of the vapor pressure of materials as a function of temperature is

  20. Weather and climate analyses using improved global water vapor observations

    National Research Council Canada - National Science Library

    Vonder Haar, Thomas H; Bytheway, Janice L; Forsythe, John M

    2012-01-01

    The NASA Water Vapor Project (NVAP) dataset is a global (land and ocean) water vapor dataset created by merging multiple sources of atmospheric water vapor to form a global data base of total and layered precipitable water vapor...

  1. Nonlinear optical properties of atomic vapor and semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Doseok [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1997-05-01

    This thesis contains the study of highly forbidden resonant second harmonic generation (SHG) in atomic potassium vapor using tunable picosecond pulses. Various output characteristics of vapor SHG have been investigated including the input intensity dependence, potassium vapor density dependence, buffer gas pressure dependence, and spatial profile. Recently, the discovery of new nonlinear optical crystals such as barium borate (β-BaB2O4, BBO) and lithium borate (LiB3O5, LBO) has greatly improved the performance of a tunable coherent optical devices based on optical parametric generation and amplification. In the second part of this thesis, a homebuilt picosecond optical parametric generator/amplifier (OPG/OPA) system is described in detail, including its construction details and output characteristics. This laser device has found many useful applications in spectroscopic studies including surface nonlinear optical spectroscopy via sum-frequency generation (SFG). The last part of this thesis reports studies on multiphoton-excited photoluminescence from porous silicon and GaN. Multiphoton excitation and photoluminescence can give numerous complementary information about semiconductors not obtainable with one-photon, above-bandgap excitation.

  2. Phosphorescence emission and excited states of 3- and 4-hydroxybenzaldehyde vapors

    Science.gov (United States)

    Itoh, Takao

    2014-01-01

    Emission spectra of 3- and 4-hydroxybenzaldehyde vapors have been measured along with the excitation and absorption spectra. It is inferred from the temperature dependence of the phosphorescence spectrum that the phosphorescence of 4-hydroxybenzaldehyde vapor originates from the T2(n, π*) state. In the case of 3-hydroxybenzaldehyde vapor, the emission is shown to consist of that of 3-hydroxybenzaldehyde and benzaldehyde vapors, with the latter molecule being generated as the result of photochemical decomposition of 3-hydroxybenzaldehyde. The interpretation of the emission spectrum of 3-hydroxybenzaldehyde is different from that reported previously. The rotational isomer responsible for appearance of the phosphorescence of 3-hydroxybenzaldehyde vapor is suggested based on DFT calculation and emission spectral data.

  3. Fault diagnosis in the steam turbo-generator of a Combined Cycle Power Plant; Diagnostico de fallas en el turbogenerador a vapor de una central de generacion de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Flores Abad, Angel

    2006-12-15

    Due to the physical nature of its components, technological processes are vulnerable to faults. These faults affect the accurate behavior of the system, causing a performance reduction, even great economical losses and in the worst case environmental and human disasters. The opportune detection of the presence of faults helps to take corrective actions and as a consequence to reduce the potential damage that faults cause. To achieve the fault detection task, technological processes have supervisory systems to monitor the process variables and provide an alarm when a variable reached a given threshold. This method has the drawback that a single fault could cause many system alarms, which difficult the fault isolation. In addition it is based on hardware redundancy; it means the use of repeated devices to do the same work. Combined cycle power plants (CCPP) are large scale systems with a high degree of fault susceptibility. Due to strict conditions in which they operate and the great number of elements they contain, including sensors and actuators. Nowadays this kind of power plants tends to dominate the electric generation market by means of fossil fuels, because they are the most efficient, profitable, with flexible operation and with less environmental impact. In the CCPP, the steam turbine (ST) is a fundamental component, since it represents the process gain, in the way that it allows the generation of additional electric energy by taking advantage of the exhaust gases of the gas turbines. In case of the ST fails, the global efficiency of the process is reduced even in a 40%. In this work a model based fault diagnosis system was developed, according to the FDI (Fault Detection and Isolation) methodology of the control theory, with the capability of detecting and isolating faults in the sensors and actuators of the ST of a CCPP. The developed system is based on the analytical redundancy which allows optimizing the hardware redundancy and getting a reduction of the

  4. Conversion degree of SO{sub 2} into SO{sub 3} and SO{sub x} emissions in steam generators; Grado de conversion de SO{sub 2} en SO{sub 3} y emisiones de SO{sub x} en generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza Garza, Jesus; Penna Garcia, Adriana; Huerta Espino, Mario [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    A large part of the electric energy produced in this country is obtained burning fossil fuels as primary energy source. These fuels are mainly coal, fuel oil, and natural gas. The first two have high percentages of sulfur, therefore producing and emitting to the air different amounts of sulfur dioxide (SO{sub 2}) and sulfur trioxide (SO{sub 3}). The relationship between this two contaminants varies depending on the type of steam generator, the rated capacity, and most of all on the sulfur content in the fuel and on the combustion system operating conditions. [Espanol] Una gran parte de la energia electrica generada en el pais se obtiene utilizando combustibles fosiles como fuente primaria de energia. Estos combustibles son principalmente carbon, combustoleo y gas natural. Los dos primeros tienen altos porcentajes de azufre, con lo cual se producen y emiten a la atmosfera diferentes cantidades de dioxido de azufre (SO{sub 2}) y trioxido de azufre (SO{sub 3}). La relacion entre estos dos contaminantes varia dependiendo del tipo de generador de vapor, la capacidad nominal y, sobre todo, de la concentracion de azufre en el combustible y de las condiciones de operacion del sistema de combustion.

  5. A copper vapor laser by using a copper-vapor-complex reaction at a low temperature

    OpenAIRE

    Kano, Toshiyuki; Taniguchi, Hiroshi; Saito, Hiroshi

    1987-01-01

    A copper vapor laser performance by using ametal-vapor-complex reaction (Cu+AlBr3) is reported. The laser operation is obtained at a low temperature without externalheating because of the AlBr3 vapors evaporating at a room temperature. The copper vapor laser using this metal-vapor-complex reaction has an advantage of deposition-free of a metallic copper to the laser tube wall, which is different from the copper halide and the organometallic copper lasers.

  6. Improved methodology for generating controlled test atmospheres.

    Science.gov (United States)

    Miller, R R; Letts, R L; Potts, W J; McKenna, M J

    1980-11-01

    Improved methodology has been developed for generating controlled test atmospheres. Vaporization of volatile liquids is accomplished in a 28 mm (O.D.) glass J-tube in conjunction with a compressed air flameless heat torch, a pressure-sensitive switch, and a positive displacement piston pump. The vaporization system has been very reliable with a variety of test materials in studies ranging from a few days to several months. The J-tube vaporization assembly minimizes the possibility of thermal decomposition of the test material and affords a better margin of safety when vaporizing potentially explosive materials.

  7. What Good is Raman Water Vapor Lidar?

    Science.gov (United States)

    Whitman, David

    2011-01-01

    Raman lidar has been used to quantify water vapor in the atmosphere for various scientific studies including mesoscale meteorology and satellite validation. Now the international networks of NDACC and GRUAN have interest in using Raman water vapor lidar for detecting trends in atmospheric water vapor concentrations. What are the data needs for addressing these very different measurement challenges. We will review briefly the scientific needs for water vapor accuracy for each of these three applications and attempt to translate that into performance specifications for Raman lidar in an effort to address the question in the title of "What good is Raman water vapor Iidar."

  8. High temperature vapors science and technology

    CERN Document Server

    Hastie, John

    2012-01-01

    High Temperature Vapors: Science and Technology focuses on the relationship of the basic science of high-temperature vapors to some areas of discernible practical importance in modern science and technology. The major high-temperature problem areas selected for discussion include chemical vapor transport and deposition; the vapor phase aspects of corrosion, combustion, and energy systems; and extraterrestrial high-temperature species. This book is comprised of seven chapters and begins with an introduction to the nature of the high-temperature vapor state, the scope and literature of high-temp

  9. Active Hydrazine Vapor Sampler (AHVS)

    Science.gov (United States)

    Young, Rebecca C.; Mcbrearty, Charles F.; Curran, Daniel J.

    1993-01-01

    The Active Hydrazine Vapor Sampler (AHVS) was developed to detect vapors of hydrazine (HZ) and monomethylhydrazine (MMH) in air at parts-per-billion (ppb) concentration levels. The sampler consists of a commercial personal pump that draws ambient air through paper tape treated with vanillin (4-hydroxy-3-methoxybenzaldehyde). The paper tape is sandwiched in a thin cardboard housing inserted in one of the two specially designed holders to facilitate sampling. Contaminated air reacts with vanillin to develop a yellow color. The density of the color is proportional to the concentration of HZ or MMH. The AHVS can detect 10 ppb in less than 5 minutes. The sampler is easy to use, low cost, and intrinsically safe and contains no toxic material. It is most beneficial for use in locations with no laboratory capabilities for instrumentation calibration. This paper reviews the development, laboratory test, and field test of the device.

  10. Vapor stabilizing surfaces for superhydrophobicity

    Science.gov (United States)

    Patankar, Neelesh

    2010-11-01

    The success of rough substrates designed for superhydrophobicity relies crucially on the presence of air pockets in the roughness grooves. This air is supplied by the surrounding environment. However, if the rough substrates are used in enclosed configurations, such as in fluidic networks, the air pockets may not be sustained in the roughness grooves. In this work a design approach based on sustaining a vapor phase of the liquid in the roughness grooves, instead of relying on the presence of air, is explored. The resulting surfaces, referred to as vapor stabilizing substrates, are deemed to be robust against wetting transition even if no air is present. Applications of this approach include low drag surfaces, nucleate boiling, and dropwise condensation heat transfer, among others.

  11. Vaporization chambers and associated methods

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Terry D.; Wilding, Bruce M.; McKellar, Michael G.; Shunn, Lee P.

    2017-02-21

    A vaporization chamber may include at least one conduit and a shell. The at least one conduit may have an inlet at a first end, an outlet at a second end and a flow path therebetween. The shell may surround a portion of each conduit and define a chamber surrounding the portion of each conduit. Additionally, a plurality of discrete apertures may be positioned at longitudinal intervals in a wall of each conduit, each discrete aperture of the plurality of discrete apertures sized and configured to direct a jet of fluid into each conduit from the chamber. A liquid may be vaporized by directing a first fluid comprising a liquid into the inlet at the first end of each conduit, directing jets of a second fluid into each conduit from the chamber through discrete apertures in a wall of each conduit and transferring heat from the second fluid to the first fluid.

  12. Internal Water Vapor Photoacoustic Calibration

    Science.gov (United States)

    Pilgrim, Jeffrey S.

    2009-01-01

    Water vapor absorption is ubiquitous in the infrared wavelength range where photoacoustic trace gas detectors operate. This technique allows for discontinuous wavelength tuning by temperature-jumping a laser diode from one range to another within a time span suitable for photoacoustic calibration. The use of an internal calibration eliminates the need for external calibrated reference gases. Commercial applications include an improvement of photoacoustic spectrometers in all fields of use.

  13. Water vapor diffusion membrane development

    Science.gov (United States)

    Tan, M. K.

    1977-01-01

    An application of the water vapor diffusion technique is examined whereby the permeated water vapor is vented to space vacuum to alleviate on-board waste storage and provide supplemental cooling. The work reported herein deals primarily with the vapor diffusion-heat rejection (VD-HR) as it applies to the Space Shuttle. A stack configuration was selected, designed and fabricated. An asymmetric cellulose acetate membrane, used in reverse osmosis application was selected and a special spacer was designed to enhance mixing and promote mass transfer. A skid-mount unit was assembled from components used in the bench unit although no attempt was made to render it flight-suitable. The operating conditions of the VD-HR were examined and defined and a 60-day continuous test was carried out. The membranes performed very well throughout the test; no membrane rupture and no unusual flux decay was observed. In addition, a tentative design for a flight-suitable VD-HR unit was made.

  14. Critical points of metal vapors

    Energy Technology Data Exchange (ETDEWEB)

    Khomkin, A. L., E-mail: alhomkin@mail.ru; Shumikhin, A. S. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-09-15

    A new method is proposed for calculating the parameters of critical points and binodals for the vapor–liquid (insulator–metal) phase transition in vapors of metals with multielectron valence shells. The method is based on a model developed earlier for the vapors of alkali metals, atomic hydrogen, and exciton gas, proceeding from the assumption that the cohesion determining the basic characteristics of metals under normal conditions is also responsible for their properties in the vicinity of the critical point. It is proposed to calculate the cohesion of multielectron atoms using well-known scaling relations for the binding energy, which are constructed for most metals in the periodic table by processing the results of many numerical calculations. The adopted model allows the parameters of critical points and binodals for the vapor–liquid phase transition in metal vapors to be calculated using published data on the properties of metals under normal conditions. The parameters of critical points have been calculated for a large number of metals and show satisfactory agreement with experimental data for alkali metals and with available estimates for all other metals. Binodals of metals have been calculated for the first time.

  15. Vapor intrusion from entrapped NAPL sources and groundwater plumes

    Science.gov (United States)

    Illangasekare, Tissa H.; Sakaki, Toshihiro; Christ, John; Petri, Bejamin; Sauck, Carolyn; Cihan, Abdullah

    2010-05-01

    Volatile organic compounds (VOC) are commonly found entrapped as non-aqueous phase liquids (NAPLs) in the soil pores or dissolved in groundwater at industrial waste sites and refineries. Vapors emitted from these contaminant sources readily disperse into the atmosphere, into air-filled void spaces within the soil, and migrate below surface structures, leading to the intrusion of contaminant vapors into indoor air through basements and other underground structures. This process referred to as vapor intrusion (VI) represents a potential threat to human health, and is a possible exposure pathway of concern to regulatory agencies. To assess whether this exposure pathway is present, remediation project managers often rely in part on highly simplified screening level models that do not take into consideration the complex flow dynamics controlled by subsurface heterogeneities and soil moisture conditions affected by the mass and heat flux boundary conditions at the land/atmospheric interface. A research study is under way to obtain an improved understanding of the processes and mechanisms controlling vapor generation from entrapped NAPL sources and groundwater plumes, their subsequent migration through the subsurface, and their attenuation in naturally heterogeneous vadose zones under various natural physical, climatic, and geochemical conditions. Experiments conducted at multiple scales will be integrated with analytical and numerical modeling and field data to test and validate existing VI theories and models. A set of preliminary experiments where the fundamental process of vapor generation from entrapped NAPL sources and dissolved plumes under fluctuating water were investigated in small cells and two-dimensional test tanks. In another task, intermediate scale experiments were conducted to generate quantitative data on how the heat and mass flux boundary conditions control the development of dynamic VI pathways. The data from the small cell and tank experiments were

  16. Performances of electrically heated microgroove vaporizers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An electrically heated microgroove vaporizer was proposed. The vaporizer mainly comprised an outer tube, an inner tube and an electrical heater cartridge. Microgrooves were fabricated on the external surface of the inner tube by micro-cutting method,which formed the flow passage for fluid between the external surface of the inner tube and the internal surface of the outer tube.Experiments related to the temperature rise response of water and the thermal conversion efficiency of vaporizer were done to estimate the influences of microgroove's direction, feed flow rate and input voltage on the performances of the vaporizer. The results indicate that the microgroove's direction dominates the vaporizer performance at a lower input voltage. The longitudina lmicrogroove vaporizer exhibits the best performances for the temperature rise response of water and thermal conversion efficiency of vaporizer. For a moderate input voltage, the microgroove's direction and the feed flow rate of water together govern the vaporizer performances. The input voltage becomes the key influencing factor when the vaporizer works at a high input voltage, resulting in the similar performances of longitudinal, oblique and latitudinal microgroove vaporizers.

  17. EPA Biofuels Research: Biofuel Vapor Generation and Monitoring Methods

    Science.gov (United States)

    The interest in renewable fuels and alternative energy sources has stimulated development of alternatives to traditional petroleum-based fuels. The EPA's Office of Transportation Air Quality (OTAQ) requires information regarding the potential health hazards ofthese fuels regardin...

  18. Generation of UV radiation by vapors of complex molecules

    Energy Technology Data Exchange (ETDEWEB)

    Barkova, L.A.; Gruzinskii, V.V.; Danilova, V.I.; Degtiarenko, K.M.; Kopylova, T.N.; Kuznetsov, A.L.

    1981-08-01

    Laser action has been obtained in the following organic compounds under pumping by XeCl excimer laser radiation at 308 nm: para-terphenyl, 2-phenylbenzoxazole, 2-(n-tolyl)-benzoxaxole, 2-(n-methoxyphenyl)-benzoxazole, 2-(n-dimethylaminophenyl)-benzoxazole, 2-biphenylbenzoxazole, (2-alpha-naphthyl)-benzoxazole, 1.4-di(n-phenylethynyl)-benzole, and paraquaterphenyl. The nontuning lasing bands covered the range of 330-370 nm, and the most short-wavelength maximum (333.5 nm) was found for 2(n-methoxyphenyl)-benzoxazole. The lasing capability of the molecules was analyzed.

  19. Photoelectron spectroscopy of phthalocyanine vapors

    Energy Technology Data Exchange (ETDEWEB)

    Berkowitz, J.

    1979-01-01

    The He(I) photoelectron spectra of several metal phthalocyanines and metal-free phthalocyanine vapor shows that: a sharp peak at 4.99 eV is an artifact due to ionization of atomic He by He(II) radiation; the first phthalocyanine peak (metal-containing or metal-free) occurs at 6.4 eV; and the metal-like d orbitals lie at least 1 to 2 eV deeper, except in the case of Fe. (DLC)

  20. Photovoltaic driven vapor compression cycles

    Science.gov (United States)

    Anand, D. K.

    Since the vast majority of heat pumps, air conditioning and refrigeration equipment employs the vapor compression cycle (VCC), the use of renewable energy represents a significant opportunity. As discussed in this report, it is clear that the use of photovoltaics (PV) to drive the VCC has more potential than any other active solar cooling approach. This potential exists due to improvements in not only the PV cells but VCC machinery and control algorithms. It is estimated that the combined improvements will result in reducing the PV cell requirements by as much as one half.

  1. Vapor Pressure Determination of VM Using the Denunder-Liquid Chromatography-Mass Spectrometry Technique

    Science.gov (United States)

    2015-01-01

    obtained using a mass flow controller (MFC), rotameter, or critical orifice , with a vacuum source. The vacuum source, which is external to the...The generator was then integrated into the vapor pressure test system. The airstream entered the side arm of the generator and passed through the

  2. Study of film boiling collapse behavior during vapor explosion

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, Masahiro; Yamano, Norihiro; Sugimoto, Jun [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Abe, Yutaka; Adachi, Hiromichi; Kobayashi, Tomoyoshi

    1996-06-01

    Possible large scale vapor explosions are safety concern in nuclear power plants during severe accident. In order to identify the occurrence of the vapor explosion and to estimate the magnitude of the induced pressure pulse, it is necessary to investigate the triggering condition for the vapor explosion. As a first step of this study, scooping analysis was conducted with a simulation code based on thermal detonation model. It was found that the pressure at the collapse of film boiling much affects the trigger condition of vapor explosion. Based on this analytical results, basic experiments were conducted to clarify the collapse conditions of film boiling on a high temperature solid ball surface. Film boiling condition was established by flooding water onto a high temperature stainless steel ball heated by a high frequency induction heater. After the film boiling was established, the pressure pulse generated by a shock tube was applied to collapse the steam film on the ball surface. As the experimental boundary conditions, materials and size of the balls, magnitude of pressure pulse and initial temperature of the carbon and stainless steel balls were varied. The transients of pressure and surface temperature were measured. It was found that the surface temperature on the balls sharply decreased when the pressure wave passed through the film on balls. Based on the surface temperature behavior, the film boiling collapse pattern was found to be categorized into several types. Especially, the pattern for stainless steel ball was categorized into three types; no collapse, collapse and reestablishment after collapse. It was thus clarified that the film boiling collapse behavior was identified by initial conditions and that the pressure required to collapse film boiling strongly depended on the initial surface temperature. The present results will provide a useful information for the analysis of vapor explosions based on the thermal detonation model. (J.P.N.)

  3. a Thermally Desorbable Miniature Passive Dosimeter for Organic Vapors

    Science.gov (United States)

    Gonzalez, Jesus Antonio

    A thermally desorbable miniature passive dosimeter (MPD) for organic vapors has been developed in conformity with theoretical and practical aspects of passive dosimeter design. The device was optimized for low sample loadings resulting from short-term and/or low concentration level exposure. This was accomplished by the use of thermal desorption rather than solvent elution, which provided the GC method with significantly higher sensitivity. Laboratory evaluation of this device for factors critical to the performance of passive dosimeters using benzene as the test vapor included: desorption efficiency (97.2%), capacity (1400 ppm-min), sensitivity (7ng/sample or 0.06 ppmv for 15 minutes sampling) accuracy and precision, concentration level, environmental conditions (i.e., air face velocity, relative humidity) and sample stability during short (15 minutes) and long periods of time (15 days). This device has demonstrated that its overall accuracy meets NIOSH and OSHA requirements for a sampling and analytical method for the exposure concentration range of 0.1 to 50 ppm (v/v) and 15 minutes exposures. It was demonstrated that the MPD operates in accordance with theoretically predicted performance and should be adequate for short-term and/or low concentration exposure monitoring of organic vapors in the workplace. In addition a dynamic vapor exposure evaluation system for passive dosimeters have been validated using benzene as the test vapor. The system is capable of generating well defined short-square wave concentration profiles suitable for the evaluation of passive dosimeters for ceiling exposure monitoring.

  4. Influence of Soil Moisture on Soil Gas Vapor Concentration for Vapor Intrusion

    OpenAIRE

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    Mathematical models have been widely used in analyzing the effects of various environmental factors in the vapor intrusion process. Soil moisture content is one of the key factors determining the subsurface vapor concentration profile. This manuscript considers the effects of soil moisture profiles on the soil gas vapor concentration away from any surface capping by buildings or pavement. The “open field” soil gas vapor concentration profile is observed to be sensitive to the soil moisture di...

  5. Transient Response of Arc Temperature and Iron Vapor Concentration Affected by Current Frequency with Iron Vapor in Pulsed Arc

    Science.gov (United States)

    Tanaka, Tatsuro; Maeda, Yoshifumi; Yamamoto, Shinji; Iwao, Toru

    2016-10-01

    TIG arc welding is chemically a joining technology with melting the metallic material and it can be high quality. However, this welding should not be used in high current to prevent cathode melting. Thus, the heat transfer is poor. Therefore, the deep penetration cannot be obtained and the weld defect sometimes occurs. The pulsed arc welding has been used for the improvement of this defect. The pulsed arc welding can control the heat flux to anode. The convention and driving force in the weld pool are caused by the arc. Therefore, it is important to grasp the distribution of arc temperature. The metal vapor generate from the anode in welding. In addition, the pulsed current increased or decreased periodically. Therefore, the arc is affected by such as a current value and current frequency, the current rate of increment and the metal vapor. In this paper, the transient response of arc temperature and the iron vapor concentration affected by the current frequency with iron vapor in pulsed arc was elucidated by the EMTF (ElectroMagnetic Thermal Fluid) simulation. As a result, the arc temperature and the iron vapor were transient response as the current frequency increase. Thus, the temperature and the electrical conductivity decreased. Therefore, the electrical field increased in order to maintain the current continuity. The current density and electromagnetic force increased at the axial center. In addition, the electronic flow component of the heat flux increased at the axial center because the current density increased. However, the heat conduction component of the heat flux decreased.

  6. Liquid-liquid contact in vapor explosion. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Segev, A.

    1978-08-01

    The contact of two liquid materials, one of which is at a temperature substantially above the boiling point of the other, can lead to fast energy conversion and a subsequent shock wave. This phenomenon is called a vapor explosion. One method of producing intimate, liquid-liquid contact (which is known to be a necessary condition for vapor explosion) is a shock tube configuration. Such experiments in which water was impacted upon molten aluminum showed that very high pressures, even larger than the thermodynamic critical pressure, could occur. The mechanism by which such sharp pressure pulses are generated is not yet clear. The report describes experiments in which cold liquids (Freon-11, Freon-22, water, or butanol) were impacted upon various hot materials (mineral oil, silicone oil, water, mercury, molten Wood's metal or molten salt mixture).

  7. An automated dynamic water vapor permeation test method

    Science.gov (United States)

    Gibson, Phillip; Kendrick, Cyrus; Rivin, Donald; Charmchii, Majid; Sicuranza, Linda

    1995-05-01

    This report describes an automated apparatus developed to measure the transport of water vapor through materials under a variety of conditions. The apparatus is more convenient to use than the traditional test methods for textiles and clothing materials, and allows one to use a wider variety of test conditions to investigate the concentration-dependent and nonlinear transport behavior of many of the semipermeable membrane laminates which are now available. The dynamic moisture permeation cell (DMPC) has been automated to permit multiple setpoint testing under computer control, and to facilitate investigation of transient phenomena. Results generated with the DMPC are in agreement with and of comparable accuracy to those from the ISO 11092 (sweating guarded hot plate) method of measuring water vapor permeability.

  8. The efficiency and stability of bubble formation by acoustic vaporization of submicron perfluorocarbon droplets.

    Science.gov (United States)

    Reznik, Nikita; Shpak, Oleksandr; Gelderblom, Erik C; Williams, Ross; de Jong, Nico; Versluis, Michel; Burns, Peter N

    2013-09-01

    Submicron droplets of liquid perfluorocarbon converted into microbubbles with applied ultrasound have been studied, for a number of years, as potential next generation extravascular ultrasound contrast agents. In this work, we conduct an initial ultra-high-speed optical imaging study to examine the vaporization of submicron droplets and observe the newly created microbubbles in the first microseconds after vaporization. It was estimated that single pulses of ultrasound at 10 MHz with pressures within the diagnostic range are able to vaporize on the order of at least 10% of the exposed droplets. However, only part of the newly created microbubbles survives immediately following vaporization - the bubbles may recondense back into the liquid droplet state within microseconds of nucleation. The probability of bubble survival within the first microseconds of vaporization was shown to depend on ultrasound excitation pressure as well as on bubble coalescence during vaporization, a behavior influenced by the presence of coating material on the newly created bubbles. The results of this study show for the first time that although initial vaporization of droplets is necessary to create echogenic bubbles, additional factors, such as coalescence and bubble shell properties, are important and should be carefully considered for the production of microbubbles for use in medical imaging.

  9. Explosive disintegration of the vapor film under influence of high heat flux

    Energy Technology Data Exchange (ETDEWEB)

    Sinkevich, O.A.; Glazkov, V.V. [Moscow Power Engineering Institute (Technical University), Moscow (Russian Federation); Ziegarnik, Yu.A.; Ivochkin, Yu.P. [Institute for High Temperatures RAS, Moscow (Russian Federation)

    2009-07-01

    The problem was formulated and solved on the stability of steady-state interface between a thin vapor film and a layer of liquid in the presence of a heat flux. Boundary conditions were derived for disturbances of the vapor-liquid interface, which generalize the known correlations on the free surface of liquid in the gravity field. These boundary conditions allow for the variation of the saturation pressure, for overheating of a liquid, its transition in the metastable area and explosive boiling, for the variation of the thickness of steady-state vapor film, and for generation of the mass flux on the vapor- liquid interface. the mode of explosive instability may arise in the nonlinear stage of development of instability because of a weak variation of the thickness of steady-state vapor film or due to overheating of a liquid and its transition in the metastable area. Due to nonlinear effects, specific solitons and the specific turbulence may arise on the vapor-liquid interface in the absence of gravity force. In the mode of explosive instability, the initially low wave amplitude rises to infinity during a finite period of time. Conditions were found in which the heat flux through the vapor-liquid interface leads to explosive instability: the initially low plane wave amplitude exhibits an explosive rise. (author)

  10. Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

    Directory of Open Access Journals (Sweden)

    Dora M. Paolucci

    2011-03-01

    Full Text Available A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index and sensor response are discussed.

  11. Economic feasibility of replacing sodium vapor and high pressure mercury vapor bulbs with LEDs for street lighting

    Directory of Open Access Journals (Sweden)

    Olusola Olorunfemi Bamisile

    2016-01-01

    Full Text Available The main aim of this article is to examine the feasibility of an energy audit program. LEDs are used to replace the sodium vapor lamps and high-pressured mercury vapor lamps that are currently used for the street lighting system in the Turkish Republic of Northern Cyprus. 44% of the fossil fuels imported into the Turkish Republic of Northern Cyprus is used for electricity generation, which makes the reduction in the consumption of electicity very important. This project will save as much as 36,880,410 kWh on site annually and 111,758,818 kWh from the source. The economic, environmental, and fossil fuels savings of this project are also evaluated.

  12. Vapor Pressures of Several Commercially Used Alkanolamines

    NARCIS (Netherlands)

    Klepacova, Katarina; Huttenhuis, Patrick J. G.; Derks, Peter W. J.; Versteeg, Geert F.; Klepáčová, Katarína

    2011-01-01

    For the design of acid gas treating processes, vapor-liquid equilibrium (VLE) data must be available of the solvents to be applied. In this study the vapor pressures of seven frequently industrially used alkanolamines (diethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, N,N-diethylethano

  13. Boron carbide whiskers produced by vapor deposition

    Science.gov (United States)

    1965-01-01

    Boron carbide whiskers have an excellent combination of properties for use as a reinforcement material. They are produced by vaporizing boron carbide powder and condensing the vapors on a substrate. Certain catalysts promote the growth rate and size of the whiskers.

  14. Water Vapor Forecasting for Chilean Sites

    Science.gov (United States)

    Marín, Julio C.; Cuevas, O.; Pozo, D.; Curé, M.

    2017-09-01

    "A number of observatories in Chile operate in the infrared region of the electromagnetic spectrum. Therefore, it is very important to them to accurately know the water vapor content of the atmosphere for a better observational planning. This talk provides an overview of the methods used to forecast water vapor over astronomical sites in Chile using observations and atmospheric numerical modeling."

  15. Can a drawover vaporizer be a pushover?

    Science.gov (United States)

    Taylor, J C; Restall, J

    1994-10-01

    Bench testing was carried out to establish whether the vapour output from an OMV50 vaporizer, as used in the Triservice apparatus, differs according to whether the carrier gas is either drawn or pushed through the vaporizer. Results show that the differences in output concentration between the two modes were clinically insignificant.

  16. Tungsten chemical vapor deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Kiichi; Takeda, Nobuo.

    1993-07-13

    A tungsten chemical vapor deposition method is described, comprising: a first step of selectively growing a first thin tungsten film of a predetermined thickness in a desired region on the surface of a silicon substrate by reduction of a WF[sub 6] gas introduced into an atmosphere of a predetermined temperature containing said silicon substrate; and a second step of selectively growing a second tungsten film of a predetermined thickness on said first thin tungsten film by reduction of said WF[sub 6] with a silane gas further introduced into said atmosphere, wherein the surface state of said substrate is monitored by a pyrometer and the switching from said first step to said second step is performed when the emissivity of infrared light from the substrate surfaces reaches a predetermined value.

  17. Soil vapor extraction with dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, N.R. [Univ. of Waterloo, Ontario (Canada)

    1996-08-01

    The physical treatment technology of soil vapor extraction (SVE) is reliable, safe, robust, and able to remove significant amounts of mass at a relatively low cost. SVE combined with a pump-and-treat system to create a dewatered zone has the opportunity to remove more mass with the added cost of treating the extracted groundwater. Various limiting processes result in a significant reduction in the overall mass removal rates from a SVE system in porous media. Only pilot scale, limited duration SVE tests conducted in low permeability media have been reported in the literature. It is expected that the presence of a fracture network in low permeability media will add another complexity to the limiting conditions surrounding the SVE technology. 20 refs., 4 figs.

