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Sample records for air puff directed

  1. Introducing the scanning air puff tonometer for biological studies

    NASA Astrophysics Data System (ADS)

    Fleury, Vincent; Al-Kilani, Alia; Boryskina, Olena P.; Cornelissen, Annemiek J. M.; Nguyen, Thi-Hanh; Unbekandt, Mathieu; Leroy, Loïc; Baffet, Georges; Le Noble, Ferdinand; Sire, Olivier; Lahaye, Elodie; Burgaud, Vincent

    2010-02-01

    It is getting increasingly evident that physical properties such as elastoviscoplastic properties of living materials are quite important for the process of tissue development, including regulation of genetic pathways. Measuring such properties in vivo is a complicated and challenging task. In this paper, we present an instrument, a scanning air puff tonometer, which is able to map point by point the viscoelastic properties of flat or gently curved soft materials. This instrument is an improved version of the air puff tonometer used by optometrists, with important modifications. The instrument allows one to obtain a direct insight into gradients of material properties in vivo. The instrument capabilities are demonstrated on substances with known elastoviscoplastic properties and several biological objects. On the basis of the results obtained, the role of the gradients of elastoviscoplastic properties is outlined for the process of angiogenesis, limb development, bacterial colonies expansion, etc. which is important for bridging the gaps in the theory of the tissue development and highlighting new possibilities for tissue engineering, based on a clarification of the role of physical features in developing biological material.

  2. Swept source OCT with air puff chamber for corneal dynamics measurements

    NASA Astrophysics Data System (ADS)

    Karnowski, Karol; Alonso-Caneiro, David; Kaluzny, Bartlomiej; Kowalczyk, Andrzej; Wojtkowski, Maciej

    2012-03-01

    None of currently used tonometers produce estimated IOP values that are free of errors. Measurement incredibility arises from indirect measurement of corneal deformation and the fact that pressure calculations are based on population averaged parameters of anterior segment. Reliable IOP values are crucial for understanding and monitoring of number of eye pathologies e.g. glaucoma. We have combined high speed swept source OCT with air-puff chamber. System provides direct measurement of deformation of cornea and anterior surface of the lens. This paper describes in details the performance of air-puff ssOCT instrument. We present different approaches of data presentation and analysis. Changes in deformation amplitude appears to be good indicator of IOP changes. However, it seems that in order to provide accurate intraocular pressure values an additional information on corneal biomechanics is necessary. We believe that such information could be extracted from data provided by air-puff ssOCT.

  3. Stress-free automatic sleep deprivation using air puffs

    PubMed Central

    Gross, Brooks A.; Vanderheyden, William M.; Urpa, Lea M.; Davis, Devon E.; Fitzpatrick, Christopher J.; Prabhu, Kaustubh; Poe, Gina R.

    2015-01-01

    Background Sleep deprivation via gentle handling is time-consuming and personnel-intensive. New Method We present here an automated sleep deprivation system via air puffs. Implanted EMG and EEG electrodes were used to assess sleep/waking states in six male Sprague-Dawley rats. Blood samples were collected from an implanted intravenous catheter every 4 hours during the 12-hour light cycle on baseline, 8 hours of sleep deprivation via air puffs, and 8 hours of sleep deprivation by gentle handling days. Results The automated system was capable of scoring sleep and waking states as accurately as our offline version (~90% for sleep) and with sufficient speed to trigger a feedback response within an acceptable amount of time (1.76 s). Manual state scoring confirmed normal sleep on the baseline day and sleep deprivation on the two manipulation days (68% decrease in non-REM, 63% decrease in REM, and 74% increase in waking). No significant differences in levels of ACTH and corticosterone (stress hormones indicative of HPA axis activity) were found at any time point between baseline sleep and sleep deprivation via air puffs. Comparison with Existing Method There were no significant differences in ACTH or corticosterone concentrations between sleep deprivation by air puffs and gentle handling over the 8-hour period. Conclusions Our system accurately detects sleep and delivers air puffs to acutely deprive rats of sleep with sufficient temporal resolution during the critical 4-5 h post learning sleep-dependent memory consolidation period. The system is stress-free and a viable alternative to existing sleep deprivation techniques. PMID:26014662

  4. Theoretical and numerical analysis of the corneal air puff test

    NASA Astrophysics Data System (ADS)

    Simonini, Irene; Angelillo, Maurizio; Pandolfi, Anna

    2016-08-01

    Ocular analyzers are used in the current clinical practice to estimate, by means of a rapid air jet, the intraocular pressure and other eye's parameters. In this study, we model the biomechanical response of the human cornea to the dynamic test with two approaches. In the first approach, the corneal system undergoing the air puff test is regarded as a harmonic oscillator. In the second approach, we use patient-specific geometries and the finite element method to simulate the dynamic test on surgically treated corneas. In spite of the different levels of approximation, the qualitative response of the two models is very similar, and the most meaningful results of both models are not significantly affected by the inclusion of viscosity of the corneal material in the dynamic analysis. Finite element calculations reproduce the observed snap-through of the corneal shell, including two applanate configurations, and compare well with in vivo images provided by ocular analyzers, suggesting that the mechanical response of the cornea to the air puff test is actually driven only by the elasticity of the stromal tissue. These observations agree with the dynamic characteristics of the test, since the frequency of the air puff impulse is several orders of magnitude larger than the reciprocal of any reasonable relaxation time for the material, downplaying the role of viscosity during the fast snap-through phase.

  5. Dynamic Sensing of Cornea Deformation during an Air Puff

    NASA Astrophysics Data System (ADS)

    Yamada, Kenji; Yamasaki, Naoyuki; Gosho, Takumi; Kiuchi, Yoshiaki; Takenaka, Jouji; Higashimori, Mitsuru; Kaneko, Makoto

    In early diagnosis of glancoma, intraocular pressure measurement is one of an important method. Non-contact method has measured eye pressure through the deformation of cornea during the increase of the force due to air puff. The deformation is influenced by the cornea stiffness as well as the eye internal pressure. Since the cornea stiffness is unknown in general, it is difficult to evaluate the ture eye pressure. The dynamic behavior of cornea under air puff may provide us with a good hint for evaluating the cornea stiffness appropriately. For this purpose, we develop the sensing system composed of a high speed camera, a mirror for producing a virtual camera, a non-contact tonometer and a slit light source. This system enables us to measure the cornea deformation under concave shape. We show the experimental data for human eyes as well as an artificial eye made by transparent material.

  6. Air puff-induced 22-kHz calls in F344 rats.

    PubMed

    Inagaki, Hideaki; Sato, Jun

    2016-03-01

    Air puff-induced ultrasonic vocalizations in adult rats, termed "22-kHz calls," have been applied as a useful animal model to develop psychoneurological and psychopharmacological studies focusing on human aversive affective disorders. To date, all previous studies on air puff-induced 22-kHz calls have used outbred rats. Furthermore, newly developed gene targeting technologies, which are essential for further advancement of biomedical experiments using air puff-induced 22-kHz calls, have enabled the production of genetically modified rats using inbred rat strains. Therefore, we considered it necessary to assess air puff-induced 22-kHz calls in inbred rats. In this study, we assessed differences in air puff-induced 22-kHz calls between inbred F344 rats and outbred Wistar rats. Male F344 rats displayed similar total (summed) duration of air puff-induced 22 kHz vocalizations to that of male Wistar rats, however, Wistar rats emitted fewer calls of longer duration, while F344 rats emitted higher number of vocalizations of shorter duration. Additionally, female F344 rats emitted fewer air puff-induced 22-kHz calls than did males, thus confirming the existence of a sex difference that was previously reported for outbred Wistar rats. The results of this study could confirm the reliability of air puff stimulus for induction of a similar amount of emissions of 22-kHz calls in different rat strains, enabling the use of air puff-induced 22-kHz calls in inbred F344 rats and derived genetically modified animals in future studies concerning human aversive affective disorders. PMID:26723270

  7. Velocity Field of Isolated Turbulent Puffs

    NASA Astrophysics Data System (ADS)

    Ghaem-Maghami, Elham; Johari, Hamid

    2006-11-01

    The velocity field of isolated turbulent puffs was investigated by the PIV technique. Particular attention was paid to the entrainment pattern of isolated puffs. Puffs were generated by injecting seeded air through a 5 mm diameter nozzle into a flow chamber with a weak co-flow. Puffs with a Reynolds number of 5,000 were examined in the range of 35 -- 75 diameters downstream of the nozzle. The injection time was varied in order to assess the effect of injection volume and impulse on the puff structure. The results indicate that as the injection volume increased, puffs elongated in the axial direction. The largest mean and fluctuating velocities were within the central portion of the puff. The maximum turbulent shear stress within the puff was as much as 2.5 times the steady jet value. The vorticity field showed the presence of vorticity throughout the puff volume. The ratio of volume flow rate at the puff center to the steady jet volume flux at the same location was largest for the smallest injection volume. The majority of entrainment into the puff occurs below the puff center while the puff cap pushes out into surrounding fluid.

  8. Velocity field of isolated turbulent puffs

    NASA Astrophysics Data System (ADS)

    Ghaem-Maghami, E.; Johari, H.

    2010-11-01

    The velocity field of isolated turbulent puffs was measured using the particle image velocimetry technique and was compared with the steady jet flow field. Puffs were generated by injecting air through a 5 mm diameter nozzle into a flow chamber with a weak coflow. Isolated puffs with a Reynolds number of 5000 were examined in the range of 40-75 diameters downstream of the nozzle. The injection time was varied in order to assess the effects of injection volume and equivalent stroke ratio on the puff structure. The results from phase-locked measurements indicate that as the injection volume increased, puffs elongated in the axial direction and became similar to starting jets in the range considered. The largest scaled fluctuating velocities and turbulent shear stress within the puffs were twice the steady jet values. Inspection of the vorticity field revealed the presence of vorticity throughout the puff volume. Entrainment takes place on the portion of the puff closest to the nozzle and the entrainment rate is greater for the puffs with the smaller injection volume. This is consistent with the observations of rapid mixing and combustion of puffs in previous studies.

  9. Corneal Viscoelastic Properties from Finite-Element Analysis of In Vivo Air-Puff Deformation

    PubMed Central

    Kling, Sabine; Bekesi, Nandor; Dorronsoro, Carlos; Pascual, Daniel; Marcos, Susana

    2014-01-01

    Biomechanical properties are an excellent health marker of biological tissues, however they are challenging to be measured in-vivo. Non-invasive approaches to assess tissue biomechanics have been suggested, but there is a clear need for more accurate techniques for diagnosis, surgical guidance and treatment evaluation. Recently air-puff systems have been developed to study the dynamic tissue response, nevertheless the experimental geometrical observations lack from an analysis that addresses specifically the inherent dynamic properties. In this study a viscoelastic finite element model was built that predicts the experimental corneal deformation response to an air-puff for different conditions. A sensitivity analysis reveals significant contributions to corneal deformation of intraocular pressure and corneal thickness, besides corneal biomechanical properties. The results show the capability of dynamic imaging to reveal inherent biomechanical properties in vivo. Estimates of corneal biomechanical parameters will contribute to the basic understanding of corneal structure, shape and integrity and increase the predictability of corneal surgery. PMID:25121496

  10. Directed percolation describes lifetime and growth of turbulent puffs and slugs.

    PubMed

    Sipos, Maksim; Goldenfeld, Nigel

    2011-09-01

    We show that directed percolation (DP) simulations in a pipe geometry in 3+1 dimensions capture the observed complex phenomenology of the transition to turbulence. At low Reynolds numbers (Re), turbulent puffs form and spontaneously relaminarize. At high Re, turbulent slugs expand uniformly into the laminar regions. In a spatiotemporally intermittent state between these two regimes of Re, puffs split and turbulent regions exhibit laminar patches. DP also captures some of the quantitative features of the transition, with a superexponentially diverging characteristic lifetime below the transition. Above the percolation threshold, active (turbulent) clusters expand into the inactive (laminar) phase with a well-defined velocity whose scaling with control parameter (Reynolds number or percolation probability) is consistent with experimental results. Our results provide strong evidence in favor of a conjecture of Pomeau. PMID:22060447

  11. Air-puff OCE for assessment of mouse cornea in vivo

    NASA Astrophysics Data System (ADS)

    Li, Jiasong; Wang, Shang; Singh, Manmohan; Aglyamov, Salavat; Emelianov, Stanislav; Twa, Michael; Larin, Kirill V.

    2014-02-01

    We characterize the relaxation rates of deformations created by focused air puffs with the use of phasestabilized swept source optical coherence elastography (PhS-SSOCE) in tissue-mimicking gelatin phantoms of various concentrations and mouse corneas of different ages in vivo. The results indicate that gelatin of varying concentrations and corneas from different aged mice have different relaxation rates. In addition, the results show that phantoms with higher concentration gelatin and corneas of older mice have higher relaxation rates, which can be attributed to stiffer material. Because this method is non-contact, noninvasive, and utilizes a minimal force which induces a deformation on the scale of μm, this method can be used to study the biomechanical properties of sensitive tissues, such as the cornea.

  12. Comparative evaluation of intraocular pressure with an air-puff tonometer versus a Goldmann applanation tonometer

    PubMed Central

    Farhood, Qasim K

    2013-01-01

    Purpose Tonometry, or measurement of intraocular pressure (IOP), is one of the most important examination procedures in ophthalmic clinics, and IOP is an important parameter in the diagnosis of glaucoma. Because there are numerous types of tonometer available, it is important to evaluate the differences in readings between different tonometers. Goldmann applanation tonometers (GATs) and noncontact air-puff tonometers (APTs) are largely available in ophthalmic clinics. The purpose of this study was to evaluate the role of AP tonometer by comparing the measurements of IOP made using this device with those made using a GAT. Patients and methods This study involved 196 eyes from 98 study participants, all of whom were patients attending an ophthalmic outpatient clinic. Each patient’s IOP was measured using both Goldmann applanation tonometry and AP tonometry, and the difference in readings between the two methods was calculated. Results The mean IOP as measured by GAT was 13.06 ± 4.774 mmHg, while that as measured by AP tonometer was 15.91 ± 6.955 mmHg. The mean difference between the two methods of measurement was 2.72 ± 2.34 mmHg. The readings obtained by AP tonometer were higher than those obtained by GAT in 74% of patients, and this difference was most obvious when the GAT measurement of IOP exceeded 24 mmHg. No statistically significant variation in IOP was noted between the devices when the patients’ age, sex, and laterality (right and left eyes) were considered. Conclusion There is a significant difference in the measurement of IOP between GATs and AP tonometers. Goldmann applanation tonometry remains the most suitable and reliable method for measuring IOP. Because measurements of IOP by AP tonometer are usually higher than those obtained by GAT regardless of the patient’s age, sex, or laterality of eyes, AP tonometry is a suitable method for community or mass screenings of IOP. PMID:23293511

  13. Combining a focused air-puff system with phase-sensitive optical coherence tomography for the detection of soft-tissue tumors based on elasticity measurement

    NASA Astrophysics Data System (ADS)

    Wang, Shang; Li, Jiasong; Vantipalli, Srilatha; Manapuram, Ravi Kiran; Ingram, Davis R.; Twa, Michael D.; Lazar, Alexander J.; Lev, Dina C.; Pollock, Raphael E.; Larin, Kirill V.

    2013-03-01

    We combine a focused air-puff system with phase-sensitive optical coherence tomography (PhS-OCT) to measure the elasticity of soft tissues. Surface waves (SWs) on soft tissues are induced by a low-pressure, short-duration air stream from an air-puff system and measured using a high-sensitivity PhS-OCT imaging system. Young's modulus of soft tissues can be quantified based on the group velocity of SWs. To precisely control the excitation pressure, the air-puff system was characterized with a high-resolution analog pressure transducer. We studied the feasibility of this method for the non-contact detection of soft-tissue tumors. Ex vivo human fat and myxoma were used for these pilot experiments. Results demonstrate that this optical non-contact technique can be used to differentiate soft-tissue tumors from normal tissues based on measurements of their elasticity.

  14. Video-Puff of Air Hits Ball of Water in Space Onboard the International Space Station (ISS)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Saturday Morning Science, the science of opportunity series of applied experiments and demonstrations, performed aboard the International Space Station (ISS) by Expedition 6 astronaut Dr. Don Pettit, revealed some remarkable findings. In this video clip, Dr. Pettit demonstrates the phenomenon of a puff of air hitting a ball of water that is free floating in space. Watch the video to see why Dr. Pettit remarks 'I'd hate think that our planet would go through these kinds of gyrations if it got whacked by a big asteroid'.

  15. Heart Rate and Heart Rate Variability Assessment Identifies Individual Differences in Fear Response Magnitudes to Earthquake, Free Fall, and Air Puff in Mice

    PubMed Central

    Kuang, Hui; Tsien, Joe Z.; Zhao, Fang

    2014-01-01

    Fear behaviors and fear memories in rodents have been traditionally assessed by the amount of freezing upon the presentation of conditioned cues or unconditioned stimuli. However, many experiences, such as encountering earthquakes or accidental fall from tree branches, may produce long-lasting fear memories but are behaviorally difficult to measure using freezing parameters. Here, we have examined changes in heartbeat interval dynamics as physiological readout for assessing fearful reactions as mice were subjected to sudden air puff, free-fall drop inside a small elevator, and a laboratory-version earthquake. We showed that these fearful events rapidly increased heart rate (HR) with simultaneous reduction of heart rate variability (HRV). Cardiac changes can be further analyzed in details by measuring three distinct phases: namely, the rapid rising phase in HR, the maximum plateau phase during which HRV is greatly decreased, and the recovery phase during which HR gradually recovers to baseline values. We showed that durations of the maximum plateau phase and HR recovery speed were quite sensitive to habituation over repeated trials. Moreover, we have developed the fear resistance index based on specific cardiac response features. We demonstrated that the fear resistance index remained largely consistent across distinct fearful events in a given animal, thereby enabling us to compare and rank individual mouse’s fear responsiveness among the group. Therefore, the fear resistance index described here can represent a useful parameter for measuring personality traits or individual differences in stress-susceptibility in both wild-type mice and post-traumatic stress disorder (PTSD) models. PMID:24667366

  16. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source.

  17. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming; Gottesfeld, Shimshon

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source. Water loss from the cell is minimized by making the conductive cathode assembly hydrophobic and the conductive anode assembly hydrophilic.

  18. Pulmonary Function in Flight (PuFF) Experiment

    NASA Technical Reports Server (NTRS)

    2003-01-01

    In this International Space Station (ISS) onboard photo, Expedition Six Science Officer Donald R. Pettit works to set up the Pulmonary Function in Flight (PuFF) experiment hardware in the Destiny Laboratory. Expedition Six is the fourth and final crew to perform the PuFF experiment. The PuFF experiment was developed to better understand what effects long term exposure to microgravity may have on the lungs. The focus is on measuring changes in the everness of gas exchange in the lungs, and on detecting changes in respiratory muscle strength. It allows astronauts to measure blood flow through the lungs, the ability of the lung to take up oxygen, and lung volumes. Each PuFF session includes five lung function tests, which involve breathing only cabin air. For each planned extravehicular (EVA) activity, a crew member performs a PuFF test within one week prior to the EVA. Following the EVA, those crew members perform another test to document the effect of exposure of the lungs to the low-pressure environment of the space suits. This experiment utilizes the Gas Analyzer System for Metabolic Analysis Physiology, or GASMAP, located in the Human Research Facility (HRF), along with a variety of other Puff equipment including a manual breathing valve, flow meter, pressure-flow module, pressure and volume calibration syringes, and disposable mouth pieces.