  18. Engineering vapor-deposited polyimides

    Science.gov (United States)

    Tsai, Feng-Yu

    The vapor deposition polymerization (VDP) of PMDA-ODA polyimide was studied parametrically to produce microcapsules and thin films with desirable properties and quality for the Inertial Confinement Fusion (ICF) experiments. The mechanical properties and gas permeability were determined at temperatures from 10 to 573 K. The VDP polyimide possessed distinct properties including lower gas permeability and stronger tensile properties from those of solution-cast Kapton, which were attributed to the presence of cross-linking. Processing parameters determining the properties of the VDP polyimide were identified: (1) utilizing air instead of nitrogen as the atmosphere of imidization increased the permeability by 140%, lowered the activation energy for permeation, and reduced the tensile strength by 30% without affecting the Young's modulus; (2) imidizing at faster heating rates increased the permeability by up to 50% and reduced the activation energy for permeation with 50% lowered tensile strength and impervious Young's modulus; (3) bi-axial stretching increased the permeability by up to three orders of magnitude. Analyses via IR spectroscopy, X-ray diffraction, and density measurement revealed that the effects of the processing parameters were results of the modifications in the crystallinity and molecular weight. The VDP polyimide underwent minor degradation in the tensile strength and elongation at break with unaffected Young's modulus and permeability upon absorbing 120 MGy of beta-radiation. Substituting a fluorinated dianhydride monomer, 6FDA, for PMDA in the optimized VDP process yielded 6FDA-ODA polyimide microcapsules and films with 50-fold increased permeability and comparable mechanical properties. The results of this study enable the production of polyimide microcapsules that will greatly facilitate the ICF experiments, and will broaden the applications of vapor-deposited polyimides in other technology fields.

  19. Vapor-barrier Vacuum Isolation System

    Science.gov (United States)

    Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

    2014-01-01

    A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

  20. Uranium droplet nuclear reactor core with MHD generator

    Science.gov (United States)

    Anghaie, Samim; Kumar, Ratan

    An innovative concept employing liquid uranium droplets as fuel in an ultrahigh-temperature vapor core reactor (UTVR) magnetohydrodynamic (MHD) generator power system for space power generation has been studied. Metallic vapor in superheated form acts as a working fluid for a closed-Rankine-type thermodynamic cycle. Usage of fuel and working fluid in this form assures certain advantages. The major technical issues emerging as a result involve a method for droplet generation, droplet transport in the reactor core, heat generation in the fuel and transport to the metallic vapor, and materials compatibility. A qualitative and quantitative attempt to resolve these issues has indicated the promise and tentative feasibility of the system.

  1. HANFORD CHEMICAL VAPORS WORKER CONCERNS & EXPOSURE EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    ANDERSON, T.J.

    2006-12-20

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors.

  2. Microbial growth with vapor-phase substrate

    Energy Technology Data Exchange (ETDEWEB)

    Hanzel, Joanna; Thullner, Martin; Harms, Hauke [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, 04318 Leipzig (Germany); Wick, Lukas Y., E-mail: lukas.wick@ufz.de [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, 04318 Leipzig (Germany)

    2011-04-15

    Limited information exists on influences of the diffusive transport of volatile organic contaminants (VOC) on bacterial activity in the unsaturated zone of the terrestrial subsurface. Diffusion of VOC in the vapor-phase is much more efficient than in water and results in effective VOC transport and high bioavailability despite restricted mobility of bacteria in the vadose zone. Since many bacteria tend to accumulate at solid-water, solid-air and air-water interfaces, such phase boundaries are of a special interest for VOC-biodegradation. In an attempt to evaluate microbial activity toward air-borne substrates, this study investigated the spatio-temporal interplay between growth of Pseudomonas putida (NAH7) on vapor-phase naphthalene (NAPH) and its repercussion on vapor-phase NAPH concentrations. Our data demonstrate that growth rates of strain PpG7 were inversely correlated to the distance from the source of vapor-phase NAPH. Despite the high gas phase diffusivity of NAPH, microbial growth was absent at distances above 5 cm from the source when sufficient biomass was located in between. This indicates a high efficiency of suspended bacteria to acquire vapor-phase compounds and influence headspace concentration gradients at the centimeter-scale. It further suggests a crucial role of microorganisms as biofilters for gas-phase VOC emanating from contaminated groundwater or soil. - Research highlights: > Suspended bacteria have a high efficiency to degrade vapor-phase naphthalene. > Bacteria influence NAPH vapor-phase concentration gradients at centimeter-scale. > Microbial growth on vapor-phase naphthalene is inversely correlated to its source. > Bacteria are good biofilters for gas-phase NAPH emanating from contaminated sites. - Suspended bacteria have a high efficiency to degrade vapor-phase naphthalene and effectively influence vapor-phase naphthalene concentration gradients at the centimeter scale.

  3. Feasibility of leak-detection instrumentation for duplex-tube steam generator. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Berkey, E.; Witkowski, R.E.

    1974-01-01

    A literature search has been carried out to determine if current state-of-the-art for sodium vapor and water vapor detectors are feasible as leak detection instrumentation for the Westinghouse duplex-tube steam generator. A commercially available probe-type water vapor detector has been identified and a thermal ionization type sodium vapor detector, currently being developed by Westinghouse, has been selected as the reference sodium-vapor leak detector. Recommendations are made concerning the experimental studies required to adapt the selected instrumentation to steam-generator plant applications. Proposed future instrumentation development programs are also identified.

  4. Hanford Tank Farm Vapors Abatement Technology and Vendor Proposals Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Burns, H. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Farrar, M. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fink, S. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-20

    Suspected chemical vapor releases from the Hanford nuclear waste tank system pose concerns for worker exposure. Washington River Protection Solutions (WRPS) contracted the Savannah River National Laboratory (SRNL) to explore abatement technologies and strategies to remediate the vapors emitted through the ventilation system. In response, SRNL conducted an evaluation of technologies to abate, or reduce, vapor emissions to below 10% of the recognized occupational exposure limits (OELs). The evaluation included a review of published literature and a broadly communicated Request for Information to commercial vendors through a Federal Business Opportunities (Fed Biz Opps) web posting. In addition, SRNL conducted a workshop and post-workshop conference calls with interested suppliers (vendors) to assess proposals of relevant technologies. This report reviews applicable technologies and summarizes the approaches proposed by the vendors who participated in the workshop and teleconference interviews. In addition, the report evaluates the estimated performance of the individual technologies for the various classes of chemical compounds present in the Hanford Chemicals of Potential Concern (COPCs) list. Similarly, the report provides a relative evaluation of the vendor proposed approaches against criteria of: technical feasibility (and maturity), design features, operational considerations, secondary waste generation, safety/regulatory, and cost / schedule. These rough order-of-magnitude (ROM) cost estimates are intended to provide a comparison basis between technologies and are not intended to be actual project estimates.

  5. Self-aggregation of vapor-liquid phase transition

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The concept of the molecular free path is introduced to derive a criterion distinguishing active molecules from inactive molecules in liquid phase. Based on molecular self-aggregation theory a concept of the critical aggregation concentration (CAC) of active molecules is proposed to describe the physical configuration before the formation of the nuclei in the process of vapor-liquid phase transition. All active molecules exist in the form of the monomer when the concentration of active molecules is lower than CAC, while the active molecules will generate aggregation once the concentration of the active molecules reaches CAC. However, these aggregates with the aggregation number N smaller than 5 can steadily exist in bulk phase. The other excess active molecules can only produce infinite aggregation and form a critical nucleus of vapor-liquid phase transition. Without outer perturbation the state point of CAC corresponds to the critical superheated or supercooled state in the process of vapor-liquid phase transition. With the aggregate property, the interfacial tension between the bulk phase and the tiny new phase is predicted and a correction is made for the classical nucleation rate in a quite good agreement with experimental results.

  6. Hanford Tank Farm Vapors Abatement Technology and Vendor Proposals Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Burns, H. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Farrar, M. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fink, S. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-20

    Suspected chemical vapor releases from the Hanford nuclear waste tank system pose concerns for worker exposure. Washington River Protection Solutions (WRPS) contracted the Savannah River National Laboratory (SRNL) to explore abatement technologies and strategies to remediate the vapors emitted through the ventilation system. In response, SRNL conducted an evaluation of technologies to abate, or reduce, vapor emissions to below 10% of the recognized occupational exposure limits (OELs). The evaluation included a review of published literature and a broadly communicated Request for Information to commercial vendors through a Federal Business Opportunities (Fed Biz Opps) web posting. In addition, SRNL conducted a workshop and post-workshop conference calls with interested suppliers (vendors) to assess proposals of relevant technologies. This report reviews applicable technologies and summarizes the approaches proposed by the vendors who participated in the workshop and teleconference interviews. In addition, the report evaluates the estimated performance of the individual technologies for the various classes of chemical compounds present in the Hanford Chemicals of Potential Concern (COPCs) list. Similarly, the report provides a relative evaluation of the vendor proposed approaches against criteria of: technical feasibility (and maturity), design features, operational considerations, secondary waste generation, safety/regulatory, and cost / schedule. These rough order magnitude (ROM) cost estimates are intended to provide a comparison basis between technologies and are not intended to be actual project estimates.

  7. Heat transfer intensification by increasing vapor flow rate in flat heat pipes

    Science.gov (United States)

    Sprinceana, Silviu; Mihai, Ioan; Beniuga, Marius; Suciu, Cornel

    2015-02-01

    Flat heat pipes have various technical applications, one of the most important being the cooling of electronic components[9]. Their continuous development is due to the fact that these devices permit heat transfer without external energetic contribution. The practical exploitation of flat heat pipes however is limited by the fact that dissipated power can only reach a few hundred watts. The present paper aims to advance a new method for the intensification of convective heat transfer. A centrifugal mini impeller, driven by a turntable which incorporates four permanent magnets was designed. These magnets are put in motion by another rotor, which in its turn includes two permanent magnets and is driven by a mini electrical motor. Rotation of the centrifugal blades generates speed and pressure increase of the cooling agent brought to vapor state within the flat micro heat pipe. It's well known that the liquid suffers biphasic transformations during heat transfer inside the heat pipe. Over the hotspot (the heat source being the electronic component) generated at one end of the heat pipe, convective heat transfer occurs, leading to sudden vaporization of the liquid. Pressures generated by newly formed vapors push them towards the opposite end of the flat heat pipe, where a finned mini heat sink is usually placed. The mini-heat exchanger is air-cooled, thus creating a cold spot, where vapors condensate. The proposed method contributes to vapor flow intensification by increasing their transport speed and thus leading to more intense cooling of the heat pipe.

  8. Applying the Water Vapor Radiometer to Verify the Precipitable Water Vapor Measured by GPS

    Directory of Open Access Journals (Sweden)

    Ta-Kang Yeh

    2014-01-01

    Full Text Available Taiwan is located at the land-sea interface in a subtropical region. Because the climate is warm and moist year round, there is a large and highly variable amount of water vapor in the atmosphere. In this study, we calculated the Zenith Wet Delay (ZWD of the troposphere using the ground-based Global Positioning System (GPS. The ZWD measured by two Water Vapor Radiometers (WVRs was then used to verify the ZWD that had been calculated using GPS. We also analyzed the correlation between the ZWD and the precipitation data of these two types of station. Moreover, we used the observational data from 14 GPS and rainfall stations to evaluate three cases. The offset between the GPS-ZWD and the WVR-ZWD ranged from 1.31 to 2.57 cm. The correlation coefficient ranged from 0.89 to 0.93. The results calculated from GPS and those measured using the WVR were very similar. Moreover, when there was no rain, light rain, moderate rain, or heavy rain, the flatland station ZWD was 0.31, 0.36, 0.38, or 0.40 m, respectively. The mountain station ZWD exhibited the same trend. Therefore, these results have demonstrated that the potential and strength of precipitation in a region can be estimated according to its ZWD values. Now that the precision of GPS-ZWD has been confirmed, this method can eventually be expanded to the more than 400 GPS stations in Taiwan and its surrounding islands. The near real-time ZWD data with improved spatial and temporal resolution can be provided to the city and countryside weather-forecasting system that is currently under development. Such an exchange would fundamentally improve the resources used to generate weather forecasts.

  9. Mechanisms of suppressing cup-burner flame with water vapor

    Institute of Scientific and Technical Information of China (English)

    CONG BeiHua; LIAO GuangXuan

    2008-01-01

    The mechanisms of suppressing a laminar methane-air co-flow diffusion flame formed on a cup burner with water vapor have been studied experimentally and numerically. The methane burned in a steel cup surrounded by a glass chimney. A mist generator produced fine droplets delivered though the glass chimney with air. These droplets were heated into water vapor when they went though the diffuser. The extinguishing limit was obtained by gradually increasing the amount of water vapor to replace the air in the coflowing oxidizer stream. Results showed that the agent concentration required for extinguishment was constant over a wide range of the oxidizer velocity, i.e., a so-called "plateau region". The measured extinguishing mass fractions of the agents were: (16.7±0.6)% for H2O, (15.9±0.6)% for CO2, and (31.9±0.6)% for N2. The computation used the Fire Dynamics Simulator (FDS) de-veloped by the NIST. The numerical simulations showed that the predicted water vapor extinguishing limits and the flickering frequency were in good agreements with the experimental observations and, more importantly, revealed that the sup-pression of cup-burner flames occurred via a partial extinction mechanism (in which the flame base drifts downstream and then blows off) rather than the global extinction mechanism of typical counter-flow diffusion flames. And the flame-base oscillation just before the blow-off was the key step for the non-premixed flame extinction in the cup burner.

  10. Mechanisms of suppressing cup-burner flame with water vapor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The mechanisms of suppressing a laminar methane-air co-flow diffusion flame formed on a cup burner with water vapor have been studied experimentally and numerically. The methane burned in a steel cup surrounded by a glass chimney. A mist generator produced fine droplets delivered though the glass chimney with air. These droplets were heated into water vapor when they went though the diffuser. The extinguishing limit was obtained by gradually increasing the amount of water vapor to replace the air in the coflowing oxidizer stream. Results showed that the agent concentration required for extinguishment was constant over a wide range of the oxidizer velocity, i.e., a so-called "plateau region". The measured extinguishing mass fractions of the agents were: (16.7 ± 0.6)% for H2O, (15.9 ± 0.6)% for CO2, and (31.9 ± 0.6)% for N2. The computation used the Fire Dynamics Simulator (FDS) de- veloped by the NIST. The numerical simulations showed that the predicted water vapor extinguishing limits and the flickering frequency were in good agreements with the experimental observations and, more importantly, revealed that the sup- pression of cup-burner flames occurred via a partial extinction mechanism (in which the flame base drifts downstream and then blows off) rather than the global extinction mechanism of typical counter-flow diffusion flames. And the flame-base oscillation just before the blow-off was the key step for the non-premixed flame extinction in the cup burner.

  11. El vapor de ruedas "Cid": de pionero de la navegación comercial a vapor a primer vapor hospital

    Directory of Open Access Journals (Sweden)

    O. González García

    Full Text Available La aparición de la máquina de vapor había hecho realidad el sueño de navegar sin depender de las fuerzas de la naturaleza. La carrera por lograr un vapor comercial eficiente había comenzado. Con retraso por la Guerra de la Independencia, España se incorporó a la carrera. Entre los primeros vapores comerciales estaba el vapor "Cid". En 1859, en la Guerra de África, ante la necesidad de una evacuación regular de bajas se designa al "Cid" como buque hospital, fue la primera vez en el mundo que se usó un vapor hospital. El Dr. Nicasio Landa fue el responsable de realizar la misión con una organización moderna, eficaz y ejemplar. Pronto los vapores de ruedas perdieron su batalla con los de hélice y el "Cid" quedó obsoleto. Sin embargo, a pesar de su corta vida operativa, poco más de quince años, escribió una importante página en la historia de la navegación en España.

  12. Thermodynamic analysis of a Rankine cycle powered vapor compression ice maker using solar energy.

    Science.gov (United States)

    Hu, Bing; Bu, Xianbiao; Ma, Weibin

    2014-01-01

    To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with increasing generation temperature. For every working fluid there is an optimal generation temperature at which organic Rankine efficiency achieves the maximum value. The cooling power per square meter collector and ice production per square meter collector per day are, respectively, 126.44 W m(-2) and 7.61 kg m(-2) day(-1) at the generation temperature of 140 °C for working fluid of R245fa, which demonstrates the feasibility of organic Rankine cycle powered vapor compression ice maker.

  13. Optical studies of vaporization and stability of fluorescently labelled perfluorocarbon droplets

    Science.gov (United States)

    Reznik, Nikita; Seo, Minseok; Williams, Ross; Bolewska-Pedyczak, Eleonora; Lee, Mike; Matsuura, Naomi; Gariepy, Jean; Foster, F. Stuart; Burns, Peter N.

    2012-11-01

    Droplets of liquid perfluorocarbon (PFC) are under study as the next generation of contrast agents for ultrasound (US). These droplets can be selectively vaporized into echogenic gas bubbles in situ by externally applied US, with numerous applications to diagnosis and therapy. However, little is known about the mechanisms of droplet vaporization and the stability of the bubbles so produced. Here we observe optically the vaporization of fluorescent PFC droplets and the stability of the newly created bubbles. Fluorescent markers were used to label selectively either the liquid PFC core or the shell of the droplets. It was found that, following vaporization, the fluorescent marker is quickly expelled from the core of the newly created bubble and is retained on the gas-liquid interface. At the same time, it was shown that bubbles retain the original shells encapsulating their droplet precursors. The efficiency of encapsulation was found to depend strongly on the nature of the stabilizing material itself. These results provide direct evidence of droplet encapsulation post-vaporization, and suggest that the behaviour of the vaporized droplets is strongly dependent on the choice of the stabilizing material for the emulsion.

  14. A predictive model for vapor concentration in a nose-only inhalation chamber

    Energy Technology Data Exchange (ETDEWEB)

    Barrow, D.M.; Blehm, K.D. (Colorado State Univ., Fort Collins (USA))

    1990-09-01

    A unique nose-only inhalation chamber was designed and constructed to deliver uniform concentrations of gas, vapor, and aerosol contaminants to mice. This research investigated the fluid dynamics of a vaporous contaminant in the vertical flow chamber. The vapor was introduced by allowing the liquid phase of the contaminant to evaporate freely into the chamber interior. A contaminant mass transfer model was developed to predict concentrations generated by the system. The mathematical model of the system used clean airflow, liquid surface area, thickness of the stagnant air layer covering the liquid, system pressure, contaminant diffusion coefficient, and contaminant vapor pressure to compute the vapor concentration delivered to exposure ports. The equation was verified by placing various containers of methyl isobutyl ketone in the chamber and determining with a photospectrometer the resulting equilibrium concentrations. Vapor pressure, diffusion coefficient, and system pressure were held constant while airflow, surface area, and stagnant air layer thickness were varied systematically within the chamber. The resulting empirical data points were compared to the curves predicted by the theoretical model. Empirical concentrations fell within 0 to 48% of the theoretical values, showing that the equation can be used to choose values for airflow, surface area, and stagnant air layer thickness that will result in chamber concentrations in close proximity to the target concentration. If an exact concentration is essential, parameters may be individually adjusted to converge on the target concentration.

  15. Analytical modeling of the subsurface volatile organic vapor concentration in vapor intrusion.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2014-01-01

    The inhalation of volatile and semi-volatile organic compounds that intrude from a subsurface contaminant source into indoor air has become the subject of health and safety concerns over the last twenty years. Building subslab and soil gas contaminant vapor concentration sampling have become integral parts of vapor intrusion field investigations. While numerical models can be of use in analyzing field data and in helping understand the subslab and soil gas vapor concentrations, they are not widely used due to the perceived effort in setting them up. In this manuscript, we present a new closed-form analytical expression describing subsurface contaminant vapor concentrations, including subslab vapor concentrations. The expression was derived using Schwarz-Christoffel mapping. Results from this analytical model match well the numerical modeling results. This manuscript also explores the relationship between subslab and exterior soil gas vapor concentrations, and offers insights on what parameters need to receive greater focus in field studies.

  16. Water Vapor Corrosion in EBC Constituent Materials

    Science.gov (United States)

    Kowalski, Benjamin; Fox, Dennis; Jacobson, Nathan S.

    2017-01-01

    Environmental Barrier Coating (EBC) materials are sought after to protect ceramic matrix composites (CMC) in high temperature turbine engines. CMCs are particularly susceptible to degradation from oxidation, Ca-Al-Mg-Silicate (CMAS), and water vapor during high temperature operation which necessitates the use of EBCs. However, the work presented here focuses on water vapor induced recession in EBC constituent materials. For example, in the presence of water vapor, silica will react to form Si(OH)4 (g) which will eventually corrode the material away. To investigate the recession rate in EBC constituent materials under high temperature water vapor conditions, thermal gravimetric analysis (TGA) is employed. The degradation process can then be modeled through a simple boundary layer expression. Ultimately, comparisons are made between various single- and poly-crystalline materials (e.g. TiO2, SiO2) against those found in literature.

  17. Static Water Vapor Feed Electrolyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a static vapor feed electrolyzer utilizing an advanced bipolar plate that produces sub-saturated H2 and O2 is proposed. This novel bipolar design can...

  18. Leidenfrost Vapor Layer Stabilization on Superhydrophobic Surfaces

    Science.gov (United States)

    Vakarelski, Ivan; Patankar, Neelesh; Marston, Jeremy; Chan, Derek; Thoroddsen, Sigurdur

    2012-11-01

    We have performed experiments to investigate the influence of the wettability of a superheated metallic sphere on the stability of a thin vapor layer during the cooling of a sphere immersed in water. For high enough sphere temperatures, a continuous vapor layer (Leidenfrost regime) is observed on the surface of non-superhydrophobic spheres, but below a critical sphere temperature the layer becomes unstable and explosively switches to nuclear boiling regime. In contrast, when the sphere surface is textured and superhydrophobic, the vapor layer is stable and gradually relaxes to the sphere surface until the complete cooling of the sphere, thus avoiding the nuclear boiling transition altogether. This finding could help in the development of heat exchange devices and of vapor layer based drag reducing technologies.

  19. Colorometric detection of ethylene glycol vapor

    Science.gov (United States)

    Helm, C.; Mosier, B.; Verostko, C. E.

    1970-01-01

    Very low concentrations of ethylene glycol in air or other gases are detected by passing a sample through a glass tube with three partitioned compartments containing reagents which successively convert the ethylene glycol vapor into a colored compound.

  20. DMSP SSMT/2 - Atmospheric Water Vapor Profiler

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SSM/T-2 sensor is a five channel, total power microwave radiometer with three channels situated symmetrically about the 183.31 GHz water vapor resonance line and...

  1. Static Water Vapor Feed Electrolyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a static vapor feed electrolyzer utilizing an advanced bipolar plate that produces sub-saturated H2 and O2 is proposed. This novel bipolar design can...

  2. Analytical modeling of the subsurface volatile organic vapor concentration in vapor intrusion

    OpenAIRE

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The inhalation of volatile and semi-volatile organic compounds that intrude from a subsurface contaminant source into indoor air has become the subject of health and safety concerns over the last twenty years. Building subslab and soil gas contaminant vapor concentration sampling have become integral parts of vapor intrusion field investigations. While numerical models can be of use in analyzing field data and in helping understand the subslab and soil gas vapor concentrations, they are not w...

  3. Binary Schemes of Vapor Bubble Growth

    Science.gov (United States)

    Zudin, Yu. B.

    2015-05-01

    A problem on spherically symmetric growth of a vapor bubble in an infi nite volume of a uniformly superheated liquid is considered. A description of the limiting schemes of bubble growth is presented. A binary inertial-thermal bubble growth scheme characterized by such specifi c features as the "three quarters" growth law and the effect of "pressure blocking" in a vapor phase is considered.

  4. Vapor Pressure of 2-Chlorovinyl Dichloroarsine (Lewisite)

    Science.gov (United States)

    2009-02-01

    Streams of Compounds for Determining Vapor Pressure 11 3. Vapor Pressure of Lewisite I from Multiple Sources: Conant, Sumner, Lewis, Keyes, Price ...number of publications in the open literature by Green and Price ,4 Lewis and Perkins,5 Mann and Pope, Mohler and Polya7 and Gibson and Johnson.8...point. (2) Banks et al.,14 reported that during the fractional distillation of the reaction products of phenyl dichloroarsine and acetylene , 2

  5. A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

    Science.gov (United States)

    McCarron, Daniel J; Hughes, Ifan G; Tierney, Patrick; Cornish, Simon L

    2007-09-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D(2) transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude.

  6. Pure component vapor pressures of organic isomers

    Science.gov (United States)

    Dang, Caroline; Bannan, Thomas; Topping, David

    2017-04-01

    Atmospheric aerosols affect the Earth's climate directly through light scattering and absorption as well as indirectly by affecting cloud formation. There are many unanswered questions about how material properties of organic aerosols affect the climate. Predicting the formation of secondary organic aerosol (SOA), arising from gas to particle partitioning of potentially millions of compounds, remains one of the most challenging aspects in this regards. Of particular importance on predicting SOA formation is the saturation vapor pressure of each component. This property is typically obtained from group contribution methods (GCMs). However, it is currently unclear as to what level of accuracy is required or attainable from such techniques. Researchers have recently been able to measure low vapor pressures (lower limit of 10-8 Pa) experimentally using various techniques, and the University of Manchester Knudsen Effusion Mass Spectrometer (KEMS) has previously been used to measure vapor pressure of low volatility organics. Our recent KEMS work shows that functional group positioning has an effect on vapor pressure that is not accurately captured with estimation methods, and that experimental vapor pressures are 1-4 orders of magnitudes lower than predictive techniques. This has atmospheric impact through the variable amount of organic aerosol that is predicted to condense. In this study we present new measurements from the KEMS that can then be used to refine different experimental vapor pressure techniques as well as to provide data sets for building regression models to improve current predictive techniques.

  7. Bioeffects due to acoustic droplet vaporization

    Science.gov (United States)

    Bull, Joseph

    2015-11-01

    Encapsulated micro- and nano-droplets can be vaporized via ultrasound, a process termed acoustic droplet vaporization. Our interest is primarily motivated by a developmental gas embolotherapy technique for cancer treatment. In this methodology, infarction of tumors is induced by selectively formed vascular gas bubbles that arise from the acoustic vaporization of vascular microdroplets. Additionally, the microdroplets may be used as vehicles for localized drug delivery, with or without flow occlusion. In this talk, we examine the dynamics of acoustic droplet vaporization through experiments and theoretical/computational fluid mechanics models, and investigate the bioeffects of acoustic droplet vaporization on endothelial cells and in vivo. Early timescale vaporization events, including phase change, are directly visualized using ultra-high speed imaging, and the influence of acoustic parameters on droplet/bubble dynamics is discussed. Acoustic and fluid mechanics parameters affecting the severity of endothelial cell bioeffects are explored. These findings suggest parameter spaces for which bioeffects may be reduced or enhanced, depending on the objective of the therapy. This work was supported by NIH grant R01EB006476.

  8. Vapor Hydrogen Peroxide Sterilization Certification

    Science.gov (United States)

    Chen, Fei; Chung, Shirley; Barengoltz, Jack

    For interplanetary missions landing on a planet of potential biological interest, United States NASA planetary protection currently requires that the flight system must be assembled, tested and ultimately launched with the intent of minimizing the bioload taken to and deposited on the planet. Currently the only NASA approved microbial reduction method is dry heat sterilization process. However, with utilization of such elements as highly sophisticated electronics and sensors in modern spacecraft, this process presents significant materials challenges and is thus an undesirable bioburden reduction method to design engineers. The objective of this work is to introduce vapor hydrogen peroxide (VHP) as an alternative to dry heat microbial reduction to meet planetary protection requirements. The VHP sterilization technology is widely used by the medical industry, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal of our study is determine the minimum VHP process conditions for PP acceptable microbial reduction levels. A series of experiments were conducted using Geobacillus stearothermophilus to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters -hydrogen peroxide concentration, number of pulses, and exposure duration -the investigation also considered the possible effect of environmental pa-rameters. Temperature, relative humidity, and material substrate effects on lethality were also studied. Based on the results, a most conservative D value was recommended. This recom-mended D value was also validated using VHP "hardy" strains that were isolated from clean-rooms and environmental populations collected from spacecraft relevant areas. The efficiency of VHP at ambient condition as well as VHP material compatibility will also be

  9. Saturn's Stratospheric Water Vapor Distribution

    Science.gov (United States)

    Hesman, B. E.

    2015-12-01

    Water is a sought after commodity in the solar system. It is used as an indication of life, planetary formation timescales, and signatures of past cometary impacts. In Saturn's atmosphere there are two sources of water: an internal primordial reservoir that is confined to the troposphere, and an external source of unknown origin that delivers water to the stratosphere. Potential sources of stratospheric water include: Saturn's main rings (via neutral infall and/or ions transported along magnetic field lines - "Ring Rain"), interplanetary dust particles, and the E-ring that is supplied with water from the plumes of Enceladus. Measuring the latitudinal and seasonal variation of H2O on Saturn will constrain the source of Saturn's stratospheric water. Cassini's Composite InfraRed Spectrometer (CIRS) has detected emission lines of H2O on Saturn at wavelengths of 40 and 50 microns. CIRS also retrieves the temperature of the stratosphere using CH4 lines at 7.7 microns. Using our retrieved temperatures, we derive the mole fraction of H2O at the 0.5-5 mbar level for comparison with water-source models. The latitudinal variation of stratospheric water vapor between 2004-2009 will be presented as a first step in understanding the external source of water on Saturn. The observed local maximum near Saturn's equator supports either a neutral infall from the rings or a source in the E-ring. We will look for secondary maxima at mid-latitudes to determine whether "Ring Rain" also contributes to the inventory of water in Saturn's upper atmosphere.

  10. 33 CFR 154.808 - Vapor control system, general.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vapor control system, general... (CONTINUED) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154.808 Vapor control system, general. (a) A vapor control system design and installation must...

  11. Modelo para estudios de estabilidad de calderas de recuperación de calor (HRSG) y turbina de vapor

    OpenAIRE

    Corasaniti, Víctor Fabián; Agüero, Jorge Luis; Bianchi Lastra, Raúl E.

    2013-01-01

    En este trabajo se presenta la determinación y validación de los parámetros de un modelo digital para estudios de estabilidad que representa dos Calderas de Recuperación de Calor (HRSG, del inglés Heat Recovery Steam Generator), conjuntamente con la Turbina de Vapor a la cual suministran vapor. Los 2 HRSG producen vapor a partir de los gases de escape de 2 turbinas de gas. El modelo de simulación se implementa en el programa PSS/E (Power System Simulator), programa usado para estudios de est...

  12. Urban emissions of water vapor in winter

    Science.gov (United States)

    Salmon, Olivia E.; Shepson, Paul B.; Ren, Xinrong; Marquardt Collow, Allison B.; Miller, Mark A.; Carlton, Annmarie G.; Cambaliza, Maria O. L.; Heimburger, Alexie; Morgan, Kristan L.; Fuentes, Jose D.; Stirm, Brian H.; Grundman, Robert; Dickerson, Russell R.

    2017-09-01

    Elevated water vapor (H2Ov) mole fractions were occasionally observed downwind of Indianapolis, IN, and the Washington, D.C.-Baltimore, MD, area during airborne mass balance experiments conducted during winter months between 2012 and 2015. On days when an urban H2Ov excess signal was observed, H2Ov emission estimates range between 1.6 × 104 and 1.7 × 105 kg s-1 and account for up to 8.4% of the total (background + urban excess) advected flow of atmospheric boundary layer H2Ov from the urban study sites. Estimates of H2Ov emissions from combustion sources and electricity generation facility cooling towers are 1-2 orders of magnitude smaller than the urban H2Ov emission rates estimated from observations. Instances of urban H2Ov enhancement could be a result of differences in snowmelt and evaporation rates within the urban area, due in part to larger wintertime anthropogenic heat flux and land cover differences, relative to surrounding rural areas. More study is needed to understand why the urban H2Ov excess signal is observed on some days, and not others. Radiative transfer modeling indicates that the observed urban enhancements in H2Ov and other greenhouse gas mole fractions contribute only 0.1°C d-1 to the urban heat island at the surface. This integrated warming through the boundary layer is offset by longwave cooling by H2Ov at the top of the boundary layer. While the radiative impacts of urban H2Ov emissions do not meaningfully influence urban heat island intensity, urban H2Ov emissions may have the potential to alter downwind aerosol and cloud properties.

  13. A two-dimensional analytical model of petroleum vapor intrusion

    Science.gov (United States)

    Yao, Yijun; Verginelli, Iason; Suuberg, Eric M.

    2016-02-01

    In this study we present an analytical solution of a two-dimensional petroleum vapor intrusion model, which incorporates a steady-state diffusion-dominated vapor transport in a homogeneous soil and piecewise first-order aerobic biodegradation limited by oxygen availability. This new model can help practitioners to easily generate two-dimensional soil gas concentration profiles for both hydrocarbons and oxygen and estimate hydrocarbon indoor air concentrations as a function of site-specific conditions such as source strength and depth, reaction rate constant, soil characteristics and building features. The soil gas concentration profiles generated by this new model are shown in good agreement with three-dimensional numerical simulations and two-dimensional measured soil gas data from a field study. This implies that for cases involving diffusion dominated soil gas transport, steady state conditions and homogenous source and soil, this analytical model can be used as a fast and easy-to-use risk screening tool by replicating the results of 3-D numerical simulations but with much less computational effort.

  14. Influence of Soil Moisture on Soil Gas Vapor Concentration for Vapor Intrusion.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2013-10-01

    Mathematical models have been widely used in analyzing the effects of various environmental factors in the vapor intrusion process. Soil moisture content is one of the key factors determining the subsurface vapor concentration profile. This manuscript considers the effects of soil moisture profiles on the soil gas vapor concentration away from any surface capping by buildings or pavement. The "open field" soil gas vapor concentration profile is observed to be sensitive to the soil moisture distribution. The van Genuchten relations can be used for describing the soil moisture retention curve, and give results consistent with the results from a previous experimental study. Other modeling methods that account for soil moisture are evaluated. These modeling results are also compared with the measured subsurface concentration profiles in the U.S. EPA vapor intrusion database.

  15. A Case Study on the Role of Water Vapor from Southwest China in Downstream Heavy Rainfall

    Institute of Scientific and Technical Information of China (English)

    PAN Yang; YU Rucong; LI Jian; XU Youping

    2008-01-01

    Based on the observation data analysis and numerical simulation, the development of an eastward- moving vortex generated in Southwest China during the period 25-27 June 2003 is studied. The water vapor budget analysis indicates that water vapor in the lower troposphere over Southwest China is transported downstream to the Yangtze and Huaihe River valleys by the southwesterly winds south of the vortex center. A potential vorticity (PV) budget analysis reveals that a positive feedback between latent heat release and low-level positive vorticity plays a vital role in the sudden development and eastward movement of the vortex. Numerical simulations are consistent with these results.

  16. Rapid synthesis of tantalum oxide dielectric films by microwave microwave-assisted atmospheric chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ndiege, Nicholas [School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (United States)], E-mail: ndiege@uiuc.edu; Subramanian, Vaidyanathan [School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (United States)], E-mail: ravisv@unr.edu; Shannon, Mark A. [Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 West Green street, Urbana, IL 61801 (United States)], E-mail: mshannon@uiuc.edu; Masel, Richard I. [School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (United States)], E-mail: r-masel@uiuc.edu

    2008-10-01

    Microwave-assisted chemical vapor deposition has been used to generate high quality, high-k dielectric films on silicon at high deposition rates with film thicknesses varying from 50 nm to 110 {mu}m using inexpensive equipment. Characterization of the post deposition products was performed by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Auger electron spectroscopy and Raman spectroscopy. Film growth was determined to occur via rapid formation and accumulation of tantalum oxide clusters from tantalum (v) ethoxide (Ta(OC{sub 2}H{sub 5}){sub 5}) vapor on the deposition surface.

  17. Redox Characteristics of Thiol Compounds Using Radicals Produced by Water Vapor Radio Frequency Discharge

    Science.gov (United States)

    Hayashi, Nobuya; Nakahigashi, Akari; Goto, Masaaki; Kitazaki, Satoshi; Koga, Kazunori; Shiratani, Masaharu

    2011-08-01

    The redox reaction between cystein and cystine is observed using radicals produced in water vapor plasma for the control of plant growth. Cystein is oxidized to cystine using the OH radical in the higher-pressure regime and cystine is reduced to cystein by the H radical generated in the lower-pressure regime. Also, the oxidative stress reaction of plants is observed when water vapor plasma is irradiated onto seeds of plants such as radish sprouts. The mechanism of the control of plant growth is explained by the change in thiol compound quantity of the plant cells induced by the radical reaction.

  18. Strong relative intensity squeezing by 4-wave mixing in Rb vapor

    CERN Document Server

    McCormick, C F; Boyer, V; Lett, P D

    2006-01-01

    We have measured -3.5 dB (-8.1 dB corrected for losses) relative intensity squeezing between the probe and conjugate beams generated by stimulated, nondegenerate four-wave mixing in hot rubidium vapor. Unlike early observations of squeezing in atomic vapors based on saturation of a two-level system, our scheme uses a resonant nonlinearity based on ground-state coherences in a three-level system. Since this scheme produces narrowband, squeezed light near an atomic resonance it is of interest for experiments involving cold atoms or atomic ensembles.

  19. Closed-loop phase diagrams, vaporization, and multicriticality in binary liquid mixtures

    Science.gov (United States)

    Caflisch, Robert G.; Walker, James S.

    1983-09-01

    The coupled Potts-Ising models of Walker and Vause, which successfully describe closed-loop phase diagrams in hydrogen-bonding mixtures, are generalized to encompass the vapor phase, and are studied using position-space renormalization-group techniques. Global phase diagrams are generated, exhibiting such features as miscibility-immiscibility criticality, liquid-vapor critical points, critical end points, and bicritical and tricritical points. In addition, new types of phase diagrams are found, involving upper and lower azeotropes, for example, which are expected to be physically realizable in experimental systems.

  20. Explosive vapor detection payload for small robots

    Science.gov (United States)

    Stimac, Phil J.; Pettit, Michael; Wetzel, John P.; Haas, John W.

    2013-05-01

    Detection of explosive hazards is a critical component of enabling and improving operational mobility and protection of US Forces. The Autonomous Mine Detection System (AMDS) developed by the US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) is addressing this challenge for dismounted soldiers. Under the AMDS program, ARA has developed a vapor sampling system that enhances the detection of explosive residues using commercial-off-the-shelf (COTS) sensors. The Explosives Hazard Trace Detection (EHTD) payload is designed for plug-and-play installation and operation on small robotic platforms, addressing critical Army needs for more safely detecting concealed or exposed explosives in areas such as culverts, walls and vehicles. In this paper, we describe the development, robotic integration and performance of the explosive vapor sampling system, which consists of a sampling "head," a vapor transport tube and an extendable "boom." The sampling head and transport tube are integrated with the boom, allowing samples to be collected from targeted surfaces up to 7-ft away from the robotic platform. During sample collection, an IR lamp in the sampling head is used to heat a suspected object/surface and the vapors are drawn through the heated vapor transport tube to an ion mobility spectrometer (IMS) for detection. The EHTD payload is capable of quickly (less than 30 seconds) detecting explosives such as TNT, PETN, and RDX at nanogram levels on common surfaces (brick, concrete, wood, glass, etc.).

  1. Vapor scavenging by atmospheric aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, E.

    1996-05-01

    Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

  2. Distribution of tropical tropospheric water vapor

    Science.gov (United States)

    Sun, De-Zheng; Lindzen, Richard S.

    1993-01-01

    Utilizing a conceptual model for tropical convection and observational data for water vapor, the maintenance of the vertical distribution of the tropical tropospheric water vapor is discussed. While deep convection induces large-scale subsidence that constrains the turbulent downgradient mixing to within the convective boundary layer and effectively dries the troposphere through downward advection, it also pumps hydrometeors into the upper troposphere, whose subsequent evaporation appears to be the major source of moisture for the large-scale subsiding motion. The development of upper-level clouds and precipitation from these clouds may also act to dry the outflow, thus explaining the low relative humidity near the tropopause. A one-dimensional model is developed to simulate the mean vertical structure of water vapor in the tropical troposphere. It is also shown that the horizontal variation of water vapor in the tropical troposphere above the trade-wind boundary layer can be explained by the variation of a moisture source that is proportional to the amount of upper-level clouds. Implications for the nature of water vapor feedback in global warming are discussed.

  3. Thermodynamics and Kinetics of Silicate Vaporization

    Science.gov (United States)

    Jacobson, Nathan S.; Costa, Gustavo C. C.

    2015-01-01

    Silicates are a common class of materials that are often exposed to high temperatures. The behavior of these materials needs to be understood for applications as high temperature coatings in material science as well as the constituents of lava for geological considerations. The vaporization behavior of these materials is an important aspect of their high temperature behavior and it also provides fundamental thermodynamic data. The application of Knudsen effusion mass spectrometry (KEMS) to silicates is discussed. There are several special considerations for silicates. The first is selection of an appropriate cell material, which is either nearly inert or has well-understood interactions with the silicate. The second consideration is proper measurement of the low vapor pressures. This can be circumvented by using a reducing agent to boost the vapor pressure without changing the solid composition or by working at very high temperatures. The third consideration deals with kinetic barriers to vaporization. The measurement of these barriers, as encompassed in a vaporization coefficient, is discussed. Current measured data of rare earth silicates for high temperature coating applications are discussed. In addition, data on magnesium-iron-silicates (olivine) are presented and discussed.

  4. A Numerical Investigation of Vapor Intrusion — the Dynamic Response of Contaminant Vapors to Rainfall Events

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1 m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in

  5. A numerical investigation of vapor intrusion--the dynamic response of contaminant vapors to rainfall events.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2012-10-15

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in determining

  6. Refraction of microwave signals by water vapor

    Science.gov (United States)

    Goldfinger, A. D.

    1980-01-01

    Tropospheric water vapor causes a refractive path length effect which is typically 5-10% of the 'dry' tropospheric effect and as large as several meters at elevation angles below 5 deg. The vertical water vapor profile is quite variable, and measurements of intensive atmospheric parameters such as temperature and humidity limited to the surface do not adequately predict the refractive effect. It is suggested that a water vapor refraction model that is a function of the amount of precipitable water alone can be successful at low elevation angles. From an extensive study of numerical ray tracings through radiosonde balloon data, such a model has been constructed. The model predicts the effect at all latitudes and elevation angles between 2 and 10 deg to an accuracy of better than 4% (11 cm at 3 deg elevation angle).

  7. Possible seasonal variability of mesospheric water vapor

    Science.gov (United States)

    Bevilacqua, R. M.; Schwartz, P. R.; Wilson, W. J.; Ricketts, W. B.; Howard, R. J.

    1985-01-01

    Ground-based spectral line measurements of the 22.2 GHz water vapor line in atmospheric emission were made at the Jet Propulsion Laboratory, which have been used to deduce the mesospheric water vapor profile. The measurements were made nearly continuously in the spring and early summer of 1984. The results indicate a temporal increase in the water vapor mixing ratio in the upper mesosphere from April through June. At 75 km, this increase is nearly by a factor of 2. Comparison of the present results with the results of a similar series of measurements made at the Haystack (radio astronomy) Observatory indicate that this temporal increase is part of a seasonal variation.

  8. Water vapor release from biofuel combustion

    Directory of Open Access Journals (Sweden)

    R. S. Parmar

    2008-03-01

    Full Text Available We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are compared to carbon in the biofuel. Fuel types included hardwood (oak and African musasa, softwood (pine and spruce, partly with green needles, and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7 on average, indicating the presence of water that is not chemically bound. This biofuel moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biofuel contributes distinctly to the water vapor in biomass burning emissions, and its influence on meteorology needs to be evaluated.

  9. Water vapor release from biofuel combustion

    Science.gov (United States)

    Parmar, R. S.; Welling, M.; Andreae, M. O.; Helas, G.

    2008-03-01

    We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are compared to carbon in the biofuel. Fuel types included hardwood (oak and African musasa), softwood (pine and spruce, partly with green needles), and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7 on average, indicating the presence of water that is not chemically bound. This biofuel moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biofuel contributes distinctly to the water vapor in biomass burning emissions, and its influence on meteorology needs to be evaluated.

  10. Water vapor release from biomass combustion

    Science.gov (United States)

    Parmar, R. S.; Welling, M.; Andreae, M. O.; Helas, G.

    2008-10-01

    We report on the emission of water vapor from biomass combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are referenced to carbon in the biomass. The investigated fuel types include hardwood (oak and African musasa), softwood (pine and spruce, partly with green needles), and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7, indicating the presence of water that is not chemically bound. This non-bound biomass moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biomass contributes significantly to the water vapor in biomass burning emissions, and its influence on the behavior of fire plumes and pyro-cumulus clouds needs to be evaluated.

  11. Vapor-Particle Separation Using Microporous Metallic Membrane in Crossflow Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Mengdawn [ORNL

    2013-01-01

    Simultaneous separation of vapor and particles in industrial processes could be a key step toward manufacturing of high-quality goods. The separation is critical for successful measurement of volatile or semi-volatile aerosol particles, which no reliable technique exists. We have developed a technique for separation of vapor and particles simultaneously using a specialty microporous metallic membrane. The separator allows the thermally denuded particles traverse straight through the membrane tube, while the vapor molecules permeate through the membrane, separate from the particles and are removed subsequently. The separation technique virtually eliminates the possibility of contamination by vapor re- condensation. We tested the prototype of the vapor-particle separator (VPS) using aerosols prepared from sodium chloride to represent non-volatile aerosols. Chemical like dioctyl phthalate was chosen to represent volatile particles. The test aerosol particles were generated by an atomizer followed by a tandem differential mobility analyser to produce a stream of monodisperse particles in the size range of 10 to 100 nm. In real world particles, we tested the VPS using diesel engine particles that is a mixture of complex chemical composition. Number concentration of the nonvolatile particles reduced as the temperature increased, but the mode diameter of the aerosol population remained unchanged. Number concentration of the volatile particles was also reduced as the temperature increased, but their mode diameters became smaller as particles shrunk in diameter. Differences in the thermal behaviour of the particles were attributed to its transition energy barrier and evaporation rate. Mass balance analysis suggests the separation of vapor and test particles was reasonably complete. Thus, we conclude the VPS could provide an effective means for quantitative characterization of aerosol volatility and separation of vapors from particles.

  12. Detection of Organic Vapors Based on Photoluminescent Bragg-Reflective Porous Silicon Interferomete.

    Science.gov (United States)

    Ahn, Jihoon; Cho, Bomin; Kim, Sungsoo; Sohn, Honglae

    2015-07-01

    Novel photoluminescent Bragg-reflective porous silicon, exhibiting dual optical properties, both the optical reflectivity and photoluminescence, was developed and used for sensing organic vapors. Photoluminescent Bragg-reflective porous silicon samples were prepared by an electrochemical etch of n-type silicon under the illumination. The etching solution consisted of a 3:1 volume mixture of aqueous 48% hydrofluoric acid and absolute ethanol. The typical etch parameters for the generation of photoluminescent Bragg-reflective porous silicon involved a periodic square wave current with 50 repeats. The surface of photoluminescent Bragg-reflective porous silicon was characterized by a FT-IR spectroscopy. Both reflectivity and photoluminescence were simultaneously measured under the exposure of organic vapors. The shift of reflection band to the longer wavelength and the quenching of photoluminescence under the exposure of various organic vapors were observed.

  13. Vapor film collapse triggered by external pressure pulse and the fragmentation of melt droplet in FCIs

    Institute of Scientific and Technical Information of China (English)

    LIN Qian; TONG Lili; CAO Xuewu; KRIVENTSEV Vladimir

    2008-01-01

    The fragmentation process of high-temperature molten drop is a key factor to determine the ratio heat transferred to power in FCIs,which estimates the possible damage degree during the hypothetical severe accident in the nuclear reactors.In this paper,the fragmentation process of melt droplet in FCIs is investigated by theoretic analysis.The fragmentation mechanism is studied when an external pressure pulse applied to a melt droplet,which is surrounded by vapor film.The vapor film collapse which induces fragmentation of melt droplet is analyzed and modeled.And then the generated pressure is calculated.The vapor film collapse model is introduced to fragmentation correlation,and the predicted fragment size is calculated and compared with experimental data.The result shows that the developed model can predict the diameter of fragments and can be used to calculate the fragmentation process appreciatively.

  14. High-Pressure Solvent Vapor Annealing with a Benign Solvent To Rapidly Enhance the Performance of Organic Photovoltaics.

    Science.gov (United States)

    Jung, Buyoung; Kim, Kangmin; Eom, Yoomin; Kim, Woochul

    2015-06-24

    A high-pressure solvent vapor annealing (HPSVA) treatment is suggested as an annealing process to rapidly achieve high-performance organic photovoltaics (OPVs); this process can be compatible with roll-to-roll processing methods and uses a benign solvent: acetone. Solvent vapor annealing can produce an advantageous vertical distribution in the active layer; however, conventional solvent vapor annealing is also time-consuming. To shorten the annealing time, high-pressure solvent vapor is exposed on the active layer of OPVs. Acetone is a nonsolvent for poly(3-hexylthiophene-2,5-diyl) (P3HT), but it can dissolve small amounts of 1-(3-methoxycarbonyl)-propyl-1,1-phenyl-(6,6)C61 (PCBM). Acetone vapor molecules can penetrate into the active layer under high vapor pressure conditions to alter the morphology. HPSVA induces a PCBM-rich phase near the cathode and facilitates the transport of free charge carriers to the electrode. Although P3HT is not soluble in acetone, locally rearranged P3HT crystallites are generated. The performance of OPV films was enhanced after HPSVA; the film treated at 30 kPa for 10 s showed optimum performance. Additionally, this HPSVA method could be adapted for mass production because the temporary exposure of films to high-pressure acetone vapor in ambient conditions also improved performance.

  15. Water vapor stable isotope observations from tropical Australia

    KAUST Repository

    Parkes, Stephen

    2015-04-01

    The response of the tropical hydrological cycle to anthropogenically induced changes in radiative forcing is one of the largest discrepancies between climate models. Paleoclimate archives of the stable isotopic composition of precipitation in the tropics indicate a relationship with precipitation amount that could be exploited to study past hydroclimate and improve our knowledge of how this region responds to changes in climate forcing. Recently modelling studies of convective parameterizations fitted with water isotopes and remote sensing of water vapor isotopes in the tropics have illustrated uncertainty in the assumed relationship with rainfall amount. Therefore there is a need to collect water isotope data in the tropics that can be used to evaluate these models and help identify the relationships between the isotopic composition of meteoric waters and rainfall intensity. However, data in this region is almost non-existent. Here we present in-situ water vapor isotopic measurements and the HDO retrievals from the co-located Total Column Carbon Observing Network (TCCON) site at Darwin in Tropical Australia. The Darwin site is interestingly placed within the tropical western pacific region and is impacted upon by a clear monsoonal climate, and key climate cycles including ENSO and Madden Julian Oscillations. The analysis of the data illustrated relationships between water vapor isotopes and humidity which demonstrated the role of precipitation processes in the wet season and air mass mixing during the dry season. Further the wet season observations show complex relationships between humidity and isotopes. A simple Rayleigh distillation model was not obeyed, instead the importance of rainfall re-evaporation in generating the highly depleted signatures was demonstrated. These data potentially provide a useful tool for evaluating model parameterizations in monsoonal regions as they demonstrate relationships with precipitation processes that cannot be observed with

  16. Low temperature vapor phase digestion of graphite

    Science.gov (United States)

    Pierce, Robert A.

    2017-04-18

    A method for digestion and gasification of graphite for removal from an underlying surface is described. The method can be utilized to remove graphite remnants of a formation process from the formed metal piece in a cleaning process. The method can be particularly beneficial in cleaning castings formed with graphite molding materials. The method can utilize vaporous nitric acid (HNO.sub.3) or vaporous HNO.sub.3 with air/oxygen to digest the graphite at conditions that can avoid damage to the underlying surface.

  17. Drag Reduction by Leidenfrost Vapor Layers

    Science.gov (United States)

    Vakarelski, Ivan U.; Marston, Jeremy O.; Chan, Derek Y. C.; Thoroddsen, Sigurdur T.

    2011-05-01

    We demonstrate and quantify a highly effective drag reduction technique that exploits the Leidenfrost effect to create a continuous and robust lubricating vapor layer on the surface of a heated solid sphere moving in a liquid. Using high-speed video, we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development of related energy saving technologies.

  18. Guidance on Soil Vapor Extraction Optimization

    Science.gov (United States)

    2001-06-01

    343 Table LNAPL DNAPL Source: after USEPA 1991 draw\\$vehandbk3.cdr aee p1 4/5/01 M~ssive Clay ) . ’C. ~AA_··’’’· --V,V~ . >:’ .’ ’·Sand...for removing orgamc contaminants with a vapor pressure greater than 0.5 mm mercury (Hg) at 200 Celsius (C). This includes common chlorinated solvents...liquids ( DNAPLs ), solvent vapors, or dissolved contaminants. • Depth to groundwater, seasonal variations, recharge and discharge information including

  19. Water vapor release from biomass combustion

    OpenAIRE

    Parmar, R. S.; Welling, M.; Andreae, M. O.; G. Helas

    2008-01-01

    We report on the emission of water vapor from biomass combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are referenced to carbon in the biomass. The investigated fuel types include hardwood (oak and African musasa), softwood (pine and spruce, partly with green needles), and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the ...

  20. Water vapor release from biofuel combustion

    OpenAIRE

    Parmar, R. S.; Welling, M.; Andreae, M. O.; G. Helas

    2008-01-01

    We report on the emission of water vapor from biofuel combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are compared to carbon in the biofuel. Fuel types included hardwood (oak and African musasa), softwood (pine and spruce, partly with green needles), and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 ...

  1. The vertical distribution of Mars water vapor

    Science.gov (United States)

    Davies, D. W.

    1979-01-01

    Analysis of observations made from the Viking 1 Orbiter indicates that the water vapor over the Viking 1 landing site is uniformly mixed with the atmosphere and not concentrated near the surface. The analysis incorporates the effects of atmospheric scattering and explains why previous earth-based observations showed a strong diurnal variation in water content. It also explains the lack of an early morning fog and removes the necessity of daily exchange of large amounts of water between the surface and the atmosphere. A water vapor volume mixing ratio of 1.5 x 10 to the -4th is inferred for the Viking 1 site in late summer.

  2. Drag Reduction by Leidenfrost Vapor Layers

    KAUST Repository

    Vakarelski, Ivan Uriev

    2011-05-23

    We demonstrate and quantify a highly effective drag reduction technique that exploits the Leidenfrost effect to create a continuous and robust lubricating vapor layer on the surface of a heated solid sphere moving in a liquid. Using high-speed video, we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development of related energy saving technologies.

  3. Direct observation of metal nanoparticles as heterogeneous nuclei for the condensation of supersaturated organic vapors: nucleation of size-selected aluminum nanoparticles in acetonitrile and n-hexane vapors.

    Science.gov (United States)

    Abdelsayed, Victor; El-Shall, M Samy

    2014-08-07

    This work reports the direct observation and separation of size-selected aluminum nanoparticles acting as heterogeneous nuclei for the condensation of supersaturated vapors of both polar and nonpolar molecules. In the experiment, we study the condensation of supersaturated acetonitrile and n-hexane vapors on charged and neutral Al nanoparticles by activation of the metal nanoparticles to act as heterogeneous nuclei for the condensation of the organic vapor. Aluminum seed nanoparticles with diameters of 1 and 2 nm are capable of acting as heterogeneous nuclei for the condensation of supersaturated acetonitrile and hexane vapors. The comparison between the Kelvin and Fletcher diameters indicates that for the heterogeneous nucleation of both acetonitrile and hexane vapors, particles are activated at significantly smaller sizes than predicted by the Kelvin equation. The activation of the Al nanoparticles occurs at nearly 40% and 65% of the onset of homogeneous nucleation of acetonitrile and hexane supersaturated vapors, respectively. The lower activation of the charged Al nanoparticles in acetonitrile vapor is due to the charge-dipole interaction which results in rapid condensation of the highly polar acetonitrile molecules on the charged Al nanoparticles. The charge-dipole interaction decreases with increasing the size of the Al nanoparticles and therefore at low supersaturations, most of the heterogeneous nucleation events are occurring on neutral nanoparticles. No sign effect has been observed for the condensation of the organic vapors on the positively and negatively charged Al nanoparticles. The present approach of generating metal nanoparticles by pulsed laser vaporization within a supersaturated organic vapor allows for efficient separation between nucleation and growth of the metal nanoparticles and, consequently controls the average particle size, particle density, and particle size distribution within the liquid droplets of the condensing vapor. Strong

  4. Motion of liquid plugs between vapor bubbles in capillary tubes: a comparison between fluids

    Science.gov (United States)

    Bertossi, Rémi; Ayel, Vincent; Mehta, Balkrishna; Romestant, Cyril; Bertin, Yves; Khandekar, Sameer

    2017-04-01

    Pulsating heat pipes (PHP) are now well-known devices in which liquid/vapor slug flow oscillates in a capillary tube wound between hot and cold sources. In this context, this paper focuses on the motion of the liquid plug, trapped between vapor bubbles, moving in capillary tubes, to try to better understand the thermo-physical phenomena involved in such devices. This study is divided into three parts. In the first part, an experimental study presents the evolution of the vapor pressure during the evaporation process of a liquid thin film deposited from a liquid plug flowing in a heated capillary tube: it is found that the behavior of the generated and removed vapor can be very different, according to the thermophysical properties of the fluids. In the second part, a transient model allows to compare, in terms of pressure and duration, the motion of a constant-length liquid plug trapped between two bubbles subjected to a constant difference of vapor pressure: the results highlight that the performances of the four fluids are also very different. Finally, a third model that can be considered as an improvement of the second one, is also presented: here, the liquid slug is surrounded by two vapor bubbles, one subjected to evaporation, the pressure in both bubbles is now a result of the calculation. This model still allows comparing the behaviors of the fluid. Even if our models are quite far from a complete model of a real PHP, results do indicate towards the applicability of different fluids as suitable working fluids for PHPs, particularly in terms of the flow instabilities which they generate.

  5. Dynamics of Vapor Layer Under a Leidenfrost Drop

    CERN Document Server

    Caswell, Thomas A

    2014-01-01

    In the Leidenfrost effect a small drop of fluid is levitated above a sufficiently hot surface, on a persistent vapor layer generated by evaporation from the drop. The vapor layer thermally insulates the drop from the surface leading to extraordinarily long drop lifetimes. The top-view shape of the levitated drops can exhibit persistent star-like vibrations. I extend recent work [Burton et al. PRL 2012] to study the bottom surface of the drop using interference-imaging. In this work I use a high-speed camera and automated image analysis to image, locate and classify the interference fringes. From the interference fringes I reconstruct the shape and height profile of the rim where the drop is closest to the surface. I measure the drop-size dependence of the planar vibrational mode frequencies, which agree well with previous work. I observe a distinct breathing mode in the average radius of the drop, the frequency of which scales differently with drop size than the other modes. This breathing mode can be tightly...

  6. Atmospheric sugar alcohols: evaporation rates and saturation vapor pressures

    Science.gov (United States)

    Bilde, M.; Zardini, A. A.; Hong, J.; Tschiskale, M.; Emanuelsson, E.

    2014-12-01

    The atmospheric partitioning between gas and condensed phase of organic molecules is poorly understood, and discrepancies exist between predicted and observed concentrations of secondary organic aerosols. A key problem is the lack of information about thermodynamic properties of semi- and low volatile organic molecules. Saturation vapor pressure and the associated temperature dependence (dH) are key parameters for improving predictive atmospheric models. In this work we combine experiments and thermodynamic modeling to investigate these parameters for a series of polyols, so-called sugar alcohols. These polyols are common in the water soluble fraction of atmospheric aerosols. In our experimental system sub-micron particles are generated by nebulization from aqueous solution, and a mono disperse fraction of the aerosol is selected using a differential mobility analyzer. The particles are allowed to evaporate in a laminar flow reactor, and changes in particle size as function of evaporation time are determined using a scanning mobility particle sizer system. In this work saturation vapor pressures of sugar alcohols at several temperatures have been inferred from such measurements using thermodynamic modeling. Results are presented and discussed in context of atmospheric gas to particle partitioning.

  7. Numerical analysis of fragmentation mechanisms in vapor explosions

    Energy Technology Data Exchange (ETDEWEB)

    Koshizuka, Seiichi; Ikeda, Hirokazu; Oka, Yoshiaki [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1998-01-01

    Fragmentation of molten metal is the key process in vapor explosions. However this process is so rapid that the mechanisms have not been clarified yet in the experimental studies. Besides, numerical simulation is difficult because we have to analyze water, steam and molten metal simultaneously with evaporation and fragmentation. The authors have been developing a new numerical method, the Moving Particle Semi-implicit (MPS) method, based on moving particles and their interactions. Grids are not necessary. Incompressible flows with fragmentation on free surfaces have been calculated successfully using the MPS method. In the present study numerical simulation of the fragmentation processes using the MPS method is carried out to investigate the mechanisms. A numerical model to calculate evaporation from water to steam is developed. In this model, new particles are generated on water-steam interfaces. Effect of evaporation is also investigated. Growth of the filament is not accelerated when the normal evaporation is considered. This is because the normal evaporation needs a longer time than the moment of the jet impingement, though the filament growth is decided in this moment. Next, rapid evaporation based on spontaneous nucleation is considered. The filament growth is markedly accelerated. This result is consistent with the experimental fact that the spontaneous nucleation temperature is a necessary condition of small-scale vapor explosions. (J.P.N.)

  8. Evaluation of the bimetallic receiver Cu-Fe under the flexion phenomenon in parabolic concentrators in the direct steam generation; Evaluacion del receptor bimetalico Cu-Fe bajo el fenomeno de flexion, en concentradores parabolicos en la generacion directa de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Flores, Vicente; Lentz, Alvaro; Almanza, Rafael [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-07-01

    In this paper the results of experimental tests as a part of the study of the flexion phenomenon of the absorbent tube in concentrators of parabolic channel during the process of direct steam generation (GDV), are presented. The flexion phenomenon of the tube has already been studied, in which it has been established that occurs under conditions of change of temperature gradients in the tube surface, when a stratified flow pattern of appears, which leads to a local overheating of the internal wall of the receiver, when the two phase flow begins, with relatively low massic flows. In the normal configuration of the absorbent iron tube, this one is surrounded with a glass tube to avoid thermal losses to the environment: when the metallic tube bends due to thermal stresses, displacements of 6 cm are reached for wrought iron with a wall thickness of 1.9 mm with selective film: for wrought iron with a wall thickness of 3.8 mm without selective film nor transparent cover bendings of 3 cm have been attained. This way the glass tube is subjected to a cross sectional shearing stress when the absorber touches it during its bending, giving rise also to the rupture of the same. In order to give a solution to this problem, at the Instituto de Engineering, a bi-metallic copper- steel tube 3 m long and 32 mm of diameter was built and installed in the parabolic concentrator and the flexion phenomenon was experienced. Results of experimental tests for the steel and the bimetallic steel receiver, without the glass cover nor the selective film and for the bimetallic receiver with the glass cover, are presented. They are compared among them departing from the temperatures in the lower and the upper part of the cross-sectional section of the tube and of the flexion of each one, concluding that the compound receiver copper-steel, up to now, fulfills better the expectations of eliminating the flexion phenomenon under the operating conditions of the solar plant during the GDV. [Spanish] Se

  9. Vaporization of atherosclerotic plaques by spark erosion

    NARCIS (Netherlands)

    C.J. Slager (Cornelis); C.E. Essed; J.C.H. Schuurbiers (Johan); N. Bom (Klaas); P.W.J.C. Serruys (Patrick); G.T. Meester (Geert)

    1985-01-01

    textabstractAn alternative to the laser irradiation of atherosclerotic lesions has been developed. A pulsed electrocardiogram R wave-triggered electrical spark erosion technique is described. Controlled vaporization of fibrous and lipid plaques with minimal thermal side effects was achieved and docu

  10. Steam vaporizers: A danger for paediatric burns.

    Science.gov (United States)

    Lonie, Sarah; Baker, Paul; Teixeira, Rodrigo

    2016-12-01

    Steam vaporizers are used to humidify air in dry environments. They are marketed to moisten children's airway secretions and thus to help relieve symptoms associated with upper respiratory tract infections. Unfortunately the steam emitted from the unit can also pose a significant risk of burns to children. Our study aimed to ascertain patterns of injury and treatment outcomes from steam burns resulting from these devices. Potential preventative measures are discussed. Children who had sustained vaporizer scald burns were identified at the outpatient burns clinic over a 10-month period (November 2014-August 2015). Medical records were reviewed retrospectively and data collected on pattern of injury, management and outcomes. Ten children were treated for vaporizer steam burns over the study period. The mean age was 1.6 years and 8 (80%) patients were male. Operative intervention was undergone in 5 (50%) cases; four acutely and one as a secondary reconstructive procedure. Hand burns accounted for 8 (80%) of cases. Steam vaporizers can cause significant burns in the paediatric population. Toddlers were most at risk, frequently sustaining hand burns that underwent skin grafting. Greater public awareness of the danger is indicated and measures to prevent such injuries should be addressed by appropriate authorities. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  11. Chemical vapor deposition of mullite coatings

    Science.gov (United States)

    Sarin, Vinod; Mulpuri, Rao

    1998-01-01

    This invention is directed to the creation of crystalline mullite coatings having uniform microstructure by chemical vapor deposition (CVD). The process comprises the steps of establishing a flow of reactants which will yield mullite in a CVD reactor, and depositing a crystalline coating from the reactant flow. The process will yield crystalline coatings which are dense and of uniform thickness.