  19. CO exposure, puff topography, and subjective effects in waterpipe tobacco smokers

    PubMed Central

    Maziak, Wasim; Rastam, Samer; Ibrahim, Iman; Ward, Kenneth D.; Shihadeh, Alan

    2009-01-01

    Introduction: Waterpipe tobacco smoking is increasing in popularity though the toxicant exposure and effects associated with this tobacco use method are not well understood. Methods: Sixty-one waterpipe tobacco smokers (56 males; mean age ± SD, 30.9 ± 9.5 years; mean number of weekly waterpipe smoking episodes, 7.8 ± 5.7; mean duration of waterpipe smoking 8.5 ± 6.1 years) abstained from smoking for at least 24 hr and then smoked tobacco from a waterpipe ad libitum in a laboratory. Before and after smoking, expired-air carbon monoxide (CO) and subjective effects were assessed; puff topography was measured during smoking. Results: The mean waterpipe use episode duration was 33.1 ± 13.1 min. Expired-air CO increased significantly from a mean of 4.0 ± 1.7 before to 35.5 ± 32.7 after smoking. On average, participants took 169 ± 100 puffs, with a mean puff volume of 511 ± 333 ml. Urge to smoke, restlessness, craving, and other tobacco abstinence symptoms were reduced significantly after smoking, while ratings of dizzy, lightheaded, and other direct effects of nicotine increased. Discussion: Expired-air CO and puff topography data indicate that, relative to a single cigarette, a single waterpipe tobacco smoking episode is associated with greater smoke exposure. Abstinent waterpipe tobacco smokers report symptoms similar to those reported by abstinent cigarette smokers, and these symptoms are reduced by subsequent waterpipe tobacco smoking. Taken together, these data are consistent with the notion that waterpipe tobacco smoking is likely associated with the risk of tobacco/nicotine dependence. PMID:19420278

  20. Balanced puff valve for imploding gas-puff experiments

    SciTech Connect

    Wong, S.; Smiley, P.; Sheridan, T.; Levine, J.; Buck, V.

    1986-08-01

    The design of a fast-acting high-pressure puff valve for use in imploding gas-puff experiments is presented. By using a pressure-balanced valve design, the valve can operate at pressures up to 500 psia. Fast opening (roughly-equal200 ..mu..s) is achieved by using a fast-moving sliding hammer to open the valve. Balanced valves as well as fast-opening valves using sliding hammers are both well-known technologies; however, this design is the first one to incorporate both features in a single design resulting in a fast-acting high-pressure puff valve.

  1. Effects of design parameters and puff topography on heating coil temperature and mainstream aerosols in electronic cigarettes

    NASA Astrophysics Data System (ADS)

    Zhao, Tongke; Shu, Shi; Guo, Qiuju; Zhu, Yifang

    2016-06-01

    Emissions from electronic cigarettes (ECs) may contribute to both indoor and outdoor air pollution and the number of users is increasing rapidly. ECs operate based on the evaporation of e-liquid by a high-temperature heating coil. Both puff topography and design parameters can affect this evaporation process. In this study, both mainstream aerosols and heating coil temperature were measured concurrently to study the effects of design parameters and puff topography. The heating coil temperatures and mainstream aerosols varied over a wide range across different brands and within same brand. The peak heating coil temperature and the count median diameter (CMD) of EC aerosols increased with a longer puff duration and a lower puff flow rate. The particle number concentration was positively associated with the puff duration and puff flow rate. These results provide a better understanding of how EC emissions are affected by design parameters and puff topography and emphasize the urgent need to better regulate EC products.

  2. AUTOMATIC AIR BURST DIRECTION FINDER

    DOEpatents

    Allard, G.A.

    1952-01-31

    This patent application describes an atomic explosion direction indicator comprising a geometric heat-scorchable indicating surface symmetrical about an axis, elevation and azimuth markings on the heat scorchable surface, and an indicating rod at the axis of said surface arranged to cast a shadow hereon, whereby heat from an atomic explosion will scorch a pattern on said surface indicative of the azimuth and elevation of said explosion.

  3. Cream of the Puffs

    ERIC Educational Resources Information Center

    Progressive Architecture, 1976

    1976-01-01

    Two air-supported membranes covering concrete shells house a swimming pool, 5,000-place seating for athletic competitions, 6,000-place seating for scholastic and ceremonial convocations, lockers, showers, offices, study space, and dining facilities. (Author/MLF)

  4. 2DPUF: A sequential gaussian puff model

    SciTech Connect

    Addis, R.P.; O`Steen, B.L.

    1990-12-31

    This report documents the Environmental Transport Section`s (ETS) two-dimensional, sequential gaussian puff transport and dispersion model for emergency response. The sequential puff scheme is described, and the dispersion equations are presented. The advantages of this model over the ETS`s PUFF/PLUME model are discussed. Options are calculating a two-dimensional wind field, interpolation procedures, and the wind field grid are described. The various grid systems for puff transport calculations and dose estimates are also described. A flow diagram for the modules comprising the 2DPUF code and a description of each module is presented.

  5. 2DPUF: A sequential gaussian puff model

    SciTech Connect

    Addis, R.P.; O'Steen, B.L.

    1990-01-01

    This report documents the Environmental Transport Section's (ETS) two-dimensional, sequential gaussian puff transport and dispersion model for emergency response. The sequential puff scheme is described, and the dispersion equations are presented. The advantages of this model over the ETS's PUFF/PLUME model are discussed. Options are calculating a two-dimensional wind field, interpolation procedures, and the wind field grid are described. The various grid systems for puff transport calculations and dose estimates are also described. A flow diagram for the modules comprising the 2DPUF code and a description of each module is presented.

  6. The airway sensory impact of nicotine contributes to the conditioned reinforcing effects of individual puffs from cigarettes⋆

    PubMed Central

    Naqvi, Nasir H.; Bechara, Antoine

    2005-01-01

    Puffs from cigarettes are the fundamental unit of smoking reward. Here, we examined the extent to which reward from puffs can be derived from the airway sensory effect of nicotine, in the absence of a direct central nervous system effect of nicotine. We did this by assessing the self-reported reward obtained from individual puffs from nicotinized, denicotinized and unlit cigarettes within 7 s of inhalation, which is before nicotine had an opportunity to reach the brain. We also assessed the self-reported strength of airway sensations elicited by the puffs. We found that nicotinized puffs were rated as both stronger and more rewarding than denicotinized and unlit puffs. We also found that the extent to which nicotine elicited reward was directly correlated with the extent to which nicotine elicited airway sensations. This indicates that the airway sensory effects of nicotine contribute to the reward from puffs, above and beyond the reward derived from the airway sensory effects of non-nicotine constituents. These findings have implications for the interpretation of studies that use puffs as experimental units to examine nicotine reward. They also have implications for the use of denicotinized and low nicotine cigarettes as aids to smoking cessation. PMID:15996724

  7. CO Exposure and Puff Topography Are Associated With Lebanese Waterpipe Dependence Scale Score

    PubMed Central

    2013-01-01

    Introduction: Waterpipe tobacco smoking involves self-administration of the dependence-producing drug nicotine. Few studies have examined if dependence in waterpipe smokers influences toxicant exposure and smoking behavior. Method: Current waterpipe tobacco smokers were categorized based on Lebanese Waterpipe Dependence Scale-11 (LWDS-11) score (LWDS-11: LOW < 7; N = 59; HIGH > 13; N = 59). Participants abstained from smoking for 12 hr and then completed a single 30-min waterpipe tobacco smoking episode. Expired-air carbon monoxide (CO) was measured before and 5 min after smoking and puff topography was measured during smoking. Results: Total mean smoking time was 30.9 min (SD = 3.5) and did not differ significantly by LWDS-11 score. CO boost was greater for participants in the HIGH versus LOW groups (62.3 vs. 43.6 ppm, p < .01). Similarly, those in the HIGH versus LOW group took more puffs (198.6 vs. 157.1 puffs, p < .01), longer duration puffs (2.7 vs. 2.3 s, p < .05), puffs with lower flow rate (10.3 vs. 12.6 L/min, p < .01), and less time between puffs (8.0 vs. 12.4 s, p < .001). Conclusion: The puff topography of waterpipe tobacco smokers can be predicted by LWDS-11 score, with those scoring higher taking longer duration and lower velocity puffs at a higher frequency. These behavioral differences may underlie the 40% greater CO exposure observed for those with higher LWDS-11 scores. To the extent that waterpipe dependence is associated with more smoke inhalation, more dependent smokers will be exposed to greater amounts of toxic smoke constituents. PMID:23616231

  8. Direct measurement of clarinet air column oscillations

    NASA Astrophysics Data System (ADS)

    Jones, Jesse; Rogers, Chris; French, Chris

    2003-10-01

    The internal oscillation of a clarinet air column has been directly measured through the implementation of hot-wire anemometry. By taking a series of measurements down the centerline of the bore, velocity and pressure modal shapes of individual harmonics are separated, measured, and plotted. Finally, composite averaged power spectra of the internal oscillation are presented and compared to acoustic measurements acquired outside the clarinet. In many cases, the even harmonics of the internal oscillation dominate over the power found in the odd harmonics. This contradicts the classic model of the clarinet as a cylindrical pipe closed at one end and open at the other (where only odd harmonics are produced). Further, the data from the direct velocity measurements also contradict the externally acquired acoustic data, where odd harmonics generally dominate for the lowest 5-9 harmonics. Thus the clarinet, in theory and practice, is generally considered incapable of generating strong even harmonics. In this research, however, it is seen that dominate even harmonics are generated, but the energy for these frequencies is largely trapped inside the clarinet, whereas the energy associated with the odd harmonics is released to the ambient. [This research was conducted with the support of Selmer Musical Instruments.

  9. Occurrence of transient puffs in a rotary-kiln incinerator simulator

    SciTech Connect

    Linak, W.P.; Kilgroe, J.D.; McSorley, J.A.; Wendt, J.O.L.; Dunn, J.E.

    1987-01-01

    This article discusses a statistically designed parametric investigation to determine which waste and kiln variables (charge mass, charge surface area, charge composition, and kiln temperature) significantly affect both instantaneous intensity and total magnitude of the puffs leaving a kiln used to incinerate simple prototype plastic wastes, ranging from polyethylene to polyvinychloride. Results show the relative ease with which failure conditions are achieved, even at high excess air values and high kiln temperatures. Transient puffs leaving the kiln contain a number of hazardous compounds. Increasing kiln temperature does not necessarily decrease the puff intensity and may in fact cause an increase. However, the total mass emitted always decreases with increasing temperature. In addition, the mass, surface area, and composition of the charge are all important.

  10. Buffer regulation of calcium puff sequences

    NASA Astrophysics Data System (ADS)

    Fraiman, Daniel; Ponce Dawson, Silvina

    2014-02-01

    Puffs are localized Ca2 + signals that arise in oocytes in response to inositol 1,4,5-trisphosphate (IP3). They are the result of the liberation of Ca2 + from the endoplasmic reticulum through the coordinated opening of IP3 receptor/channels clustered at a functional release site. The presence of buffers that trap Ca2 + provides a mechanism that enriches the spatio-temporal dynamics of cytosolic calcium. The expression of different types of buffers along the cell's life provides a tool with which Ca2 + signals and their responses can be modulated. In this paper we extend the stochastic model of a cluster of IP3R-Ca2 + channels introduced previously to elucidate the effect of buffers on sequences of puffs at the same release site. We obtain analytically the probability laws of the interpuff time and of the number of channels that participate of the puffs. Furthermore, we show that under typical experimental conditions the effect of buffers can be accounted for in terms of a simple inhibiting function. Hence, by exploring different inhibiting functions we are able to study the effect of a variety of buffers on the puff size and interpuff time distributions. We find the somewhat counter-intuitive result that the addition of a fast Ca2 + buffer can increase the average number of channels that participate of a puff.

  11. Air Breathing Direct Methanol Fuel Cell

    DOEpatents

    Ren; Xiaoming

    2003-07-22

    A method for activating a membrane electrode assembly for a direct methanol fuel cell is disclosed. The method comprises operating the fuel cell with humidified hydrogen as the fuel followed by running the fuel cell with methanol as the fuel.

  12. ESTIMATING CONCENTRATIONS DOWNWIND FROM AN INSTANTANEOUS PUFF RELEASE

    EPA Science Inventory

    This document provides an approach to estimating concentrations downwind of an instantaneous puff release. Dispersion of the puff is described by the Gaussian puff equation, using the didpersion parameters presented in Meteorology and Atomic Energy. The primary purpose of this wo...

  13. INPUFF: A SINGLE SOURCE GAUSSIAN PUFF DISPERSION ALGORITHM. USER'S GUIDE

    EPA Science Inventory

    INPUFF is a Gaussian INtegrated PUFF model. The Gaussian puff diffusion equation is used to compute the contribution to the concentration at each receptor from each puff every time step. Computations in INPUFF can be made for a single point source at up to 25 receptor locations. ...

  14. Analytical puff modelling of light-wind dispersion in stable and unstable conditions

    NASA Astrophysics Data System (ADS)

    Luhar, Ashok K.

    2011-01-01

    The puff modelling technique can describe dispersion in light winds by accounting for streamwise diffusion. A simple analytical puff model is formulated for stable as well as unstable stratification. In the stable case, the model is a slight generalisation of the Gaussian puff model of Thomson and Manning (2001), whereas in the unstable case it incorporates a probability density function approach to account for the observed skewness of the vertical turbulent velocities. An evaluation conducted using a well-known dataset collected under stable conditions suggests that the performance of the model is comparable to some of the top-performing models based on more complex techniques. However, it is apparent that some of the observed complex dispersion behaviour that arises due to the non-Gaussian characteristics of the wind direction distribution cannot be properly modelled by using the hourly-averaged meteorology. Since there are no suitable datasets for evaluation under unstable conditions, the puff model is benchmarked against a full three-dimensional Lagrangian particle model. The results show that the puff model is capable of describing most of the well-known features of convective dispersion observed under moderate winds, and that it simulates light-wind dispersion characteristics that are in good agreement with the particle model predictions. The results also highlight that the time since the start of tracer release is an important parameter in light winds. Quantitative estimates as to when the effects of streamwise diffusion in unstable flows can be neglected are also given.

  15. Reactive puff model SCICHEM: Model enhancements and performance studies

    NASA Astrophysics Data System (ADS)

    Chowdhury, B.; Karamchandani, P. K.; Sykes, R. I.; Henn, D. S.; Knipping, E.

    2015-09-01

    The SCICHEM model incorporates complete gas phase, aqueous and aerosol phase chemistry within a state-of-the-science Gaussian puff model SCIPUFF (Second-order Closure Integrated Puff). The model is a valuable tool that can be used to calculate the impacts of a single source or a small number of sources on downwind ozone and PM2.5. The model has flexible data requirements: it can be run with routine surface and upper air observations or with prognostic meteorological model outputs and source emissions are specified in a simple text format. This paper describes significant advances to the dispersion and chemistry components of the model in the latest release, SCICHEM 3.0. Some of the major advancements include modeling of skewed turbulence for convective boundary layer and updated chemistry schemes (CB05 gas phase chemical mechanism; AERO5 aerosol and aqueous modules). The results from SCICHEM 3.0 are compared with observations from a tracer study as well as aircraft measurements of reactive species in power plant plumes from two field studies. The results with the tracer experiment (Copenhagen study) show that the incorporation of skewed turbulence improves the calculation of tracer dispersion and transport. The comparisons with the Cumberland and Dolet Hills power plume measurements show good correlation between the observed and predicted concentrations of reactive gaseous species at most downwind distances from the source.

  16. Direct Air Capture of CO2 by Physisorbent Materials.

    PubMed

    Kumar, Amrit; Madden, David G; Lusi, Matteo; Chen, Kai-Jie; Daniels, Emma A; Curtin, Teresa; Perry, John J; Zaworotko, Michael J

    2015-11-23

    Sequestration of CO2, either from gas mixtures or directly from air (direct air capture, DAC), could mitigate carbon emissions. Here five materials are investigated for their ability to adsorb CO2 directly from air and other gas mixtures. The sorbents studied are benchmark materials that encompass four types of porous material, one chemisorbent, TEPA-SBA-15 (amine-modified mesoporous silica) and four physisorbents: Zeolite 13X (inorganic); HKUST-1 and Mg-MOF-74/Mg-dobdc (metal-organic frameworks, MOFs); SIFSIX-3-Ni, (hybrid ultramicroporous material). Temperature-programmed desorption (TPD) experiments afforded information about the contents of each sorbent under equilibrium conditions and their ease of recycling. Accelerated stability tests addressed projected shelf-life of the five sorbents. The four physisorbents were found to be capable of carbon capture from CO2-rich gas mixtures, but competition and reaction with atmospheric moisture significantly reduced their DAC performance. PMID:26440308

  17. He Puff System For Dust Detector Upgrade

    SciTech Connect

    B. Rais, C.H. Skinner A.L. Roquemore

    2010-10-01

    Local detection of surface dust is needed for the safe operation of next-step magnetic fusion devices such as ITER. An electrostatic dust detector, based on a 5 cm x 5 cm grid of interlocking circuit traces biased to 50 V, has been developed to detect dust on remote surfaces and was successfully tested for the first time on the National Spherical Torus Experiment (NSTX). We report on a helium puff system that clears residual dust from this detector and any incident debris or fibers that might cause a permanent short circuit. The entire surface of the detector was cleared of carbon particles by two consecutive helium puffs delivered by three nozzles of 0.45 mm inside diameter. The optimal configuration was found to be with the nozzles at an angle of 30o with respect to the surface of the detector and a helium backing pressure of 6 bar. __________________________________________________

  18. Air pollution directional risk assessment for siting a landfill.

    PubMed

    Chen, Wei-Yea; Kao, Jehng-Jung

    2008-12-01

    Air pollution directional risk (APDR) is an essential factor to be assessed when selecting an appropriate landfill site. Because air pollutants generated from a landfill are diffused and transported by wind in different directions and speeds, areas surrounding the landfill will be subject to different associated risks, depending on their relative position from the landfill. This study assesses potential APDRs imposed from a candidate landfill site on its adjacent areas on the basis of the pollutant distribution simulated by a dispersion model, wind directions and speeds from meteorological monitoring data, and population density. A pollutant distribution map layer was created using a geographic information system and layered onto a population density map to obtain an APDR map layer. The risk map layer was then used in this study to evaluate the suitability of a candidate site for placing a landfill. The efficacy of the proposed procedure was demonstrated for a siting problem in central Taiwan, Republic of China. PMID:19189752

  19. Passive radiative cooling below ambient air temperature under direct sunlight.

    PubMed

    Raman, Aaswath P; Anoma, Marc Abou; Zhu, Linxiao; Rephaeli, Eden; Fan, Shanhui

    2014-11-27

    Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive cooling below ambient air temperature has been demonstrated using a technique known as radiative cooling, in which a device exposed to the sky is used to radiate heat to outer space through a transparency window in the atmosphere between 8 and 13 micrometres. Peak cooling demand, however, occurs during the daytime. Daytime radiative cooling to a temperature below ambient of a surface under direct sunlight has not been achieved because sky access during the day results in heating of the radiative cooler by the Sun. Here, we experimentally demonstrate radiative cooling to nearly 5 degrees Celsius below the ambient air temperature under direct sunlight. Using a thermal photonic approach, we introduce an integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window. When exposed to direct sunlight exceeding 850 watts per square metre on a rooftop, the photonic radiative cooler cools to 4.9 degrees Celsius below ambient air temperature, and has a cooling power of 40.1 watts per square metre at ambient air temperature. These results demonstrate that a tailored, photonic approach can fundamentally enable new technological possibilities for energy efficiency. Further, the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day. PMID:25428501

  20. 14 CFR 380.11 - Payment to direct air carrier(s).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... carrier(s). Except for air taxi operators and commuter air carriers (which are governed by 14 CFR 298.38) and Canadian charter air taxi operators (which are governed by 14 CFR 294.32), the direct air...