  12. Thermodynamics of incongruently vaporizing tungsten diselenide

    Energy Technology Data Exchange (ETDEWEB)

    Schiffman, R.A.; Franzen, H.F.; Ziegler, R.J.

    1982-03-01

    The incongruent vaporization of WSe/sub 2/ was investigated by a simultaneous weight-loss-mass-spectrometric Knudsen effusion technique in the temperature range 1290-1720 K. For the reaction (1/2)WSe/sub 2/(s) ..-->.. (1/2)W(s) + Se(g), ..delta..H/sub 298//sup 0/ = 311 +/- 3 kJ/mol.

  13. Multilead, Vaporization-Cooled Soldering Heat Sink

    Science.gov (United States)

    Rice, John

    1995-01-01

    Vaporization-cooled heat sink proposed for use during soldering of multiple electrical leads of packaged electronic devices to circuit boards. Heat sink includes compliant wicks held in grooves on edges of metal fixture. Wicks saturated with water. Prevents excessive increases in temperature at entrances of leads into package.

  14. Solvent-vapor-assisted imprint lithography

    NARCIS (Netherlands)

    Voicu, Nicoleta E.; Ludwigs, Sabine; Crossland, Edward J. W.; Andrew, Piers; Steiner, Ullrich

    2007-01-01

    Sub-micrometer features are replicated into high-molecular-weight polymer resists by using solvent-assisted nanoimprint lithography (see figure). By swelling the polymer in a controlled solvent-vapor atmosphere, millibar pressures and ambient temperatures are sufficient to achieve high-fidelity

  15. Vaporization of synthetic fuels. Final report. [Thesis

    Energy Technology Data Exchange (ETDEWEB)

    Sirignano, W.A.; Yao, S.C.; Tong, A.Y.; Talley, D.

    1983-01-01

    The problem of transient droplet vaporization in a hot convective environment is examined. The main objective of the present study is to develop an algorithm for the droplet vaporization which is simple enough to be feasibly incorporated into a complete spray combustion analysis and yet will also account for the important physics such as liquid-phase internal circulation, unsteady droplet heating and axisymmetric gas-phase convection. A simplified liquid-phase model has been obtained based on the assumption of the existence of a Hill's spherical vortex inside the droplet together with some approximations made in the governing diffusion equation. The use of the simplified model in a spray situation has also been examined. It has been found that droplet heating and vaporization are essentially unsteady and droplet temperature is nonuniform for a significant portion of its lifetime. It has also been found that the droplet vaporization characteristic can be quite sensitive to the particular liquid-phase and gas-phase models. The results of the various models are compared with the existing experimental data. Due to large scattering in the experimental measurements, particularly the droplet diameter, no definite conclusion can be drawn based on the experimental data. Finally, certain research problems which are related to the present study are suggested for future studies.

  16. Atomic lithium vapor laser isotope separation

    CERN Document Server

    Olivares, I E

    2002-01-01

    An atomic vapor laser isotope separation in lithium was performed using tunable diode lasers. The method permits also the separation of the isotopes between the sup 6 LiD sub 2 and the sup 7 LiD sub 1 lines using a self-made mass separator which includes a magnetic sector and an ion beam designed for lithium. (Author)

  17. Vaporization of fault water during seismic slip

    Science.gov (United States)

    Chen, Jianye; Niemeijer, André R.; Fokker, Peter A.

    2017-06-01

    Laboratory and numerical studies, as well as field observations, indicate that phase transitions of pore water might be an important process in large earthquakes. We present a model of the thermo-hydro-chemo-mechanical processes, including a two-phase mixture model to incorporate the phase transitions of pore water, occurring during fast slip (i.e., a natural earthquake) in order to investigate the effects of vaporization on the coseismic slip. Using parameters from typical natural faults, our modeling shows that vaporization can indeed occur at the shallow depths of an earthquake, irrespective of the wide variability of the parameters involved (sliding velocity, friction coefficient, gouge permeability and porosity, and shear-induced dilatancy). Due to the fast kinetics, water vaporization can cause a rapid slip weakening even when the hydrological conditions of the fault zone are not favorable for thermal pressurization, e.g., when permeability is high. At the same time, the latent heat associated with the phase transition causes the temperature rise in the slip zone to be buffered. Our parametric analyses reveal that the amount of frictional work is the principal factor controlling the onset and activity of vaporization and that it can easily be achieved in earthquakes. Our study shows that coseismic pore fluid vaporization might have played important roles at shallow depths of large earthquakes by enhancing slip weakening and buffering the temperature rise. The combined effects may provide an alternative explanation for the fact that low-temperature anomalies were measured in the slip zones at shallow depths of large earthquakes.

  18. Plasma Spray-Physical Vapor Deposition (PS-PVD) of Ceramics for Protective Coatings

    Science.gov (United States)

    Harder, Bryan J.; Zhu, Dongming

    2011-01-01

    In order to generate advanced multilayer thermal and environmental protection systems, a new deposition process is needed to bridge the gap between conventional plasma spray, which produces relatively thick coatings on the order of 125-250 microns, and conventional vapor phase processes such as electron beam physical vapor deposition (EB-PVD) which are limited by relatively slow deposition rates, high investment costs, and coating material vapor pressure requirements. The use of Plasma Spray - Physical Vapor Deposition (PS-PVD) processing fills this gap and allows thin (coatings of less than 100 microns to be generated with the flexibility to tailor microstructures by changing processing conditions. Coatings of yttria-stabilized zirconia (YSZ) were applied to NiCrAlY bond coated superalloy substrates using the PS-PVD coater at NASA Glenn Research Center. A design-of-experiments was used to examine the effects of process variables (Ar/He plasma gas ratio, the total plasma gas flow, and the torch current) on chamber pressure and torch power. Coating thickness, phase and microstructure were evaluated for each set of deposition conditions. Low chamber pressures and high power were shown to increase coating thickness and create columnar-like structures. Likewise, high chamber pressures and low power had lower growth rates, but resulted in flatter, more homogeneous layers

  19. Study of optical techniques for the Ames unitary wind tunnels. Part 2: Light sheet and vapor screen

    Science.gov (United States)

    Lee, George

    1992-01-01

    Light sheet and vapor screen methods have been studied with particular emphasis on those systems that have been used in large transonic and supersonic wind tunnels. The various fluids and solids used as tracers or light scatters and the methods for tracing generation have been studied. Light sources from high intensity lamps and various lasers have been surveyed. Light sheet generation and projection methods were considered. Detectors and location of detectors were briefly studied. A vapor screen system and a technique for location injection of tracers for the NASA Ames 9 by 7 foot Supersonic Wind Tunnel were proposed.

  20. Employment of vapor pressure data in the description of vapor-liquid equilibrium with direct method

    Energy Technology Data Exchange (ETDEWEB)

    Morbidelli, M.; Carra, S.

    1981-07-01

    A general procedure for inserting vapor-pressure data of pure components into equations of state provides a straightforward scheme for the extension of direct methods to the study of phase equilibria of polar mixtures and of solutions containing nonvolatile electrolytes. It makes the equation of state applicable to all compounds and to the shole temperature range and more accurate in the prediction of both multicomponent and pure vapor-liquid equilibria.

  1. Vaporous Hydrogen Peroxide (VHP) Decontamination of a C-141B Starlifter Aircraft: Validation of VHP and Modified VHP (mVHP) Fumigation Decontamination Process via VHP-Sensor, Biological Indicator, and HD Simulant in a Large-Scale Environment

    Science.gov (United States)

    2007-03-01

    21 18. G. stearothermophilus ATCC 7953VHP Exposure Test Results ..................... 33 19. Vapor Cup ...provided forced air circulation. An anemometer , located downstream of the main blower, measured and recorded the airflow generated by the mVHP system...Station) Height (inches) 1 670 8 2 890 48 3 1230 72 3.4.2 Chemical Warfare Agent Simulant Vapor Analysis Vapor cups were prepared for residual chemical

  2. Vapor-modulated heat pipe for improved temperature control

    Science.gov (United States)

    Edwards, D. K.; Eninger, J. E.; Ludeke, E. E.

    1978-01-01

    Dryout induced by vapor throttling makes control of equipment temperature less dependent on variations in sink environment. Mechanism controls flow of vapor in heat pipe by using valve in return path to build difference in pressure and also difference in saturation temperature of the vapor. In steady state, valve closes just enough to produce partial dryout that achieves required temperature drop.

  3. 40 CFR 52.255 - Gasoline transfer vapor control.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Gasoline transfer vapor control. 52.255... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.255 Gasoline transfer vapor control. (a) “Gasoline” means any petroleum distillate having a Reid vapor pressure of 4 pounds or...

  4. 40 CFR 52.787 - Gasoline transfer vapor control.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Gasoline transfer vapor control. 52.787... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.787 Gasoline transfer vapor control. (a) Gasoline means any petroleum distillate having a Reid vapor pressure of 4 pounds or...

  5. 21 CFR 888.4220 - Cement monomer vapor evacuator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a device intended for use during surgery to contain or...

  6. Membrane-assisted vapor stripping: energy efficient hybrid distillation-vapor permeation process for alcohol-water separation

    Science.gov (United States)

    BACKGROUND: Energy efficient alternatives to distillation for alcohol recovery from dilute solution are needed to improve biofuel sustainability. A process integrating steam stripping with a vapor compression step and a vapor permeation membrane separation step is proposed. The...

  7. Effects of vapor pressure/velocity and concentration on condensation heat transfer for steam-ethanol vapor mixture

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Junjie; Yang, Yusen; Hu, Shenhua; Zhen, Kejian; Liu, Jiping [Xi' an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an (China)

    2007-11-15

    When a steam-ethanol vapor mixture condenses on a vertical flat plate, the form of the condensate film changes and many drops are created. This non-film condensation is called pseudo-dropwise or Marangoni condensation. This paper aims to study the main influencing factors on the Marangoni condensation of steam-ethanol vapor.The factors include the ethanol concentration, vapor pressure, vapor velocity and vapor-to-surface temperature difference. The experiments show that the heat transfer coefficient has a maximum value of approximately 42 kW/m{sup 2} K when the ethanol concentration is 1%. At the low concentrations of 0.5, 1, 5.1 and 9.8%, the condensation heat transfer is greater than for pure steam. In addition, the heat transfer for all vapor mixtures increases with both the rise of vapor pressure and vapor velocity. (orig.)

  8. Effects of vapor pressure/velocity and concentration on condensation heat transfer for steam-ethanol vapor mixture

    Science.gov (United States)

    Yan, Junjie; Yang, Yusen; Hu, Shenhua; Zhen, Kejian; Liu, Jiping

    2007-11-01

    When a steam-ethanol vapor mixture condenses on a vertical flat plate, the form of the condensate film changes and many drops are created. This non-film condensation is called pseudo-dropwise or Marangoni condensation. This paper aims to study the main influencing factors on the Marangoni condensation of steam-ethanol vapor.The factors include the ethanol concentration, vapor pressure, vapor velocity and vapor-to-surface temperature difference. The experiments show that the heat transfer coefficient has a maximum value of approximately 42 kW/m2 K when the ethanol concentration is 1%. At the low concentrations of 0.5, 1, 5.1 and 9.8%, the condensation heat transfer is greater than for pure steam. In addition, the heat transfer for all vapor mixtures increases with both the rise of vapor pressure and vapor velocity.

  9. Membrane-assisted vapor stripping: energy efficient hybrid distillation-vapor permeation process for alcohol-water separation

    Science.gov (United States)

    BACKGROUND: Energy efficient alternatives to distillation for alcohol recovery from dilute solution are needed to improve biofuel sustainability. A process integrating steam stripping with a vapor compression step and a vapor permeation membrane separation step is proposed. The...

  10. Atmospheric sugar alcohols: evaporation rates and saturation vapor pressures

    DEFF Research Database (Denmark)

    Bilde, Merete; Zardini, Alessandro Alessio; Hong, Juan

    volatile organic molecules. Saturation vapor pressure and the associated temperature dependence (dH) are key parameters for improving predictive atmospheric models. In this work we combine experiments and thermodynamic modeling to investigate these parameters for a series of polyols, so-called sugar......The atmospheric partitioning between gas and condensed phase of organic molecules is poorly understood, and discrepancies exist between predicted and observed concentrations of secondary organic aerosols. A key problem is the lack of information about thermodynamic properties of semi- and low...... alcohols. These polyols are common in the water soluble fraction of atmospheric aerosols. In our experimental system sub-micron particles are generated by nebulization from aqueous solution, and a mono disperse fraction of the aerosol is selected using a differential mobility analyzer. The particles...

  11. The experimental and numerical investigation of a grooved vapor chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ming [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China); Liu Zhongliang [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)], E-mail: liuzhl@bjut.edu.cn; Ma Guoyuan [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)

    2009-02-15

    An effective thermal spreader can achieve more uniform heat flux distribution and thus enhance heat dissipation of heat sinks. Vapor chamber is one of highly effective thermal spreaders. In this paper, a novel grooved vapor chamber was designed. The grooved structure of the vapor chamber can improve its axial and radial heat transfer and also can form the capillary loop between condensation and evaporation surfaces. The effect of heat flux, filling amount and gravity to the performance of this vapor chamber is studied by experiment. From experiment, we also obtained the best filling amount of this grooved vapor chamber. By comparing the thermal resistance of a solid copper plate with that of the vapor chamber, it is suggested that the critical heat flux condition should be maintained to use vapor chamber as efficient thermal spreaders for electronics cooling. A two-dimensional heat and mass transfer model for the grooved vapor chamber is developed. The numerical simulation results show the thickness distribution of liquid film in the grooves is not uniform. The temperature and velocity field in vapor chamber are obtained. The thickness of the liquid film in groove is mainly influenced by pressure of vapor and liquid beside liquid-vapor interface. The thin liquid film in heat source region can enhance the performance of vapor chamber, but if the starting point of liquid film is backward beyond the heat source region, the vapor chamber will dry out easily. The optimal filling ratio should maintain steady thin liquid film in heat source region of vapor chamber. The vapor condenses on whole condensation surface, so that the condensation surface achieves great uniform temperature distribution. By comparing the experimental results with numerical simulation results, the reliability of the numerical model can be verified.

  12. The Influence of Chemical Composition on LNG Pool Vaporization

    Directory of Open Access Journals (Sweden)

    Yu Zhidong

    2017-01-01

    Full Text Available A model is used to examine the influence of chemical composition on the vaporization rate of LNG during spreading. Calculations have been performed whereby the vaporization rate of the LNG mixtures has been compared to the vaporization of pure methane under the initial conditions. The detailed results indicate that the vaporization rate LNG mixture is different to that of pure methane. LNG as the liquid mixture gets rich in ethane and isobaric latent heat increases rapidly, leading to the rate vaporization of LNG decrease in compared to pure methane.

  13. Cumulus convection and the terrestrial water-vapor distribution

    Science.gov (United States)

    Donner, Leo J.

    1988-01-01

    Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.

  14. Vapor Pressure of Pentafluoroethane and Trifluoroiodomethane

    Institute of Scientific and Technical Information of China (English)

    Zhang Chang; Duan Yuanyuan; Shi Lin; Zhu Mingshan; Han Lizhong

    2001-01-01

    Pentafluoroethane (HFC-125) and trifluoroiodomethane (CF3I) are considered as promising refrigerant alternatives, especially as components in mixtures, to replace CFCs or HCFCs. Effective uses of HFC-125 and CF3I require that the thermophysical properties be accurately measured. In the present work, vapor pressure data of HFC-125 and CF3I have been measured in the temperature range from 292 to 337 K and 288 to 336 K,respectively. Maximum total pressure uncertainty of HFC-125 data is estimated to be within ±1.2 kPa and ±780 Pa for CF3I. Based on the data set and literature values, the vapor pressure equations for HFC-125 and CF3I have been developed. The relative deviation of the equations correlate the measurements within 0.022% for HFC-125 and 0.068% for CF3I, respectively.

  15. Modelling vaporous cavitation on fluid transients

    CERN Document Server

    Shu, Jian-Jun

    2014-01-01

    A comprehensive study of the problem of modelling vaporous cavitation in transmission lines is presented. The two-phase homogeneous equilibrium vaporous cavitation model which has been developed is compared with the conventional column separation model. The latter predicts unrealistically high pressure spikes because of a conflict arising from the prediction of negative cavity sizes if the pressure is not permitted to fall below the vapour pressure, or the prediction of negative absolute pressures if the cavity size remains positive. This is verified by a comparison of predictions with previously published experimental results on upstream, midstream and downstream cavitation. The new model has been extended to include frequency-dependent friction. The characteristics predicted by the frequency-dependent friction model show close correspondence with experimental data.

  16. Experimental study of external fuel vaporization

    Science.gov (United States)

    Szetela, E. J.; Tevelde, J. A.

    1982-01-01

    The fuel properties used in the design of a flash vaporization system for aircraft gas turbine engines were evaluated in experiments using a flowing system to determine critical temperature and pressure, boiling points, dew points, heat transfer coefficients, deposit formation rates, and deposit removal. Three fuels were included in the experiments: Jet-A, an experimental referree broad specification fuel, and a premium No. 2 diesel fuel. Engine conditions representing a NASA Energy Efficient Engine at sea-level take-off, cruise, and idle were simulated in the vaporization system and it was found that single phase flow was maintained in the heat exchanger and downstream of the throttle. Deposits encountered in the heat exchanger represented a thermal resistance as high as 1300 sq M K/watt and a deposit formation rate over 1000 gC/sq cm hr.

  17. Atomic vapor spectroscopy in integrated photonic structures

    CERN Document Server

    Ritter, Ralf; Pernice, Wolfram; Kübler, Harald; Pfau, Tilman; Löw, Robert

    2015-01-01

    We investigate an integrated optical chip immersed in atomic vapor providing several waveguide geometries for spectroscopy applications. The narrow-band transmission through a silicon nitride waveguide and interferometer is altered when the guided light is coupled to a vapor of rubidium atoms via the evanescent tail of the waveguide mode. We use grating couplers to couple between the waveguide mode and the radiating wave, which allow for addressing arbitrary coupling positions on the chip surface. The evanescent atom-light interaction can be numerically simulated and shows excellent agreement with our experimental data. This work demonstrates a next step towards miniaturization and integration of alkali atom spectroscopy and provides a platform for further fundamental studies of complex waveguide structures.

  18. Apparatus and method for thermal power generation

    Science.gov (United States)

    Cohen, Paul; Redding, Arnold H.

    1978-01-01

    An improved thermal power plant and method of power generation which minimizes thermal stress and chemical impurity buildup in the vaporizing component, particularly beneficial under loss of normal feed fluid and startup conditions. The invention is particularly applicable to a liquid metal fast breeder reactor plant.

  19. Vapor-phase heat-transport system

    Energy Technology Data Exchange (ETDEWEB)

    Hedstrom, J.C.

    1983-01-01

    A vapor-phase heat-transport system is being tested in one of the passive test cells at Los Alamos. The system consists of one selective-surface collector and a condenser inside a water storage tank. The refrigerant, R-11, can be returned to the collector by gravity or with a pump. Results from several operating configurations are presented, together with a comparison with other passive systems. A new self-pumping concept is presented.

  20. Vapor Crystal Growth (VCG) experiment Cell

    Science.gov (United States)

    1992-01-01

    The image shows a test cell of Crystal Growth experiment inside the Vapor Crystal Growth System (VCGS) furnace aboard the STS-42, International Microgravity Laboratory-1 (IML-1), mission. The goal of IML-1, a pressurized marned Spacelab module, was to explore in depth the complex effects of weightlessness of living organisms and materials processing. More than 200 scientists from 16 countires participated in the investigations.

  1. Kinetics of metal salt vapor lasers

    Energy Technology Data Exchange (ETDEWEB)

    Kazarian, M.A.; Trofimov, A.N.

    1979-02-01

    A kinetic model is constructed for lasers operating on metal salt vapors. Different operating regimes of these lasers are considered, and it is shown that during transition from double-pulse regime to pulse-train regime or regular-pulse regime it is necessary to take into account accumulation effects. Numerical calculations for copper halogenides are carried out. It is shown how different operating regimes have widely different lasing conditions. This is due to the accumulation effects mentioned above.

  2. Making Ceramic Fibers By Chemical Vapor

    Science.gov (United States)

    Revankar, Vithal V. S.; Hlavacek, Vladimir

    1994-01-01

    Research and development of fabrication techniques for chemical vapor deposition (CVD) of ceramic fibers presented in two reports. Fibers of SiC, TiB2, TiC, B4C, and CrB2 intended for use as reinforcements in metal-matrix composite materials. CVD offers important advantages over other processes: fibers purer and stronger and processed at temperatures below melting points of constituent materials.

  3. Laser Velocimetry of Chemical Vapor Deposition Flows

    Science.gov (United States)

    1993-01-01

    Laser velocimetry (LV) is being used to measure the gas flows in chemical vapor deposition (CVD) reactors. These gas flow measurements can be used to improve industrial processes in semiconductor and optical layer deposition and to validate numerical models. Visible in the center of the picture is the graphite susceptor glowing orange-hot at 600 degrees C. It is inductively heated via the copper cool surrounding the glass reactor.

  4. Biofiltration of solvent vapors from air

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Young-sook.

    1993-01-01

    For various industrial solvent vapors, biofiltration promises to offer a cost-effective emission control technology. Exploiting the full potential of this technology will help attain the goals of the Clean Air Act Amendments of 1990. Concentrating on large volumes of volatile industrial solvents, stable multicomponent microbial enrichments capable of growing a mineral medium with solvent vapors as their only source of carbon and energy were obtained from soil and sewage sludge. These consortia were immobilized on an optimized porous solid support (ground peat moss and perlite). The biofilter material was packed in glass columns connected to an array of pumps and flow meters that allowed the independent variation of superficial velocity and solvent vapor concentrations. In various experiments, single solvents, such as methanol, butanol, acetonitrile, hexane and nitrobenzene, and solvent mixtures, such as benzene-toluene-xylene (BTX) and chlorobenzene-o-dichlorobenzene (CB/DCB) were biofiltered with rates ranging from 15 to334 g solvent removed per m[sup 3] filter volume /h. Pressure drops were low to moderate (0-10 mmHg/m) and with periodic replacement of moisture, the biofiltration activity could be maintained for a period of several months. The experimental data on methanol biofiltration were subjected to mathematical analysis and modeling by the group of Dr. Baltzis at NJIT for a better understanding and a possible scale up of solvent vapor biofilters. In the case of chlorobenzenes and nitrobenzene, the biofilter columns had to be operated with water recirculation in a trickling filter mode. To prevent inactivation of the trickling filter by acidity during CB/DCB removal, pH control was necessary, and the removal rate of CB/DCB was strongly influenced by the flow rate of the recyling water. Nitrobenzene removal in a trickling filter did not require pH control, since the nitro group was reduced and volatilized as ammonia.

  5. Optical droplet vaporization of nanoparticle-loaded stimuli-responsive microbubbles

    Science.gov (United States)

    Si, Ting; Li, Guangbin; Wu, Qiang; Zhu, Zhiqiang; Luo, Xisheng; Xu, Ronald X.

    2016-03-01

    A capillary co-flow focusing process is developed to generate stimuli-responsive microbubbles (SRMs) that comprise perfluorocarbon (PFC) suspension of silver nanoparticles (SNPs) in a lipid shell. Upon continuous laser irradiation at around their surface plasmon resonance band, the SNPs effectively absorb electromagnetic energy, induce heat accumulation in SRMs, trigger PFC vaporization, and eventually lead to thermal expansion and fragmentation of the SRMs. This optical droplet vaporization (ODV) process is further simulated by a theoretical model that combines heat generation of SNPs, phase change of PFC, and thermal expansion of SRMs. The model is validated by benchtop experiments, where the ODV process is monitored by microscopic imaging. The effects of primary process parameters on behaviors of ODV are predicted by the theoretical model, indicating the technical feasibility for process control and optimization in future drug delivery applications.

  6. Heat transfer by condensation of low pressure metal vapors.

    Science.gov (United States)

    Huang, Y. S.; Lyman, F. A.; Lick, W. J.

    1972-01-01

    The film condensation of low pressure metal vapors on isothermal vertical flat plates or tubes is considered. The liquid film is treated as a thin layer in which the acceleration and pressure forces are negligible and across which the temperature distribution is linear. The average behavior of the vapor is found from the linearized one-dimensional vapor flow equations. In order to calculate the rate of condensation, a consistent distribution function for the vapor particles at the liquid-vapor interface is necessary and is determined. The result of the analysis is a set of algebraic equations from which one can predict the condensation rate of low pressure metal vapors. A large but continuous temperature decrease in the vapor is predicted and calculated.

  7. Water vapor distribution in protoplanetary disks

    CERN Document Server

    Du, Fujun

    2014-01-01

    Water vapor has been detected in protoplanetary disks. In this work we model the distribution of water vapor in protoplanetary disks with a thermo-chemical code. For a set of parameterized disk models, we calculate the distribution of dust temperature and radiation field of the disk with a Monte Carlo method, and then solve the gas temperature distribution and chemical composition. The radiative transfer includes detailed treatment of scattering by atomic hydrogen and absorption by water of Lyman alpha photons, since the Lyman alpha line dominates the UV spectrum of accreting young stars. In a fiducial model, we find that warm water vapor with temperature around 300 K is mainly distributed in a small and well-confined region in the inner disk. The inner boundary of the warm water region is where the shielding of UV field due to dust and water itself become significant. The outer boundary is where the dust temperature drops below the water condensation temperature. A more luminous central star leads to a more ...

  8. Steady State Vapor Bubble in Pool Boiling

    Science.gov (United States)

    Zou, An; Chanana, Ashish; Agrawal, Amit; Wayner, Peter C.; Maroo, Shalabh C.

    2016-02-01

    Boiling, a dynamic and multiscale process, has been studied for several decades; however, a comprehensive understanding of the process is still lacking. The bubble ebullition cycle, which occurs over millisecond time-span, makes it extremely challenging to study near-surface interfacial characteristics of a single bubble. Here, we create a steady-state vapor bubble that can remain stable for hours in a pool of sub-cooled water using a femtosecond laser source. The stability of the bubble allows us to measure the contact-angle and perform in-situ imaging of the contact-line region and the microlayer, on hydrophilic and hydrophobic surfaces and in both degassed and regular (with dissolved air) water. The early growth stage of vapor bubble in degassed water shows a completely wetted bubble base with the microlayer, and the bubble does not depart from the surface due to reduced liquid pressure in the microlayer. Using experimental data and numerical simulations, we obtain permissible range of maximum heat transfer coefficient possible in nucleate boiling and the width of the evaporating layer in the contact-line region. This technique of creating and measuring fundamental characteristics of a stable vapor bubble will facilitate rational design of nanostructures for boiling enhancement and advance thermal management in electronics.

  9. Marketing Practices of Vapor Store Owners

    Science.gov (United States)

    Gowin, Mary; Wann, Taylor Franklin

    2015-01-01

    Objectives. We examined the marketing strategies for local vapor stores in a large metropolitan area in Oklahoma. Methods. Vapor store owners or managers (n = 33) participated in individual interviews regarding marketing practices in 2014. We asked owners about their marketing strategies and the groups they targeted. We transcribed the interviews and analyzed them for themes. Results. Store owners used a variety of marketing strategies to bring new customers to their stores and keep current customers coming back. These marketing strategies showed many parallels to tobacco industry strategies. Most owners engaged in some form of traditional marketing practices (e.g., print media), but only a few used radio or television advertising because of budget constraints. Owners used social media and other forms of electronic communication, pricing discounts and specials, and loyalty programs. Owners also had booths at local events, sponsored community events, and hosted them in their stores. Owners attempted to target different groups of users, such as college students and long-term smokers. Conclusions. Local vapor store marketing practices closely resemble current and former tobacco industry marketing strategies. Surveillance of marketing practices should include local and Web-based strategies. PMID:25880960

  10. Steady State Vapor Bubble in Pool Boiling.

    Science.gov (United States)

    Zou, An; Chanana, Ashish; Agrawal, Amit; Wayner, Peter C; Maroo, Shalabh C

    2016-02-03

    Boiling, a dynamic and multiscale process, has been studied for several decades; however, a comprehensive understanding of the process is still lacking. The bubble ebullition cycle, which occurs over millisecond time-span, makes it extremely challenging to study near-surface interfacial characteristics of a single bubble. Here, we create a steady-state vapor bubble that can remain stable for hours in a pool of sub-cooled water using a femtosecond laser source. The stability of the bubble allows us to measure the contact-angle and perform in-situ imaging of the contact-line region and the microlayer, on hydrophilic and hydrophobic surfaces and in both degassed and regular (with dissolved air) water. The early growth stage of vapor bubble in degassed water shows a completely wetted bubble base with the microlayer, and the bubble does not depart from the surface due to reduced liquid pressure in the microlayer. Using experimental data and numerical simulations, we obtain permissible range of maximum heat transfer coefficient possible in nucleate boiling and the width of the evaporating layer in the contact-line region. This technique of creating and measuring fundamental characteristics of a stable vapor bubble will facilitate rational design of nanostructures for boiling enhancement and advance thermal management in electronics.

  11. Experimental Study on Unconfined Vapor Cloud Explosion

    Institute of Scientific and Technical Information of China (English)

    毕明树; ABULITI; Abudula

    2003-01-01

    An experimental system was setup to study the pressure field of unconfined vapor cloud explosions.The semi-spherical vapor clouds were formed by slotted 0.02mm polyethylene film.In the Center of the cloud was an ignition electrode that met ISO6164"Explosion protection System" and NFPA68 "Guide for Venting of Deflagrations". A data-acquisition system,with dymame responding time less than 0.001s with 0.5% accuracy,recorded the pressure-time diagram of acetylene-air mixture explosion with stoichiometrical ratio.The initial cloud diameters varied from 60cm to 300cm.Based on the analysis of experimental data,the quantitative relationship is obtained for the cloud explosion pressure,the cloud radius and the distance from ignition point .Present results provide a useful way to evaluate the building damage caused by unconfined vapor cloud explosions and to determine the indispensable explosion grade in the application of multi-energy model.