  1. Effects of air flow directions on composting process temperature profile

    SciTech Connect

    Kulcu, Recep; Yaldiz, Osman

    2008-07-01

    In this study, chicken manure mixed with carnation wastes was composted by using three different air flow directions: R1-sucking (downward), R2-blowing (upward) and R3-mixed. The aim was to find out the most appropriate air flow direction type for composting to provide more homogenous temperature distribution in the reactors. The efficiency of each aeration method was evaluated by monitoring the evolution of parameters such as temperature, moisture content, CO{sub 2} and O{sub 2} ratio in the material and dry material losses. Aeration of the reactors was managed by radial fans. The results showed that R3 resulted in a more homogenous temperature distribution and high dry material loss throughout the composting process. The most heterogeneous temperature distribution and the lowest dry material loss were obtained in R2.

  2. Plasma puff initiation of high Coulomb transfer switches

    NASA Technical Reports Server (NTRS)

    Venable, D. D.; Choi, E. H.

    1990-01-01

    The plasma-puff triggering mechanism based on a hypocycloidal pinch geometry was investigated to determine the optimal operating conditions for the azimuthally uniform surface flashover which initiates plasma-puff under wide range of fill gas pressure of Ar, He and N2. The optimal fill gas pressure for the azimuthally uniform plasma-puff was about 120 mTorr and 450 Torr for He and N2, and between 120 mTorr and 5 Torr for Ar. The inverse pinch switch was triggered with the plasma-puff and the switching capability under various electrical parameters and working gas pressures of Ar, He and N2 was determined. It was also shown that the azimuthally uniform switching discharges were dependent on the type of fill gas and its fill pressure. A new concept of plasma-focus driven plasma-puff was also discussed in comparison with the hypocycloidal pinch plasma-puff triggering. The main discharge of inverse pinch switch with plasma-focus driven plasma-puff trigger is found to be more azimuthally uniform than that with hypocycloidal pinch plasma-puff trigger in a gas pressure region between 80 mTorr and 1 Torr.

  3. Splitting of a turbulent puff in pipe flow

    NASA Astrophysics Data System (ADS)

    Shimizu, Masaki; Manneville, Paul; Duguet, Yohann; Kawahara, Genta

    2014-12-01

    The transition to turbulence of the flow in a pipe of constant radius is numerically studied over a range of Reynolds numbers where turbulence begins to expand by puff splitting. We first focus on the case \\operatorname{Re}=2300 where splitting occurs as discrete events. Around this value only long-lived pseudo-equilibrium puffs can be observed in practice, as typical splitting times become very long. When \\operatorname{Re} is further increased, the flow enters a more continuous puff splitting regime where turbulence spreads faster. Puff splitting presents itself as a two-step stochastic process. A splitting puff first emits a chaotic pseudopod made of azimuthally localized streaky structures at the downstream (leading) laminar-turbulent interface. This structure can later expand azimuthally as it detaches from the parent puff. Detachment results from a collapse of turbulence over the whole cross-section of the pipe. Once the process is achieved a new puff is born ahead. Large-deviation consequences of elementary stochastic processes at the scale of the streak are invoked to explain the statistical nature of splitting and the Poisson-like distributions of splitting times reported by Avila et al (2011 Science 333 192-6).

  4. Time-dependent buoyant puff model for explosive sources

    SciTech Connect

    Kansa, E.J.

    1997-10-01

    This paper presents a new model for explosive puff rise histories that is derived from the strong conservative form of the partial differential equations of mass, momenta, and total energy that are integrated over space to yield a coupled system of time dependent nonlinear ordinary differential equations (ODEs). By allowing the dimensions of the puff to evolve laterally and horizontally, the initial rising spherical shaped puff evolves into a rising ellipsoidal shaped mushroom cloud. This model treats the turbulence that is generated by the puff itself and the ambient atmospheric turbulence as separate mechanisms in determining the puff history. The puff rise history was found to depend not only upon the mass and initial temperature of the explosion, but also upon the local stability conditions of the ambient atmosphere through which the puff rises. This model was calibrated by comparison with the Roller Coaster experiments, ranging from unstable to very stable atmospheric conditions; the agreement of the model history curves with these experimental curves was within 10%.

  5. ‘Trigger’ Events Precede Calcium Puffs in Xenopus Oocytes

    PubMed Central

    Rose, Heather J.; Dargan, Sheila; Shuai, Jianwei; Parker, Ian

    2006-01-01

    The liberation of calcium ions sequestered in the endoplasmic reticulum through inositol 1,4,5-trisphosphate receptors/channels (IP3Rs) results in a spatiotemporal hierarchy of calcium signaling events that range from single-channel openings to local Ca2+ puffs believed to arise from several to tens of clustered IP3Rs to global calcium waves. Using high-resolution confocal linescan imaging and a sensitive Ca2+ indicator dye (fluo-4-dextran), we show that puffs are often preceded by small, transient Ca2+ elevations that we christen “trigger events”. The magnitude of triggers is consistent with their arising from the opening of a single IP3 receptor/channel, and we propose that they initiate puffs by recruiting neighboring IP3Rs within the cluster by a regenerative process of Ca2+-induced Ca2+ release. Puff amplitudes (fluorescence ratio change) are on average ∼6 times greater than that of the triggers, suggesting that at least six IP3Rs may simultaneously be open during a puff. Trigger events have average durations of ∼12 ms, as compared to 19 ms for the mean rise time of puffs, and their spatial extent is ∼3 times smaller than puffs (respective widths at half peak amplitude 0.6 and 1.6 μm). All these parameters were relatively independent of IP3 concentration, although the proportion of puffs showing resolved triggers was greatest (∼80%) at low [IP3]. Because Ca2+ puffs constitute the building blocks from which cellular IP3-mediated Ca2+ signals are constructed, the events that initiate them are likely to be of fundamental importance for cell signaling. Moreover, the trigger events provide a useful yardstick by which to derive information regarding the number and spatial arrangement of IP3Rs within clusters. PMID:16980363

  6. Future directions in air quality research: economic issues.

    PubMed

    Adams, Richard M; Horst, Robert L

    2003-06-01

    Our challenge was to address future directions in air quality research that involve economic issues. The paper outlines the role of economics in the evaluation of air pollution impacts on environmental systems and describes existing research. We identify studies that address economic effects in the agricultural sector, in the commercial forest sector, and in unmanaged natural systems. Effects related to ozone exposure are highlighted. The summary of available research is followed by a discussion of research recommendations. Several short-term recommendations are identified that can augment some of the new research being considered by scientists. A more ambitious, long-term research project is outlined for valuing air pollution impacts in unmanaged natural environments. Specifically, the paper describes possible advantages of an 'integrated assessment' framework that more formally brings together the complex relationships that exist in both ecological and economic systems. A final section contains thoughts on the importance of education (i.e., information transfer) in the research process, especially in relation to policy. It is further noted that education should be inclusive of all members of the research team, throughout all stages of the research process. PMID:12676216

  7. Autoignition of hydrogen and air using direct numerical simulation

    NASA Astrophysics Data System (ADS)

    Doom, Jeffrey; Mahesh, Krishnan

    2008-11-01

    Direct numerical simulation (DNS) is used to study to auto--ignition in laminar vortex rings and turbulent diffusion flames. A novel, all--Mach number algorithm developed by Doom et al (J. Comput. Phys. 2007) is used. The chemical mechanism is a nine species, nineteen reaction mechanism for H2 and Air from Mueller at el (Int. J. Chem. Kinet. 1999). The vortex ring simulations inject diluted H2 at ambient temperature into hot air, and study the effects of stroke ratio, air to fuel ratio and Lewis number. At smaller stroke ratios, ignition occurs in the wake of the vortex ring and propagates into the vortex core. At larger stroke ratios, ignition occurs along the edges of the trailing column before propagating towards the vortex core. The turbulent diffusion flame simulations are three--dimensional and consider the interaction of initially isotropic turbulence with an unstrained diffusion flame. The simulations examine the nature of distinct ignition kernels, the relative roles of chemical reactions, and the relation between the observed behavior and laminar flames and the perfectly stirred reactor problem. These results will be discussed.

  8. The influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation.

    NASA Astrophysics Data System (ADS)

    Fišer, J.; Jícha, M.

    2013-04-01

    The paper deals with instigation of influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation. CFD approach was used for investigation and model geometry was based on small aircraft cabin mock-up geometry. Model was also equipped by nine seats and five manikins that represent passengers. The air jet direction was observed for selected ambient environment parameters and several types of air duct geometry and influence of main air duct geometry on jets direction is discussed. The model was created in StarCCM+ ver. 6.04.014 software and polyhedral mesh was used.

  9. Comparison of beam emission spectroscopy and gas puff imaging edge fluctuation measurements in National Spherical Torus Experiment

    SciTech Connect

    Sechrest, Y.; Munsat, T.; Smith, D.; Stotler, D. P.; Zweben, S. J.

    2015-05-15

    In this study, the close physical proximity of the Gas Puff Imaging (GPI) and Beam Emission Spectroscopy (BES) diagnostics on the National Spherical torus Experiment (NSTX) is leveraged to directly compare fluctuation measurements, and to study the local effects of the GPI neutral deuterium puff during H-mode plasmas without large Edge Localized Modes. The GPI and BES views on NSTX provide partially overlapping coverage of the edge and scrape-off layer (SOL) regions above the outboard midplane. The separation in the toroidal direction is 16°, and field lines passing through diagnostic views are separated by ∼20 cm in the direction perpendicular to the magnetic field. Strong cross-correlation is observed, and strong cross-coherence is seen for frequencies between 5 and 15 kHz. Also, probability distribution functions of fluctuations measured ∼3 cm inside the separatrix exhibit only minor deviations from a normal distribution for both diagnostics, and good agreement between correlation length estimates, decorrelation times, and structure velocities is found at the ±40% level. While the two instruments agree closely in many respects, some discrepancies are observed. Most notably, GPI normalized fluctuation levels exceed BES fluctuations by a factor of ∼9. BES mean intensity is found to be sensitive to the GPI neutral gas puff, and BES normalized fluctuation levels for frequencies between 1 and 10 kHz are observed to increase during the GPI puff.

  10. Time-dependent buoyant puff model for explosive sources

    SciTech Connect

    Kansa, E.J.

    1997-01-01

    Several models exist to predict the time dependent behavior of bouyant puffs that result from explosions. This paper presents a new model that is derived from the strong conservative form of the conservation partial differential equations that are integrated over space to yield a coupled system of time dependent nonlinear ordinary differential equations. This model permits the cloud to evolve from an intial spherical shape not an ellipsoidal shape. It ignores the Boussinesq approximation, and treats the turbulence that is generated by the puff itself and the ambient atmospheric tubulence as separate mechanisms in determining the puff history. The puff cloud rise history was found to depend no only on the mass and initial temperature of the explosion, but also upon the stability conditions of the ambient atmosphere. This model was calibrated by comparison with the Roller Coaster experiments.

  11. Differing ERP patterns caused by suction and puff stimuli.

    PubMed

    Choi, Mi-Hyun; Kim, Hyung-Sik; Baek, Ji-Hye; Lee, Jung-Chul; Park, Sung-Jun; Jeong, Ul-Ho; Gim, Seon-Young; You, Ji Hye; Kim, Sung-Pil; Lim, Dae-Woon; Kim, Hyun-Jun; Chung, Soon-Cheol

    2015-05-01

    The present study compared event-related potential (ERP) patterns for two stimuli types, puff and suction, by applying these stimuli to the fingers; ERP patterns for the two stimuli were compared at C3, an area related to somatosensory perception, and at FC5, an area related to motor function. Participants were 12 healthy males in their 20s (mean age=23.1±2.0 years). One session consisted of a Control Phase (3s), a Stimulation Phase (3s), and a Rest Phase (9s). During the Stimulation Phase, a 4-psi suction or puff stimulus was applied to the first joint of the right index finger. After completion of the session, a subjective magnitude test was presented. In all phases, electroencephalography signals were recorded. We extracted maximum positive amplitude and minimum negative amplitude as well as relevant latency values for C3 and FC5 signals. Suction and puff stimuli had similar subjective magnitude scores. For both C3 and FC5, the maximum and minimum amplitude latency was reached earlier for the suction stimulus than for the puff stimulus. In conclusion, when suction and puff stimuli of the same intensity were applied to the fingers, the suction stimulus caused a more sensitive response in the somatosensory area (C3) and motor area (FC5) than did the puff stimulus. PMID:25823997

  12. Deuterium Gas-Puff Z-Pinch on GIT-12 Generator

    NASA Astrophysics Data System (ADS)

    Klir, Daniel; Kravarik, Jozef; Kubes, Pavel; Rezac, Karel; Shishlov, Alexander; Kokshenev, Vladimir; Ratakhin, Nicolai; Kovalchuk, Boris; Labetsky, Aleksey; Kurmaev, Nikolay; Fursov, Fedor

    2011-10-01

    Deuterium gas-puff experiments have been carried out on the GIT-12 generator at the High Current Electronics Institute in Tomsk. During the initial experiment in May 2011, we used mainly double shell gas puffs with the outer and inner diameter of 100 and 30 mm, respectively. Single shell and shell-on-solid fill gas puffs were, however, also tested. The linear mass density of deuterium varied between 50 and 80 μg/cm. When a plasma-opening-switch (POS) was used, the current reached the peak of above 2.5 MA within 300 ns. The peak neutron yield from D(d,n)3He reactions exceeded 1011. In all shots, the neutron emission started during the stagnation. At the beginning of the neutron production, there was the correlation between the neutron emission and soft X-rays. Nevertheless, the peak of the neutron emission occurred 50 ns after the soft X-ray peak. At this very moment, hard X-rays above 1 MeV were detected. In the case of POS, > 800 keV widths of side-on neutron spectra implied > 200 keV deuterons moving in the radial direction. Work supported by the MSMT grants LA08024, ME09087, LC528.

  13. Air shower arrival directions measured at Buckland Park

    NASA Technical Reports Server (NTRS)

    Gerhardy, P. R.; Prescott, J. R.; Protheroe, R. J.; Clay, R. W.; Patterson, J. R.; Gregory, A. G.

    1985-01-01

    The Buckland Park air shower array was operated for 3 years from 1979 to 1981 particularly for the study of anisotropies in the region of the knee of the size spectrum. The array which has been described in detail elsewhere was situated at a latitude of 35 S and had an effective size threshold of approx 3 x 10 to the 5th power particles (approx 3 x 10 to the 15th power Ev for vertical showers). A number of results from this experiment have already been published including anisotropy analyses (Gerhardy and Clay, 1983) and searches for very high energy gamma ray sources. The final distribution of measured shower arrival directions are presented here. These 1.3 x 10 to the 5th power events were selected as indicated in detail in Gerhardy and Clay (1983) and were essentially those events with well measured arrival directions. They are the same data set used in the above reference but no complete sky map has previously been presented.

  14. New directions: Air pollution challenges for developing megacities like Delhi

    NASA Astrophysics Data System (ADS)

    Kumar, Prashant; Khare, Mukesh; Harrison, Roy M.; Bloss, William J.; Lewis, Alastair C.; Coe, Hugh; Morawska, Lidia

    2015-12-01

    Most major cities around the world experience periods of elevated air pollution levels, which exceed international health-based air quality standards (Kumar et al., 2013). Although it is a global problem, some of the highest air pollution levels are found in rapidly expanding cities in India and China. The sources, emissions, transformations and broad effects of meteorology on air pollution are reasonably well accounted in air quality control strategies in many developed cities; however these key factors remain poorly constrained in the growing cities of countries with emerging economies. We focus here on Delhi, one of the largest global population centres, which faces particular air pollution challenges, now and in the future.

  15. Puff-Plume Atmospheric Deposition Model.

    1992-06-24

    Version: 00 PFPL is an interactive transport and diffusion program developed for real-time calculation of the location and concentration of toxic or radioactive materials during an accidental release. Deposition calculations are included. The potential exists at the Savannah River Plant for releases of either toxic gases or radionuclides. The automated system developed to provide real-time information on the trajectory and concentration of an accidental release consists of meteorological towers, a minicomputer, and a network ofmore » terminals called the Weather Information and Display (WIND) System. PFPL which simulates either instantaneous (puff) or continuous (plume) releases is the primary code used at Savannah River for emergency response. Data files are provided for demonstration. The software for archiving the required on-line meteorological data is not included. Subroutines used for graphic display of results and operational control of the DEC VT100 and Tektronix terminals in the terminal network are included. Anyone wishing t use these routines must make appropriate modifications to the file TERMINALS.DAT. The DAT files provided were copied during the afternoon of December 28, 1983. Test runs attempting to use these files should specify release times on or before that date. Any user wishing to obtain numerical output only form the model based on conditions in his locality must supply appropriate wind data for the program.« less

  16. Direct effects of energy-related air pollutants on plant sexual reproduction

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1987-12-08

    Our completed research program concentrated on the direct in vivo effects of energy-related air pollutants on plant sexual reproduction. Direct air pollution effects on plant sexual reproduction have been studied for SO{sub 2} and NO{sub 2}, two of the three major air pollutants.

  17. Impact of Aerosol Direct Effect on East Asian Air Quality During the EAST-AIRE Campaign

    NASA Astrophysics Data System (ADS)

    Wang, J.; Allen, D. J.; Pickering, K. E.; Li, Z.

    2015-12-01

    Three WRF-Chem simulations were conducted for East Asia region during March 2005 East Asian Studies of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE) Intensive Observation Campaign (IOC) period to investigate the direct effects of aerosols on surface radiation and air quality. WRF-Chem captured the temporal and spatial variations of meteorological fields, trace gases, and aerosol loadings. Surface shortwave radiation changes due to the aerosol direct effect (ADE) were calculated and compared with data from six World Radiation Data Center (WRDC) stations. The comparison indicated that WRF-Chem can simulate the surface short wave radiation moderately well, with temporal correlations between 0.4 and 0.7, and high biases between 9 to 120 W/m2. Domain-wide, WRF-Chem showed a decrease of 22 W/m2 in surface SW radiation due to the aerosol direct effect, consistent with observational studies. The ADE demonstrates diverse influences on air quality in East Asian. For example, the surface concentration of PM2.5 increases in eastern China (~11.1%) due to ADE, but decreases in central China (-7.3%), western China (-8.8%), and Sichuan Basin (-4%). Surface 1-hour maximum ozone is reduced by 2.3%, owing to less radiation reaching the surface due to the ADE. Since PM2.5 pollution raises serious public concern in China, regulations that control the emissions of PM2.5 and its precursors have been implemented. We investigate the impact of reducing two different types of aerosols, sulfate (scattering) and black carbon (absorbing), by cutting 80% of SO2 and black carbon (BC) emissions in two sensitivity simulations. We found that reducing SO2 emissions results in the decline of PM2.5 as much as 16mg/m3 in eastern China, and 20mg/m3 in the Sichuan Basin. Reducing the BC emissions by the same percentage causes the PM2.5 to decrease as much as 40mg/m3 in eastern China, and 25mg/m3 in the Sichuan Basin. The monthly averaged surface 1-hour maximum ozone increases 3

  18. Study of gas-puff Z-pinches on COBRA

    NASA Astrophysics Data System (ADS)

    Qi, N.; Rosenberg, E. W.; Gourdain, P. A.; de Grouchy, P. W. L.; Kusse, B. R.; Hammer, D. A.; Bell, K. S.; Shelkovenko, T. A.; Potter, W. M.; Atoyan, L.; Cahill, A. D.; Evans, M.; Greenly, J. B.; Hoyt, C. L.; Pikuz, S. A.; Schrafel, P. C.; Kroupp, E.; Fisher, A.; Maron, Y.

    2014-11-01

    Gas-puff Z-pinch experiments were conducted on the 1 MA, 200 ns pulse duration Cornell Beam Research Accelerator (COBRA) pulsed power generator in order to achieve an understanding of the dynamics and instability development in the imploding and stagnating plasma. The triple-nozzle gas-puff valve, pre-ionizer, and load hardware are described. Specific diagnostics for the gas-puff experiments, including a Planar Laser Induced Fluorescence system for measuring the radial neutral density profiles along with a Laser Shearing Interferometer and Laser Wavefront Analyzer for electron density measurements, are also described. The results of a series of experiments using two annular argon (Ar) and/or neon (Ne) gas shells (puff-on-puff) with or without an on- (or near-) axis wire are presented. For all of these experiments, plenum pressures were adjusted to hold the radial mass density profile as similar as possible. Initial implosion stability studies were performed using various combinations of the heavier (Ar) and lighter (Ne) gasses. Implosions with Ne in the outer shell and Ar in the inner were more stable than the opposite arrangement. Current waveforms can be adjusted on COBRA and it was found that the particular shape of the 200 ns current pulse affected on the duration and diameter of the stagnated pinched column and the x-ray yield.

  19. Study of gas-puff Z-pinches on COBRA

    SciTech Connect

    Qi, N.; Rosenberg, E. W.; Gourdain, P. A.; Grouchy, P. W. L. de; Kusse, B. R.; Hammer, D. A.; Bell, K. S.; Shelkovenko, T. A.; Potter, W. M.; Atoyan, L.; Cahill, A. D.; Evans, M.; Greenly, J. B.; Hoyt, C. L.; Pikuz, S. A.; Schrafel, P. C.; Kroupp, E.; Fisher, A.; Maron, Y.

    2014-11-15

    Gas-puff Z-pinch experiments were conducted on the 1 MA, 200 ns pulse duration Cornell Beam Research Accelerator (COBRA) pulsed power generator in order to achieve an understanding of the dynamics and instability development in the imploding and stagnating plasma. The triple-nozzle gas-puff valve, pre-ionizer, and load hardware are described. Specific diagnostics for the gas-puff experiments, including a Planar Laser Induced Fluorescence system for measuring the radial neutral density profiles along with a Laser Shearing Interferometer and Laser Wavefront Analyzer for electron density measurements, are also described. The results of a series of experiments using two annular argon (Ar) and/or neon (Ne) gas shells (puff-on-puff) with or without an on- (or near-) axis wire are presented. For all of these experiments, plenum pressures were adjusted to hold the radial mass density profile as similar as possible. Initial implosion stability studies were performed using various combinations of the heavier (Ar) and lighter (Ne) gasses. Implosions with Ne in the outer shell and Ar in the inner were more stable than the opposite arrangement. Current waveforms can be adjusted on COBRA and it was found that the particular shape of the 200 ns current pulse affected on the duration and diameter of the stagnated pinched column and the x-ray yield.

  20. Impact of aerosol direct effect on East Asian air quality during the EAST-AIRE campaign

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Allen, Dale J.; Pickering, Kenneth E.; Li, Zhanqing; He, Hao

    2016-06-01

    WRF-Chem simulations were performed for the March 2005 East Asian Studies of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE) Intensive Observation Campaign (IOC) to investigate the direct effects of aerosols on surface radiation and air quality. Domain-wide, WRF-Chem showed a decrease of 20 W/m2 in surface shortwave (SW) radiation due to the aerosol direct effect (ADE), consistent with observational studies. The ADE caused 24 h surface PM2.5 (particulate matter with diameter < 2.5 µm) concentrations to increase in eastern China (4.4%), southern China (10%), western China (2.3%), and the Sichuan Basin (9.6%), due to different aerosol compositions in these four regions. Conversely, surface 1 h maximum ozone was reduced by 2.3% domain-wide and up to 12% in eastern China because less radiation reached the surface. We also investigated the impact of reducing SO2 and black carbon (BC) emissions by 80% on aerosol amounts via two sensitivity simulations. Reducing SO2 decreased surface PM2.5 concentrations in the Sichuan Basin and southern China by 5.4% and decreased ozone by up to 6 ppbv in the Sichuan Basin and Southern China. Reducing BC emissions decreased PM2.5 by 3% in eastern China and the Sichuan Basin but increased surface ozone by up to 3.6 ppbv in eastern China and the Sichuan Basin. This study indicates that the benefits of reducing PM2.5 associated with reducing absorbing aerosols may be partially offset by increases in ozone at least for a scenario when NOx and VOC emissions are unchanged.

  1. Suppressing effect of Ca^{2+} blips on puff amplitudes by inhibiting channels to prevent recovery.

    PubMed

    Chen, Yuan; Qi, Hong; Li, Xiang; Cai, Meichun; Chen, Xingqiang; Liu, Wen; Shuai, Jianwei

    2016-08-01

    As local signals, calcium puffs arise from the concerted opening of a few nearby inositol 1,4,5-trisphospate receptor channels to release Ca^{2+} ions from the endoplasmic reticulum. Although Ca^{2+} puffs have been well studied, little is known about the modulation of cytosolic basal Ca^{2+} concentration ([Ca^{2+}]_{Basal}) on puff dynamics. In this paper we consider a puff model to study how the statistical properties of puffs are modulated by [Ca^{2+}]_{Basal}. The puff frequency and lifetime trivially increase with the increasing [Ca^{2+}]_{Basal}, but an unexpected result is that the puff amplitude and the maximum open-channel number of the puff show decreasing relationship with the increasing [Ca^{2+}]_{Basal}. The underlying dynamics is related not only to the increasing puff frequency which gives a shorter recovery time, but also to the increasing frequency of blips with only one channel open. We indicate that Ca^{2+} blips cause the channels to be inhibited and prevent their recovery during interpuff intervals, resulting in the suppressing effect on puff amplitudes. With increasing [Ca^{2+}]_{Basal}, more blips occur to cause more channels to be inhibited, leaving fewer channels available for puff events. This study shows that the blips may play relevant functions in global Ca^{2+} waves through modulating puff dynamics. PMID:27627339

  2. Suppressing effect of C a2 + blips on puff amplitudes by inhibiting channels to prevent recovery

    NASA Astrophysics Data System (ADS)

    Chen, Yuan; Qi, Hong; Li, Xiang; Cai, Meichun; Chen, Xingqiang; Liu, Wen; Shuai, Jianwei

    2016-08-01

    As local signals, calcium puffs arise from the concerted opening of a few nearby inositol 1,4,5-trisphospate receptor channels to release C a2 + ions from the endoplasmic reticulum. Although C a2 + puffs have been well studied, little is known about the modulation of cytosolic basal C a2 + concentration ([Ca2 +] Basal) on puff dynamics. In this paper we consider a puff model to study how the statistical properties of puffs are modulated by [Ca2 +] Basal. The puff frequency and lifetime trivially increase with the increasing [Ca2 +] Basal, but an unexpected result is that the puff amplitude and the maximum open-channel number of the puff show decreasing relationship with the increasing [Ca2 +] Basal. The underlying dynamics is related not only to the increasing puff frequency which gives a shorter recovery time, but also to the increasing frequency of blips with only one channel open. We indicate that C a2 + blips cause the channels to be inhibited and prevent their recovery during interpuff intervals, resulting in the suppressing effect on puff amplitudes. With increasing [Ca2 +] Basal, more blips occur to cause more channels to be inhibited, leaving fewer channels available for puff events. This study shows that the blips may play relevant functions in global C a2 + waves through modulating puff dynamics.

  3. Dosage-based parameters for characterization of puff dispersion results.

    PubMed

    Berbekar, Eva; Harms, Frank; Leitl, Bernd

    2015-01-01

    A set of parameters is introduced to characterize the dispersion of puff releases based on the measured dosage. These parameters are the dosage, peak concentration, arrival time, peak time, leaving time, ascent time, descent time and duration. Dimensionless numbers for the scaling of the parameters are derived from dimensional analysis. The dimensionless numbers are tested and confirmed based on a statistically representative wind tunnel dataset. The measurements were carried out in a 1:300 scale model of the Central Business District in Oklahoma City. Additionally, the effect of the release duration on the puff parameters is investigated. PMID:25278155

  4. Plasma-puff initiation of high Coulomb transfer switches

    NASA Technical Reports Server (NTRS)

    Venable, D. D.; Han, K. S.

    1993-01-01

    The plasma-puff triggering mechanism based on a hypocycloidal pinch geometry was investigated to determine the optimal operating conditions for an azimuthally uniform surface flashover which initiates plasma-puff under wide ranges of fill gas pressures of Ar, He and N2. The optimal fill gas pressures for the azimuthally uniform plasma-puff were about 120 mTorr less than P(opt) less than 450 Torr for He and N2. For Argon 120 mTorr less than P(opt) less than 5 Torr for argon. The inverse pinch switch was triggered with the plasma-puff and the switching capability under various electrical parameters and working gas pressures of Ar, He and N2 was determined. It was also shown that the azimuthally uniform switching discharges were dependent on the type of fill gas and its fill pressure. A new concept of plasma-focus driven plasma-puff was also discussed in comparison with hypocycloidal pinch plasma-puff triggering. The main discharge of the inverse pinch switch with the plasma-focus driven plasma-puff trigger is found to be more azimuthally uniform than that with the hypocycloidal pinch plasma-puff trigger in a gas pressure region between 80 mTorr and 1 Torr. In order to assess the effects of plasma current density on material erosion of electrodes, emissions from both an inverse-pinch plasma switch (INPIStron) and from a spark gap switch under test were studied with an optical multichannel analyzer (OMA). The color temperature of the argon plasma was approximately 4,000 K which corresponded with the peak continuum emission near 750 nm. There are the strong line emissions of argon in the 650 - 800 nm range and a lack of line emissions of copper and other solid material used in the switch. This indicates that the plasma current density during closing is low and the hot spot or hot filament in the switch is negligible. This result also indicates considerable reduction of line emission with the INPIStron switch over that of a spark-gap switch. However, a strong carbon line

  5. Air service to small communities, directions for the future. [conference

    NASA Technical Reports Server (NTRS)

    Vittek, J. F., Jr. (Editor)

    1974-01-01

    The seminar on the problems of providing air service to low and medium density points is reported. National transport policies and programs are discussed along with the technology aspects. Recommendations for ATC, CAB, and FAA are included.

  6. 77 FR 64763 - Airworthiness Directives; Lindstrand Hot Air Balloons Ltd Appliances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-23

    ... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will... Directives; Lindstrand Hot Air Balloons Ltd Appliances AGENCY: Federal Aviation Administration (FAA... adopt a new airworthiness directive (AD) for certain Lindstrand Hot Air Balloons Ltd female...

  7. 78 FR 70209 - Airworthiness Directives; XtremeAir GmbH Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect...-047-AD; Amendment 39-17674; AD 2013-23-19] RIN 2120-AA64 Airworthiness Directives; XtremeAir GmbH.... SUMMARY: We are adopting a new airworthiness directive (AD) for XtremeAir GmbH Model XA42 airplanes....

  8. Properties of extruded chia-corn meal puffs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the properties of extruded corn meal puffs containing chia. Mixtures of corn meal and chia seeds (0-20%) were processed in a laboratory-scale twin-screw extruder at different moisture contents (18-22%) and final heating zone temperatures (120-160 °C). Extrusion processing pro...

  9. Simulation of Tracer Concentration Data in the Brush Creek Drainage Flow Using an Integrated Puff Model.

    NASA Astrophysics Data System (ADS)

    Rao, K. Shankar; Eckman, Richard M.; Hosker, Rayford P., Jr.

    1989-07-01

    During the 1984 ASCOT field study in Brush Creek Valley, two perfluorocarbon tracers were released into the nocturnal drainage flow at two different heights. The resulting surface concentrations were sampled at 90 sites, and vertical concentration profiles at 11 sites. These detailed tracer measurements provide a valuable dataset for developing and testing models of pollutant transport and dispersion in valleys.In this paper, we present the results of Gaussian puff model simulations of the tracer releases in Brush Creek Valley. The model was modified to account for the restricted lateral dispersion in the valley, and for the gross elevation differences between the release site and the receptors. The variable wind fields needed to transport the puffs were obtained by interpolation between wind profiles measured using tethered balloons at five along-valley sites. Direct turbulence measurements were used to estimate diffusion. Subsidence in the valley flow was included for elevated releases.Two test simulations-covering different nights, tracers, and release heights-were performed. The predicted hourly concentrations were compared with observations at 51 ground-level locations. At most sites, the predicted and observed concentrations agree within a factor of 2 to 6. For the elevated release simulation, the observed mean concentration is 40 pL/L, the predicted mean is 21 pL/L, the correlation coefficient between the observed and predicted concentrations is 0.24, and the index of agreement is 0.46. For the surface release simulation, the observed mean is 85 pL/L, and the predicted mean is 73 pL/L. The correlation coefficient is 0.23, and the index of agreement is 0.42. The results suggest that this modified puff model can be used as a practical tool for simulating pollutant transport and dispersion in deep valleys.

  10. Development and testing of a portable wind sensitive directional air sampler

    NASA Technical Reports Server (NTRS)

    Deyo, J.; Toma, J.; King, R. B.

    1975-01-01

    A portable wind sensitive directional air sampler was developed as part of an air pollution source identification system. The system is designed to identify sources of air pollution based on the directional collection of field air samples and their analysis for TSP and trace element characteristics. Sources can be identified by analyzing the data on the basis of pattern recognition concepts. The unit, designated Air Scout, receives wind direction signals from an associated wind vane. Air samples are collected on filter slides using a standard high volume air sampler drawing air through a porting arrangement which tracks the wind direction and permits collection of discrete samples. A preset timer controls the length of time each filter is in the sampling position. At the conclusion of the sampling period a new filter is automatically moved into sampling position displacing the previous filter to a storage compartment. Thus the Air Scout may be set up at a field location, loaded with up to 12 filter slides, and left to acquire air samples automatically, according to the wind, at any timer interval desired from 1 to 30 hours.

  11. Experimental Results from Plasma Shell on Deuterium Gas-puff Z-pinch on the Current Level of 3 MA

    NASA Astrophysics Data System (ADS)

    Rezac, K.; Klir, D.; Kubes, P.; Kravarik, J.; Shishlov, A.; Labetsky, A.; Kokshenev, V.; Ratakhin, N.; GIT-12 Team

    2013-10-01

    The experiments with a plasma shell on deuterium gas-puff Z-pinch were carried out on the GIT-12 generator at IHCE in Tomsk. We diagnosed Z-pinch shots with deuterium linear mass of about 100 μg/cm. The outer shell of the load was formed by 48 plasma guns positioned on diameter of 350 mm, the diameter of the nozzle producing deuterium inner shell gas-puff was 80 mm. Results obtained from X-ray and neutron diagnostics, especially neutron time-of-flight signals, where 15 MeV neutrons (in radial direction) and 22 MeV neutrons (in axial direction) were registered, are presented. Obtained implosion velocity of the gas-puff had the value of 4 . 5 ×107 cm/s, neutron yield from D(d,n)3He reaction was in order of 1012 neutrons/shot on a current level of about 2.7 MA. The time correlations of the TOF diagnostics with other diagnostics such as electrical characteristics, an MCP frames, and a visible streak camera are also presented. Work supported by MEYS CR research programs No. ME090871, No. LG13029, by GACR grant No. P205/12/0454, grant CRA IAEA No. 17088 and RFBR research project No. 13-08-00479-a.

  12. Penetration of Air Jets Issuing from Circular, Square, and Elliptical Orifices Directed Perpendicularly to an Air Stream

    NASA Technical Reports Server (NTRS)

    Ruggeri, Robert S.; Callaghan, Edmund E.; Bowden, Dean T.

    1950-01-01

    An experimental investigation was conducted to determine the penetration of air jets d.irected perpendicularlY to an air stream. Jets Issuing from circular, square, and. elliptical orifices were investigated. and. the jet penetration at a position downstream of the orifice was determined- as a function of jet density, jet velocity, air-stream d.enaity, air-stream velocity, effective jet diameter, and. orifice flow coeffIcient. The jet penetrations were determined for nearly constant values of air-stream density at three tunnel-air velocities arid for a large range of Jet velocities and. densities. The results were correlated in terms of dimensionless parameters and the penetrations of the various shapes were compared. Greater penetration was obtained. with the square orifices and the elliptical orifices having an axis ratio of 4:1 at low tunnel-air velocities and low jet pressures than for the other orifices investigated. The square orifices gave the best penetrations at the higher values of tunnel-air velocity and jet total pressure.

  13. Direct control of air gap flux in permanent magnet machines

    DOEpatents

    Hsu, John S.

    2000-01-01

    A method and apparatus for field weakening in PM machines uses field weakening coils (35, 44, 45, 71, 72) to produce flux in one or more stators (34, 49, 63, 64), including a flux which counters flux normally produced in air gaps between the stator(s) (34, 49, 63, 64) and the rotor (20, 21, 41, 61) which carries the PM poles. Several modes of operation are introduced depending on the magnitude and polarity of current in the field weakening coils (35, 44, 45, 71, 72). The invention is particularly useful for, but not limited to, the electric vehicle drives and PM generators.

  14. Direct Numerical Simulation of Air Layer Drag Reduction over a Backward-facing Step

    NASA Astrophysics Data System (ADS)

    Kim, Dokyun; Moin, Parviz

    2010-11-01

    Direct Numerical Simulation (DNS) of two-phase flow is performed to investigate the air layer drag reduction (ALDR) phenomenon in turbulent flow over a backward-facing step. In their experimental study, Elbing et al. (JFM, 2008) have observed a stable air layer on an entire flat plate if air is injected beyond the critical air-flow rate. In the present study, air is injected at the step on the wall into turbulent water flow for ALDR. The Reynolds and Weber numbers based on the water properties and step height are 22,800 and 560, respectively. An inlet section length before the step is 3h and the post expansion length is 30h, where h is the step height. The total number of grid points is about 271 million for DNS. The level set method is used to track the phase interface and the structured-mesh finite volume solver is used with an efficient algorithm for two-phase DNS. Two cases with different air-flow rates are performed to investigate the mechanism and stability of air layer. For high air-flow rate, the stable air layer is formed on the plate and more than 90% drag reduction is obtained. In the case of low air-flow rate, the air layer breaks up and ALDR is not achieved. The parameters governing the stability of air layer from the numerical simulations is also consistent with the results of stability analysis.

  15. Transdermal Uptake of Diethyl Phthalate and Di(n-butyl) Phthalate Directly from Air: Experimental Verification

    PubMed Central

    Bekö, Gabriel; Koch, Holger M.; Salthammer, Tunga; Schripp, Tobias; Toftum, Jørn; Clausen, Geo

    2015-01-01

    Background Fundamental considerations indicate that, for certain phthalate esters, dermal absorption from air is an uptake pathway that is comparable to or greater than inhalation. Yet this pathway has not been experimentally evaluated and has been largely overlooked when assessing uptake of phthalate esters. Objectives This study investigated transdermal uptake, directly from air, of diethyl phthalate (DEP) and di(n-butyl) phthalate (DnBP) in humans. Methods In a series of experiments, six human participants were exposed for 6 hr in a chamber containing deliberately elevated air concentrations of DEP and DnBP. The participants either wore a hood and breathed air with phthalate concentrations substantially below those in the chamber or did not wear a hood and breathed chamber air. All urinations were collected from initiation of exposure until 54 hr later. Metabolites of DEP and DnBP were measured in these samples and extrapolated to parent phthalate intakes, corrected for background and hood air exposures. Results For DEP, the median dermal uptake directly from air was 4.0 μg/(μg/m3 in air) compared with an inhalation intake of 3.8 μg/(μg/m3 in air). For DnBP, the median dermal uptake from air was 3.1 μg/(μg/m3 in air) compared with an inhalation intake of 3.9 μg/(μg/m3 in air). Conclusions This study shows that dermal uptake directly from air can be a meaningful exposure pathway for DEP and DnBP. For other semivolatile organic compounds (SVOCs) whose molecular weight and lipid/air partition coefficient are in the appropriate range, direct absorption from air is also anticipated to be significant. Citation Weschler CJ, Bekö G, Koch HM, Salthammer T, Schripp T, Toftum J, Clausen G. 2015. Transdermal uptake of diethyl phthalate and di(n-butyl) phthalate directly from air: experimental verification. Environ Health Perspect 123:928–934; http://dx.doi.org/10.1289/ehp.1409151 PMID:25850107

  16. Performance of PEM Liquid-Feed Direct Methanol-Air Fuel Cells

    NASA Technical Reports Server (NTRS)

    Narayanan, S. R.