  12. Marketing practices of vapor store owners.

    Science.gov (United States)

    Cheney, Marshall; Gowin, Mary; Wann, Taylor Franklin

    2015-06-01

    We examined the marketing strategies for local vapor stores in a large metropolitan area in Oklahoma. Vapor store owners or managers (n = 33) participated in individual interviews regarding marketing practices in 2014. We asked owners about their marketing strategies and the groups they targeted. We transcribed the interviews and analyzed them for themes. Store owners used a variety of marketing strategies to bring new customers to their stores and keep current customers coming back. These marketing strategies showed many parallels to tobacco industry strategies. Most owners engaged in some form of traditional marketing practices (e.g., print media), but only a few used radio or television advertising because of budget constraints. Owners used social media and other forms of electronic communication, pricing discounts and specials, and loyalty programs. Owners also had booths at local events, sponsored community events, and hosted them in their stores. Owners attempted to target different groups of users, such as college students and long-term smokers. Local vapor store marketing practices closely resemble current and former tobacco industry marketing strategies. Surveillance of marketing practices should include local and Web-based strategies.

  13. Water vapor release from biomass combustion

    Directory of Open Access Journals (Sweden)

    R. S. Parmar

    2008-10-01

    Full Text Available We report on the emission of water vapor from biomass combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are referenced to carbon in the biomass. The investigated fuel types include hardwood (oak and African musasa, softwood (pine and spruce, partly with green needles, and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7, indicating the presence of water that is not chemically bound. This non-bound biomass moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biomass contributes significantly to the water vapor in biomass burning emissions, and its influence on the behavior of fire plumes and pyro-cumulus clouds needs to be evaluated.

  14. Vapor Sensing Theoretical Study on Optical Microcavities

    Institute of Scientific and Technical Information of China (English)

    ZHANG Le-xin; ZHANG Ran; LI Zhi-quan

    2007-01-01

    When the organic vapors absorbed to the surface of porous silicon(PS), capillary condensation takes place due to the porous structure of the PS layer, accordingly resulting in the effective refractive index changing. For PS multi-layer microcavities, the different resonant peaks shift in the reflectivity spectrum of porous silicon microcavities(PSMs). The optical sensing model is set up by applying Bruggeman effective medium approximation theory, capillary condensation process and transfer matrix theoretically analytical method of one-dimensional photonic crystals. At the same time, comprehensively researched on are the sensing characteristics of PSMs which are exposed to give concentration organic vapors. At last, made is the theoretical simulation for sensing model of the PSMs in case of saturation by using computer numerical calculation, and found is the linearity relation between the refractive index of organic solvent and the peak-shift. At the same time deduced is the peak-shift as a function of the concentration of ethanol vapors.

  15. Distribution of Water Vapor in Molecular Clouds

    CERN Document Server

    Melnick, Gary J; Snell, Ronald L; Bergin, Edwin A; Hollenbach, David J; Kaufman, Michael J; Li, Di; Neufeld, David A

    2010-01-01

    We report the results of a large-area study of water vapor along the Orion Molecular Cloud ridge, the purpose of which was to determine the depth-dependent distribution of gas-phase water in dense molecular clouds. We find that the water vapor measured toward 77 spatial positions along the face-on Orion ridge, excluding positions surrounding the outflow associated with BN/KL and IRc2, display integrated intensities that correlate strongly with known cloud surface tracers such as CN, C2H, 13CO J =5-4, and HCN, and less well with the volume tracer N2H+. Moreover, at total column densities corresponding to Av < 15 mag., the ratio of H2O to C18O integrated intensities shows a clear rise approaching the cloud surface. We show that this behavior cannot be accounted for by either optical depth or excitation effects, but suggests that gas-phase water abundances fall at large Av. These results are important as they affect measures of the true water-vapor abundance in molecular clouds by highlighting the limitations...

  16. Nuclear vapor thermal reactor propulsion technology

    Science.gov (United States)

    Maya, Isaac; Diaz, Nils J.; Dugan, Edward T.; Watanabe, Yoichi; McClanahan, James A.; Wen-Hsiung Tu, Carman, Robert L.

    1993-01-01

    The conceptual design of a nuclear rocket based on the vapor core reactor is presented. The Nuclear Vapor Thermal Rocket (NVTR) offers the potential for a specific impulse of 1000 to 1200 s at thrust-to-weight ratios of 1 to 2. The design is based on NERVA geometry and systems with the solid fuel replaced by uranium tetrafluoride (UF4) vapor. The closed-loop core does not rely on hydrodynamic confinement of the fuel. The hydrogen propellant is separated from the UF4 fuel gas by graphite structure. The hydrogen is maintained at high pressure (˜100 atm), and exits the core at 3,100 K to 3,500 K. Zirconium carbide and hafnium carbide coatings are used to protect the hot graphite from the hydrogen. The core is surrounded by beryllium oxide reflector. The nuclear reactor core has been integrated into a 75 klb engine design using an expander cycle and dual turbopumps. The NVTR offers the potential for an incremental technology development pathway to high performance gas core reactors. Since the fuel is readily available, it also offers advantages in the initial cost of development, as it will not require major expenditures for fuel development.

  17. Physical Vapor Deposition of Thin Films

    Science.gov (United States)

    Mahan, John E.

    2000-01-01

    A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

  18. Laser vaporization in the management of CIN.

    Science.gov (United States)

    Vetrano, G; Ciolli, P; Carboni, S; Scardamaglia, P; Aleandri, V; Verrico, M; Corosu, R

    2010-01-01

    To evaluate the effectiveness of laser CO2 vaporization in high-grade cervical intraepithelial neoplasias and to assess the diagnostic reliability of cytology, colposcopy, microbiology and HPV tests in predicting recurrence in a long-term outcome. Forty-four patients affectd by high-grade cervical intraepithelial neoplasia (HG-CIN) were submitted to laser CO2 vaporization and followed-up a minimum of five years. Vaginal smears for microbiological examination were detected. HPV testing was performed by polymerase chain reaction (PCR). The average age of the patients was 19.5 years (range 15-24). The cure rate after a single treatment was 95%. Two cases (5%) revealed HG-CIN persistence after three months. The five year follow-up of all cases submitted to a second laser procedure revealed negative cytologic and colposcopic findings. A higher degree of expertise and experience from the colposcopist and long-term follow-up proves the effectiveness of laser vaporization in the management of CIN in young women. It has been suggested that HPV infection alone may not be sufficient to promote carcinogenesis and that other cofactors could be involved. Microbiological tests are important to identify and treat any inflammation which might represent a cofactor of HPV infection in the pathogenesis of cervical dysplasia. Cytocolposcopic long-term follow-up, microbiological and HPV tests can improve regression of disease.

  19. Designing polymer surfaces via vapor deposition

    Directory of Open Access Journals (Sweden)

    Ayse Asatekin

    2010-05-01

    Full Text Available Chemical Vapor Deposition (CVD methods significantly augment the capabilities of traditional surface modification techniques for designing polymeric surfaces. In CVD polymerization, the monomer(s are delivered to the surface through the vapor phase and then undergo simultaneous polymerization and thin film formation. By eliminating the need to dissolve macromolecules, CVD enables insoluble polymers to be coated and prevents solvent damage to the substrate. Since de-wetting and surface tension effects are absent, CVD coatings conform to the geometry of the underlying substrate. Hence, CVD polymers can be readily applied to virtually any substrate: organic, inorganic, rigid, flexible, planar, three-dimensional, dense, or porous. CVD methods integrate readily with other vacuum processes used to fabricate patterned surfaces and devices. CVD film growth proceeds from the substrate up, allowing for interfacial engineering, real-time monitoring, thickness control, and the synthesis of films with graded composition. This article focuses on two CVD polymerization methods that closely translate solution chemistry to vapor deposition; initiated CVD and oxidative CVD. The basic concepts underlying these methods and the resultant advantages over other thin film coating techniques are described, along with selected applications where CVD polymers are an enabling technology.

  20. High-speed off-axis holographic cinematography with a copper-vapor-pumped dye laser.

    Science.gov (United States)

    Lauterborn, W; Judt, A; Schmitz, E

    1993-01-01

    A series of coherent light pulses is generated by pumping a dye laser with the pulsed output of a copper-vapor laser at rates of as much as 20 kHz. Holograms are recorded at this pulse rate on a rotating holographic plate. This technique of high-speed holographic cinematography is demonstrated by viewing the bubble filaments that appear in water under the action of a sound field of high intensity.

  1. Sirio.NET: A new tool for managing results in eddy current inspection of steam generators and heat exchangers; Sirio.NET: Una nueva herramienta para la gestion de resultados en las inspecciones por Corrientes Inducidas de los Generadores de Vapor y Cambiadores de Calor

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, M.; Marquez, A.; Rodriguez, A. L.

    2014-07-01

    The results management and control of the inspections by currents induced of tube bundles of components such as steam generators, heat exchangers, etc., by the large volume of data generated, requires the use of highly specialized tools of information management, based on database structures. (Author)

  2. Sparsity-driven tomographic reconstruction of atmospheric water vapor using GNSS and InSAR observations

    Science.gov (United States)

    Heublein, Marion; Alshawaf, Fadwa; Zhu, Xiao Xiang; Hinz, Stefan

    2016-04-01

    An accurate knowledge of the 3D distribution of water vapor in the atmosphere is a key element for weather forecasting and climate research. On the other hand, as water vapor causes a delay in the microwave signal propagation within the atmosphere, a precise determination of water vapor is required for accurate positioning and deformation monitoring using Global Navigation Satellite Systems (GNSS) and Interferometric Synthetic Aperture Radar (InSAR). However, due to its high variability in time and space, the atmospheric water vapor distribution is difficult to model. Since GNSS meteorology was introduced about twenty years ago, it has increasingly been used as a geodetic technique to generate maps of 2D Precipitable Water Vapor (PWV). Moreover, several approaches for 3D tomographic water vapor reconstruction from GNSS-based estimates using the simple least squares adjustment were presented. In this poster, we present an innovative and sophisticated Compressive Sensing (CS) concept for sparsity-driven tomographic reconstruction of 3D atmospheric wet refractivity fields using data from GNSS and InSAR. The 2D zenith wet delay (ZWD) estimates are obtained by a combination of point-wise estimates of the wet delay using GNSS observations and partial InSAR wet delay maps. These ZWD estimates are aggregated to derive realistic wet delay input data of 100 points as if corresponding to 100 GNSS sites within an area of 100 km × 100 km in the test region of the Upper Rhine Graben. The made-up ZWD values can be mapped into different elevation and azimuth angles. Using the Cosine transform, a sparse representation of the wet refractivity field is obtained. In contrast to existing tomographic approaches, we exploit sparsity as a prior for the regularization of the underdetermined inverse system. The new aspects of this work include both the combination of GNSS and InSAR data for water vapor tomography and the sophisticated CS estimation. The accuracy of the estimated 3D water

  3. Finding organic vapors - a Monte Carlo approach

    Science.gov (United States)

    Vuollekoski, Henri; Boy, Michael; Kerminen, Veli-Matti; Kulmala, Markku

    2010-05-01

    Aerosols have an important role in regulating the climate both directly by absorbing and scattering solar radiation, as well as indirectly by acting as cloud condensation nuclei. While it is known that their net effect on radiative forcing is negative, several key aspects remain mysterious. There exist plenty of known primary sources of particles due to both natural and man-made origin - for example desert dust, volcanic activity and tire debris. On the other hand, it has been shown that the formation of secondary particles, by nucleation from precursor vapors, is a frequent, global phenomenon. However, the very earliest steps in new particle formation - nucleation and early growth by condensation - have many big question marks on them. While several studies have indicated the importance of a sufficient concentration of sulphuric acid vapor for the process, it has also been noted that this is usually not enough. Heads have therefore turned to organic vapors, which in their multitude could explain various observed characteristics of new particle formation. But alas, the vast number of organic compounds, their complex chemistry and properties that make them difficult to measure, have complicated the quantifying task. Nevertheless, evidence of organic contribution in particles of all size classes has been found. In particular, a significant organic constituent in the very finest particles suggests the presence of a high concentration of very low-volatile organic vapors. In this study, new particle formation in the boreal forest environment of Hyytiälä, Finland, is investigated in a process model. Our goal is to quantify the concentration, to find the diurnal profile and to get hints of the identity of some organic vapors taking part in new particle formation. Previous studies on the subject have relied on data analysis of the growth rate of the observed particles. However, due to the coarse nature of the methods used to calculate growth rates, this approach has its

  4. Phosphorus- and boron-doped hydrogenated amorphous silicon films prepared using vaporized liquid cyclopentasilane

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Takashi, E-mail: mtakashi@jaist.ac.jp [Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, 923-1292 (Japan); Takagishi, Hideyuki; Shen, Zhongrong; Ohdaira, Keisuke; Shimoda, Tatsuya [Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, 923-1292 (Japan); Japan Science and Technology Agency, ALCA, Nomi, Ishikawa, 923-1211 (Japan)

    2015-08-31

    A simple, inexpensive method for fabricating a hydrogenated amorphous silicon (a-Si:H) film using thermal chemical vapor deposition from cyclopentasilane (CPS) at atmospheric pressure with a substrate temperature of 370 °C is described. The reactant gas was generated from liquid CPS by vaporization in the deposition chamber. The vaporized CPS gas was transformed immediately into a-Si:H film on a heated substrate. The a-Si:H films could be doped either n- or p-type by dissolving appropriate amounts of white phosphorus or decaborane, respectively, in the liquid CPS before vaporization. This process allows deposition of doped a-Si:H films of photovoltaic device-quality without the need for handling, storage, or transportation of large amounts of gaseous reactants. - Highlights: • B and P doped a-Si:H films made from liquid materials is presented. • Decaborane and white phosphorus is dissolved in the liquid materials. • A simple, inexpensive method for fabricating a-Si:H films using non-vacuum process. • The doped a-Si:H films with usable quality for photovoltaic devices are deposited.

  5. Electrospray droplet exposure to organic vapors: metal ion removal from proteins and protein complexes.

    Science.gov (United States)

    DeMuth, J Corinne; McLuckey, Scott A

    2015-01-20

    The exposure of aqueous nanoelectrospray droplets to various organic vapors can dramatically reduce sodium adduction on protein ions in positive ion mass spectra. Volatile alcohols, such as methanol, ethanol, and isopropanol lead to a significant reduction in sodium ion adduction but are not as effective as acetonitrile, acetone, and ethyl acetate. Organic vapor exposure in the negative ion mode, on the other hand, has essentially no effect on alkali ion adduction. Evidence is presented to suggest that the mechanism by which organic vapor exposure reduces alkali ion adduction in the positive mode involves the depletion of alkali metal ions via ion evaporation of metal ions solvated with organic molecules. The early generation of metal/organic cluster ions during the droplet desolvation process results in fewer metal ions available to condense on the protein ions formed via the charged residue mechanism. These effects are demonstrated with holomyoglobin ions to illustrate that the metal ion reduction takes place without detectable protein denaturation, which might be revealed by heme loss or an increase in charge state distribution. No evidence is observed for denaturation with exposure to any of the organic vapors evaluated in this work.

  6. Copper-vapor-catalyzed chemical vapor deposition of graphene on dielectric substrates

    Science.gov (United States)

    Yang, Chao; Wu, Tianru; Wang, Haomin; Zhang, Xuefu; Shi, Zhiyuan; Xie, Xiaoming

    2017-07-01

    Direct synthesis of high-quality graphene on dielectric substrates is important for its application in electronics. In this work, we report the process of copper-vapor-catalyzed chemical vapor deposition of high-quality and large graphene domains on various dielectric substrates. The copper vapor plays a vital role on the growth of transfer-free graphene. Both single-crystal domains that are much larger than previous reports and high-coverage graphene films can be obtained by adjusting the growth duration. The quality of the obtained graphene was verified to be comparable with that of graphene grown on Cu foil. The progress reported in this work will aid the development of the application of transfer-free graphene in the future.

  7. Effects of vertical distribution of water vapor and temperature on total column water vapor retrieval error

    Science.gov (United States)

    Sun, Jielun

    1993-01-01

    Results are presented of a test of the physically based total column water vapor retrieval algorithm of Wentz (1992) for sensitivity to realistic vertical distributions of temperature and water vapor. The ECMWF monthly averaged temperature and humidity fields are used to simulate the spatial pattern of systematic retrieval error of total column water vapor due to this sensitivity. The estimated systematic error is within 0.1 g/sq cm over about 70 percent of the global ocean area; systematic errors greater than 0.3 g/sq cm are expected to exist only over a few well-defined regions, about 3 percent of the global oceans, assuming that the global mean value is unbiased.

  8. Commercial Alloys for Sulfuric Acid Vaporization in Thermochemical Hydrogen Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Thomas M. Lillo; Karen M. Delezene-Briggs

    2005-10-01

    Most thermochemical cycles being considered for producing hydrogen include a processing stream in which dilute sulfuric acid is concentrated, vaporized and then decomposed over a catalyst. The sulfuric acid vaporizer is exposed to highly aggressive conditions. Liquid sulfuric acid will be present at a concentration of >96 wt% (>90 mol %) H2SO4 and temperatures exceeding 400oC [Brown, et. al, 2003]. The system will also be pressurized, 0.7-3.5 MPa, to keep the sulfuric acid in the liquid state at this temperature and acid concentration. These conditions far exceed those found in the commercial sulfuric acid generation, regeneration and handling industries. Exotic materials, e.g. ceramics, precious metals, clad materials, etc., have been proposed for this application [Wong, et. al., 2005]. However, development time, costs, reliability, safety concerns and/or certification issues plague such solutions and should be considered as relatively long-term, optimum solutions. A more cost-effective (and relatively near-term) solution would be to use commercially-available metallic alloys to demonstrate the cycle and study process variables. However, the corrosion behavior of commercial alloys in sulfuric acid is rarely characterized above the natural boiling point of concentrated sulfuric acid (~250oC at 1 atm). Therefore a screening study was undertaken to evaluate the suitability of various commercial alloys for concentration and vaporization of high-temperature sulfuric acid. Initially alloys were subjected to static corrosion tests in concentrated sulfuric acid (~95-97% H2SO4) at temperatures and exposure times up to 200oC and 480 hours, respectively. Alloys with a corrosion rate of less than 5 mm/year were then subjected to static corrosion tests at a pressure of 1.4 MPa and temperatures up to 375oC. Exposure times were shorter due to safety concerns and ranged from as short as 5 hours up to 144 hours. The materials evaluated included nickel-, iron- and cobalt

  9. Generating Units

    Data.gov (United States)

    Department of Homeland Security — Generating Units are any combination of physically connected generators, reactors, boilers, combustion turbines, and other prime movers operated together to produce...

  10. Plasma and Ion Assistance in Physical Vapor Deposition: AHistorical Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2007-02-28

    Deposition of films using plasma or plasma-assist can betraced back surprisingly far, namely to the 18th century for arcs and tothe 19th century for sputtering. However, only since the 1960s thecoatings community considered other processes than evaporation for largescale commercial use. Ion Plating was perhaps the first importantprocess, introducing vapor ionization and substrate bias to generate abeam of ions arriving on the surface of the growing film. Ratherindependently, cathodic arc deposition was established as an energeticcondensation process, first in the former Soviet Union in the 1970s, andin the 1980s in the Western Hemisphere. About a dozen various ion-basedcoating technologies evolved in the last decades, all characterized byspecific plasma or ion generation processes. Gridded and gridless ionsources were taken from space propulsion and applied to thin filmdeposition. Modeling and simulation have helped to make plasma and ionseffects to be reasonably well understood. Yet--due to the complex, oftennon-linear and non-equilibrium nature of plasma and surfaceinteractions--there is still a place for the experience plasma"sourcerer."

  11. Generational diversity.

    Science.gov (United States)

    Kramer, Linda W

    2010-01-01

    Generational diversity has proven challenges for nurse leaders, and generational values may influence ideas about work and career planning. This article discusses generational gaps, influencing factors and support, and the various generational groups present in today's workplace as well as the consequences of need addressing these issues. The article ends with a discussion of possible solutions.

  12. Vapor layers reduce drag without the crisis

    Science.gov (United States)

    Vakarelski, Ivan; Berry, Joseph; Chan, Derek; Thoroddsen, Sigurdur

    2016-11-01

    The drag of a solid sphere moving in fluid is known to be only a function of the Reynolds number, Re and diminishes rapidly at the drag crisis around Re 3 ×105. A Leidenfrost vapor layer on a hot sphere surface can trigger the onset of the drag crisis at lower Re. By using a range of high viscosity perfluorocarbon liquids, we show that the drag reduction effect, can occur over a wide range of Re, from as low as 600. The Navier slip model with a viscosity dependent slip length captures the observed drag reduction and wake shape.

  13. Atom Interferometry in a Warm Vapor

    CERN Document Server

    Biedermann, G W; Rakholia, A V; Jau, Y -Y; Wheeler, D R; Sterk, J D; Burns, G R

    2016-01-01

    We demonstrate matterwave interference in a warm vapor of rubidium atoms. Established approaches to light pulse atom interferometry rely on laser cooling to concentrate a large ensemble of atoms into a velocity class resonant with the atom optical light pulse. In our experiment, we show that clear interference signals may be obtained without laser cooling. This effect relies on the Doppler selectivity of the atom interferometer resonance. This interferometer may be configured to measure accelerations, and we demonstrate that multiple interferometers may be operated simultaneously by addressing multiple velocity classes.

  14. Time-resolved detection of relative intensity squeezed nanosecond pulses in a 87Rb vapor

    CERN Document Server

    Agha, Imad H; Messin, Gaetan; Grangier, Philippe

    2010-01-01

    We present experimental studies on the generation and detection of pulsed, relative-intensity squeezed light in a warm rubidium vapor. The noise correlations between a pulsed probe beam and its conjugate -generated through nearly-degenerate four-wave mixing in a double-lambda system- are studied via time-resolved balanced detection. We observe -0.96 dB of time-resolved relative intensity squeezing with 50 nanosecond pulses at 1 MHz repetition rate. (-1.34 dB corrected for loss).

  15. Time-resolved detection of relative intensity squeezed nanosecond pulses in a Rb87 vapor

    CERN Document Server

    Agha, Imad H; Glorieux, Quentin; Coudreau, Thomas; Grangier, Philippe; Messin, Gaetan

    2011-01-01

    We present theoretical and experimental results on the generation and detection of pulsed, relative-intensity squeezed light in a hot Rb87 vapor. The intensity noise correlations between a pulsed probe beam and its conjugate, generated through nearly-degenerate four-wave mixing in a double-lambda system, are studied numerically and measured experimentally via time-resolved balanced detection. We predict and observe about -1 dB of time-resolved relative intensity squeezing with 50 nanosecond pulses at 1 MHz repetition rate. (-1.34 dB corrected for loss).

  16. Methods for calculation of engineering parameters for gas separation. [vapor pressure and solubility of gases in organic liquids

    Science.gov (United States)

    Lawson, D. D.

    1979-01-01

    A group additivity method is generated which allows estimation, from the structural formulas alone, of the energy of vaporization and the molar volume at 25 C of many nonpolar organic liquids. Using these two parameters and appropriate thermodynamic relations, the vapor pressure of the liquid phase and the solubility of various gases in nonpolar organic liquids are predicted. It is also possible to use the data to evaluate organic and some inorganic liquids for use in gas separation stages or liquids as heat exchange fluids in prospective thermochemical cycles for hydrogen production.

  17. Water recovery by catalytic treatment of urine vapor

    Science.gov (United States)

    Budininkas, P.; Quattrone, P. D.; Leban, M. I.

    1980-01-01

    The objective of this investigation was to demonstrate the feasibility of water recovery on a man-rated scale by the catalytic processing of untreated urine vapor. For this purpose, two catalytic systems, one capable of processing an air stream containing low urine vapor concentrations and another to process streams with high urine vapor concentrations, were designed, constructed, and tested to establish the quality of the recovered water.

  18. Lunar absorption spectrophotometer for measuring atmospheric water vapor.

    Science.gov (United States)

    Querel, Richard R; Naylor, David A

    2011-02-01

    A novel instrument has been designed to measure the nighttime atmospheric water vapor column abundance by near-infrared absorption spectrophotometry of the Moon. The instrument provides a simple, effective, portable, and inexpensive means of rapidly measuring the water vapor content along the lunar line of sight. Moreover, the instrument is relatively insensitive to the atmospheric model used and, thus, serves to provide an independent calibration for other measures of precipitable water vapor from both ground- and space-based platforms.

  19. Air exchange rates and alternative vapor entry pathways to inform vapor intrusion exposure risk assessments.

    Science.gov (United States)

    Reichman, Rivka; Roghani, Mohammadyousef; Willett, Evan J; Shirazi, Elham; Pennell, Kelly G

    2016-11-12

    Vapor intrusion (VI) is a term used to describe indoor air (IA) contamination that occurs due to the migration of chemical vapors in the soil and groundwater. The overall vapor transport process depends on several factors such as contaminant source characteristics, subsurface conditions, building characteristics, and general site conditions. However, the classic VI conceptual model does not adequately account for the physics of airflow around and inside a building and does not account for chemical emissions from alternative "preferential" pathways (e.g. sewers and other utility connections) into IA spaces. This mini-review provides information about recent research related to building air exchange rates (AERs) and alternative pathways to improve the accuracy of VI exposure risk assessment practices. First, results from a recently published AER study for residential homes across the United States (US) are presented and compared to AERs recommended by the US Environmental Protection Agency (USEPA). The comparison shows considerable differences in AERs when season, location, building age, and other factors are considered. These differences could directly impact VI assessments by influencing IA concentration measurements. Second, a conceptual model for sewer gas entry into buildings is presented and a summary of published field studies is reported. The results of the field studies suggest that alternative pathways for vapors to enter indoor spaces warrant consideration. Ultimately, the information presented in this mini-review can be incorporated into a multiple-lines-of-evidence approach for assessing site-specific VI exposure risks.

  20. Vaporization of a mixed precursors in chemical vapor deposition for YBCO films

    Science.gov (United States)

    Zhou, Gang; Meng, Guangyao; Schneider, Roger L.; Sarma, Bimal K.; Levy, Moises

    1995-01-01

    Single phase YBa2Cu3O7-delta thin films with T(c) values around 90 K are readily obtained by using a single source chemical vapor deposition technique with a normal precursor mass transport. The quality of the films is controlled by adjusting the carrier gas flow rate and the precursor feed rate.

  1. Sublimation characterization and vapor pressure estimation of an HIV nonnucleoside reverse transcriptase inhibitor using thermogravimetric analysis.

    Science.gov (United States)

    Xie, Minli; Ziemba, Theresa M; Maurin, Michael B

    2003-01-01

    The purpose of this research is to investigate the sublimation process of DPC 963, a second-generation nonnucleoside reverse transcriptase inhibitor for HIV-1 retrovirus, and to better understand the effect of sublimation during active pharmaceutical ingredient (API) manufacture and formulation development, especially the drying processes. Sublimation of DPC 963 at 150 degrees C and above was determined by thermogravimetric analysis-Fourier transform infrared (TGA-FTIR). The rates of sublimation at different temperatures were measured using isothermal TGA. Condensed material was collected and analyzed by differential scanning calorimetry (DSC), x-ray powder diffraction (XRPD), and infrared (IR) spectrometry. Benzoic acid was used as a reference standard to derive a linear logarithmic relationship between sublimation/evaporation rate and vapor pressure specific to the TGA system used in this study. Sublimation and evaporation of DPC 963 were found to follow apparent zero-order kinetics. Using the Eyring equation, the enthalpy and entropy of the sublimation and evaporation processes were obtained. The enthalpies of sublimation and evaporation were found to be 29 and 22 kcal/mol, respectively. The condensed material from the vapor phase was found to exist in 2 physical forms, amorphous and crystalline. Using benzoic acid as a reference standard, vapor pressure of DPC 963 at different temperatures was calculated using the linear logarithmic relationship obtained. DPC 963 undergoes sublimation at appreciable rates at 150 degrees C and above but this is not likely to pose a serious issue during the manufacturing process. Vapor pressure estimation using thermogravimetric analysis provided sufficient accuracy to be used as a fast, simple, and safe alternative to the traditional methods of vapor pressure determination.

  2. Excessively High Vapor Pressure of Al-based Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    Jae Im Jeong

    2015-10-01

    Full Text Available Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the vapor pressure of crystalline Al near its melting temperature, 873 K. Our results strongly suggest the possibility of fabricating nanocrystallites or thin films by evaporation at low temperatures.

  3. Viscous Coalescence of Two Drops in a Saturated Vapor Phase

    Science.gov (United States)

    Baroudi, Lina; Nagel, Sidney R.; Morris, Jeffrey F.; Lee, Taehun

    2016-11-01

    When two liquid drops come into contact, a microscopic liquid bridge forms between them and rapidly expands until the two drops merge into a single bigger drop. Numerous studies have been devoted to the investigation of the coalescence singularity in the case where the drops coalesce in a medium of negligible vapor pressure such as vacuum or air. However, coalescence of liquid drops may also take place in a medium of relatively high vapor pressure (condensable vapor phase), where the effect of the surrounding vapor phase should not be neglected, such as the merging of drops in clouds. In this study, we carry out Lattice Boltzmann numerical simulations to investigate the dynamics of viscous coalescence in a saturated vapor phase. Attention is paid to the effect of the vapor phase on the formation and growth dynamics of the liquid bridge in the viscous regime. We observe that the onset of the coalescence occurs earlier and the expansion of the bridge initially proceeds faster when the coalescence takes place in a saturated vapor compared to the coalescence in a non-condensable gas. The initially faster evolution of the coalescence process in the saturated vapor is caused by the vapor transport through condensation during the early stages of the coalescence.

  4. The liquid to vapor phase transition in excited nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, J.B.; Moretto, L.G.; Phair, L.; Wozniak, G.J.; Beaulieu, L.; Breuer, H.; Korteling, R.G.; Kwiatkowski, K.; Lefort, T.; Pienkowski, L.; Ruangma, A.; Viola, V.E.; Yennello, S.J.

    2001-05-08

    For many years it has been speculated that excited nuclei would undergo a liquid to vapor phase transition. For even longer, it has been known that clusterization in a vapor carries direct information on the liquid-vapor equilibrium according to Fisher's droplet model. Now the thermal component of the 8 GeV/c pion + 197 Au multifragmentation data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model, thus providing the strongest evidence yet of the liquid to vapor phase transition.

  5. The liquid to vapor phase transition in excited nuclei

    CERN Document Server

    Elliott, J B; Phair, L; Wozniak, G J; Lefort, T; Beaulieu, L; Kwiatkowski, K K; Hsi, W C; Pienkowski, L; Breuer, H; Korteling, R G; Laforest, R; Martin, E; Ramakrishnan, E; Rowland, D; Ruangma, A; Viola, V E; Winchester, E M; Yennello, S J

    2002-01-01

    For many years it has been speculated that excited nuclei would undergo a liquid to vapor phase transition. For even longer, it has been known that clusterization in a vapor carries direct information on the liquid- vapor equilibrium according to Fisher's droplet model. Now the thermal component of the 8 GeV/c pion + 197Au multifragmentation data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model, thus providing the strongest evidence yet of the liquid to vapor phase transition.

  6. A heated vapor cell unit for DAVLL in atomic rubidium

    OpenAIRE

    McCarron, Daniel J.; Hughes, Ifan G.; Tierney, Patrick; Cornish, Simon L

    2007-01-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D2 transitions in atomic rubidium is described. A 5 cm-long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field...

  7. UV Discharge Lamp on Alcohol Vapor

    Science.gov (United States)

    Avtaeva, Svetlana; Heneral, Andrij

    2009-10-01

    The non coherent sources of UV radiation based on safe and nontoxic gaseous mixtures have good aspects for different applications. The paper reports about experimental investigations of the high voltage capacitive discharge in alcohol vapor. The time-integrated emission spectra have been studied in the wavelength interval from 200 to 400 nm at alcohol vapor pressure of 1 Torr. In the spectra the most intensive bands were vibrational bands of the CO(b->a) transition with heads at 283.3 (0-0), 297.7 (0-1), 313.4 (0-2), 330.5 (0-3) and 349.3 nm (0-4). The (0-2) band of CO molecules superimposes with (0-0) and (1-1) vibrational bands of the CH(C->X) transition with Q-heads at 314.49 and 315.66 nm on the long wavelength side and with bands of OH radicals with intensity maximums at 308.1 and 309.2 nm (A->X transition) on the short wavelength side. No other radiating species were detected. The emitting surface area of the lamp is 220 cm^2, average output power of the UV radiation is 70 mW and the estimated efficiency is 0.2%. This source of UV radiation can be applied in photochemistry, in medicine, for disinfection of medical tools, in ecology and for purification and disinfection of water from different pathogenic microorganisms.