    1995-01-01

    A direct methanol-air fuel cell operating at near atmospheric pressure, low-flow rate air, and at temperatures close to 60oC would tremendously enlarge the scope of potential applications. While earlier studies have reported performance with oxygen, the present study focuses on characterizing the performance of a PEM liquid feed direct methanol-air cell consisting of components developed in house. These cells employ Pt-Ru catalyst in the anode, Pt at the cathode and Nafion 117 as the PEM. The effect of pressure, flow rate of air and temperature on cell performance has been studied. With air, the performance level is as high as 0.437 V at 300 mA/cm2 (90oC, 20 psig, and excess air flow) has been attained. Even more significant is the performance level at 60oC, 1 atm and low flow rates of air (3-5 times stoichiometric), which is 0.4 V at 150 mA/cm2. Individual electrode potentials for the methanol and air electrode have been separated and analyzed. Fuel crossover rates and the impact of fuel crossover on the performance of the air electrode have also been measured. The study identifies issues specific to the methanol-air fuel cell and provides a basis for improvement strategies.

  17. A comparison of operational Lagrangian particle and adaptive puff models for plume dispersion forecasting

    NASA Astrophysics Data System (ADS)

    Souto, M. J.; Souto, J. A.; Pérez-Muñuzuri, V.; Casares, J. J.; Bermúdez, J. L.

    Transport and dispersion of pollutants in the lower atmosphere are predicted by using both a Lagrangian particle model (LPM) and an adaptive puff model (APM2) coupled to the same mesoscale meteorological prediction model PMETEO. LPM and APM2 apply the same numerical solutions for plume rise; but, for advection and plume growth, LPM uses a stochastic surrogate to the pollutant conservation equation, and APM2 applies interpolated winds and standard deviations from the meteorological model, using a step-wise Gaussian approach. The results of both models in forecasting the SO 2 ground level concentration (glc) around the 1400 MWe coal-fired As Pontes Power Plant are compared under unstable conditions. In addition, meteorological and SO 2 glc numerical results are compared to field measurements provided by 17 fully automated SO 2 glc remote stations, nine meteorological towers and one Remtech PA-3 SODAR, from a meteorological and air quality monitoring network located 30 km around the power plant.

  18. 30 CFR 75.341 - Direct-fired intake air heaters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Direct-fired intake air heaters. 75.341 Section 75.341 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.341 Direct-fired intake air heaters. (a) If any system used to...

  19. 30 CFR 75.341 - Direct-fired intake air heaters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Direct-fired intake air heaters. 75.341 Section 75.341 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.341 Direct-fired intake air heaters. (a) If any system used to...

  20. Characteristics of Puff Dispersion in an Urban Environment

    SciTech Connect

    Doran, J. C.; Allwine, K Jerry; Flaherty, Julia E.; Clawson, Kirk L.; Carter, Roger G.

    2007-05-01

    A series of instantaneous releases of sulfur hexafluoride tracer were carried out as part of the Joint Urban 2003 field campaign conducted in Oklahoma City. Data from a set of ten fast-response tracer samplers were used to examine the crosswind and along-wind spread of the tracer, the decay of tracer concentrations, and the retention of tracer in an urban environment within approximately 1km of the release locations. The time variation of the median values of the tracer concentrations, normalized by the peak value observed at a given sampler, for a set of 3 or 4 puff releases during a study period could be described by an exponential decay with characteristic decay times on the order of one to two minutes. The longer times were found for early morning releases and the shorter times were associated with later morning or afternoon releases, suggesting that atmospheric stability may affect puff dispersion even in urban environments. The median retention times, i.e., the times required for 99% of the exposure to be realized at a given location, were found to be reasonably well correlated with the median decay times. These characteristic time scales should be regarded as lower limits for concentration decay in an urban area because the analysis excluded a number of anomalous cases in which the concentrations from one release could not be readily distinguished from contributions from a previous release. In general, the variation of the along-wind dispersion parameter, σx, did not appear to be well described by linear dependencies on either the effective advection speeds of the puffs or the distance from the release point. Lateral puff dispersion as measured by σy, was roughly 70% of the along-wind dispersion at distances of 0.5 to 1 km from the release point.

  1. Effect of Deuterium Gas Puff On The Edge Plasma In NSTX

    SciTech Connect

    Zweben, S. J.

    2014-02-20

    This paper describes a detailed examination of the effects of a relatively small pulsed deuterium gas puff on the edge plasma and edge turbulence in NSTX. This gas puff caused little or no change in the line-averaged plasma density or total stored energy, or in the edge density and electron temperature up to the time of the peak of the gas puff. The radial profile of the Dα light emission and the edge turbulence within this gas puff did not vary significantly over its rise and fall, implying that these gas puffs did not significantly perturb the local edge plasma or edge turbulence. These measurements are compared with modeling by DEGAS 2, UEDGE, and with simplified estimates for the expected effects of this gas puff.

  2. Radiative Properties of Argon Gas-Puff Implosions on COBRA

    NASA Astrophysics Data System (ADS)

    Ouart, Nicholas; Qi, Niansheng; de Grouchy, Phil; Shelkovenko, Tatiana; Pikuz, Sergei; Giuliani, John; Dasgupta, Arati; Apruzese, John; Clark, Robert; Hammer, David; Kusse, Bruce

    2015-11-01

    Gas-puff Z-pinch experiments were performed on the 1 MA COBRA pulsed power generator at Cornell University. The gas puffs were injected into the load region from a triple nozzle. The load region had an anode-cathode gap of 2.5 cm. The standard diagnostics on COBRA include time-integrated pinhole cameras, a time-integrated axially resolved x-ray spectrometer, filtered photo-conducting detectors, and time-gated XUV cameras. We will focus mainly on results from pinhole images and x-ray spectra from argon gas puffs including some with a SO2 dopant. The x-ray time-integrated pinhole images feature a tight axially uniform plasma column with a diameter of approximately 1 mm for argon gas implosion. The x-ray spectrometer used mica crystals (2d =19.84 Å) and captured the argon K-shell radiation from different crystal reflections. A 1-D multi-zone argon and sulfur non-LTE kinetics code with radiation transport is used to model the K-shell emission for the purpose of inferring the plasma conditions and the interaction of gas from the inner annulus with the central jet. This work is supported by DOE/NNSA.

  3. Pattern recognition methods and air pollution source identification. [based on wind direction

    NASA Technical Reports Server (NTRS)

    Leibecki, H. F.; King, R. B.

    1978-01-01

    Directional air samplers, used for resolving suspended particulate matter on the basis of time and wind direction were used to assess the feasibility of characterizing and identifying emission source types in urban multisource environments. Filters were evaluated for 16 elements and X-ray fluorescence methods yielded elemental concentrations for direction, day, and the interaction of direction and day. Large numbers of samples are necessary to compensate for large day-to-day variations caused by wind perturbations and/or source changes.

  4. Effects of air cavity on fly-ear inspired directional microphones: a numerical study

    NASA Astrophysics Data System (ADS)

    Liu, Haijun; Yu, Miao

    2011-04-01

    The superacute ear of the parasitoid fly Ormia ochracea has inspired the development of a variety of novel miniature directional microphones for sound source localization, in which the effects of air cavity backing the eardrums are often neglected without validation. In the original testing on the fly ear, the integrity of the air space is shown not to be the key to the intertympnal coupling. However, it does not necessarily mean that the tympanum can be treated as in vacuo, and the effects of the air cavity backing the eardrums have yet to be fully understood. In this article, a normalized version of our previous model of air-backed circular membranes is derived to study the conditions under which the air cavity can be indeed neglected. This model is then used to study a fly-ear inspired directional microphone design with two clamped circular membranes mechanically coupled by a bridge. The performance of the directional microphone with air cavity is evaluated in comparison to its counterpart in vacuo. This article not only provides more insights into the fly ear phenomena, but builds a theoretical foundation on whether and how to take the air cavity into account in the design of pressure sensors and directional microphones in general.

  5. Puffs and gene regulation--molecular insights into the Drosophila ecdysone regulatory hierarchy.

    PubMed

    Thummel, C S

    1990-12-01

    Sixteen years ago, Michael Ashburner and his colleagues proposed a hierarchical model for the genetic control of polytene chromosome puffing by the steroid hormone ecdysone. The recent molecular isolation and characterization of three early ecdysone-inducible genes has confirmed many aspects of this model--these genes are directly induced by ecdysone, repressed by ecdysone-induced proteins, and appear to encode DNA binding regulatory proteins. The three early genes are also remarkably similar in structure. They are all unusually long and complex, with multiple transcripts that direct the synthesis of several related proteins from each locus. Proteins encoded by two of the early genes bind to both early and late ecdysone-induced puffs, implying that they are key regulators in the hierarchy. PMID:2127884

  6. Compositional profiling and sensorial analysis of multi-wholegrain extruded puffs as affected by fructan inclusion.

    PubMed

    Handa, C; Goomer, S

    2015-09-01

    Rice grits, corn grits, pulse, wholegrain - finger millet and sorghum were utilized in the production of multigrain extruded puffs using a single screw extruder. The effect of inclusion of fructan - fructoligosaccharide in multi-wholegrain (MWG) extruded puffs was examined. MWG fructan enriched puffs puffs had 450 % higher dietary fiber content than the control puff (CP). These puffs can be categorized as 'Good Source' of fiber as it suffices 17.2 % DV of fiber. Puffs were rated 8.1 ± 0.6, 8.3 ± 0.7, 8.1 ± 0.6, 7.5 ± 0.5 and 8.2 ± 0.6 for color, flavor, texture, appearance and overall acceptability respectively. The scores for all the attributes were found to be not significantly different (p < 0.05) from CP. The MWG fructan puffs were rated higher on flavor than the CP having a score of 8.3 ± 0.7 as opposed to 8.2 ± 0.4 for CP. This indicates that the nutritional quality and acceptability of MWG extruded puffs could be improved by the inclusion of fructans. PMID:26345016

  7. Wind Direction Bias in Generating Wind Roses and Conducting Sector-Based Air-Dispersion Modeling

    SciTech Connect

    Droppo, James G.; Napier, Bruce A.

    2008-07-01

    Certain widely used wind rose programs and air dispersion models use an overly-simple data-transfer algorithm that induces a directional bias in their output products. The purpose of this paper is to provide a revised algorithm that corrects the aliasing bias that occurs when the internals in reported wind direction data are on the same order of magnitude, but not equal to the intervals used in the wind direction summaries. The directional bias issue arises when output products in 22.5-degree sectors are produced from 10-degree wind direction data, which affects the results of simulations of air and surface concentrations using widely applied air-dispersion models. Datasets or models with the bias discussed here give consistent positive biases (approximately 30%) for cardinal direction sectors (north, south, east, and west) and consistent negative biases for all the other sectors (approximately -10%). Data summary and air dispersion programs providing outputs in directions sectors that do not match the observational sectors need to be checked for this bias. A revised data-transfer algorithm is provided that corrects the aliasing bias that can occur in transferring wind direction data between different sectors widths.

  8. Improving the performance of a compression ignition engine by directing flow of inlet air

    NASA Technical Reports Server (NTRS)

    Kemper, Carlton

    1946-01-01

    The object of this report is to present the results of tests performed by the National Advisory Committee for Aeronautics to determine the effect on engine performance of directing the flow of the inlet air to a 5-inch by 7-inch cylinder, solid injection, compression ignition engine, After a few preliminary tests, comparative runs were made at a speed of 1500 r.p.m. with and without directed air flow. It was found that directing the flow of the inlet air toward the fuel injection valve gave steadier engine operation, and an appreciable increase in power, and decreased fuel consumption. The results indicate the possibility of improving the performance of a given type of combustion chamber without changing its shape and with no change in valve timing. They would also seem to prove that directional turbulence, set up before the inlet valve of a four-stroke cycle engine, continues in the engine cylinder throughout the compression stroke.

  9. Puff/Plume for Windows 95-NT

    1998-05-20

    PFPL-NT is a GUI event-driven scientific application integrating 14 background processes to access the consequences of accidental releases of hazardous materials from production facilities and transportation vehicles. A simple straight-line Gaussian assumption has been employed with observations from meteorological towers to calculate and visually display plume directions, plume width, and dose/concentration estimates in the immediate vicinity of a radiological or chemical release.

  10. Ultraviolet germicidal irradiation: future directions for air disinfection and building applications.

    PubMed

    Miller, Shelly L; Linnes, Jacqueline; Luongo, Julia

    2013-01-01

    Ultraviolet germicidal irradiation (UVGI) for air disinfection applications has relied on low-pressure mercury vapor lamps for decades. New design requirements have generated the need for alternatives in some uses. This study describes the current state of UVGI technology and describes future directions for technology development, including the use of lamps produced from nontoxic materials and light-emitting diode lamps. Important applications are discussed such as the use of ultraviolet germicidal lamps in developing countries, in heating, ventilating and air-conditioning systems to improve energy efficiency and indoor air quality, and for whole room disinfection. PMID:23581680

  11. Reducing the cost of Ca-based direct air capture of CO2.

    PubMed

    Zeman, Frank

    2014-10-01

    Direct air capture, the chemical removal of CO2 directly from the atmosphere, may play a role in mitigating future climate risk or form the basis of a sustainable transportation infrastructure. The current discussion is centered on the estimated cost of the technology and its link to "overshoot" trajectories, where atmospheric CO2 levels are actively reduced later in the century. The American Physical Society (APS) published a report, later updated, estimating the cost of a one million tonne CO2 per year air capture facility constructed today that highlights several fundamental concepts of chemical air capture. These fundamentals are viewed through the lens of a chemical process that cycles between removing CO2 from the air and releasing the absorbed CO2 in concentrated form. This work builds on the APS report to investigate the effect of modifications to the air capture system based on suggestions in the report and subsequent publications. The work shows that reduced carbon electricity and plastic packing materials (for the contactor) may have significant effects on the overall price, reducing the APS estimate from $610 to $309/tCO2 avoided. Such a reduction does not challenge postcombustion capture from point sources, estimated at $80/tCO2, but does make air capture a feasible alternative for the transportation sector and a potential negative emissions technology. Furthermore, air capture represents atmospheric reductions rather than simply avoided emissions. PMID:25207956

  12. Comparison of Puff Topography, Toxicant Exposure, and Subjective Effects in Low- and High-Frequency Waterpipe Users: A Double-Blind, Placebo-Control Study

    PubMed Central

    Cobb, Caroline O.; Blank, Melissa D.; Morlett, Alejandra; Shihadeh, Alan; Jaroudi, Ezzat; Karaoghlanian, Nareg; Kilgalen, Barbara; Austin, Janet; Weaver, Michael F.

    2015-01-01

    Introduction: Clinical laboratory work among intermittent and daily waterpipe tobacco smokers has revealed significant risks for tobacco dependence and disease associated with waterpipe tobacco smoking (WTS). No studies have compared these groups directly. This study examined whether WTS frequency was associated with differential puff topography, toxicant exposure, and subjective response using a placebo-control design. Methods: Eighty participants reporting WTS of 2–5 episodes (LOW; n = 63) or ≥20 episodes (HIGH; n = 17) per month for ≥6 months completed 2 double-blind, counterbalanced 2-hr sessions that were preceded by ≥12hr of tobacco abstinence. Sessions differed by product smoked ad libitum for 45+ min: preferred brand/flavor of waterpipe tobacco (active) or a flavor-matched tobacco-free waterpipe product (placebo). Outcomes included puff topography, plasma nicotine, carboxyhemoglobin (COHb), and subjective response. Results: HIGH users had more puffs, shorter inter-puff-intervals, and a higher total puff volume for placebo relative to active, as well as relative to LOW users during placebo. Plasma nicotine concentrations increased when smoking active (but not placebo) with no significant differences between groups at 25min post-product administration. COHb increased significantly during all conditions; the largest increase was for HIGH users when smoking placebo. There was some evidence of higher baseline scores for nicotine/tobacco nicotine abstinence symptomology. Conclusions: Higher frequency waterpipe users may be more sensitive to the effects of waterpipe smoke nicotine content. Among HIGH users, higher baseline nicotine/tobacco abstinence symptoms may indicate greater nicotine dependence. These data support continued surveillance of WTS and development of dependence measures specific to this product. PMID:25257982

  13. Edge turbulence measurements in NSTX by gas puff imaging

    NASA Astrophysics Data System (ADS)

    Maqueda, R. J.; Wurden, G. A.; Zweben, S.; Roquemore, L.; Kugel, H.; Johnson, D.; Kaye, S.; Sabbagh, S.; Maingi, R.

    2001-01-01

    Turbulent filaments in visible light emission corresponding mainly to density fluctuations at the edge have been observed in large aspect ratio tokamaks: TFTR, ASDEX, Alcator C-Mod, and DIII-D. This article reports on similar turbulent structures observed in the National Spherical Torus Experiment (NSTX) using a fast-framing, intensified, digital visible camera. These filaments were previously detected mainly in high recycling regions, such as at limiters or antennas, where the line emission from neutral atoms was modulated by the fluctuations in local plasma density. However, by introducing controlled edge gas puffs, i.e., gas puff imaging, we have increased the brightness and contrast in the fluctuation images and allowed the turbulent structure to be measured independently of the recycling. A set discrete fiber-optically coupled sight-lines also measured the frequency spectra of these light fluctuations with a 200 kHz bandwidth. Initial results in NSTX show that the turbulent filaments are well aligned with the magnetic field which can be up to 45° from the horizontal at the outer midplane of NSTX. The dominant wavelength perpendicular to the magnetic field is ˜7-11 cm, corresponding to a k⊥ ρs of ˜0.3 at an assumed Te=25 eV, and the frequency spectra has a typical broad shape characteristic of edge turbulence extending to about 100 kHz. By imaging a He gas puff along a magnetic field line the characteristic radial scalelength appears to be in the 3-5 cm range.

  14. Gas puff Z-pinch implosions with external Bz field on COBRA

    NASA Astrophysics Data System (ADS)

    Qi, N.; de Grouchy, P.; Schrafel, P. C.; Atoyan, L.; Potter, W. M.; Cahill, A. D.; Gourdain, P.-A.; Greenly, J. B.; Hammer, D. A.; Hoyt, C. L.; Kusse, B. R.; Pikuz, S. A.; Shelkovenko, T. A.

    2014-12-01

    We present preliminary experimental results on mitigating Magneto-Rayleigh-Taylor (MRT) instabilities by applying an external Bz field. The experiments were conducted on the 1-MA, 200-ns COBRA generator at Cornell University. In the experiments, a triple-nozzle was used to produce z-pinch loads from concentric outer and inner annular gas puffs and a center gas puff column. A single coil was used to produce a Bz field in the pinch region. We have used two 4-frame 2-ns gated EUV cameras to obtain images of the imploding plasmas, in which the MRT instabilities were observed. The MRT instabilities can grow when the plasma accelerates toward the axis. With a triple gas puff (outer, inner and center puff), reduced acceleration or de-acceleration of the imploding plasma occurred when the outer puff plasma imploded onto the inner annular puff plasma resulting a relatively stable implosion. In the absent of the inner annular gas puff, the imploding outer annular plasma continued to accelerate toward the axis. Large turbulent flares at the edge of the implosion or pinch plasma were observed. The implosion was not stable. To stabilize the implosion without the inner gas puff, a Bz field was applied. This external Bz field was compressed by the outer imploding plasma shell. A relatively stable implosion was observed. Increasing the Bz field to 2-kG resulted in a relatively fatter pinch plasma.

  15. Radius scaling of X-radiation from gas-puff implosions on an inductive driver

    SciTech Connect

    Mosher, D.; Stephanakis, S. J.; Apruzese, J. P.; Black, D. C.; Boller, J. R.; Commisso, R. J.; Myers, M. C.; Peterson, G. G.; Weber, B. V.; Young, F. C.

    1997-05-05

    The output of X radiation from gas-puff implosions is studied in reference to its theoretical prediction by simple model. Results show that the gas-puff radius, but not implosion time, controls radiation yield. Radius-scaling models being fairly reliable may lead to an overestimation sometimes. (AIP)

  16. Direct effects of energy-related air pollutants on plant sexual reproduction. Final report, February 1, 1979--January 31, 1982

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1987-12-08

    Our completed research program concentrated on the direct in vivo effects of energy-related air pollutants on plant sexual reproduction. Direct air pollution effects on plant sexual reproduction have been studied for SO{sub 2} and NO{sub 2}, two of the three major air pollutants.

  17. 'Carcinogens in a puff': smoking in Hong Kong movies.

    PubMed

    Ho, Sai-Yin; Wang, Man-Ping; Lai, Hak-Kan; Hedley, Anthony J; Lam, Tai-Hing

    2010-12-01

    Smoking scenes in movies, exploited by the tobacco industry to circumvent advertisement bans, are linked to adolescent smoking. Recently, a Hong Kong romantic comedy Love in a puff put smoking at centre stage, with numerous smoking scenes and words that glamourise smoking. Although WHO has issued guidelines on reducing the exposure of children to smoking in movies, none is adopted in Hong Kong. Comprehensive tobacco control strategies are urgently needed to protect young people in Hong Kong from cigarette promotion in movies. PMID:20852325

  18. Deuterium gas puff Z-pinch at currents of 2 to 3 mega-ampere

    NASA Astrophysics Data System (ADS)

    Klir, D.; Shishlov, A. V.; Kubes, P.; Rezac, K.; Fursov, F. I.; Kokshenev, V. A.; Kovalchuk, B. M.; Kravarik, J.; Kurmaev, N. E.; Labetsky, A. Yu.; Ratakhin, N. A.

    2012-03-01

    Deuterium gas-puff experiments have been carried out on the GIT-12 generator at the Institute of High Current Electronics in Tomsk. The emphasis was put on the study of plasma dynamics and neutron production in double shell gas puffs. A linear mass density of deuterium (D2) varied between 50 and 85 μg/cm. Somewhat problematic was a spread of the D2 gas at a large diameter in the central anode-cathode region. The generator operated in two regimes, with and without a plasma opening switch (POS). When the POS was used, a current reached a peak of 2.7 MA with a 200 ns rise time. Without the POS, a current rise time approached 1500 ns. The influence of different current rise times on neutron production was researched. Obtained results were important for comparison of fast deuterium Z-pinches with plasma foci. Average DD neutron yields with and without the POS were about 1011. The neutron yield seems to be dependent on a peak voltage at the Z-pinch load. In all shots, the neutron emission started during stagnation. At the beginning of the neutron production, the neutron emission correlated with soft x-rays and a significant fraction of neutrons could be explained by the thermonuclear mechanism. Nevertheless, a peak of the neutron emission occurred 40 ns after a soft x-ray peak. At this very moment, hard x-rays above 1 MeV were detected and a rapid expansion with a velocity of 3×105 m/s was observed. In the case of the POS, 1 MeV widths of radial neutron spectra implied that there are deuterons with the energy above 200 keV moving in the radial direction. On the basis of D2 gas puff experiments in the 0.3-17 MA region, the neutron yield dependence on a current as Y∝I3.0±0.2 was proposed.

  19. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  20. Hypersonic lateral and directional stability characteristics of aeroassist flight experiment configuration in air and CF4

    NASA Technical Reports Server (NTRS)

    Micol, John R.; Wells, William L.

    1993-01-01

    Hypersonic lateral and directional stability characteristics measured on a 60 deg half-angle elliptical cone, which was raked at an angle of 73 deg from the cone centerline and with an ellipsoid nose (ellipticity equal to 2.0 in the symmetry plane), are presented for angles of attack from -10 to 10 deg. The high normal-shock density ratio of a real gas was simulated by tests at a Mach number of 6 in air and CF4 (density ratio equal to 5.25 and 12.0, respectively). Tests were conducted in air at Mach 6 and 10 and in CF4 at Mach 6 to examine the effects of Mach number, Reynolds number, and normal-shock density ratio. Changes in Mach number from 6 to 10 in air or in Reynolds number by a factor of 4 at Mach 6 had a negligible effect on lateral and directional stability characteristics. Variations in normal-shock density ratio had a measurable effect on lateral and directional aerodynamic coefficients, but no significant effect on lateral and directional stability characteristics. Tests in air and CF4 indicated that the configuration was laterally and directionally stable through the test range of angle of attack.

  1. Effects of source conditions, vertical diffusivity and spatial resolution of wind data on simulation results based on the tephra-tracking model PUFF: a case study from the Kirishima 2011 eruption

    NASA Astrophysics Data System (ADS)

    Kiyosugi, K.; Koyaguchi, T.

    2012-12-01

    Understanding how pyroclasts disperse from volcanic plumes is a fundamental problem of volcanology to reconstruct eruption conditions from tephra fallout deposits. Tephra dispersion is not only a scientifically interesting but also socially and economically important problem (e.g., the air traffic disruption caused by the 2010 Eyjafjallaokull volcano eruption). PUFF is a tephra-tracking model developed by the University of Alaska for the use of aviation service alert. In this model, position vector of each particle at a time step is calculated with Lagrangian formulation using local wind velocity and terminal gravitational fallout vector at one time step before; diffusivity due to turbulent behavior is simulated by a random walk formulation. We applied this model to the sub-Plinian phase of the Kirishima 2011 eruption to test the effects of simulation parameters on the features of tephra dispersion and fallout deposits in the field. We systematically investigated the effects of two parameters of PUFF model to tephra dispersion: vertical diffusivity and spatial resolution of wind data. Our results show that, as the value of vertical diffusivity increases, the distribution of settled particles on the ground surface becomes a more elongated shape in the wind direction. This effect is more remarkable for finer particles. These results indicate that the simulation results of the diffusion advection models in general depend on the assumed vertical diffusivity and the spatial resolution of wind data as well as on the source condition (e.g., the release levels of particles and grain size distribution). During the 2011 Kirishima eruption, a sub-Plinian eruption plume of 8 km high was observed by weather radars. The plume extended southeastward around the vent (~60 km), and traveled in the higher altitudes eastward (about 900 km from the vent). The simulation results of PUFF reconstructed these qualitative features observed in the satellite images and the deposits near the

  2. Automation for "Direct-to" Clearances in Air-Traffic Control

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; McNally, David

    2006-01-01

    A method of automation, and a system of computer hardware and software to implement the method, have been invented to assist en-route air-traffic controllers in the issuance of clearances to fly directly to specified waypoints or navigation fixes along straight paths that deviate from previously filed flight plans. Such clearances, called "direct-to" clearances, have been in use since before the invention of this method and system.

  3. Toward a predictive model of Ca2+ puffs

    NASA Astrophysics Data System (ADS)

    Thul, R.; Thurley, K.; Falcke, M.

    2009-09-01

    We investigate the key characteristics of Ca2+ puffs in deterministic and stochastic frameworks that all incorporate the cellular morphology of IP3 receptor channel clusters. In the first step, we numerically study the Ca2+ liberation in a three-dimensional representation of a cluster environment with reaction-diffusion dynamics in both the cytosol and the lumen. These simulations reveal that Ca2+ concentrations at a releasing cluster range from 80 to 170 μM and equilibrate almost instantaneously on the time scale of the release duration. These highly elevated Ca2+ concentrations eliminate Ca2+ oscillations in a deterministic model of an IP3R channel cluster at physiological parameter values as revealed by a linear stability analysis. The reason lies in the saturation of all feedback processes in the IP3R gating dynamics, so that only fluctuations can restore experimentally observed Ca2+ oscillations. In this spirit, we derive master equations that allow us to analytically quantify the onset of Ca2+ puffs and hence the stochastic time scale of intracellular Ca2+ dynamics. Moving up the spatial scale, we suggest to formulate cellular dynamics in terms of waiting time distribution functions. This approach prevents the state space explosion that is typical for the description of cellular dynamics based on channel states and still contains information on molecular fluctuations. We illustrate this method by studying global Ca2+ oscillations.

  4. Olive Oil Based Emulsions in Frozen Puff Pastry Production

    NASA Astrophysics Data System (ADS)

    Gabriele, D.; Migliori, M.; Lupi, F. R.; de Cindio, B.

    2008-07-01

    Puff pastry is an interesting food product having different industrial applications. It is obtained by laminating layers of dough and fats, mainly shortenings or margarine, having specific properties which provides required spreading characteristic and able to retain moisture into dough. To obtain these characteristics, pastry shortenings are usually saturated fats, however the current trend in food industry is mainly oriented towards unsatured fats such as olive oil, which are thought to be safer for human health. In the present work, a new product, based on olive oil, was studied as shortening replacer in puff pastry production. To ensure the desired consistency, for the rheological matching between fat and dough, a water-in-oil emulsion was produced based on olive oil, emulsifier and a hydrophilic thickener agent able to increase material structure. Obtained materials were characterized by rheological dynamic tests in linear viscoelastic conditions, aiming to setup process and material consistency, and rheological data were analyzed by using the weak gel model. Results obtained for tested emulsions were compared to theological properties of a commercial margarine, adopted as reference value for texture and stability. Obtained emulsions are characterized by interesting rheological properties strongly dependent on emulsifier characteristics and water phase composition. However a change in process temperature during fat extrusion and dough lamination seems to be necessary to match properly typical dough rheological properties.

  5. Beyond DNA puffs: What can we learn from studying sciarids?

    PubMed

    Simon, Claudio Roberto; Siviero, Fábio; Monesi, Nadia

    2016-07-01

    Members of the Sciaridae family attracted the interest of researchers because of the demonstration that the DNA puff regions, which are formed in the salivary gland polytene chromosomes at the end of the fourth larval instar, constitute sites of developmentally regulated gene amplification. Besides contributing to a deeper understanding of the process of gene amplification, the study of sciarids has also provided important insights on other biological processes such as sex determination, programmed cell death, insect immunity, telomere maintenance, and nucleolar organizing regions (NOR) formation. Open questions in sciarids include among others, early development, the role of noncoding RNAs in gene amplification and the relationship between gene amplification and transcription in DNA puff forming regions. These and other questions can now be pursued with next generation sequencing techniques and experiments using RNAi experiments, since this latter technique has been shown to be feasible in sciarids. These new perspectives in the field of sciarid biology open the opportunity to consolidate sciarid species as important emerging models. genesis 54:361-378, 2016. © 2016 Wiley Periodicals, Inc. PMID:27178805

  6. 30 CFR 75.341 - Direct-fired intake air heaters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Direct-fired intake air heaters. 75.341 Section 75.341 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... measurement of the carbon monoxide concentration at the bottom of each shaft, slope, or in the drift...

  7. 30 CFR 75.341 - Direct-fired intake air heaters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Direct-fired intake air heaters. 75.341 Section 75.341 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... measurement of the carbon monoxide concentration at the bottom of each shaft, slope, or in the drift...

  8. 30 CFR 75.341 - Direct-fired intake air heaters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Direct-fired intake air heaters. 75.341 Section 75.341 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... measurement of the carbon monoxide concentration at the bottom of each shaft, slope, or in the drift...

  9. 75 FR 43092 - Airworthiness Directives; Viking Air Limited (Type Certificate Previously Held by Bombardier, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ..., Flammability Reduction and Maintenance and Inspection Requirements'' (66 FR 23086, May 7, 2001). In addition to...; 2. Is not a ``significant rule''under the DOT Regulatory Policies and Procedures (44 FR 11034... Directives; Viking Air Limited (Type Certificate Previously Held by Bombardier, Inc.) Model DHC-7...

  10. 76 FR 10220 - Airworthiness Directives; Viking Air Limited (Type Certificate No. A-815 Formerly Held by...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-24

    ... ] December 7, 2010 (75 FR 75932). That NPRM proposed to require repetitively inspecting the elevator control... Order 12866, (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034...-020-AD; Amendment 39-16611; AD 2011-05-02] RIN 2120-AA64 Airworthiness Directives; Viking Air...

  11. Electric power generating plant having direct-coupled steam and compressed-air cycles

    DOEpatents

    Drost, M.K.

    1981-01-07

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  12. Electric power generating plant having direct coupled steam and compressed air cycles

    DOEpatents

    Drost, Monte K.

    1982-01-01

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  13. 78 FR 40063 - Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters (Type Certificate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ...We propose to supersede an existing airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-64E helicopters. The existing AD requires checks of the main rotor blades for a crack. This proposed AD would retain the actions of the existing AD, would reflect that the type certificate (TC) for this model helicopter has been transferred to Erickson Air-Crane Incorporated......

  14. Instant conversion of air to a clathrate hydrate: CO(2) hydrates directly from moist air and moist CO(2)(g).

    PubMed

    Devlin, J Paul; Monreal, I Abrrey

    2010-12-23

    The rapid conversion of vapor mixtures containing the gases CO(2), H(2)S, and HCN to clathrate hydrates was reported recently. The novel method is based on the pulsing of warm vapor mixtures, including a carrier gas, into a cold condensation chamber. With cooling, the vapors, which also include ∼1% water and either tetrahydrofuran or trimethylene oxide as a catalyst, nucleate aqueous solution nanodroplets that, on a millisecond time scale, crystallize as hydrate nanoparticles that consume 100% of the water. Humid air approximates the content of mixtures used successfully in the vapor-to-hydrate conversions. FTIR spectra are examined for gas hydrates formed directly from air and air enriched with CO(2), as well as hydrate particles for which CO(2)(g) serves as both guest and aerosol medium. In each instance all of the water in the condensed phase converts to a clathrate hydrate. The subsecond ether-catalyzed formation of the hydrates near 230 K requires only a few percent of the CO(2) pressure used in conventional processes that yield fractional amounts of gas hydrates on an hour time scale in the same temperature range. PMID:21105676

  15. Lamination of pharmaceutical tablets due to air entrapment: direct visualization and influence of the compact thickness.

    PubMed

    Mazel, V; Busignies, V; Diarra, H; Tchoreloff, P

    2015-01-30

    Capping and lamination are two problems that are often faced during the industrial manufacturing of pharmaceutical tablets. Several reasons have been proposed to explain these phenomena. Among them, air entrapment is supposed to play a role in some cases. Nevertheless, no direct proof were given to prove that air entrapment can promote lamination or capping and various publications have questioned this hypothesis. In this article, using a model product compacted on a compression simulator, a direct proof of the implication of air entrapment during lamination was given. In fact, at the surface of the compact, defects with a spherical shape, clearly linked with an entrapped bubble of air, began to appear on the surface of the compact just below the pressure level to which lamination was observed. Moreover it was also observed that, when the compact thickness increased, the lamination pressure decreased, meaning that the compact thickness can promote lamination. As a conclusion, contrary to what is said in some publications, air entrapment can be involved when problems of lamination occur, and, in this case, powder desaeration should be considered. PMID:25522829

  16. Temperature Evolution of a 1 MA Triple-Nozzle Gas-Puff Z-Pinch

    NASA Astrophysics Data System (ADS)

    de Grouchy, Philip; Banasek, Jacob; Engelbrecht, Joey; Qi, Niansheng; Atoyan, Levon; Byvank, Tom; Cahill, Adam; Moore, Hannah; Potter, William; Ransohoff, Lauren; Hammer, David; Kusse, Bruce; Laboratory of Plasma Studies Team

    2015-11-01

    Mitigation of the Rayleigh-Taylor instability (RTI) plays a critical role in optimizing x-ray output at high-energy ~ 13 keV using the triple-nozzle Krypton gas-puff at Sandia National Laboratory. RTI mitigation by gas-puff density profiling using a triple-nozzle gas-puff valve has recently been recently demonstrated on the COBRA 1MA z-pinch at Cornell University. In support of this work we investigate the role of shell cooling in the growth of RTI during gas-puff implosions. Temperature measurements within the imploding plasma shell are recorded using a 527 nm, 10 GW Thomson scattering diagnostic for Neon, Argon and Krypton puffs. The mass-density profile is held constant at 22 microgram per centimeter for all three puffs and the temperature evolution of the imploding material is recorded. In the case of Argon puffs we find that the shell ion and electron effective temperatures remain in equilibrium at around 1keV for the majority of the implosion phase. In contrast scattered spectra from Krypton are dominated by of order 10 keV effective ion temperatures. Supported by the NNSA Stewardship Sciences Academic Programs.

  17. 3D simulations of gas puff effects on edge density and ICRF coupling in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Bobkov, V.; Lunt, T.; Noterdaeme, J.-M.; Coster, D.; Bilato, R.; Jacquet, P.; Brida, D.; Feng, Y.; Wolfrum, E.; Guimarais, L.; the ASDEX Upgrade Team

    2016-03-01

    In recent experiments, a local gas puff was found to be an effective way to tailor the scrape-off layer (SOL) density and improve the ion cyclotron range of frequency (ICRF) power coupling in tokamaks. In order to quantitatively reproduce these experiments, to understand the corresponding physics and to optimize the gas valve positions and rates, simulations were carried out with the 3D edge plasma transport code EMC3-EIRENE in ASDEX Upgrade. An inter-ELM phase of an H-mode discharge with a moderate gas puff rate (1.2  ×  1022 electrons s-1) is used in our simulations. We simulated cases with gas puff in the lower divertor, the outer mid-plane and the top of the machine while keeping other conditions the same. Compared with the lower divertor gas puff, the outer mid-plane gas puff can increase the local density in front of the antennas most effectively, while a toroidally uniform but significantly smaller enhancement is found for the top gas puff. Good agreement between our simulations and experiments is obtained. With further simulations, the mechanisms of SOL density tailoring via local gas puffing and the strategies of gas puff optimization are discussed in the paper.

  18. Rapid monitoring of soil, water, and air dusts by direct large-area alpha spectrometry.

    PubMed

    Sill, C W

    1995-07-01

    During retrieval and disposition of wastes containing transuranium elements, continuous monitoring of the air, water, and soil for alpha emitters was required to ensure that safety limits were not exceeded and that the waste itself was not disturbed unknowingly. Direct measurements by alpha spectrometry were particularly promising because of their potential speed, sensitivity, and their ability to identify transuranium radionuclides under field conditions. Soil samples or settled dusts were finely ground, suspended in 80% ethanol, sprayed onto circular stainless steel pans, and dried on a hotplate. Water samples were mounted directly by spraying. Air dusts were collected with a high-volume air sampler on 20- by 25-cm membrane filters. The samples were then analyzed directly in a large pressurized gridded ionization chamber without further sample preparation. The lower limits of detection for 10-min counting times were 1.5 Bq g-1 (40 pCi g-1) for 100-mg soil samples, and 4 x 10(-2) Bq m-3 (10(-12) microCi mL-1) for a 10-min air sample taken at 0.4 m3 min-1 (14 cubic feet per minute) and counted without waiting for decay of radon progeny. PMID:7790211

  19. Application of amine-tethered solid sorbents for direct CO2 capture from the ambient air.

    PubMed

    Choi, Sunho; Drese, Jeffrey H; Eisenberger, Peter M; Jones, Christopher W

    2011-03-15

    While current carbon capture and sequestration (CCS) technologies for large point sources can help address the impact of CO(2) buildup on global climate change, these technologies can at best slow the rate of increase of the atmospheric CO(2) concentration. In contrast, the direct CO(2) capture from ambient air offers the potential to be a truly carbon negative technology. We propose here that amine-based solid adsorbents have significant promise as key components of a hypothetical air capture process. Specifically, the CO(2) capture characteristics of hyperbranched aminosilica (HAS) materials are evaluated here using CO(2) mixtures that simulate ambient atmospheric concentrations (400 ppm CO(2) = "air capture") as well as more traditional conditions simulating flue gas (10% CO(2)). The air capture experiments demonstrate that the adsorption capacity of HAS adsorbents are only marginally influenced even with a significant dilution of the CO(2) concentration by a factor of 250, while capturing CO(2) reversibly without significant degradation of performance in multicyclic operation. These results suggest that solid amine-based air capture processes have the potential to be an effective approach to extracting CO(2) from the ambient air. PMID:21323309

  20. Multiple-component analysis of cigarette combustion gases on a puff-by-puff basis using a dual infrared tunable diode laser system

    NASA Astrophysics Data System (ADS)

    Plunkett, Susan E.; Parrish, Milton; Shafer, Kenneth E., Jr.; Nelson, David D., Jr.; McManus, J. Barry; Jimenez, Jose L.; Zahniser, Mark S.