  8. Plantas indicadoras de clomazone na fase vapor

    Directory of Open Access Journals (Sweden)

    Fábio Schreiber

    2013-10-01

    Full Text Available A volatilização representa um processo importante no deslocamento de agrotóxicos para o ambiente. As características físico-químicas da molécula do clomazone indicam que este possui potencial de volatilização. Em vista do exposto, para a realização deste estudo, foram conduzidos dois experimentos com o objetivo de avaliar a suscetibilidade das espécies: pepino, melão, milho, sorgo e arroz a diferentes formulações do herbicida clomazone na fase vapor. Para isso, foram utilizadas caixas de vidro hermeticamente fechadas, com a presença de diferentes formulações de clomazone e as espécies vegetais. As formulações utilizadas foram Gamit 360 CS®, Gamit 500 EC® e Gamit Star®. Com os resultados obtidos, foi possível concluir que, dentre as espécies avaliadas, independente da formulação utilizada, a de menor tolerância ao herbicida clomazone na fase vapor foi o sorgo, seguido do milho e do arroz.

  9. Water vapor interactions with polycrystalline titanium surfaces

    Science.gov (United States)

    Azoulay, A.; Shamir, N.; Volterra, V.; Mintz, M. H.

    1999-02-01

    The initial interactions of water vapor with polycrystalline titanium surfaces were studied at room temperature. Measurements of water vapor surface accumulation were performed in a combined surface analysis system incorporating direct recoils spectrometry (DRS), Auger electron spectroscopy and X-ray photoelectron spectroscopy. The kinetics of accommodation of the water dissociation fragments (H, O and OH) displayed a complex behavior depending not only on the exposure dose but also on the exposure pressure. For a given exposure dose the efficiency of chemisorption increased with increasing exposure pressure. DRS measurements indicated the occurrence of clustered hydroxyl moieties with tilted O-H bonds formed even at very low surface coverage. A model which assumes two parallel routes of chemisorption, by direct collisions (Langmuir type) and by a precursor state is proposed to account for the observed behavior. The oxidation efficiency of water seemed to be much lower than that of oxygen. No Ti 4+ states were detected even at high water exposure values. It is likely that hydroxyl species play an important role in the reduced oxidation efficiency of water.

  10. An apparatus for vapor conversion of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, K.; Matsumoto, I.

    1983-03-23

    The installation for vapor conversion of hydrocarbons (Uv) with the formation of a mixture of H2 and C02 is a catalyst chamber (KK) filled with longitudinally disposed thin pipes (with thin walls) or with pipe units made of dolomite, MgO or potassium aluminate. These pipes have a multilayered coating (Pk) on their internal and external surfaces (Pv), which contain catalytically active components. Such pipes or pipe units form a honeycombed structure with through longitudinal channels. The catalyst chamber itself is made of a ceramic material and has a heating winding outside for heating the catalyst. To save fuel and to increase the efficiency (KPD) of the heating device, the catalyst chamber is in turn enclosed by two additional shells filled with heat conducting packings which are easily penetrated by the gases being processed. The hydrocarbon vapors or gaseous fuel from the natural gas or methane and the steam are fed through the above cited heat exchange layers with packings into the facial part of the catalytic chamber, in which the conversion of the hydrocarbons occurs with the production of H2 and C02. From the catalyzer layer the mixture of gases and steam goes through a refrigerator into a trap for the steam excess and when it is necessary, into a C02 absorber and then, pure H2 is discharged from the latter. Such a catalytic installation is convenient to use for producing pure H2 from natural gas, methane, propane or kerosene.

  11. Thermodynamic Analysis of a Rankine Cycle Powered Vapor Compression Ice Maker Using Solar Energy

    Directory of Open Access Journals (Sweden)

    Bing Hu

    2014-01-01

    Full Text Available To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with increasing generation temperature. For every working fluid there is an optimal generation temperature at which organic Rankine efficiency achieves the maximum value. The cooling power per square meter collector and ice production per square meter collector per day are, respectively, 126.44 W m−2 and 7.61 kg m−2 day−1 at the generation temperature of 140°C for working fluid of R245fa, which demonstrates the feasibility of organic Rankine cycle powered vapor compression ice maker.

  12. Thermodynamic Analysis of a Rankine Cycle Powered Vapor Compression Ice Maker Using Solar Energy

    Science.gov (United States)

    Hu, Bing; Bu, Xianbiao; Ma, Weibin

    2014-01-01

    To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with increasing generation temperature. For every working fluid there is an optimal generation temperature at which organic Rankine efficiency achieves the maximum value. The cooling power per square meter collector and ice production per square meter collector per day are, respectively, 126.44 W m−2 and 7.61 kg m−2 day−1 at the generation temperature of 140°C for working fluid of R245fa, which demonstrates the feasibility of organic Rankine cycle powered vapor compression ice maker. PMID:25202735

  13. Study of the extraction of residual heat for a steam generator in the presence of incondensables modeling with TRACE: PKL experiment III G1.1; Estudio de la extraccion del calor residual por un generador de vapor en presencia de incondensables modelado con TRACE: experimento PKL III G1.1

    Energy Technology Data Exchange (ETDEWEB)

    Berna, C.; Escriva, A.; Munuz-Cobo, J. L.; Romero, A.

    2012-07-01

    This paper made the simulation of the PKL III G1.1 experiment using SNAP interface and the TRACE code. This experiment aims to essentially the study of the extraction of the residual heat of the steam generator in the presence of gases incondensables.

  14. Investigation on the use digital controls instead of PID analog controls in the level control of steam generators of nuclear power PWR; Investigacao sobre o uso de controladores digitais em substituicao aos controladores analogicos PID para o controle de nivel de geradores de vapor de centrais nucleares PWR

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga, Marco Antonio Bayout

    2012-07-01

    The aim of this study is to identify current alternatives for the implementation of digital controllers in the level control of steam generators of nuclear power PWR (Pressurized Water Reaetor). It is intended to identify the types of digital controls that are available from the theoretical and conceptual viewpoints for this purpose. We investigate the advantages and disadvantages of each controller model. From this assessment are pointed the most suitable models in hierarchical scale. This evaluation also serves to suggest possible types of control installation as a whole, where the level control of the steam generators becomes just one of many controls that are part of the plant. In this case, the use of digital controls allows the non-linear and multivariable treatment which is characteristic of complex systems, such as the nuclear power generation. The treatment of nonlinearities and multivariable aspects allows a more detailed study of the stability of these plants when they are subject to transients or several accidents, such as the case of losing external power of transients. In the specific case of steam generators, the instabilities result from the emergence of the shrink and swell phenomenas, depending on the load variations of thermonuclear plant. The application of several types and digital controllers, considering these inherent characteristics of the level control of steam generators, allows to infer which types of controllers are more appropriate to treat instabilities of this type and to make conjectures in its use for the cases of more complex instabilities, considering the integration of all nucleus-plant controls.

  15. Vapor and gas sampling of single-shell tank 241-B-102 using the in situ vapor sampling system

    Energy Technology Data Exchange (ETDEWEB)

    Lockrem, L.L.

    1997-08-05

    The Vapor Issue Resolution Program tasked the Vapor Team (the team) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-B-102. This document presents sampling data resulting from the April 18, 1996 sampling of SST 241-B-102. Analytical results will be presented in a separate report issued by Pacific Northwest National Laboratory (PNNL), which supplied and analyzed the sampling media. The team, consisting of Sampling and Mobile Laboratories (SML) and Special Analytical Studies (SAS) personnel, used the vapor sampling system (VSS) to collect representative samples of the air, gases, and vapors from the headspace of SST 241-B-102 with sorbent traps and SUMMA canisters.

  16. Contributions to the Data on Theoretical Metallurgy. 3. The Free Energies of Vaporization and Vapor Pressures of Inorganic Substances

    Science.gov (United States)

    1935-01-01

    an approximate vapor-pressure equation is included. 0 Liquid- Gas ((Si0.).) log P (at.)=- 13+7.65. Monosilane .-Vapor pressures of the hydride, SiB4...91 0 0 0 AImonbrom- monosilane .--Stock and Sonieski (393) (179-275*) have determined the vapor pressure of monobrom- monosilane , SiHtBr. The results are...11. P. =275.5°; A!!2,&.j5,648; AS,.6=20.5, AH,..,=5,558; AFmj,=-460. The above authors find 179.30 for the melting point. Dibrom- monosilane .-The vapor

  17. Water Vapor Adsorption Capacity of Thermally Fluorinated Carbon Molecular Sieves for CO2 Capture

    Directory of Open Access Journals (Sweden)

    Jin-Young Jung

    2013-01-01

    Full Text Available The surfaces of carbon molecular sieves (CMSs were thermally fluorinated to adsorb water vapor. The fluorination of the CMSs was performed at various temperatures (100, 200, 300, and 400°C to investigate the effects of the fluorine gas (F2 content on the surface properties. Fluorine-related functional groups formed were effectively generated on the surface of the CMSs via thermal fluorination process, and the total pore volume and specific surface area of the pores in the CMSs increased during the thermal fluorination process, especially those with diameters ≤ 8 Å. The water vapor adsorption capacity of the thermally fluorinated CMSs increased compared with the as-received CMSs, which is attributable to the increased specific surface area and to the semicovalent bonds of the C–F groups.

  18. Kinetics of laser pulse vaporization of uranium dioxide by mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.

    1981-11-01

    Safety analyses of nuclear reactors require knowledge of the evaporation behavior of UO/sub 2/ at temperatures well above the melting point of 3140 K. In this study, rapid transient heating of a small spot on a UO/sub 2/ specimen was accomplished by a laser pulse, which generates a surface temperature excursion. This in turn vaporizes the target surface and the gas expands into vacuum. The surface temperature transient was monitored by a fast-response automatic optical pyrometer. The maximum surface temperatures investigated range from approx. 3700 K to approx. 4300 K. A computer program was developed to simulate the laser heating process and calculate the surface temperature evolution. The effect of the uncertainties of the high temperature material properties on the calculation was included in a sensitivity study for UO/sub 2/ vaporization. The measured surface temperatures were in satisfactory agreements.

  19. MgB{sub 2} thin films by hybrid physical-chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xi, X.X. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]. E-mail: xxx4@psu.edu; Pogrebnyakov, A.V. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Xu, S.Y.; Chen, K.; Cui, Y.; Maertz, E.C. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Zhuang, C.G. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Physics, Peking University, Beijing 100871 (China); Li, Qi [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Lamborn, D.R. [Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Redwing, J.M. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Liu, Z.K.; Soukiassian, A.; Schlom, D.G.; Weng, X.J.; Dickey, E.C. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Chen, Y.B.; Tian, W.; Pan, X.Q. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Cybart, S.A. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Dynes, R.C. [Department of Physics, University of California, Berkeley, CA 94720 (United States)

    2007-06-01

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB{sub 2} thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB{sub 2} films. The epitaxial pure MgB{sub 2} films grown by HPCVD show higher-than-bulk T {sub c} due to tensile strain in the films. The HPCVD films are the cleanest MgB{sub 2} materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB{sub 2}. The carbon-alloyed HPCVD films demonstrate record-high H {sub c2} values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB{sub 2} Josephson junctions.

  20. Glutaraldehyde vapor cross-linked nanofibrous PVA mat with in situ formed silver nanoparticles.

    Science.gov (United States)

    Destaye, Addisu Getachew; Lin, Cheng-Keng; Lee, Cheng-Kang

    2013-06-12

    Polyvinyl alcohol (PVA) nanofibrous mat can be easily prepared via electrospinning its aqueous solution. However, the obtained nanofibrous mat is instantaneously dissolved in water. Therefore, rendering the environmentally friendly nanofibrous mat water insoluble by cross-linking mechanism is of great interest. The electrospun PVA nanofibrous mat with an average fiber diameter of ca. 400 nm could be effectively cross-linked by glutaraldehyde vapor at room temperature. The cross-linking not only resulted in a water-insoluble nanofibrous mat but also generated an excess amount of unreacted aldehyde functional groups that could reduce silver salts into silver nanoparticles. The in situ formed silver nanoparticles along the fibrous surface showed excellent antimicrobial activity against Escherichia coli. The vapor cross-linked nanofibrous mat shows a high potential to be used for efficiently capturing and killing pathogenic bacteria.

  1. Modeling Two-Phase Flow and Vapor Cycles Using the Generalized Fluid System Simulation Program

    Science.gov (United States)

    Smith, Amanda D.; Majumdar, Alok K.

    2017-01-01

    This work presents three new applications for the general purpose fluid network solver code GFSSP developed at NASA's Marshall Space Flight Center: (1) cooling tower, (2) vapor-compression refrigeration system, and (3) vapor-expansion power generation system. These systems are widely used across engineering disciplines in a variety of energy systems, and these models expand the capabilities and the use of GFSSP to include fluids and features that are not part of its present set of provided examples. GFSSP provides pressure, temperature, and species concentrations at designated locations, or nodes, within a fluid network based on a finite volume formulation of thermodynamics and conservation laws. This paper describes the theoretical basis for the construction of the models, their implementation in the current GFSSP modeling system, and a brief evaluation of the usefulness of the model results, as well as their applicability toward a broader spectrum of analytical problems in both university teaching and engineering research.

  2. Airborne Lidar Observations of Water Vapor Variability in the Northern Atlantic Trades

    Science.gov (United States)

    Kiemle, Christoph; Groß, Silke; Wirth, Martin; Bugliaro, Luca

    2017-04-01

    During the NARVAL (Next Generation Aircraft Remote Sensing for Validation Studies) field experiments in December 2013 and August 2016 the DLR lidar WALES (Water vapor Lidar Experiment in Space) was operated on board the German research aircraft HALO. The lidar simultaneously provided two-dimensional curtains of atmospheric backscatter and humidity along the flight track with high accuracy and spatial resolution, in order to help improve our knowledge on the coupling between water vapor, clouds, and circulation in the trades. The variability of water vapor, ubiquitous in our measurements, poses challenges to climate models because it acts on the small-scale low-cloud cover. Aloft, the very dry free troposphere in the subsiding branch of the Hadley cell acts as an open window in a greenhouse, efficiently cooling the lower troposphere. Secondary circulations between radiatively heated and cooled regions are supposed to occur, adding complexity to the situation. After recently having identified them to be mainly responsible for the uncertainty in global climate sensitivity, such interactions between shallow convection, circulation and radiation are at the heart of present scientific debate, endorsed by the WCRP (World Climate Research Programme) "Grand Challenge on Clouds, Circulation and Climate Sensitivity". Out of the wealth of about 30 winter and 60 summer flight hours totaling 75000 km of data over the Tropical Atlantic Ocean east of Barbados, several representative lidar segments from different flights are presented, together with Meteosat Second Generation (MSG) images and dropsonde profiles. All observations indicate high heterogeneity of the humidity in the lowest 5 km, as well as high variability of the depth of the cloud layer (1 - 2 km thick) and of the sub-cloud boundary layer ( 1 km thick). Layer depths and partial water vapor columns within the layers may vary by up to a factor of 2, and on a large range of horizontal scales. Occasionally, very dry, up

  3. Instant Generation

    Science.gov (United States)

    Loveland, Elaina

    2017-01-01

    Generation Z students (born between 1995-2010) have replaced millennials on college campuses. Generation Z students are entrepreneurial, desire practical skills with their education, and are concerned about the cost of college. This article presents what need to be known about this new generation of students.

  4. Isosteric Vapor Pressure – Temperature Data for Water Sorption in Hardened Cement Paste: Enthalpy, Entropy and Sorption Isotherms at Different Temperatures

    DEFF Research Database (Denmark)

    Radjy, Fariborz; Sellevold, Erik J.; Hansen, Kurt Kielsgaard

    and the temperatures range from 2 to 95 °C, differing for the specimen types. The data has been analyzed to yield differential enthalpy and entropy of adsorption, as well as the dependence of the relative vapor pressure on temperature at various constant moisture contents. The implications for the coefficient......PART I: In order to generate isosteric (constant mass) vapor pressure – temperature data (P-T data) for adsorbed pore water in hydrated cement paste, the Thermo Piestic Analysis system (the TPA system) described herein was developed. The TPA system generates high precision equilibrium isosteric P....... The accuracies for pressure, enthalpy and entropy are found to be 0.5% or less. PART II: The TPA-system has been used to generate water vapor pressure – temperature data for room temperature – and steam cured hardened cement pastes as well as porous vycor glass. The moisture contents range from saturated to dry...

  5. Studies on micro-structures at vapor-liquid interfaces of film boiling on hot liquid surface at arriving of a shock pressure

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Akira; Lee, S. [Tokyo Inst. of Tech. (Japan)

    1998-01-01

    In vapor explosions, a pressure wave (shock wave) plays a fundamental role in the generation, propagation and escalation of the explosion. Transient volume change by rapid heat flow from a high temperature liquid to a low temperature volatile one and phase change generate micro-scale flow and the pressure wave. One of key issues for the vapor explosion is to make clear the mechanism to support the explosive energy release from hot drop to cold liquid. According to our observations by an Image Converter Camera, growth rate of vapor film around a hot tin drop became several times higher than that around a hot Platinum tube at the same conditions when a pressure pulse collapsed the film. The thermally induced fragmentation was followed by the explosive growth rate of the hot drop. In the previous report, we have proposed that the interface instability and fragmentation model in which the fine Taylor instability of vapor-liquid interface at the collapsing and re-growth phase of vapor film and the instability induced by the high pressure spots at the drop surface were assumed. In this study, the behavior of the vapor-liquid interface region at arrival of a pressure pulse was investigated by the CIPRIS code which is able to simulate dynamics of transient multi-phase interface regions. It is compared with the observation results. Through detailed investigations of these results, the mechanisms of the thermal fragmentation of single drop are discussed. (J.P.N.)

  6. Experimental Study of Water Droplet Vaporization on Nanostructured Surfaces

    Science.gov (United States)

    Padilla, Jorge, Jr.

    -99. Heat transfer coefficients were determined from thermal measurements in the test apparatus. All experiments were conducted inside an ISO Class 5 clean room enclosure. It was observed that when a liquid water droplet impinged upon the ZnO nanostructured at surface temperatures less than 140 degrees C, the nominally spherical droplet spread into a thin film over the surface. The film thickness depended on many parameters but in general it measured approximately 100-400 micrometers. As a result, it was found that the droplet evaporated by film evaporation without initiating nucleate boiling. At wall superheat levels of 10-20 degrees C, it was found in some cases that the heat transfer coefficients were nearly 4 times greater than for those of nucleate boiling at the same superheat level. For these conditions, no bubble nucleation was observed visually, and, nevertheless, extremely high heat transfer coefficients resulting from rapid evaporation of the thin liquid film formed by the spreading droplet were observed. At high wall superheat levels, the vaporization process exhibited Leidenfrost droplet vaporization. The extreme wetting of the nanostructured surfaces resulted in high Leidenfrost transition temperatures in the range of 310-376 degrees C, among the highest in the literature, exceeding those exhibited by bare metal surfaces by 100 degrees C or more. The Leidenfrost transition was detected from a recording of the acoustic signal generated from each experiment during the deposition and subsequent evaporation process. It was defined as the first point for which there is no disturbance to the acoustical signal in the form of a sizzling sound beyond the initial violent popping generated during the droplet deposition. The results document a trend of increasing Leidenfrost temperature with decreasing contact angle, which is consistent with earlier studies. The results of this study are compared with earlier work in this area and the implications for applications are

  7. Directional infrared emission resulting from cascade population inversion and four-wave mixing in Rb vapor.

    Science.gov (United States)

    Akulshin, Alexander; Budker, Dmitry; McLean, Russell

    2014-02-15

    Directional infrared emission at 1.37 and 5.23 μm is generated in Rb vapors that are stepwise excited by low-power cw resonant light. The radiation at 5.23 μm originating from amplified spontaneous emission on the 5D(5/2)→6P(3/2) transition and wave mixing consists of forward- and backward-directed components with distinctive spectral and spatial properties. Diffraction-limited light at 1.37 μm generated in the copropagating direction only is a product of parametric wave mixing around the 5P(3/2)→5D(5/2)→6P(3/2)→6S(1/2)→5P(3/2) transition loop. This highly nondegenerate mixing process involves one externally applied and two internally generated optical fields. Similarities between wave mixing generated blue and 1.37 μm light are demonstrated.

  8. Improvement of efficiency and temperature control of induction heating vapor source on electron cyclotron resonance ion source.

    Science.gov (United States)

    Takenaka, T; Kiriyama, R; Muramatsu, M; Kitagawa, A; Uchida, T; Kurisu, Y; Nozaki, D; Yano, K; Yoshida, Y; Sato, F; Kato, Y; Iida, T

    2012-02-01

    An electron cyclotron resonance ion source (ECRIS) is used to generate multicharged ions for many kinds of the fields. We have developed an evaporator by using induction heating method that can generate pure vapor from solid state materials in ECRIS. We develop the new matching and protecting circuit by which we can precisely control the temperature of the induction heating evaporator. We can control the temperature within ±15 °C around 1400 °C under the operation pressure about 10(-4) Pa. We are able to use this evaporator for experiment of synthesizing process to need pure vapor under enough low pressure, e.g., experiment of generation of endohedral Fe-fullerene at the ECRIS.

  9. Building America Top Innovations 2012: Vapor Retarder Classification

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-01-01

    This Building America Top Innovations profile describes research in vapor retarders. Since 2006 the IRC has permitted Class III vapor retarders like latex paint (see list above) in all climate zones under certain conditions thanks to research by Building America teams.

  10. New mobile Raman lidar for measurement of tropospheric water vapor

    Institute of Scientific and Technical Information of China (English)

    XIE Chenbo; ZHOU Jun; YUE Guming; QI Fudi; FAN Aiyuan

    2007-01-01

    The content of water vapor in atmosphere is very little and the ratio of volume of moisture to air is about 0.1%-3%,but water vapor is the most active molecule in atmosphere.There are many absorption bands in infrared(IR)wavelength for water vapor,and water vapor is also an important factor in cloud formation and precipitation,therefore it takes a significant position in the global radiation budget and climatic changes.Because of the advantages of the high resolution,wide range,and highly automatic operation,the Raman lidar has become a new-style and useful tool to measure water vapor.In this paper,first,the new mobile Raman lidar's structure and specifications were introduced.Second,the process method of lidar data was described.Finally,the practical and comparative experiments were made over Hefei City in China.The results of measurement show that this lidar has the ability to gain profiles of ratio of water vapor mixing ratio from surface to a height of about 8 km at night.Mean-while,the measurement of water vapor in daytime has been taken,and the profiles of water vapor mixing ratio at ground level have been detected.

  11. Heterogeneous and homogeneous reactions of pyrolysis vapors from pine wood

    NARCIS (Netherlands)

    Hoekstra, E.; Westerhof, R.J.M.; Brilman, D.W.F.; Swaaij, van W.P.M.; Kersten, S.R.A.; Hogendoorn, J.A.; Windt, M.

    2012-01-01

    To maximize oil yields in the fast pyrolysis of biomass it is generally accepted that vapors need to be rapidly quenched. The influence of the heterogeneous and homogeneous vapor-phase reactions on yields and oil composition were studied using a fluidized-bed reactor. Even high concentrations of min

  12. Vapor Measurements from the GSFC Stratospheric Ozone Lidar

    Science.gov (United States)

    McGee, T.

    2003-01-01

    Water vapor measurements from the GSFC Stratospheric Ozone Lidar were made for the first time during a campaign at NOAA's Mauna Loa Observatory. Comparisons were made among the GSFC lidar, the NOAA Lidar and water vapor sondes which were flown from the observatory at times coincident with the lidar measurements.

  13. Vapor Pressure of Methyl Salicylate and n-Hexadecane

    Science.gov (United States)

    2014-01-01

    and n-hexadecane are similar to those of sulfur mustard (HD) and VX , respectively. 15. SUBJECT TERMS Methyl salicylate Vapor pressure Volatility...2- chloroethyl) sulfide (HD) and O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothiolate ( VX ), respectively. Vapor pressure similarities make... gas chromatographic (GC) equipment and methodology, and as before, the GC was equipped with a flame-ionization detector. Saturator calibration and

  14. Water vapor and gas transport through polymeric membranes

    NARCIS (Netherlands)

    Metz, S.J.

    2003-01-01

    Water vapor transport through polymeric materials plays an important role in a large number of applications such as: food packaging, breathable clothing, roofing membranes, diapers, and the removal of water vapor from gas streams (e.g. dehydration of natural gas or the drying of compressed air). Dep

  15. 46 CFR 154.438 - Design vapor pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank type A are...

  16. 46 CFR 154.436 - Design vapor pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.436 Section 154.436 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS...-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5 kPa...

  17. 46 CFR 154.445 - Design vapor pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type B are...

  18. 46 CFR 154.419 - Design vapor pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.419 Section 154.419 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.419 Design vapor pressure. The Po of an integral tank must not exceed 24.5 kPa gauge (3.55...

  19. 46 CFR 154.426 - Design vapor pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.426 Section 154.426 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge (3.55...

  20. 46 CFR 154.451 - Design vapor pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of an...

  1. Heat-Exchange Fluids for Sulfuric Acid Vaporizers

    Science.gov (United States)

    Lawson, D. D.; Petersen, G. R.

    1982-01-01

    Some fluorine-substituted organic materials meet criteria for heat-exchange fluids in contact with sulfuric acid. Most promising of these are perfluoropropylene oxide polymers with degree of polymerization (DP) between 10 and 50. It is desirable to have DP in high range because vapor pressure of material decreases as DP increases, and high-DP liquids have lower loss due to vaporization.

  2. Water vapor and Gas Transport through Polymeric Membranes

    NARCIS (Netherlands)

    Metz, S.J.

    2003-01-01

    Water vapor transport through polymeric materials plays an important role in a large number of applications such as: food packaging, breathable clothing, roofing membranes, diapers, and the removal of water vapor from gas streams (e.g. dehydration of natural gas or the drying of compressed air).

  3. BIODEGRADATION OF HYDROCARBON VAPORS IN THE UNSATURATED ZONE

    Science.gov (United States)

    The time-averaged concentration of hydrocarbon and oxygen vapors were measured in the unsaturated zone above the residually contaminated capillary fringe at the U.S. Coast Guard Air Station in Traverse City, Michigan. Total hydrocarbon and oxygen vapor concentrations were observe...

  4. Toxicology of petroleum naphtha distillate vapors.

    Science.gov (United States)

    Wilson, F W

    1976-12-01

    A unique opportunity was presented to observe the potentially toxic effects of an acute exposure to the vapors of petroleum naphtha distillate on a relatively large number of individuals. The immediate manifestation in all was dyspnea. The action on motor vehicle combustion suggested that some of this could have been due to oxygen deprivation; however, all individuals were dyspneic for several minutes after exposure. A few were cyanotic for several minutes after exposure. All were excited. Tremulousness and mild nausea followed the initial symptoms but were of brief duration. One individual manifested numerous premature ventricular contractions. Since his exposure was brief and since none of the others showed similar findings, it is unlikely that the exposure was causal. The central nervous system depression described in acute exposure cases of the intact (not distillate) petroleum naphtha fumes was not observed in any of this series. There were no delayed manifestations or complications.

  5. Biodegradation of methanol vapor in a biofilter

    Institute of Scientific and Technical Information of China (English)

    Durai Arulneyam; T. Swaminathan

    2003-01-01

    Volatile organic compounds (VOCs) are a new class of air pollutants posing threat to the environment. Newer technologies are being developed for their control among which biofiltration seem to be most attractive. Biofiltration of methanol vapor from air stream was evaluated in this study. Experimental investigations were conducted on a laboratory scale biofilter, containing mixture of compost and polystyrene inert particles as the filter materials. Mixed consortium of activated sludge was used as an inoculum. The continuous performance of biofilter for methanol removal was monitored for different concentrations and flow rates. The removal efficiencies decreased at higher concentrations and higher gas flow rates. A maximum elimination capacity of 85 g/(m3.h) was achieved. The response of biofilter to upset loading operation showed that the biofilm in the biofilters was quite stable and quickly adapted to adverse operational conditions.

  6. Water vapor sorption hysteresis of ceramic bricks

    Science.gov (United States)

    Koronthalyova, Olga

    2016-07-01

    A quantification of the hysteretic effects and their thorough analysis was carried out for three types of ceramic bricks. Water vapor adsorption/desorption isotherms were measured by the standard desiccator method. The desorption measurements were carried out from capillary moisture content as well as from equilibrium moisture content corresponding to the relative humidity of 98 %. For all three tested types of bricks the hysteretic effects were present but their significance differed depending on the particular type of brick. Significant differences were noticed also in desorption curves determined from capillary moisture content and from equilibrium moisture content corresponding to the relative humidity of 98 %. Based on the measured data a possible correlation between pore structure parameters and noticed hysteretic effects as well as relevance of the open pore model are discussed. The obtained adsorption/desorption curves were approximated by an analytical relation.

  7. Crystallization of Membrane Proteins by Vapor Diffusion

    Science.gov (United States)

    Delmar, Jared A.; Bolla, Jani Reddy; Su, Chih-Chia; Yu, Edward W.

    2016-01-01

    X-ray crystallography remains the most robust method to determine protein structure at the atomic level. However, the bottlenecks of protein expression and purification often discourage further study. In this chapter, we address the most common problems encountered at these stages. Based on our experiences in expressing and purifying antimicrobial efflux proteins, we explain how a pure and homogenous protein sample can be successfully crystallized by the vapor diffusion method. We present our current protocols and methodologies for this technique. Case studies show step-by-step how we have overcome problems related to expression and diffraction, eventually producing high quality membrane protein crystals for structural determinations. It is our hope that a rational approach can be made of the often anecdotal process of membrane protein crystallization. PMID:25950974

  8. Kinetics of wet sodium vapor complex plasma

    Science.gov (United States)

    Mishra, S. K.; Sodha, M. S.

    2014-04-01

    In this paper, we have investigated the kinetics of wet (partially condensed) Sodium vapor, which comprises of electrons, ions, neutral atoms, and Sodium droplets (i) in thermal equilibrium and (ii) when irradiated by light. The formulation includes the balance of charge over the droplets, number balance of the plasma constituents, and energy balance of the electrons. In order to evaluate the droplet charge, a phenomenon for de-charging of the droplets, viz., evaporation of positive Sodium ions from the surface has been considered in addition to electron emission and electron/ion accretion. The analysis has been utilized to evaluate the steady state parameters of such complex plasmas (i) in thermal equilibrium and (ii) when irradiated; the results have been graphically illustrated. As a significant outcome irradiated, Sodium droplets are seen to acquire large positive potential, with consequent enhancement in the electron density.

  9. Helium liquefier cycles with saturated vapor compression

    Science.gov (United States)

    Minta, M.; Smith, J. L., Jr.

    The three refrigeration stages of the conventional helium liquefaction cycle are related to liquid nitrogen precooling, the use of expansion engines, and a J-T expansion. For an operation of helium refrigerators at temperatures below 4.2 K reduced pressure levels are required. Such an operation makes it necessary to enhance the compressor size and the heat exchanger surface area. In the case of 1.8 K refrigerators, practical cycles with three pressure levels are employed. It is pointed out that the saturated-vapor-compression (SVC) helium cycle provides an alternative solution to these problems. The present investigation is concerned with the design study of a SVC helium liquifier operating at elevated pressures. The study was conducted to demonstrate the potential of the SVC cycle on the basis of a direct comparison with a conventional cycle using the same precooling expanders and a supercritical wet expander instead of a J-T valve.