    1999-10-01

    A dual infrared tunable diode laser system (IR-TDL) has been developed for the simultaneous detection of multiple gaseous components in cigarette smoke. The high spectral resolution (0.001 cm-1) and rapid time response (20 Hz) of the TDL system are ideal for separating the absorptions from the multitude of gas phase components found in this matrix. The combustion products are sampled into a 0.3 liter, 18 meter multiple pass absorption cell with a flow response time of 0.15 seconds, which provides ample time resolution to observe variations within each 2-second puff. Two independent beam paths allow simultaneous detection in two wavelength regions; the first for ethylene and ammonia and the second for formaldehyde. Rapid scan-sweep integration with direct absorption permits absolute gas concentrations to be determined on-line. A nonlinear least squares procedure is used for `fingerprint' fitting of up to four gases with each diode. Results demonstrating the instrument sensitivity and time response, along with potential caveats, for several gaseous components will be presented.

  1. Estimation of dispersion parameters from photographic density measurements on smoke puffs

    NASA Astrophysics Data System (ADS)

    Yassky, D.

    An extension is proposed of methods that use "optical boundaries" of smoke-plumes in order to estimate atmospheric dispersion parameters. Use is made here of some properties of photographic optics and concentration distributions of light absorbing puffs having no multiple scattering. An array of relative photometric densities, measured on a single photograph of a puff, is shown to be of use in numerical estimation of a puff's dispersive parameters. The proposed method's performance is evaluated by means of computer simulation which includes estimates of the influence of photogrammetric and photometric errors. Future experimental validation of the proposed method may introduce fast and inexpensive ways of obtaining extensive atmospheric dispersion data bases.

  2. Research on plasma-puff initiation of high Coulomb transfer switches

    NASA Technical Reports Server (NTRS)

    Venable, Demetrius D.; Han, Kwang S.

    1993-01-01

    The plasma-puff triggering mechanism based on hypocycloidal pinch geometry was investigated to determine the optimal operating conditions for an azimuthally uniform surface flashover which initiates plasma-puff under wide ranges of fill gas pressures of Ar, He and N2. Research is presented and resulting conference papers are attached. These papers include 'Characteristics of Plasma-Puff Trigger for an Inverse-Pinch Plasma Switch'; 'Ultra-High-Power Plasma Switch INPUTS for Pulse Power Systems'; 'Characteristics of Switching Plasma in an Inverse-Pinch Switch'; 'Comparative Study of INPIStron and Spark Gap'; and 'INPIStron Switched Pulsed Power for Dense Plasma Pinches.'

  3. Developing the Pulsed Fission-Fusion (PuFF) Engine

    NASA Technical Reports Server (NTRS)

    Adams, Robert B.; Cassibry, Jason; Bradley, David; Fabisinski, Leo; Statham, Geoffrey

    2014-01-01

    In September 2013 the NASA Innovative Advanced Concept (NIAC) organization awarded a phase I contract to the PuFF team. Our phase 1 proposal researched a pulsed fission-fusion propulsion system that compressed a target of deuterium (D) and tritium (T) as a mixture in a column, surrounded concentrically by Uranium. The target is surrounded by liquid lithium. A high power current would flow down the liquid lithium and the resulting Lorentz force would compress the column by roughly a factor of 10. The compressed column would reach criticality and a combination of fission and fusion reactions would occur. Our Phase I results, summarized herein, review our estimates of engine and vehicle performance, our work to date to model the fission-fusion reaction, and our initial efforts in experimental analysis.

  4. Assessment of air quality in and around a steel industry with direct reduction iron route.

    PubMed

    Jena, Pradip K; Behera, Dillip K; Mishra, C S K; Mohanty, Saswat K

    2011-10-01

    The coal based Direct Reduced Iron (DRI) route for secondary steel production is now a preferred choice in India. Steel making is invariably associated with emission of air pollutants into the environment. Air quality monitoring was carried out in Winter, Summer and Rainy seasons of 2008 in eight monitoring stations in the work zone and five stations in the residential zone of an Integrated Steel Industry located in Orissa state, India. Four air quality parameters i.e. SPM, RSPM, SO2 and NO2 were monitored. Mean SPM and RSPM values were found to be significantly high (p < 0.01) at stations nearer to source in both work zone and residential zone .The highest average SPM and RSPM values in the work zone recorded were 4869 microg/m3 and 1420 microg/m3 and in the residential zone 294 microg/m3 and 198 microg/m3 respectively. No significant difference in the SO2 and NO2 levels was observed between the work and residential zones. In general, the values of air pollutants were highest in Winter followed by Summer and Rainy season. SPM and RSPM values exceeded the National Air Quality Standards (NAAQS) in both the residential and work zones. PMID:23505821

  5. Analytical modeling of squeeze air film damping of biomimetic MEMS directional microphone

    NASA Astrophysics Data System (ADS)

    Ishfaque, Asif; Kim, Byungki

    2016-08-01

    Squeeze air film damping is introduced in microelectromechanical systems due to the motion of the fluid between two closely spaced oscillating micro-structures. The literature is abundant with different analytical models to address the squeeze air film damping effects, however, there is a lack of work in modeling the practical sensors like directional microphones. Here, we derive an analytical model of squeeze air film damping of first two fundamental vibration modes, namely, rocking and bending modes, of a directional microphone inspired from the fly Ormia ochracea's ear anatomy. A modified Reynolds equation that includes compressibility and rarefaction effects is used in the analysis. Pressure distribution under the vibrating diaphragm is derived by using Green's function. From mathematical modeling of the fly's inspired mechanical model, we infer that bringing the damping ratios of both modes in the critical damping range enhance the directional sensitivity cues. The microphone parameters are varied in derived damping formulas to bring the damping ratios in the vicinity of critical damping, and to show the usefulness of the analytical model in tuning the damping ratios of both modes. The accuracy of analytical damping results are also verified by finite element method (FEM) using ANSYS. The FEM results are in full compliance with the analytical results.

  6. Modification of plasma flows with gas puff in the scrape-off layer of ADITYA tokamak

    SciTech Connect

    Sangwan, Deepak; Jha, Ratneshwar; Brotankova, Jana; Gopalkrishna, M. V.

    2013-06-15

    The parallel Mach numbers are measured at three locations in the scrape-off layer (SOL) plasma of ADITYA tokamak by using Mach probes. The flow pattern is constructed from these measurements and the modification of flow pattern is observed by introducing a small puff of working gas. In the normal discharge, there is an indication of shell structure in the SOL plasma flows, which is removed during the gas puff. The plasma parameters, particle flux and Reynolds stress are also measured in the normal discharge and in the discharge with gas puff. It is observed that Reynolds stress and Mach number are coupled in the near SOL region and decoupled in the far SOL region. The coupling in the near SOL region gets washed away during the gas puff.

  7. The Coronal-Dimming Footprint of a Streamer-Puff Coronal Mass Ejection: Confirmation of the Magnetic-Arch-Blowout Scenario

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Sterling, Alphonse C.

    2007-01-01

    A streamer puff is a recently identified variety of coronal mass ejection (CME) of narrow to moderate width. It (1) travels our along a streamer, transiently inflating the streamer but leaving it largely intact, and (2) occurs in step with a compact ejective flare in an outer flank of the base of the streamer. These aspects suggest the following magnetic-arch-blowout scenario for the production of these CMEs: the magnetic explosion that produces the flare also produces a plasmoid that explodes up the leg of an outer loop of the arcade base of the streamer, blows out the top of this loop, and becomes the core of the CME. In this paper, we present a streamer-puff CME that produced a coronal-dimming footprint. The coronal dimming, its magnetic setting, and the timing and magnetic setting of a strong compact ejective flare within the dimming footprint nicely confirm the magnetic-arch-blowout scenario. From these observations, together with several published cases of a trans-equatorial CME produced in tandem with an ejective flare or filament eruption that was far offset from directly under the CME, we propose the following. Streamer-puff CMEs are a subclass (one variety) of a broader class of "over-and-out" CMEs that are often much larger than streamer puffs but are similar to them in that they are produced by the blowout of a large quasi-potential magnetic arch by a magnetic explosion that erupts from one foot of the large arch, where it is marked by a filament eruption and/or an ejective flare.

  8. Continuous monitoring of polychlorinated biphenyls in air using direct sampling APCI/ITMS

    NASA Astrophysics Data System (ADS)

    Yamada, Masuyoshi; Suga, Masao; Waki, Izumi; Sakamoto, Masami; Morita, Masatoshi

    2005-06-01

    We report a continuous monitoring system of polychlorinated biphenyls (PCBs) in air, which uses direct sampling atmospheric pressure chemical ionization (APCI)/ion trap mass spectrometry (ITMS). In APCI, humidity in the atmosphere, which fluctuates from 0 to 10 vol.%, influences PCB sensitivity. In dry air (0.5% humidity), the detection limits of Di- to Hp-chlorinated biphenyls (CB) are 0.01-0.44 [mu]g/Nm3 ([mu]g/m3 at normal condition) with time resolution of 1 min, whereas the sensitivity decreases to less than 1/10 when water vapor concentration is 10 vol.%. The sensitivity decrease is calibrated in real-time using an internal standard, trichlorophenol. In order to obtain the calibration accuracy of +/-30%, we dilute the sample gas by dry air, decreasing the water vapor concentration below 1%. We applied the monitor to measure Di- to Hp-CB in ventilation air from a PCB decomposition plant. The monitored PCB concentration levels agreed well with that by high-resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS).

  9. Direct and indirect air particle cytotoxicity in human alveolar epithelial cells.

    PubMed

    Orona, N S; Astort, F; Maglione, G A; Saldiva, P H N; Yakisich, J S; Tasat, D R

    2014-08-01

    Air particulate matter has been associated with adverse impact on the respiratory system leading to cytotoxic and proinflammatory effects. The biological mechanisms behind these associations may be initiated by inhaled small size particles, particle components (soluble fraction) and/or mediators released by particle-exposed cells (conditioned media). The effect of Urban Air Particles from Buenos Aires (UAP-BA) and Residual Oil Fly Ash (ROFA) a surrogate of ambient air pollution, their Soluble Fractions (SF) and Conditioned Media (CM) on A549 lung epithelial cells was examined. After 24 h exposure to TP (10 and 100 μg/ml), SF or CM, several biological parameters were assayed on cultured A549 cells. We tested cell viability by MTT, superoxide anion (O₂(-)) generation by NBT and proinflammatory cytokine (TNFα, IL-6 and IL-8) production by ELISA. UAP-BA particles or its SF (direct effect) did not modify cell viability and generation of O₂(-) for any of the doses tested. On the contrary, UAP-BA CM (indirect effect) reduced cell viability and increased both generation of O₂(-) and IL-8 production. Exposure to ROFA particles, SF or ROFA CM reduced proliferation and O₂(-) but, stimulated IL-8. It is worth to note that UAP-BA and ROFA depicted distinct effects on particle-exposed A549 cells implicating morphochemical dependence. These in vitro findings support the hypothesis that particle-induced lung inflammation and disease may involve lung-derived mediators. PMID:24590061

  10. Direct measurements of air-sea CO2 exchange over a coral reef

    NASA Astrophysics Data System (ADS)

    McGowan, Hamish A.; MacKellar, Mellissa C.; Gray, Michael A.

    2016-05-01

    Quantification of CO2 exchange with the atmosphere over coral reefs has relied on microscale measurements of pCO2 gradients across the air-sea interfacial boundary; shipboard measurements of air-sea CO2 exchange over adjacent ocean inferred to represent over reef processes or ecosystem productivity modeling. Here we present by way of case study the first direct measurements of air-sea CO2 exchange over a coral reef made using the eddy covariance method. Research was conducted during the summer monsoon over a lagoonal platform reef in the southern Great Barrier Reef, Australia. Results show the reef flat to be a net source of CO2 to the atmosphere of similar magnitude as coastal lakes, while adjacent shallow and deep lagoons were net sinks as was the surrounding ocean. This heterogeneity in CO2 exchange with the atmosphere confirms need for spatially representative direct measurements of CO2 over coral reefs to accurately quantify their role in atmospheric carbon budgets.

  11. Direct Air Capture of CO2 - an Overview of Carbon Engineering's Technology and Pilot Plant Development

    NASA Astrophysics Data System (ADS)

    Holmes, G.; Corless, A.

    2014-12-01

    At Carbon Engineering, we are developing and commercializing technology to scrub CO2 directly from atmospheric air at industrial scale. By providing atmospheric CO2 for use in fuel production, we can enable production of transportation fuels with ultra-low carbon intensities, which command price premiums in the growing set of constrained fuels markets such as California's LCFS. We are a Calgary based startup founded in 2009 with 10 employees, and we are considered a global leader in the direct air capture (DAC) field. We will review CE's DAC technology, based on a wet-scrubbing "air contactor" which absorbs CO2 into aqueous solution, and a chemical looping "regeneration" component, which liberates pure CO2 from this aqueous solution while re-making the original absorption chemical. CE's DAC tecnology exports purified atmospheric CO2, combined with the combustion CO2 from plant energy usage, as the end product. We will also discuss CE's 2014-2015 end-to-end Pilot Demonstration Unit. This is a $7M technology demonstration plant that CE is building with the help of key industrial partners and equipment vendors. Vendor design and engineering requirements have been used to specify the pilot air contactor, pellet reactor, calciner, and slaker modules, as well as auxiliary systems. These modules will be run for several months to obtain the engineering and performance data needed for subsequent commercial plant design, as well as to test the residual integration risks associated with CE's process. By the time of the AGU conference, the pilot is expected to be in late stages of fabrication or early stages of site installation.

  12. Rapid monitoring of soil, smears, and air dusts by direct large-area alpha spectrometry

    SciTech Connect

    Sill, C.W.

    1992-01-01

    Experimental conditions to permit rapid monitoring of soils, smears, and air dusts for transuranic (TRU) radionuclides under field conditions are described. The monitoring technique involves direct measurement of alpha emitters by alpha spectrometry using a large-area detector to identify and quantify the radionuclides present. The direct alpha spectrometry employs a circular gridded ionization chamber 35 cm in diameter which accommodates either a circular sample holder 25 cm in diameter or a rectangular one 20 by 25 cm (8 by 10 in.). Soils or settled dusts are finely ground, suspended in 30% ethanol, and sprayed onto a 25-cm stainless steel dish. Air dusts are collected with a high-volume sampler onto 20- by 25-cm membrane filters. Removable contamination is collected from surfaces onto a 20- by 25-cm filter using an 18-cm (7-in.) paint roller to hold the large filter in contact with the surface during sample collection. All three types of samples are then counted directly in the alpha spectrometer and no other sample preparation is necessary. Some results obtained are described.

  13. Direct calculation of acoustic streaming including the boundary layer phenomena in an ultrasonic air pump

    NASA Astrophysics Data System (ADS)

    Wada, Yuji; Koyama, Daisuke; Nakamura, Kentaro

    2012-05-01

    Direct finite difference fluid simulation of acoustic streaming on the fine-meshed three-dimensiona model by graphics processing unit (GPU)-oriented calculation array is discussed. Airflows due to the acoustic traveling wave are induced when an intense sound field is generated in a gap between a bending transducer and a reflector. Calculation results showed good agreement with the measurements in the pressure distribution. In addition to that, several flow-vortices were observed near the boundary of the reflector and the transducer, which have been often discussed in acoustic tube near the boundary, and have never been observed in the calculation in the ultrasonic air pump of this type.

  14. Creating nanoporosity in silver nanocolumns by direct exposure to radio-frequency air plasma

    NASA Astrophysics Data System (ADS)

    El Mel, Abdel-Aziz; Stephant, Nicolas; Hamon, Jonathan; Thiry, Damien; Chauvin, Adrien; Chettab, Meriem; Gautron, Eric; Konstantinidis, Stephanos; Granier, Agnès; Tessier, Pierre-Yves

    2015-12-01

    Nanoporous materials are of great importance for a broad range of applications including catalysis, optical sensors and water filtration. Although several approaches already exist for the creation of nanoporous materials, the race for the development of versatile methods, more suitable for the nanoelectronics industry, is still ongoing. In this communication we report for the first time on the possibility of generating nanoporosity in silver nanocolumns using a dry approach based on the oxidation of silver by direct exposure to a commercially available radio-frequency air plasma. The silver nanocolumns are created by glancing angle deposition using magnetron sputtering of a silver target in pure argon plasma. We show that upon exposure to the rf air plasma, the nanocolumns transform from solid silver into nanoporous silver oxide. We further show that by tuning the plasma pressure and the exposure duration, the oxidation process can be finely adjusted allowing for precisely controlling the morphology and the nanoporosity of the silver oxide nanocolumns. The generation of porosity within the silver nanocolumns is explained according to a cracking-induced oxidation mechanism based on two repeated events occurring alternately during the oxidation process: (i) oxidation of silver upon exposure to the air plasma and (ii) generation of nanocracks and blisters within the oxide layer due to the high internal stress generated within the material during oxidation.

  15. Passive cathodic water/air management device for micro-direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Peng, Hsien-Chih; Chen, Po-Hon; Chen, Hung-Wen; Chieng, Ching-Chang; Yeh, Tsung-Kuang; Pan, Chin; Tseng, Fan-Gang

    A high efficient passive water/air management device (WAMD) is proposed and successfully demonstrated in this paper. The apparatus consists of cornered micro-channels and air-breathing windows with hydrophobicity arrangement to regulate liquids and gases to flow on their predetermined pathways. A high performance water/air separation with water removal rate of about 5.1 μl s -1 cm -2 is demonstrated. The performance of the proposed WAMD is sufficient to manage a cathode-generated water flux of 0.26 μl s -1 cm -2 in the micro-direct methanol fuel cells (μDMFCs) which are operated at 100 mW cm -2 or 400 mA cm -2. Furthermore, the condensed vapors can also be collected and recirculated with the existing micro-channels which act as a passive water recycling system for μDMFCs. The durability testing shows that the fuel cells equipped with WAMD exhibit improved stability and higher current density.

  16. Creating nanoporosity in silver nanocolumns by direct exposure to radio-frequency air plasma.

    PubMed

    El Mel, Abdel-Aziz; Stephant, Nicolas; Hamon, Jonathan; Thiry, Damien; Chauvin, Adrien; Chettab, Meriem; Gautron, Eric; Konstantinidis, Stephanos; Granier, Agnès; Tessier, Pierre-Yves

    2016-01-01

    Nanoporous materials are of great importance for a broad range of applications including catalysis, optical sensors and water filtration. Although several approaches already exist for the creation of nanoporous materials, the race for the development of versatile methods, more suitable for the nanoelectronics industry, is still ongoing. In this communication we report for the first time on the possibility of generating nanoporosity in silver nanocolumns using a dry approach based on the oxidation of silver by direct exposure to a commercially available radio-frequency air plasma. The silver nanocolumns are created by glancing angle deposition using magnetron sputtering of a silver target in pure argon plasma. We show that upon exposure to the rf air plasma, the nanocolumns transform from solid silver into nanoporous silver oxide. We further show that by tuning the plasma pressure and the exposure duration, the oxidation process can be finely adjusted allowing for precisely controlling the morphology and the nanoporosity of the silver oxide nanocolumns. The generation of porosity within the silver nanocolumns is explained according to a cracking-induced oxidation mechanism based on two repeated events occurring alternately during the oxidation process: (i) oxidation of silver upon exposure to the air plasma and (ii) generation of nanocracks and blisters within the oxide layer due to the high internal stress generated within the material during oxidation. PMID:26611109

  17. Air pollution and climate response to aerosol direct radiative effects: A modeling study of decadal trends across the northern hemisphere

    EPA Science Inventory

    Decadal hemispheric Weather Research and Forecast-Community Multiscale Air Quality simulations from 1990 to 2010 were conducted to examine the meteorology and air quality responses to the aerosol direct radiative effects. The model's performance for the simulation of hourly surfa...