  10. Chemical vapor deposition coating for micromachines

    Energy Technology Data Exchange (ETDEWEB)

    MANI,SEETHAMBAL S.; FLEMING,JAMES G.; SNIEGOWSKI,JEFFRY J.; DE BOER,MAARTEN P.; IRWIN,LAWRENCE W.; WALRAVEN,JEREMY A.; TANNER,DANELLE M.; DUGGER,MICHAEL T.

    2000-04-21

    Two major problems associated with Si-based MEMS devices are stiction and wear. Surface modifications are needed to reduce both adhesion and friction in micromechanical structures to solve these problems. In this paper, the authors will present a process used to selectively coat MEMS devices with tungsten using a CVD (Chemical Vapor Deposition) process. The selective W deposition process results in a very conformal coating and can potentially solve both stiction and wear problems confronting MEMS processing. The selective deposition of tungsten is accomplished through silicon reduction of WF{sub 6}, which results in a self-limiting reaction. The selective deposition of W only on polysilicon surfaces prevents electrical shorts. Further, the self-limiting nature of this selective W deposition process ensures the consistency necessary for process control. Selective tungsten is deposited after the removal of the sacrificial oxides to minimize process integration problems. This tungsten coating adheres well and is hard and conducting, requirements for device performance. Furthermore, since the deposited tungsten infiltrates under adhered silicon parts and the volume of W deposited is less than the amount of Si consumed, it appears to be possible to release stuck parts that are contacted over small areas such as dimples. Results from tungsten deposition on MEMS structures with dimples will be presented. The effect of wet and vapor phase cleanings prior to the deposition will be discussed along with other process details. The W coating improved wear by orders of magnitude compared to uncoated parts. Tungsten CVD is used in the integrated-circuit industry, which makes this approach manufacturable.

  11. Numerical simulation of superheated vapor bubble rising in stagnant liquid

    Science.gov (United States)

    Samkhaniani, N.; Ansari, M. R.

    2017-09-01

    In present study, the rising of superheated vapor bubble in saturated liquid is simulated using volume of fluid method in OpenFOAM cfd package. The surface tension between vapor-liquid phases is considered using continuous surface force method. In order to reduce spurious current near interface, Lafaurie smoothing filter is applied to improve curvature calculation. Phase change is considered using Tanasawa mass transfer model. The variation of saturation temperature in vapor bubble with local pressure is considered with simplified Clausius-Clapeyron relation. The couple velocity-pressure equation is solved using PISO algorithm. The numerical model is validated with: (1) isothermal bubble rising and (2) one-dimensional horizontal film condensation. Then, the shape and life time history of single superheated vapor bubble are investigated. The present numerical study shows vapor bubble in saturated liquid undergoes boiling and condensation. It indicates bubble life time is nearly linear proportional with bubble size and superheat temperature.

  12. On the acoustic properties of vaporized submicron perfluorocarbon droplets.

    Science.gov (United States)

    Reznik, Nikita; Lajoinie, Guillaume; Shpak, Oleksandr; Gelderblom, Erik C; Williams, Ross; de Jong, Nico; Versluis, Michel; Burns, Peter N

    2014-06-01

    The acoustic characteristics of microbubbles created from vaporized submicron perfluorocarbon droplets with fluorosurfactant coating are examined. Utilizing ultra-high-speed optical imaging, the acoustic response of individual microbubbles to low-intensity diagnostic ultrasound was observed on clinically relevant time scales of hundreds of milliseconds after vaporization. It was found that the vaporized droplets oscillate non-linearly and exhibit a resonant bubble size shift and increased damping relative to uncoated gas bubbles due to the presence of coating material. Unlike the commercially available lipid-coated ultrasound contrast agents, which may exhibit compression-only behavior, vaporized droplets may exhibit expansion-dominated oscillations. It was further observed that the non-linearity of the acoustic response of the bubbles was comparable to that of SonoVue microbubbles. These results suggest that vaporized submicron perfluorocarbon droplets possess the acoustic characteristics necessary for their potential use as ultrasound contrast agents in clinical practice.

  13. Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing

    Science.gov (United States)

    Piszter, Gábor; Kertész, Krisztián; Bálint, Zsolt; Biró, László Péter

    2016-01-01

    Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings. PMID:27618045

  14. Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing

    Directory of Open Access Journals (Sweden)

    Gábor Piszter

    2016-09-01

    Full Text Available Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings.

  15. Vaporization characteristics of carbon heat shields under radiative heating.

    Science.gov (United States)

    Davy, W. C.; Bar-Nun, A.

    1972-01-01

    Study of the vaporization characteristics of samples of ATJ graphite, a material that has been considered for use on a Jovian probe. These samples were subjected to radiative heating loads of approximately 2 kW/sq cm in argon atmospheres of pressures from 0.00046 to 1 atm. Surface temperatures, mass loss rates, and spatially resolved emission spectral data were recorded. These data are analyzed to determine carbon vapor pressure as a function of temperature and are compared with current models for the vapor pressure of carbon. The effects of finite vaporization (i.e., nonequilibrium) rates are considered and compared with experiment. Estimates of the heat of vaporization from an energy balance are also presented.

  16. Tracing water vapor and ice during dust growth

    CERN Document Server

    Krijt, Sebastiaan; Bergin, Edwin A

    2016-01-01

    The processes that govern the evolution of dust and water (in the form of vapor or ice) in protoplanetary disks are intimately connected. We have developed a model that simulates dust coagulation, dust dynamics (settling, turbulent mixing), vapor diffusion, and condensation/sublimation of volatiles onto grains in a vertical column of a protoplanetary disk. We employ the model to study how dust growth and dynamics influence the vertical distribution of water vapor and water ice in the region just outside the radial snowline. Our main finding is that coagulation (boosted by the enhanced stickiness of icy grains) and the ensuing vertical settling of solids results in water vapor being depleted, but not totally removed, from the region above the snowline on a timescale commensurate with the vertical turbulent mixing timescale. Depending on the strength of the turbulence and the temperature, the depletion can reach factors of up to ${\\sim}50$ in the disk atmosphere. In our isothermal column, this vapor depletion r...

  17. Experimental Validation of Hybrid Distillation-Vapor Permeation Process for Energy Efficient Ethanol-Water Separation

    Science.gov (United States)

    The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation step,...

  18. Experimental Validation of Hybrid Distillation-Vapor Permeation Process for Energy Efficient Ethanol-Water Separation

    Science.gov (United States)

    The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation step,...

  19. Improvement of copper vapor laser characteristics by zinc additive

    Science.gov (United States)

    Shpenik, Yurij; Kelman, Volodymyr; Zhmenyak, Yurij

    2008-10-01

    The influence of Zn atom additive on ``pure'' copper vapor laser output characteristics was studied. Two-section discharge tube (DT) with an external heated Zn reservoir placed at the center between ceramic sections with Cu pieces was elaborated. The pulsed periodical longitudinal discharge was excited in the DT with Cu-Zn-Ne admixture by a traditional circuit using thyratron generator with resonant overcharge of a storage capacitor. Experimental investigations established that the width, energy and power of laser pulses increased when Zn atoms at appropriate temperature ˜ 500 ^oC of zinc containing reservoir diffuse into discharge. The registered increasing of pulse energy was up to 50% comparatively with the energy without additive with peak energy at ˜ 600 ^oC. Additional absorption experiments and modeling the absorption of Zn atom resonant line in the DT (taking into account Doppler and dispersion line broadening) consistent with the conclusion that not only optical resonant pumping by 213.9 nm Zn atom line, but other processes also might be taken into account to explain the influence effects (second kind collisions between resonance state zinc and metastable copper state atoms).

  20. Wind Generators

    Science.gov (United States)

    1989-01-01

    When Enerpro, Inc. president, Frank J. Bourbeau, attempted to file a patent on a system for synchronizing a wind generator to the electric utility grid, he discovered Marshall Space Flight Center's Frank Nola's power factor controller. Bourbeau advanced the technology and received a NASA license and a patent for his Auto Synchronous Controller (ASC). The ASC reduces generator "inrush current," which occurs when large generators are abruptly brought on line. It controls voltage so the generator is smoothly connected to the utility grid when it reaches its synchronous speed, protecting the components from inrush current damage. Generator efficiency is also increased in light winds by applying lower than rated voltage. Wind energy is utilized to drive turbines to generate electricity for utility companies.

  1. Hybrid Vapor Stripping-Vapor Permeation Process for Recovery and Dehydration of 1-Butanol and Acetone/Butanol/Ethanol from Dilute Aqueous Solutions. Part 2. Experimental Validation with Simple Mixtures and Actual Fermentation Broth

    Science.gov (United States)

    BACKGROUND: In Part1 of this work, a process integrating vapor stripping, vapor compression, and a vapor permeation membrane separation step, Membrane Assisted Vapor Stripping (MAVS), was predicted to produce energy savings compared to traditional distillation systems for separat...

  2. Hybrid Vapor Stripping-Vapor Permeation Process for Recovery and Dehydration of 1-Butanol and Acetone/Butanol/Ethanol from Dilute Aqueous Solutions. Part 2. Experimental Validation with Simple Mixtures and Actual Fermentation Broth

    Science.gov (United States)

    BACKGROUND: In Part1 of this work, a process integrating vapor stripping, vapor compression, and a vapor permeation membrane separation step, Membrane Assisted Vapor Stripping (MAVS), was predicted to produce energy savings compared to traditional distillation systems for separat...

  3. Rainfall generation

    Science.gov (United States)

    Sharma, Ashish; Mehrotra, Raj

    This chapter presents an overview of methods for stochastic generation of rainfall at annual to subdaily time scales, at single- to multiple-point locations, and in a changing climatic regime. Stochastic rainfall generators are used to provide inputs for risk assessment of natural or engineering systems that can undergo failure under sustained (high or low) extremes. As a result, generation of rainfall has evolved to provide options that adequately represent such conditions, leading to sequences that exhibit low-frequency variability of a nature similar to the observed rainfall. The chapter consists of three key sections: the first two outlining approaches for rainfall generation using endogenous predictor variables and the third highlighting approaches for generation using exogenous predictors often simulated to represent future climatic conditions. The first section presents approaches for generation of annual and seasonal rainfall and daily rainfall, both at single-point locations and multiple sites, with an emphasis on alternatives that ensure appropriate representation of low-frequency variability in the generated rainfall sequences. The second section highlights advancements in the subdaily rainfall generation procedures including commonly used approaches for daily to subdaily rainfall generation. The final section (generation using exogenous predictors) presents a range of alternatives for stochastic downscaling of rainfall for climate change impact assessments of natural and engineering systems. We conclude the chapter by outlining some of the key challenges that remain to be addressed, especially in generation under climate change conditions, with an emphasis on the importance of incorporating uncertainty present in both measurements and models, in the rainfall sequences that are generated.

  4. Obliquity-Controlled Water Vapor/Trace Gas Feedback in the Martian Greenhouse Cycle

    Science.gov (United States)

    Mischna, M. A.; Baker, V. R.; Milliken, R.; Richardson, M. I.; Lee, C.

    2013-12-01

    We have explored possible mechanisms for the generation of warm, wet climates on early Mars as a result of greenhouse warming by both water vapor and periodic volcanic trace gas emissions, using the Mars Weather Research and Forecasting (MarsWRF) general circulation model. The presence of both water vapor (a strong greenhouse gas) and other trace greenhouse gases (such as SO2) in a predominantly CO2 atmosphere may act, under certain conditions, to elevate surface temperatures above the freezing point of liquid water, at least episodically. The levels of warming obtained in our simulations do not reach the values seen in Johnson et al., (2008, JGR, 113, E08005), nor are they widespread for extended periods. Rather, warming above 273 K is found in more localized environments and for geologically brief periods of time. Such periodic episodes are controlled by two factors. First is the obliquity of the planet, which plays a significant role is ';activating' extant surface water ice reservoirs, allowing levels of atmospheric water vapor to rise when obliquity is high, and fall precipitously when the obliquity is low. During these low-obliquity periods, the atmosphere is all but incapable of supporting warm surface temperatures except for brief episodes localized wholly in the tropics; thus, there is a natural regulator in the obliquity cycle for maintaining periodic warming. Second is the presence of a secondary trace gas 'trigger', like volcanically released SO2, in the atmosphere. In the absence of such a trace gas, water vapor alone appears incapable of raising temperatures above the melting point; however, by temporarily raising the baseline global temperatures (in the absence of warming by water vapor) by 10-15 K, as with SO2, the trigger gas keeps atmospheric temperatures sufficiently warm, especially during nighttime, to maintain levels of water vapor in the atmosphere that provide the needed warming. Furthermore, we find that global warming can be achieved more

  5. Vapor-induced transfer of bacteria in the absence of mechanical disturbances

    KAUST Repository

    Ayoub, George M.

    2014-09-01

    Transfer of bacteria through water vapor generated at moderate temperatures (30-50. °C) in passive solar stills, has scarcely been reported. The objective of this research was to investigate whether bacteria in highly humid atmospheres can get transferred through water vapor in the absence of other transfer media to find their way to the distillate. To achieve this objective, passive solar reactors were chosen as the medium for experimentation, and distillation experiments were conducted by spiking a pure bacterial culture (Escherichia coli, Klebsiella pneumonia or Enterococcus faecalis) in low mineralized water vs. highly mineralized water in the dark under moderate temperatures ranges (30-35. °C, 40-45. °C and 50-55. °C). Results showed that bacteria indeed get transferred with the vapor in stills when not exposed to solar U.V. radiation. The trends observed were adequately explained by a zero-modified Hurdle-Poisson model. The numbers of cultivable bacterial colonies transferred were bacterial size, water type and temperature dependent with highest transfers occurring in E. faecalis>. E. coli>. K. pneumonia at the 40. °C range in low mineralized water. Proper management strategies are recommended to achieve complete disinfection in solar stills. © 2014 Elsevier B.V.

  6. Observation of Mountain Lee Waves with MODIS NIR Column Water Vapor

    Science.gov (United States)

    Lyapustin, A.; Alexander, M. J.; Ott, L.; Molod, A.; Holben, B.; Susskind, J.; Wang, Y.

    2014-01-01

    Mountain lee waves have been previously observed in data from the Moderate Resolution Imaging Spectroradiometer (MODIS) "water vapor" 6.7 micrometers channel which has a typical peak sensitivity at 550 hPa in the free troposphere. This paper reports the first observation of mountain waves generated by the Appalachian Mountains in the MODIS total column water vapor (CWV) product derived from near-infrared (NIR) (0.94 micrometers) measurements, which indicate perturbations very close to the surface. The CWV waves are usually observed during spring and late fall or some summer days with low to moderate CWV (below is approx. 2 cm). The observed lee waves display wavelengths from3-4 to 15kmwith an amplitude of variation often comparable to is approx. 50-70% of the total CWV. Since the bulk of atmospheric water vapor is confined to the boundary layer, this indicates that the impact of thesewaves extends deep into the boundary layer, and these may be the lowest level signatures of mountain lee waves presently detected by remote sensing over the land.

  7. Stimulation of vapor nucleation on perfect and imperfect hexagonal lattice surfaces

    Science.gov (United States)

    Shevkunov, S. V.

    2008-12-01

    Monte Carlo simulations of water vapor nucleation on a perfect crystal surface and on a surface with defects are performed. Mass exchange with the vapor phase is modeled by using an open ensemble. Cluster-substrate interaction is described in terms of conventional atom-atom potentials. The Hamiltonian of the system includes expressions for electrostatic, polarization, exchange, and dispersion interactions. The Gibbs free energy and work of adsorption are calculated by Monte Carlo simulation in the bicanoĭnical ensemble. The microscopic structure of nuclei is analyzed in terms of pair correlation functions. Periodic boundary conditions are used to simulate an infinite substrate surface. Molecule-substrate and molecule-molecule long-range electrostatic interactions are calculated by summing the Fourier harmonics of the electrostatic potential. Dispersion interactions are calculated by direct summation over layers of unit cells. Nucleation on a surface with matching structure follows a layer-by-layer mechanism. The work of adsorption per molecule of a monolayer on the substrate surface has a maximum as a function of nucleus size. The steady rate of nucleation of islands of supercritical size is evaluated. The work of adsorption per molecule for layer-by-layer film growth is an oscillating function of cluster size. As a function of layer number, it has a minimum depending on the vapor pressure. The electric field generated by a microscopic surface protrusion destroys the layered structure of the condensate and eliminates free-energy nucleation barriers. However, point lattice defects do not stimulate explosive nucleation.

  8. Performance Analysis of Organic Rankine-vapor Compression Ice Maker Utilizing Food Industry Waste Heat

    Directory of Open Access Journals (Sweden)

    Bing Hu

    2015-05-01

    Full Text Available To develop the organic Rankine-vapor compression ice maker driven by food industry exhaust gases and engine cooling water, an organic Rankine-vapor compression cycle system was employed for ice making and a thermodynamic model was developed and the effects of working fluid types, hot water temperature and condensation temperature on the system performance were analyzed and the ice making capacity from unit mass hot water and unit power waste heat were evaluated. The calculated results show that the working fluid type and the temperatures of heat source and condensation have important effects on the system performance. The system can achieve optimal performance when use R245fa as power and refrigeration medium. The ice quantity generated from per ton hot water is 86.42 kg and the ice-making rate for per kW waste heat is 2.27 kg/h, when the temperatures of hot water and condensation are respectively 100 and 40°C. A conclusion can be draw by the calculation and analysis that using organic Rankine-vapor compression system for ice making from food industry waste heat is feasible.

  9. Nuclear design of the burst power ultrahigh temperature UF4 vapor core reactor system

    Science.gov (United States)

    Kahook, Samer D.; Dugan, Edward T.

    1991-01-01

    Static and dynamic neutronic analyses are being performed, as part of an integrated series of studies, on an innovative burst power UF4 Ultrahigh Temperature Vapor Core Reactor (UTVR)/Disk Magnetohydrodynamic (MHD) generator for space nuclear power applications. This novel reactor concept operates on a direct, closed Rankine cycle in the burst power mode (hundreds of MWe for thousands of seconds). The fuel/working fluid is a mixture of UF4 and metal fluoride. Preliminary calculations indicate high overall system efficiencies (≊20%), small radiator size (≊5 m2/MWe), and high specific power (≊5 kWe/kg). Neutronic analysis has revealed a number of attractive features for this novel reactor concept. These include some unique and very effective inherent negative reactivity control mechanisms such as the vapor-fuel density power coefficient of reactivity, the direct neutronic coupling among the multiple fissioning core regions (the central vapor core and the surrounding boiler columns), and the mass flow coupling feedback between the fissioning cores.

  10. Non-equilibrium phenomena near vapor-liquid interfaces

    CERN Document Server

    Kryukov, Alexei; Puzina, Yulia

    2013-01-01

    This book presents information on the development of a non-equilibrium approach to the study of heat and mass transfer problems using vapor-liquid interfaces, and demonstrates its application to a broad range of problems. In the process, the following peculiarities become apparent: 1. At vapor condensation on the interface from gas-vapor mixture, non-condensable components can lock up the interface surface and condensation stops completely. 2. At the evolution of vapor film on the heater in superfluid helium (He-II), the boiling mass flux density from the vapor-liquid interface is effectively zero at the macroscopic scale. 3. In problems concerning the motion of He-II bridges inside capillaries filled by vapor, in the presence of axial heat flux the He-II bridge cannot move from the heater as would a traditional liquid, but in the opposite direction instead. Thus the heater attracts the superfluid helium bridge. 4. The shape of liquid-vapor interface at film boiling on the axis-symmetric heaters immersed in l...

  11. Oxidation/vaporization of silicide coated columbium base alloys

    Science.gov (United States)

    Kohl, F. J.; Stearns, C. A.

    1971-01-01

    Mass spectrometric and target collection experiments were made at 1600 K to elucidate the mode of oxidative vaporization of two columbium alloys, fused-slurry-coated with a complex silicide former (Si-20Cr-Fe). At oxygen pressures up to 0.0005 torr the major vapor component detected by mass spectrometry for oxidized samples was gaseous silicon monoxide. Analysis of condensates collected at oxygen pressures of 0.1, 1.0 and 10 torr revealed that chromium-, silicon-, iron- and tungsten- containing species were the major products of vaporization. Equilibrium thermochemical diagrams were constructed for the metal-oxygen system corresponding to each constituent metal in both the coating and base alloy. The major vaporizing species are expected to be the gaseous oxides of chromium, silicon, iron and tungsten. Plots of vapor phase composition and maximum vaporization rate versus oxygen pressure were calculated for each coating constituent. The major contribution to weight loss by vaporization at oxygen pressures above 1 torr was shown to be the chromium-containing species.

  12. Ionic Vapor Composition in Pyridinium-Based Ionic Liquids.

    Science.gov (United States)

    Chaban, Vitaly V; Prezhdo, Oleg V

    2016-05-26

    Strong electrostatic interactions in ionic compounds make vaporization a complex process. The gas phase can contain a broad range of ionic clusters, and the cluster composition can differ greatly from that in the liquid phase. Room-temperature ionic liquids (RTILs) constitute a complicated case due to their ionic nature, asymmetric structure, and a huge versatility of ions and ionic clusters. This work reports vapor-liquid equilibria and vapor compositions of butylpyridinium (BPY) RTILs formed with hexafluorophosphate (PF6), trifluoromethanesulfonate (TF), and bis(trifluoromethanesulfonyl)imide (TFSI) anions. Unlike inorganic crystals, the pyridinium-based RTILs contain significant percentages of charged clusters in the vapor phase. Ion triplets and ion quadruplets each constitute up to 10% of the vapor phase composition. Triples prevail over quadruples in [BPY][PF6] due to the size difference of the cation and the anion. The percentage of charged ionic clusters in the gas phase is in inverse proportion to the mass of the anion. The largest identified vaporized ionic cluster comprises eight ions, with a formation probability below 1%. Higher temperature fosters formation of larger clusters due to an increase of the saturated vapor density.

  13. Generative Semantics

    Science.gov (United States)

    Bagha, Karim Nazari

    2011-01-01

    Generative semantics is (or perhaps was) a research program within linguistics, initiated by the work of George Lakoff, John R. Ross, Paul Postal and later McCawley. The approach developed out of transformational generative grammar in the mid 1960s, but stood largely in opposition to work by Noam Chomsky and his students. The nature and genesis of…

  14. Enhanced Attenuation Technologies: Passive Soil Vapor Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K.; Looney, B.; Kamath, R.; Adamson, D.; Newell, C.

    2010-03-15

    Passive soil vapor extraction (PSVE) is an enhanced attenuation (EA) approach that removes volatile contaminants from soil. The extraction is driven by natural pressure gradients between the subsurface and atmosphere (Barometric Pumping), or by renewable sources of energy such as wind or solar power (Assisted PSVE). The technology is applicable for remediating sites with low levels of contamination and for transitioning sites from active source technologies such as active soil vapor extraction (ASVE) to natural attenuation. PSVE systems are simple to design and operate and are more cost effective than active systems in many scenarios. Thus, PSVE is often appropriate as an interim-remedial or polishing strategy. Over the past decade, PSVE has been demonstrated in the U.S. and in Europe. These demonstrations provide practical information to assist in selecting, designing and implementing the technology. These demonstrations indicate that the technology can be effective in achieving remedial objectives in a timely fashion. The keys to success include: (1) Application at sites where the residual source quantities, and associated fluxes to groundwater, are relatively low; (2) Selection of the appropriate passive energy source - barometric pumping in cases with a deep vadose zone and barrier (e.g., clay) layers that separate the subsurface from the atmosphere and renewable energy assisted PSVE in other settings and where higher flow rates are required. (3) Provision of sufficient access to the contaminated vadose zones through the spacing and number of extraction wells. This PSVE technology report provides a summary of the relevant technical background, real-world case study performance, key design and cost considerations, and a scenario-based cost evaluation. The key design and cost considerations are organized into a flowchart that dovetails with the Enhanced Attenuation: Chlorinated Organics Guidance of the Interstate Technology and Regulatory Council (ITRC). The PSVE

  15. New Regenerative Cycle for Vapor Compression Refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Mark J. Bergander

    2005-08-29

    The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and

  16. Processes Controlling Water Vapor in the Winter Arctic Stratospheric Middleworld

    Science.gov (United States)

    Pfister, Leonhard; Selkirk, Henry; Jensen, Eric; Sachse, Glenn; Podolske, James; Schoeberl, Mark; Browell, Edward; Ismail, Syed; Hipskind, R. Stephen (Technical Monitor)

    2000-01-01

    Water vapor in the winter arctic stratospheric middleworld is import-an: for two reasons: (1) the arctic middleworld is a source of air for the upper Troposphere because of the generally downward motion, and thus its water vapor content helps determine upper tropospheric water, a critical part of the earth's radiation budget; and (2) under appropriate conditions, relative humidities will be large, even to the point of stratospheric cirrus cloud formation, leading to the production of active chlorine species that could destroy ozone. On a number of occasions during SOLVE, clouds were observed in the stratospheric middleworld by the DC-8 aircraft. These tended to coincide with regions of low temperatures, though some cases suggest water vapor enhancements due to troposphere-to-stratosphere transport. The goal of this work is to understand the importance of processes in and at the edge of the arctic stratospheric middleworld in determining water vapor at these levels. Specifically, is water vapor at these levels determined largely by the descent of air from above, or are clouds both within and at the edge of the stratospheric middleworld potentially important? How important is troposphere-to-stratosphere transport of air in determining stratospheric middleworld water vapor content? To this end, we will first examine the minimum saturation mixing ratios along theta/EPV tubes during the SOLVE winter and compare these with DC-8 water vapor observations. This will be a rough indicator of how high relative humidities can get, and the likelihood of cirrus cloud formation in various parts of the stratospheric middleworld. We will then examine saturation mixing ratios along both diabatic and adiabatic trajectories, comparing these values with actual aircraft water vapor observations, both in situ and remote. Finally, we will attempt to actually predict water vapor using minimum saturation mixing ratios along trajectories, cloud injection (derived from satellite imagery) along

  17. Vapor-induced transfer of bacteria in the absence of mechanical disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Ayoub, G.M., E-mail: gayoub@aub.edu.lb [Department of Civil and Environmental Engineering, American University of Beirut (Lebanon); Dahdah, L.; Alameddine, I. [Department of Civil and Environmental Engineering, American University of Beirut (Lebanon); Malaeb, L. [Water Desalination and Reuse Research Center, KAUST, Thuwal 23955-6900 (Saudi Arabia)

    2014-09-15

    Graphical abstract: - Highlights: • Study is first to investigate the possibility of transfer of bacteria through vapor. • Bacteria exhibited transfer in the absence of mechanical disturbances in reactors. • Gram positive smaller bacteria transferred more than gram negative larger bacteria. • Transfer probability increases at optimal growth temperature of mesophilic bacteria. • Salinity lowers bacterial survival and has synergistic effect with temperature. - Abstract: Transfer of bacteria through water vapor generated at moderate temperatures (30–50 °C) in passive solar stills, has scarcely been reported. The objective of this research was to investigate whether bacteria in highly humid atmospheres can get transferred through water vapor in the absence of other transfer media to find their way to the distillate. To achieve this objective, passive solar reactors were chosen as the medium for experimentation, and distillation experiments were conducted by spiking a pure bacterial culture (Escherichia coli, Klebsiella pneumonia or Enterococcus faecalis) in low mineralized water vs. highly mineralized water in the dark under moderate temperatures ranges (30–35 °C, 40–45 °C and 50–55 °C). Results showed that bacteria indeed get transferred with the vapor in stills when not exposed to solar U.V. radiation. The trends observed were adequately explained by a zero-modified Hurdle–Poisson model. The numbers of cultivable bacterial colonies transferred were bacterial size, water type and temperature dependent with highest transfers occurring in E. faecalis > E. coli > K. pneumonia at the 40 °C range in low mineralized water. Proper management strategies are recommended to achieve complete disinfection in solar stills.

  18. Vapor Flow Resistance of Dry Soil Layer to Soil Water Evaporation in Arid Environment: An Overview

    Directory of Open Access Journals (Sweden)

    Xixi Wang

    2015-08-01

    Full Text Available Evaporation from bare sandy soils is the core component of the hydrologic cycle in arid environments, where vertical water movement dominates. Although extensive measurement and modeling studies have been conducted and reported in existing literature, the physics of dry soil and its function in evaporation is still a challenging topic with significant remaining issues. Thus, an overview of the previous findings will be very beneficial for identifying further research needs that aim to advance our understanding of the vapor flow resistance (VFR effect on soil water evaporation as influenced by characteristics of the dry soil layer (DSL and evaporation zone (EZ. In this regard, six measurement and four modeling studies were overviewed. The results of these overviewed studies, along with the others, affirm the conceptual dynamics of DSL and EZ during drying or wetting processes (but not both within dry sandy soils. The VFR effect tends to linearly increase with DSL thickness (δ when δ < 5 cm and is likely to increase as a logarithmic function of δ when δ ≥ 5 cm. The vaporization-condensation-movement (VCM dynamics in a DSL depend on soil textures: sandy soils can form a thick (10 to 20 cm DSL while sandy clay soils may or may not have a clear DSL; regardless, a DSL can function as a transient EZ, a vapor condensation zone, and/or a vapor transport medium. Based on the overview, further studies will need to generate long-term continuous field data, develop hydraulic functions for very dry soils, and establish an approach to quantify the dynamics and VFR effects of DSLs during wetting-drying cycles as well as take into account such effects  when using conventional (e.g., Penman-Monteith evaporation models.

  19. Excess liquid in heat-pipe vapor spaces

    Science.gov (United States)

    Eninger, J. E.; Edwards, D. K.

    1977-01-01

    A mathematical model is developed of excess liquid in heat pipes that is used to calculate the parameters governing the axial flow of liquid in fillets and puddles that form in vapor spaces. In an acceleration field, the hydrostatic pressure variation is taken into account, which results in noncircular meniscus shapes. The two specific vapor-space geometries considered are circular and the 'Dee-shape' that is formed by a slab wick in a circular tube. Also presented are theoretical and experimental results for the conditions under which liquid slugs form at the ends of the vapor spaces. These results also apply to the priming of arteries.

  20. Preliminary assessment of halogenated alkanes as vapor-phase tracers

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Michael C.; Moore, Joseph N.; Hirtz, Paul

    1991-01-01

    New tracers are needed to evaluate the efficiency of injection strategies in vapor-dominated environments. One group of compounds that seems to meet the requirements for vapor-phase tracing are the halogenated alkanes (HCFCs). HCFCs are generally nontoxic, and extrapolation of tabulated thermodynamic data indicate that they will be thermally stable and nonreactive in a geothermal environment. The solubilities and stabilities of these compounds, which form several homologous series, vary according to the substituent ratios of fluorine, chlorine, and hydrogen. Laboratory and field tests that will further define the suitability of HCFCs as vapor-phase tracers are under way.

  1. Raman lidar measurements of tropospheric water vapor over Hefei

    Institute of Scientific and Technical Information of China (English)

    Yonghua Wu(吴永华); Huanling Hu(胡欢陵); Shunxing Hu(胡顺星); Jun Zhou(周军)

    2003-01-01

    L625 Raman lidar has been developed for water vapor measurements over Hefei, China since September2000. By transmitting laser beam of frequency-tripled Nd:YAG laser, Raman scattering signals of watervapor and nitrogen molecules are simultaneously detected by the cooled photomultipliers with photoncounting mode. Water vapor mixing ratios measured by Raman lidar show the good agreements withradiosonde observations, which indicates this Raman lidar is reliable. Many observation cases show thataerosol optical parameters have the good correlation with water vapor distribution in the lower troposphere.

  2. Boiling Heat Transfer on Porous Surfaces with Vapor Channels

    Institute of Scientific and Technical Information of China (English)

    吴伟; 杜建华; 王补宣

    2002-01-01

    Boiling heat transfer on porous coated surfaces with vapor channels was investigated experimentally to determine the effects of the size and density of the vapor channels on the boiling heat transfer. Observations showed that bubbles escaping from the channels enhanced the heat transfer. Three regimes were identified: liquid flooding, bubbles in the channel and the bottom drying out region. The maximum heat transfer occurred for an optimum vapor channel density and the boiling heat transfer performance was increased if the channels were open to the bottom of the porous coating.

  3. Shock wave of vapor-liquid two-phase flow

    Institute of Scientific and Technical Information of China (English)

    Liangju ZHAO; Fei WANG; Hong GAO; Jingwen TANG; Yuexiang YUAN

    2008-01-01

    The shock wave of vapor-liquid two-phase flow in a pressure-gain steam injector is studied by build-ing a mathematic model and making calculations. The results show that after the shock, the vapor is nearly com-pletely condensed. The upstream Mach number and the volume ratio of vapor have a great effect on the shock. The pressure and Mach number of two-phase shock con-form to the shock of ideal gas. The analysis of available energy shows that the shock is an irreversible process with entropy increase.

  4. Controlling the vapor pressure of a mercury lamp

    Science.gov (United States)

    Grossman, M.W.; George, W.A.

    1988-05-24

    The invention described herein discloses a method and apparatus for controlling the Hg vapor pressure within a lamp. This is done by establishing and controlling two temperature zones within the lamp. One zone is colder than the other zone. The first zone is called the cold spot. By controlling the temperature of the cold spot, the Hg vapor pressure within the lamp is controlled. Likewise, by controlling the Hg vapor pressure of the lamp, the intensity and linewidth of the radiation emitted from the lamp is controlled. 2 figs.

  5. Surface acoustic wave vapor sensors based on resonator devices

    Science.gov (United States)

    Grate, Jay W.; Klusty, Mark

    1991-05-01

    Surface acoustic wave (SAW) devices fabricated in the resonator configuration have been used as organic vapor sensors and compared with delay line devices more commonly used. The experimentally determined mass sensitivities of 200, 300, and 400 MHz resonators and 158 MHz delay lines coated with Langmuir-Blodgett films of poly(vinyl tetradecanal) are in excellent agreement with theoretical predictions. The response of LB- and spray-coated sensors to various organic vapors were determined, and scaling laws for mass sensitivities, vapor sensitivities, and detection limits are discussed. The 200 MHz resonators provide the lowest noise levels and detection limits of all the devices examined.

  6. Quality Assurance Project Plan for waste tank vapor characterization

    Energy Technology Data Exchange (ETDEWEB)

    Suydam, C.D. Jr.

    1993-12-01

    This Quality Assurance Project Plan, WHC-SD-WM-QAPP-013, applies to four separate vapor sampling tasks associated with Phases 1 and 2 of the Tank Vapor Issue Resolution Program and support of the Rotary Mode Core Drilling Portable Exhauster Permit. These tasks focus on employee safety concerns and tank ventilation emission control design requirements. Previous characterization efforts and studies are of insufficient accuracy to adequately define the problem. It is believed that the technology and maturity of sampling and analytical methods can be sufficiently developed to allow the characterization of the constituents of the tank vapor space.

  7. Vaporization Studies of Olivine via Knudsen Effusion Mass Spectrometry

    Science.gov (United States)

    Costa, G. C. C.; Jacobson, N. S.

    2014-01-01

    Olivine is the major mineral in the Earth's upper mantle occurring predominantly in igneous rocks and has been identified in meteorites, asteroids, the Moon and Mars. Among many other important applications in planetary and materials sciences, the thermodynamic properties of vapor species from olivine are crucial as input parameters in computational modelling of the atmospheres of hot, rocky exoplanets (lava planets). There are several weight loss studies of olivine vaporization in the literature and one Knudsen Effusion Mass Spectrometry (KEMS) study. In this study, we examine a forsterite-rich olivine (93% forsterite and 7% fayalite, Fo93Fa7) with KEMS to further understand its vaporization and thermodynamic properties.

  8. Heat Transfer in Flue Gas with Vapor Condensation

    Institute of Scientific and Technical Information of China (English)

    贾力; 彭晓峰

    2002-01-01

    This paper combines the film model with Nusselt's condensation theory to analyze the effects of water vapor condensation on the heat transfer performance of flue gas flowing through a vertical tube. The analysis compares the condensation and convective heat transfer rates. For the concentration range investigated, the water vapor condensation transfers more energy than the flue gas convection, but the convective heat transfer can not be neglected. The heat transfer intensification due to the condensation increased as the water vapor fraction increased. The theoretical results compared well with experimental data.

  9. Cycle simulation of the low-temperature triple-effect absorption chiller with vapor compression unit

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.S.; Lee, H.

    1999-07-01

    The construction of a triple-effect absorption chiller machine using the lithium bromide-water solution as a working fluid is strongly limited by corrosion problems caused by the high generator temperature. In this work, three new cycles having the additional vapor compression units were suggested in order to lower the generator temperature of a triple-effect absorption chiller. Each new cycle has one compressor located at the different position which was used to elevate the pressure of the refrigerant vapor. Computer simulations were carried out in order to examine both the basic triple-effect cycle and three new cycles. All types of triple-effect absorption chiller cycles were found to be able to lower the temperature of high-temperature generator to the more favorable operation range. The COPs of three cycles calculated by considering the additional compressor works showed a small level of decrease or increase compared with that of the basic triple-effect cycle. Consequently, a low-temperature triple-effect absorption chiller can be possibly constructed by adapting one of three new cycles. A great advantage of these new cycles over the basic one is that the conventionally used lithium bromide-water solution can be successfully used as a working fluid without the danger of corrosion.

  10. Shape correction of optical surfaces using plasma chemical vaporization machining with a hemispherical tip electrode.

    Science.gov (United States)

    Takino, Hideo; Yamamura, Kazuya; Sano, Yasuhisa; Mori, Yuzo

    2012-01-20

    We propose a plasma chemical vaporization machining device with a hemispherical tip electrode for optical fabrication. Radio-frequency plasma is generated close to the electrode under atmospheric conditions, and a workpiece is scanned relative to the stationary electrode under three-axis motion control to remove target areas on a workpiece surface. Experimental results demonstrate that surface removal progresses although process gas is not forcibly supplied to the plasma. The correction of shape errors on conventionally polished spheres is performed. As a result, highly accurate smooth surfaces with the desired rms shape accuracy of 3 nm are successfully obtained, which confirms that the device is effective for the fabrication of optics.

  11. Relative-intensity squeezing at audio frequencies using four-wave mixing in an atomic vapor

    CERN Document Server

    McCormick, C F; Lett, P D; Marino, A M

    2007-01-01

    We demonstrate the use of four-wave mixing in hot atomic vapor to generate up to -7.1 dB of measured relative-intensity squeezing. Due to its intrinsic simplicity, our system is strongly decoupled from environmental noise, and we observe more than -4 dB of squeezing down to frequencies as low as 5 kHz. This robust source of narrowband squeezed light may be useful for a variety of applications, such as coupling to atomic ensembles and enhancing the sensitivity of photothermal spectroscopy.

  12. Results of Vapor Space Monitoring of Flammable Gas Watch List Tanks

    Energy Technology Data Exchange (ETDEWEB)

    MCCAIN, D.J.

    2000-09-27

    This report documents the measurement of headspace gas concentrations and monitoring results from the Hanford tanks that have continuous flammable gas monitoring. The systems used to monitor the tanks are Standard Hydrogen Monitoring Systems. Further characterization of the tank off-gases was done with Gas Characterization systems and vapor grab samples. The background concentrations of all tanks are below the action level of 6250 ppm. Other information which can be derived from the measurements (such as generation rate, released rate, and ventilation rate) is also discussed.

  13. Enhanced four-wave mixing via crossover resonance in cesium vapor

    CERN Document Server

    de Silans, T Passerat; Felinto, D; Tabosa, J W R

    2011-01-01

    We report on the observation of enhanced four-wave mixing via crossover resonance in a Doppler broadened cesium vapor. Using a single laser frequency, a resonant parametric process in a double-$\\Lambda$ level configuration is directly excited for a specific velocity class. We investigate this process in different saturation regimes and demonstrate the possibility of generating intensity correlation and anti-correlation between the probe and conjugate beams. A simple theoretical model is developed that accounts qualitatively well to the observed results.

  14. Identification of a wagging vibrational mode of water molecules at the water/vapor interface.

    Science.gov (United States)

    Perry, Angela; Neipert, Christine; Ridley, Christina; Space, Brian; Moore, Preston B

    2005-05-01

    An improved time correlation function description of sum frequency generation (SFG) spectroscopy was applied to theoretically describe the water/vapor interface. The resulting spectra compare favorably in shape and relative magnitude to extant experimental results in the O-H stretching region of water. Further, the SFG spectra show a well-defined intermolecular mode at 875 cm(-1) that has significant intensity. The resonance is due to a wagging mode localized on a single water molecule. It represents a well-defined population of water molecules at the interface that, along with the free O-H modes, represent the dominant interfacial species.

  15. Modulation of the photonic band structure topology of a honeycomb lattice in an atomic vapor

    CERN Document Server

    Zhang, Yiqi; Belić, Milivoj R; Wu, Zhenkun; Zhang, Yanpeng

    2015-01-01

    In an atomic vapor, a honeycomb lattice can be constructed by utilizing the three-beam interference method. In the method, the interference of the three beams splits the dressed energy level periodically, forming a periodic refractive index modulation with the honeycomb profile. The energy band topology of the honeycomb lattice can be modulated by frequency detunings, thereby affecting the appearance (and disappearance) of Dirac points and cones in the momentum space. This effect can be usefully exploited for the generation and manipulation of topological insulators.

  16. (Mol. Stuntz por arrastre de vapor

    Directory of Open Access Journals (Sweden)

    Ximena Araneda

    2014-01-01

    Full Text Available El objetivo del presente estudio fue elaborar y evaluar jugo de maqui (Aristotelia chilensis(Mol. Stuntz, paraser considerado potencialmente como una bebida funcional de origen natural, sin aditivos químicos y mínimoprocesamiento, mediante la técnica de arrastre por vapor de tipo artesanal. Se utilizó fruto recolectado deforma manual en la Región de La Araucanía (Chile. Se elaboraron dos jugos concentrados, con azúcar y sinazúcar. Se realizaron análisis tales como: contenido de sólidos solubles, pH, acidez, contenido de humedad,materia seca (MS, cenizas totales, azúcares totales (AT, proteína cruda (PC, polifenoles totales (PFT ycarbohidratos totales (CHT, destacando el contenido de polifenoles para el jugo sin azúcar con 993,2 mg 100mL-1EAG y para el jugo con azúcar con 829,208 mg 100 mL-1EAG. Por lo tanto, la técnica permite extraerjugo de maqui con un mínimo procesamiento, presentando éste una alta concentración de polifenoles.

  17. Copper vapor laser prospects in glaucoma treatment

    Science.gov (United States)

    Nesterov, Arcady P.; Novoderezhkin, Vladimir I.; Egorov, Alexey E.; Shaban, Naim; Ponomarev, Igor V.

    1996-05-01

    New advances of copper vapor laser (CVL-laser) have been studied. Two wavelength radiation of the laser (511 nm and 578 nm) gives deeper permeability into organic tissues. Besides, the short pulse prevents the warm relaxation of small vessels. The technical data of CVL-laser: operating regime -- pulse, pulse duration -- 20 ns, pulse frequency 15000 pulse/sec. The shutter works in intervals from 0.05 to 2.0 sec. The power varies in accordance with wavelength: 511 nm (green) -- 1.5 W, 578 nm (yellow) -- 1, 2 W. The diameter of coagulate may be different: 100, 150, 400, 1000 mkm. We chose CVL-laser 'Femta,' created by P. N. Lebedev Physical Institute of RAS, for ophthalmological use. Thirty eight eyes of 37 patients with different types and stages of glaucoma were studied and treated with CVL-laser. The operations of photomydriasis, gonioplasty and trabeculoplasty have been performed. CVL- laser demonstrated efficient application in treatment of interior eye segment of glaucoma patients. The advantages and disadvantages of the CVL-laser application in glaucoma surgery were discussed.

  18. Ionized Physical Vapor Deposition and Diagnostics

    Science.gov (United States)

    Ruzic, D. N.; Hayden, D. B.; Juliano, D. R.

    1997-11-01

    Magnetron sputtering is a typical method of physical vapor deposition (PVD) often used in depositing metal interconnects between layers of a semiconductor substrate. However, conventional PVD places an upper limit on the aspect ratio (depth:width) of features to be filled due to the isotropic velocity distribution of the sputtered neutrals. At higher aspect ratios the sputtered particles can coat the sides of a trench before filling it, thus pinching off the trench and leaving either an open circuit or a high resistivity connection. In our system an ICP coil is introduced between the magnetron target and substrate, creating a secondary plasma that can ionize a significant fraction of the sputtered neutral atoms. A negatively biased substrate will accelerate these ions normally, giving a directional flux that can fill the trench from the bottom up. The deposition rates and metal flux ionization fractions are measured with a quartz crystal microbalance and a multi-grid analyzer. Plasma conditions are measured with a time-resolved Langmuir probe system. Both diagnostics are employed for various pressures, magnetron and RF powers, and background gas types. The ability of the system to fill higher aspect ratio features is also discussed.

  19. DSMC simulation of Europa water vapor plumes

    Science.gov (United States)

    Berg, J. J.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.

    2016-10-01

    A computational investigation of the physics of water vapor plumes on Europa was performed with a focus on characteristics relevant to observation and spacecraft mission operations. The direct simulation Monte Carlo (DSMC) method was used to model the plume expansion assuming a supersonic vent source. The structure of the plume was determined, including the number density, temperature, and velocity fields. The possibility of ice grain growth above the vent was considered and deemed probable for large (diameter > ∼20 m) vents at certain Mach numbers. Additionally, preexisting grains of three diameters (0.1, 1, 50 μm) were included and their trajectories examined. A preliminary study of photodissociation of H2O into OH and H was performed to demonstrate the behavior of daughter species. A set of vent parameters was evaluated including Mach number (Mach 2, 3, 5), reduced temperature as a proxy for flow energy loss to the region surrounding the vent, and mass flow rate. Plume behavior was relatively insensitive to these factors, with the notable exception of mass flow rate. With an assumed mass flow rate of ∼1000 kg/s, a canopy shock occurred and a maximum integrated line of sight column density of ∼1020 H2O molecules/m2 was calculated, comparing favorably with observation (Roth et al., 2014a).

  20. Acoustic Droplet Vaporization in Biology and Medicine

    Directory of Open Access Journals (Sweden)

    Chung-Yin Lin

    2013-01-01

    Full Text Available This paper reviews the literature regarding the use of acoustic droplet vaporization (ADV in clinical applications of imaging, embolic therapy, and therapeutic delivery. ADV is a physical process in which the pressure waves of ultrasound induce a phase transition that causes superheated liquid nanodroplets to form gas bubbles. The bubbles provide ultrasonic imaging contrast and other functions. ADV of perfluoropentane was used extensively in imaging for preclinical trials in the 1990s, but its use declined rapidly with the advent of other imaging agents. In the last decade, ADV was proposed and explored for embolic occlusion therapy, drug delivery, aberration correction, and high intensity focused ultrasound (HIFU sensitization. Vessel occlusion via ADV has been explored in rodents and dogs and may be approaching clinical use. ADV for drug delivery is still in preclinical stages with initial applications to treat tumors in mice. Other techniques are still in preclinical studies but have potential for clinical use in specialty applications. Overall, ADV has a bright future in clinical application because the small size of nanodroplets greatly reduces the rate of clearance compared to larger contrast agent bubbles and yet provides the advantages of ultrasonographic contrast, acoustic cavitation, and nontoxicity of conventional perfluorocarbon contrast agent bubbles.

  1. High temperature measurement of water vapor absorption

    Science.gov (United States)

    Keefer, Dennis; Lewis, J. W. L.; Eskridge, Richard

    1985-01-01

    An investigation was undertaken to measure the absorption coefficient, at a wavelength of 10.6 microns, for mixtures of water vapor and a diluent gas at high temperature and pressure. The experimental concept was to create the desired conditions of temperature and pressure in a laser absorption wave, similar to that which would be created in a laser propulsion system. A simplified numerical model was developed to predict the characteristics of the absorption wave and to estimate the laser intensity threshold for initiation. A non-intrusive method for temperature measurement utilizing optical laser-beam deflection (OLD) and optical spark breakdown produced by an excimer laser, was thoroughly investigated and found suitable for the non-equilibrium conditions expected in the wave. Experiments were performed to verify the temperature measurement technique, to screen possible materials for surface initiation of the laser absorption wave and to attempt to initiate an absorption wave using the 1.5 kW carbon dioxide laser. The OLD technique was proven for air and for argon, but spark breakdown could not be produced in helium. It was not possible to initiate a laser absorption wave in mixtures of water and helium or water and argon using the 1.5 kW laser, a result which was consistent with the model prediction.

  2. Chemical vapor deposited fiber coatings and chemical vapor infiltrated ceramic matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Kmetz, M.A.

    1992-01-01

    Conventional Chemical Vapor Deposition (CVD) and Organometallic Chemical Vapor Deposition (MOCVD) were employed to deposit a series of interfacial coatings on SiC and carbon yarn. Molybdenum, tungsten and chromium hexacarbonyls were utilized as precursors in a low temperature (350[degrees]C) MOCVD process to coat SiC yarn with Mo, W and Cr oxycarbides. Annealing studies performed on the MoOC and WOC coated SiC yarns in N[sub 2] to 1,000[degrees]C establish that further decomposition of the oxycarbides occurred, culminating in the formation of the metals. These metals were then found to react with Si to form Mo and W disilicide coatings. In the Cr system, heating in N[sub 2] above 800[degrees]C resulted in the formation of a mixture of carbides and oxides. Convention CVD was also employed to coat SiC and carbon yarn with C, Bn and a new interface designated BC (a carbon-boron alloy). The coated tows were then infiltrated with SiC, TiO[sub 2], SiO[sub 2] and B[sub 4]C by a chemical vapor infiltration process. The B-C coatings were found to provide advantageous interfacial properties over carbon and BN coatings in several different composite systems. The effectiveness of these different coatings to act as a chemically inert barrier layer and their relationship to the degree of interfacial debonding on the mechanical properties of the composites were examined. The effects of thermal stability and strength of the coated fibers and composites were also determined for several difference atmospheres. In addition, a new method for determining the tensile strength of the as-received and coated yarns was also developed. The coated fibers and composites were further characterized by AES, SEM, XPS, IR and X-ray diffraction analysis.

  3. Report Generator

    OpenAIRE

    2016-01-01

    Download data from HP Quality Center using of OTA Client. Implementation must be scalable to all projects under test. That is, it will be possible to generate automatically test reports at least for 2010, Modulaser and Gen2 (FW or SW). Report Generator is a software implemented in VBA that allows get data from HP Quality Center for export it (either tables, charts or text) to a document in Word format. Report Generator es un Software implementado en VBA que permite extraer datos de HP Q...

  4. Geostationary satellite-based 6.7 μm band best water vapor information layer analysis over the Tibetan Plateau

    Science.gov (United States)

    Di, Di; Ai, Yufei; Li, Jun; Shi, Wenjing; Lu, Naimeng

    2016-05-01

    The best water vapor information layer (BWIL) of the 6.7 μm water vapor absorption infrared (IR) band for the FengYun-2E is investigated over the Tibetan Plateau with standard atmospheric profile and European Centre for Medium-Range Weather Forecasts (ECMWF) operational model analysis data. The sensitivity tests show that surface characteristics over the Tibetan Plateau have a significant influence on the BWIL. To be specific, topographic elevation, colder skin temperature, and lower emissivity tend to lift the altitude of the BWIL, decrease its magnitude, and narrow the half-width range. The results from statistical analysis indicate that the altitude of the BWIL reaches the highest in summer and the lowest in winter. Meanwhile, the altitude of the BWIL is highly correlated with the water vapor amount above 500 hPa over the Tibetan Plateau and above 300 hPa over the East China Plain, respectively. The diurnal variation in the BWIL is synchronous with the diurnal variation in the surface skin temperature. It can be concluded from the study that surface characteristics over high terrain in dry and cold atmospheres have more significant impacts on the BWIL. With multiple water vapor absorption IR bands, the imagers on board the new generation of geostationary satellites will provide crucial improvement in water vapor remote sensing over the current single water vapor band on board the FY-2 series according to the analysis in this study.

  5. Direct synthesis of large area graphene on insulating substrate by gallium vapor-assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Katsuhisa, E-mail: k.murakami@bk.tsukuba.ac.jp; Hiyama, Takaki; Kuwajima, Tomoya; Fujita, Jun-ichi [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573 (Japan); Tsukuba Research Center for Interdisciplinary Materials Science, University of Tsukuba, Tsukuba 305-8573 (Japan); Tanaka, Shunsuke; Hirukawa, Ayaka [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573 (Japan); Kano, Emi [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573 (Japan); National Institute for Materials Science, Tsukuba 305-0047 (Japan); Takeguchi, Masaki [National Institute for Materials Science, Tsukuba 305-0047 (Japan)

    2015-03-02

    A single layer of graphene with dimensions of 20 mm × 20 mm was grown directly on an insulating substrate by chemical vapor deposition using Ga vapor catalysts. The graphene layer showed highly homogeneous crystal quality over a large area on the insulating substrate. The crystal quality of the graphene was measured by Raman spectroscopy and was found to improve with increasing Ga vapor density on the reaction area. High-resolution transmission electron microscopy observations showed that the synthesized graphene had a perfect atomic-scale crystal structure within its grains, which ranged in size from 50 nm to 200 nm.

  6. Chemical Fractionation in the Silicate Vapor Atmosphere of the Earth

    CERN Document Server

    Pahlevan, Kaveh; Eiler, John; 10.1016/j.epsl.2010.10.03

    2010-01-01

    Despite its importance to questions of lunar origin, the chemical composition of the Moon is not precisely known. In recent years, however, the isotopic composition of lunar samples has been determined to high precision and found to be indistinguishable from the terrestrial mantle despite widespread isotopic heterogeneity in the Solar System. In the context of the giant-impact hypothesis, this level of isotopic homogeneity can evolve if the proto-lunar disk and post-impact Earth undergo turbulent mixing into a single uniform reservoir while the system is extensively molten and partially vaporized. In the absence of liquid-vapor separation, such a model leads to the lunar inheritance of the chemical composition of the terrestrial magma ocean. Hence, the turbulent mixing model raises the question of how chemical differences arose between the silicate Earth and Moon. Here we explore the consequences of liquid-vapor separation in one of the settings relevant to the lunar composition: the silicate vapor atmosphere...

  7. Vapor Compressor Driven Hybrid Two-Phase Loop Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Phase I project successfully demonstrated the feasibility of the vapor compression hybrid two-phase loop (VCHTPL). The test results showed the high...

  8. Optofluidic ring resonator sensors for rapid DNT vapor detection.

    Science.gov (United States)

    Sun, Yuze; Liu, Jing; Frye-Mason, Greg; Ja, Shiou-jyh; Thompson, Aaron K; Fan, Xudong

    2009-07-01

    We demonstrated rapid 2,4-dinitrotoluene (DNT) vapor detection at room temperature based on an optofluidic ring resonator (OFRR) sensor. With the unique on-column separation and detection features of OFRR vapor sensors, DNT can be identified from other interferences coexisting in the analyte sample mixture, which is especially useful in the detection of explosives from practical complicated vapor samples usually containing more volatile analytes. The DNT detection limit is approximately 200 pg, which corresponds to a solid phase microextraction (SPME) sampling time of only 1 second at room temperature from equilibrium headspace. A theoretical analysis was also performed to account for the experimental results. Our study shows that the OFRR vapor sensor is a promising platform for the development of a rapid, low-cost, and portable analytical device for explosive detection and monitoring.

  9. Water Vapor-Mediated Volatilization of High-Temperature Materials

    Science.gov (United States)

    Meschter, Peter J.; Opila, Elizabeth J.; Jacobson, Nathan S.

    2013-07-01

    Volatilization in water vapor-containing atmospheres is an important and often unexpected mechanism of degradation of high-temperature materials during processing and in service. Thermodynamic properties data sets for key (oxy)hydroxide vapor product species that are responsible for material transport and damage are often uncertain or unavailable. Estimation, quantum chemistry calculation, and measurement methods for thermodynamic properties of these species are reviewed, and data judged to be reliable are tabulated and referenced. Applications of water vapor-mediated volatilization include component and coating recession in turbine engines, oxidation/volatilization of ferritic steels in steam boilers, chromium poisoning in solid-oxide fuel cells, vanadium transport in hot corrosion and degradation of hydrocracking catalysts, Na loss from Na β"-Al2O3 tubes, and environmental release of radioactive isotopes in a nuclear reactor accident or waste incineration. The significance of water vapor-mediated volatilization in these applications is described.

  10. Acid Vapor Weathering of Apatite and Implications for Mars

    Science.gov (United States)

    Hausrath, E. M.; Golden, D. C.; Morris, R. V.; Ming, D. W.

    2008-03-01

    Acid vapor experiments containing apatite, olivine, glass, and a mixture of these phases suggest that secondary phosphates brushite, strengite and others may have formed. Similar reactions may have formed similar minerals in Paso Robles.

  11. On the Acoustic Properties of Vaporized Submicron Perfluorocarbon Droplets

    NARCIS (Netherlands)

    Reznik, Nikita; Lajoinie, Guillaume; Shpak, Oleksandr; Gelderblom, Erik C.; Williams, Ross; Jong, de Nico; Versluis, Michel; Burns, Peter N.

    2014-01-01

    The acoustic characteristics of microbubbles created from vaporized submicron perfluorocarbon droplets with fluorosurfactant coating are examined. Utilizing ultra-high-speed optical imaging, the acoustic response of individual microbubbles to low-intensity diagnostic ultrasound was observed on clini

  12. Cesium vapor thermionic converter anomalies arising from negative ion emission

    Energy Technology Data Exchange (ETDEWEB)

    Rasor, Ned S., E-mail: ned.rasor@gmail.com [532 Pauley Woods Circle Kettering, Ohio 45429 (United States)

    2016-08-14

    Compelling experimental evidence is given that a longstanding limit encountered on cesium vapor thermionic energy converter performance improvement and other anomalies arise from thermionic emission of cesium negative ions. It is shown that the energy that characterizes thermionic emission of cesium negative ions is 1.38 eV and, understandably, is not the electron affinity 0.47 eV determined for the photodetachment threshold of the cesium negative ion. The experimental evidence includes measurements of collector work functions and volt-ampere characteristics in quasi-vacuum cesium vapor thermionic diodes, along with reinterpretation of the classic Taylor-Langmuir S-curve data on electron emission in cesium vapor. The quantitative effects of negative ion emission on performance in the ignited, unignited, and quasi-vacuum modes of cesium vapor thermionic converter operation are estimated.

  13. Dynamics of vapor emissions at wire explosion threshold.

    Science.gov (United States)

    Belony, Paul A; Kim, Yong W

    2010-10-01

    X-pinch plasmas have been actively studied in the recent years. Numerical simulation of the ramp-up of metallic vapor emissions from wire specimens shows that under impulsive Ohmic heating the wire core invariably reaches a supercritical state before explosion. The heating rate depends sensitively on the local wire resistance, leading to highly variable vapor emission flux along the wire. To examine the vapor emission process, we have visualized nickel wire explosions by means of shock formation in air. In a single explosion as captured by shadowgraphy, there usually appear several shocks with spherical or cylindrical wave front originating from different parts of the wire. Growth of various shock fronts in time is well characterized by a power-law scaling in one form or another. Continuum emission spectra are obtained and calibrated to measure temperature near the explosion threshold. Shock front structures and vapor plume temperature are examined.

  14. Investigation of vapor film motion regularities at boiling liquids

    Directory of Open Access Journals (Sweden)

    Zeigarnik Y.U.

    2013-04-01

    Full Text Available The experimental investigation of the saturated Freon-113 and distilled water film boiling on spheres with different diameters at atmospheric pressure under conditions of free convection is executed. With high-speed video average thickness and cumulative distribution function of vapor film as a function of the angle was measured. It was found that with increasing the angle the average thickness of vapor film can change by different laws depending on diameter of the sphere and the temperature difference. It was found also that the increase in the average vapor film thickness with increasing angle is more connected with the increase of large components of cumulative distribution function. It also noted the presence of quasi-periodic pulsations of the vapor film thickness in the lower part, which eventually largely determine the behavior of the interface at large angles.

  15. Single molecule DNA detection with an atomic vapor notch filter

    National Research Council Canada - National Science Library

    Uhland, Denis; Rendler, Torsten; Widmann, Matthias; Lee, Sang-Yun; Wrachtrup, Jörg; Gerhardt, Ilja

    2015-01-01

    .... Here we present the use of the narrow-band filtering properties of hot atomic sodium vapor to selectively filter the excitation light from the red-shifted fluorescence of dye labeled single-stranded DNA molecules...

  16. Solvent vapor annealing of an insoluble molecular semiconductor

    KAUST Repository

    Amassian, Aram

    2010-01-01

    Solvent vapor annealing has been proposed as a low-cost, highly versatile, and room-temperature alternative to thermal annealing of organic semiconductors and devices. In this article, we investigate the solvent vapor annealing process of a model insoluble molecular semiconductor thin film - pentacene on SiO 2 exposed to acetone vapor - using a combination of optical reflectance and two-dimensional grazing incidence X-ray diffraction measurements performed in situ, during processing. These measurements provide valuable and new insight into the solvent vapor annealing process; they demonstrate that solvent molecules interact mainly with the surface of the film to induce a solid-solid transition without noticeable swelling, dissolving or melting of the molecular material. © 2010 The Royal Society of Chemistry.

  17. A New Way to Study Water-Vapor Absorption Coefficient

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In the visible spectrum, the atmospheric attenuations to sunlight mainly include aerosol scattering, atmospheric molecule Rayleigh scattering and ozone absorption, while in the near-infrared spectrum (from 650 nm to 1000 nm), we must take water-vapor absorption into account. Based on the atmospheric correction theory, using spectrum irradiance data measured by Instantaneous Ground spectrometer, ozone content measured by Microtops Ⅱ ozone monitor,water-vapor content and aerosol optical thickness measured by sun photometer, we give a new way to study water-vapor absorption to sunlight, and the result shows that the main peak values of water-vapor absorption coefficients are 0.025 cm-1, 0.073 cm-1, 0.124 cm-1, 0.090 cm-1, 0.141cm-1 and 0.417 cm-1, which respectively lie at 692 nm, 725 nm, 761 nm, 818 nm, 912 nm and 937 nm.

  18. Review of Various Air Sampling Methods for Solvent Vapors.

    Science.gov (United States)

    Vapors of trichloroethylene, toluene, methyl ethyl ketone, and butyl cellosolve in air were collected using Scotchpac and Tedlar bags, glass ...prescription bottles , and charcoal adsorption tubes. Efficiencies of collection are reported. (Author)

  19. Vapor Intrusion Facility Boundaries - Approximate Extent of Contamination

    Data.gov (United States)

    U.S. Environmental Protection Agency — Theses polygons represent the approximate extent of contamination for Vapor Intrusion facilities. Polygons for non-Federal Facility sites were updated in January,...

  20. Effect of Precipitable Water Vapor Amount on Radiative Cooling Performance

    Science.gov (United States)

    Hu, Mingke; Zhao, Bin; Ao, Xianze; Pei, Gang

    2017-05-01

    A radiative cooler based on aluminum-evaporated polyvinyl-fluoride surface was employed to investigate the effect of precipitable water vapor amount on its radiative cooling performance. A mathematic model of steady heat transfer that considers the spectral radiant distribution of the sky, the transparent cover and the collecting surface was established. The results indicate that the amount of precipitable water vapor shows a remarkable and negative effect on radiative cooling performance of the radiative cooler. Both the temperature difference between the cooler and surroundings and the net radiative cooling power decrease as the precipitable water vapor amount increases. The net radiative cooling power drops by about 41.0% as the the precipitable water vapor amount changes from 1.0 cm to 7.0 cm. Besides, the radiative cooler shows better cooling performance in winter than in summer. The net radiative cooling power in summer of Hefei is about 82.2% of that in winter.