  18. DIRECT TRACE ANALYSIS OF VOLATILE ORGANIC COMPOUNDS IN AIR USING ION TRAP MASS SPECTROMETERS WITH FILTERED NOISE FIELDS

    EPA Science Inventory

    Two ion trap mass spectrometers and direct air sampling interfaces are being evaluated in the laboratory for monitoring toxic air pollutants in real time. he mass spectrometers are the large, laboratory-based Finnigan MAT ion trap (ITMS) and the compact, field-deployable Teledyne...

  19. New dual gas puff imaging system with up-down symmetry on experimental advanced superconducting tokamak

    NASA Astrophysics Data System (ADS)

    Liu, S. C.; Shao, L. M.; Zweben, S. J.; Xu, G. S.; Guo, H. Y.; Cao, B.; Wang, H. Q.; Wang, L.; Yan, N.; Xia, S. B.; Zhang, W.; Chen, R.; Chen, L.; Ding, S. Y.; Xiong, H.; Zhao, Y.; Wan, B. N.; Gong, X. Z.; Gao, X.

    2012-12-01

    Gas puff imaging (GPI) offers a direct and effective diagnostic to measure the edge turbulence structure and velocity in the edge plasma, which closely relates to edge transport and instability in tokamaks. A dual GPI diagnostic system has been installed on the low field side on experimental advanced superconducting tokamak (EAST). The two views are up-down symmetric about the midplane and separated by a toroidal angle of 66.6°. A linear manifold with 16 holes apart by 10 mm is used to form helium gas cloud at the 130×130 mm (radial versus poloidal) objective plane. A fast camera is used to capture the light emission from the image plane with a speed up to 390 804 frames/s with 64×64 pixels and an exposure time of 2.156 μs. The spatial resolution of the system is 2 mm at the objective plane. A total amount of 200 Pa.L helium gas is puffed into the plasma edge for each GPI viewing region for about 250 ms. The new GPI diagnostic has been applied on EAST for the first time during the recent experimental campaign under various plasma conditions, including ohmic, L-mode, and type-I, and type-III ELMy H-modes. Some of these initial experimental results are also presented.

  20. Direct numerical simulation of turbulent non-premixed methane-air flames

    SciTech Connect

    Chen, J.H.; Card, J.M.; Day, M.; Mahalingam, S.

    1995-07-01

    Turbulent non-premixed stoichiometric methane-air flames have been studied using the direct numerical simulation approach. A global one- step mechanism is used to describe the chemical kinetics, and molecular transport is modeled with constant Lewis numbers for individual species. The effect of turbulence on the internal flame structure and extinction characteristics of methane-air flames is evaluated. The flame is wrinkled and in some regions extinguished by the turbulence, while the turbulence is weakened in the vicinity of the flame due to a combination of dilatation and a 25:1 increase in kinematic viscosity across the flame. Reignition followed by partially-premixed burning is observed in the present results. Local curvature effects are found to be important in determining the local stoichiometry of the flame, and hence, the location of the peak reaction rate relative to the stoichiometric surface. The results presented in this study demonstrate the feasibility of incorporating global-step kinetics for the oxidation of methane into direct numerical simulations of homogeneous turbulence to study the flame structure.

  1. Direct numerical simulations of turbulent non-premixed methane-air flames modeled with reduced kinetics

    NASA Technical Reports Server (NTRS)

    Card, J. M.; Chen, J. H.; Day, M.; Mahalingam, S.

    1994-01-01

    Turbulent non-premixed stoichiometric methane-air flames modeled with reduced kinetics have been studied using the direct numerical simulation approach. The simulations include realistic chemical kinetics, and the molecular transport is modeled with constant Lewis numbers for individual species. The effect of turbulence on the internal flame structure and extinction characteristics of methane-air flames is evaluated. Consistent with earlier DNS with simple one-step chemistry, the flame is wrinkled and in some regions extinguished by the turbulence, while the turbulence is weakened in the vicinity of the flame due to a combination of dilatation and an increase in kinematic viscosity. Unlike previous results, reignition is observed in the present simulations. Lewis number effects are important in determining the local stoichiometry of the flame. The results presented in this work are preliminary but demonstrate the feasibility of incorporating reduced kinetics for the oxidation of methane with direct numerical simulations of homogeneous turbulence to evaluate the limitations of various levels of reduction in the kinetics and to address the formation of thermal and prompt NO(x).

  2. Future Directions of Supersonic Combustion Research: Air Force/NASA Workshop on Supersonic Combustion

    NASA Technical Reports Server (NTRS)

    Tishkoff, Julian M.; Drummond, J. Philip; Edwards, Tim; Nejad, Abdollah S.

    1997-01-01

    The Air Force Office of Scientific Research, the Air Force Wright Laboratory Aero Propulsion and Power Directorate, and the NASA Langley Research Center held a joint supersonic combustion workshop on 14-16 May 1996. The intent of this meeting was to: (1) examine the current state-of-the-art in hydrocarbon and/or hydrogen fueled scramjet research; (2) define the future direction and needs of basic research in support of scramjet technology; and (3) when appropriate, help transition basic research findings to solve the needs of developmental engineering programs in the area of supersonic combustion and fuels. A series of topical sessions were planned. Opening presentations were designed to focus and encourage group discussion and scientific exchange. The last half-day of the workshop was set aside for group discussion of the issues that were raised during the meeting for defining future research opportunities and directions. The following text attempts to summarize the discussions that took place at the workshop.

  3. Along-wind dispersion of puffs released in a built-up urban area

    NASA Astrophysics Data System (ADS)

    Zhou, Ying; Hanna, Steven R.

    2007-12-01

    The SF6 gas tracer observations for puffs released near the ground during the Joint Urban 2003 (JU2003) urban dispersion experiment in Oklahoma City have been analysed. The JU2003 observations, at distances of about 100-1,100 m from the source, show that, at small times, when the puff is still within the built-up downtown domain, the standard deviation of the concentration time series, σt, is influenced by the initial puff spread due to buildings near the source and by hold-up in the wakes of large buildings at the sampler locations. This effect is parameterised by assuming an initial σto of about 42 s, leading to a comprehensive similarity formula: σt = 42 + 0.1 t. The second term, 0.1 t, is consistent with an earlier similarity relation, σt = 0.1 t, derived from puff observations in many experiments over rural terrain. The along-wind dispersion coefficient, σx, is assumed to equal σt u, in which u is the puff speed calculated as the distance from the source to the sampler, x, divided by the time after the release that the maximum concentration is observed at the sampler. σx can be expressed as σx = σxo + 0.14 x, with the initial σxo of 45 m. This initial σxo agrees with the suggestion of an initial plume spread of about 40 m, made by McElroy and Pooler from analysis of the 1960s’ St. Louis urban dispersion experiment. The puff speeds, u, are initially only about 20% of the observed wind speed, averaged over about 80 street-level and rooftop anemometers in the city, but approach the mean observed wind speed as the puffs grow vertically. The scatter in the σt data is about ± a factor of two or three at any given travel time. The maximum σt is about 250 s, and the maximum duration of the puff over the sampler, Dt, sometimes called the retention time, is about 1,100 s or 18 min for these puffs and distances.

  4. Effects of User Puff Topography, Device Voltage, and Liquid Nicotine Concentration on Electronic Cigarette Nicotine Yield: Measurements and Model Predictions

    PubMed Central

    Talih, Soha; Balhas, Zainab; Eissenberg, Thomas; Salman, Rola; Karaoghlanian, Nareg; El Hellani, Ahmad; Baalbaki, Rima; Saliba, Najat

    2015-01-01

    Introduction: Some electronic cigarette (ECIG) users attain tobacco cigarette–like plasma nicotine concentrations while others do not. Understanding the factors that influence ECIG aerosol nicotine delivery is relevant to regulation, including product labeling and abuse liability. These factors may include user puff topography, ECIG liquid composition, and ECIG design features. This study addresses how these factors can influence ECIG nicotine yield. Methods: Aerosols were machine generated with 1 type of ECIG cartridge (V4L CoolCart) using 5 distinct puff profiles representing a tobacco cigarette smoker (2-s puff duration, 33-ml/s puff velocity), a slow average ECIG user (4 s, 17 ml/s), a fast average user (4 s, 33 ml/s), a slow extreme user (8 s, 17 ml/s), and a fast extreme user (8 s, 33 ml/s). Output voltage (3.3–5.2 V or 3.0–7.5 W) and e-liquid nicotine concentration (18–36 mg/ml labeled concentration) were varied. A theoretical model was also developed to simulate the ECIG aerosol production process and to provide insight into the empirical observations. Results: Nicotine yields from 15 puffs varied by more than 50-fold across conditions. Experienced ECIG user profiles (longer puffs) resulted in higher nicotine yields relative to the tobacco smoker (shorter puffs). Puff velocity had no effect on nicotine yield. Higher nicotine concentration and higher voltages resulted in higher nicotine yields. These results were predicted well by the theoretical model (R 2 = 0.99). Conclusions: Depending on puff conditions and product features, 15 puffs from an ECIG can provide far less or far more nicotine than a single tobacco cigarette. ECIG emissions can be predicted using physical principles, with knowledge of puff topography and a few ECIG device design parameters. PMID:25187061

  5. Direct Detection of C_2H_2 in Air and Human Breath by Cw-Crds

    NASA Astrophysics Data System (ADS)

    Schmidt, Florian M.; Vaittinen, Olavi; Metsälä, Markus; Halonen, Lauri

    2010-06-01

    Continuous wave cavity ring-down spectroscopy (cw-CRDS) is an established cavity-enhanced absorption technique that can provide the necessary sensitivity, selectivity and fast acquisition time for many applications involving the detection of trace species. We present a simple but highly sensitive cw-CRDS spectrometer based on an external cavity diode laser operating in the near-infrared region. This instrument allows us to directly detect acetylene (C_2H_2) mixing ratios in air with a detection limit of 120 parts per trillion by volume (pptv) measuring on a C_2H_2 absorption line at 6565.620 cm-1. Acetylene is a combustion product that is routinely used in environmental monitoring as a marker for anthropogenic emissions. In a recent work, the spectrometer was employed to measure the level of acetylene in indoor and outdoor air in Helsinki. Continuous flow measurements with high time resolution (one minute) revealed strong fluctuations in the acetylene mixing ratio in outdoor air during daytime. Due to its non-invasive nature and fast response time, the analysis of exhaled breath for medical diagnostics is an excellent and straightforward alternative to methods using urine or blood samples. In an ongoing study, the cw-CRDS instrument is used to establish the baseline level of acetylene in the breath of the healthy population. An elevated amount of acetylene in breath could indicate exposure to combustion exhausts or other volatile organic compound (VOC) rich sources. The latest results of this investigation will be presented. F. M. Schmidt, O. Vaittinen, M. Metsälä, P. Kraus and L. Halonen, submitted for publication in Appl. Phys. B.

  6. Bioassay-directed chemical analysis and detection of mutagenicity in ambient air of the coke oven.

    PubMed

    Dobiás, L; Kůsová, J; Gajdos, O; Vidová, P; Gajdosová, D; Havránková, J; Fried, M; Binková, B; Topinka, J

    1999-09-30

    In the present study, we summarize the results of studies on the mutagenic potential of the main fractions and subfractions of extractable organic material (EOM) in the ambient air at the workplaces of the coke oven. The objective of our experiments was to apply the Bioassay-Directed Chemical Analysis (with the use of the Ames test) for the identification of the differences in the mutagenicity of these fractions, in relationship to the complex mixture of EOM in occupational air. From the evaluation of results, it is possible to deduce the following conclusions: (1) The comparison of the mutagenicity in the main fractions (basic, acidic, neutral) demonstrates the existence of differences in mutagenic potential. Of the total mutagenicity, 20.4% is in the basic fraction, 25.4% in the acidic fraction and 54.2% in the neutral fraction. (2) In general, 90.1% of the mutagenicity found in the basic, acidic and neutral fractions together was associated with the requirement of metabolic activation in vitro (+S9). In the case of the neutral fraction, it was 51.8%. (3) These results also suggest that frameshift mutations are the major component (53.8%) of the total mutagenicity of the main fractions. (4) With regards to the mutagenicity of organic compounds in the neutral fraction it appeared that genotoxicants of its subfractions (slightly and moderately polar and aromatic) play the main role. Carcinogenic aromatic hydrocarbons (PAH) and genotoxic nitrocompounds play an important role as determinants of the mutagenic potential of complex mixtures of harmful compounds in ambient air. This is confirmed first by the results of short-term bacterial tests. PMID:10575437

  7. CO2 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Boomer, R.J.; Cole, R.; Kovar, M.; Prieditis, J.; Vogt, J.; Wehner, S.

    1999-02-24

    The application cyclic CO2, often referred to as the CO2 Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 Huff-n-Puff process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in capital-intensive miscible projects. Texaco Exploration and Production Inc. and the US Department of Energy have teamed up in a attempt to develop the CO2 Huff-n-Puff process in the Grayburg and San Andres formations which are light oil, shallow shelf carbonate reservoirs that exist throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir.

  8. Experimental investigation and modeling of a direct-coupled PV/T air collector

    SciTech Connect

    Shahsavar, A.; Ameri, M.

    2010-11-15

    Photovoltaic/thermal (PV/T) systems refer to the integration of photovoltaic and solar thermal technologies into one single system, in that both useful heat energy and electricity are produced. The impetus of this paper is to model a direct-coupled PV/T air collector which is designed, built, and tested at a geographic location of Kerman, Iran. In this system, a thin aluminum sheet suspended at the middle of air channel is used to increase the heat exchange surface and consequently improve heat extraction from PV panels. This PV/T system is tested in natural convection and forced convection (with two, four and eight fans operating) and its unsteady results are presented in with and without glass cover cases. A theoretical model is developed and validated against experimental data, where good agreement between the measured values and those calculated by the simulation model were achieved. Comparisons are made between electrical performance of the different modes of operation, and it is concluded that there is an optimum number of fans for achieving maximum electrical efficiency. Also, results show that setting glass cover on photovoltaic panels leads to an increase in thermal efficiency and decrease in electrical efficiency of the system. (author)

  9. Direct numerical simulation of a turbulent stably stratified air flow above a wavy water surface

    NASA Astrophysics Data System (ADS)

    Druzhinin, O. A.; Troitskaya, Yu. I.; Zilitinkevich, S. S.

    2016-01-01

    The influence of the roughness of the underlaying water surface on turbulence is studied in a stably stratified boundary layer (SSBL). Direct numerical simulation (DNS) is conducted at various Reynolds (Re) and Richardson (Ri) numbers and the wave steepness ka. It is shown that, at constant Re, the stationary turbulent regime is set in at Ri below the threshold value Ri c depending on Re. At Ri > Ri c , in the absence of turbulent fluctuations near the wave water surface, three-dimensional quasiperiodical structures are identified and their threshold of origin depends on the steepness of the surface wave on the water surface. This regime is called a wave pumping regime. The formation of three-dimensional structures is explained by the development of parametric instability of the disturbances induced by the surface water in the air flow. The DNS results are quite consistent with prediction of the theoretical model of the SSBL flow, in which solutions for the disturbances of the fields of velocity and temperature in the wave pumping regime are found to be a solution of a two-dimensional linearized system with the heterogeneous boundary condition, which is caused by the presence of the surface wave. In addition to the turbulent fluctuations, the three-dimensional structures in the wave pumping regime provide for the transfer of impulse and heat, i.e., the increase in the roughness of the water-air boundary caused by the presence of waves intensifies the exchange in the SSBL.

  10. The influence of bowl offset on air motion in a direct injection diesel engine

    SciTech Connect

    McKinley, T.L.; Primus, R.J

    1988-01-01

    The influence of bowl offset on motored mean flow and turbulence in a direct injection diesel engine has been examined with the aid of a multi-dimensional flow code. Results are presented for three piston geometries. The bowl geometry of each piston was the same, while the offset between the bowl and the cylinder axis was varied from 0.0 to 9.6% of the bore. The swirl ratio at intake valve closing was also varied from 2.60 to 4.27. It was found that the angular momentum of the air at TDC was decreased by less than 8% when the bowl was offset. Nevertheless, the mean (squish and swirl) flows were strongly affected by the offset. In addition, the distribution of turbulent kinetic energy (predicted by the /delta/-e model) was modified. Moderate increases (10% or less) in mass averaged turbulence intensity at TDC with offset were observed.

  11. Use of MODIS/AIRS Direct Broadcast Data for Short Term Weather Forecasting

    NASA Technical Reports Server (NTRS)

    Jedlovec, Gary

    2003-01-01

    Operational weather forecasting relies heavily on real time data and modeling products for forecast preparation and dissemination of significant weather information to the public. The key to this success is access to real time data and integration of the data and products into weather decision support systems. NASA's Short-term Prediction Research and Transition (SPORT) Program has demonstrated this capability with MODIS and AIRS data through several local NWS Forecast Offices. This presentation will describe the use of real time EOS Direct Broadcast (DB) data in local weather forecast operations, highlight the utility of real time data from the EOS DB systems, and provide insight into how EOS DB data can have the most impact on the weather forecast community.

  12. Fuel-air mixing and distribution in a direct-injection stratified-charge rotary engine

    NASA Technical Reports Server (NTRS)

    Abraham, J.; Bracco, F. V.

    1989-01-01

    A three-dimensional model for flows and combustion in reciprocating and rotary engines is applied to a direct-injection stratified-charge rotary engine to identify the main parameters that control its burning rate. It is concluded that the orientation of the six sprays of the main injector with respect to the air stream is important to enhance vaporization and the production of flammable mixture. In particular, no spray should be in the wake of any other spray. It was predicted that if such a condition is respected, the indicated efficiency would increase by some 6 percent at higher loads and 2 percent at lower loads. The computations led to the design of a new injector tip that has since yielded slightly better efficiency gains than predicted.

  13. Change of 180 degrees in the direction of a uniform current of air

    NASA Technical Reports Server (NTRS)

    Witoszynski, C

    1926-01-01

    In the construction of aerodynamic tunnels, it is a very important matter to obtain a uniform current of air in the sections where measurements are to be made. The straight type ordinarily used for attaining a uniform current and generally recommended for use, has great defects. If we desire to avoid these defects, it is well to give the canals of the tunnel such a form that the current, after the change of direction of its asymptotes, approximates a uniform and rectilinear movement. But for this, the condition must be met that at no place does the flow exceed the maximum velocity assumed, equal to the velocity in the straight parts of the canal.

  14. LOCATING NEARBY SOURCES OF AIR POLLUTION BY NONPARAMETRIC REGRESSION OF ATMOSPHERIC CONCENTRATIONS ON WIND DIRECTION. (R826238)

    EPA Science Inventory

    The relationship of the concentration of air pollutants to wind direction has been determined by nonparametric regression using a Gaussian kernel. The results are smooth curves with error bars that allow for the accurate determination of the wind direction where the concentrat...

  15. Direct effects of energy-related air pollutants on plant sexual reproduction. Progress report, February 1, 1981-January 31, 1982

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1982-10-07

    Direct effects of SO/sub 2/ and NO/sub 2/ on plant sexual reproduction were studied including essential botanical research into modes of anthesis, pollination, pollen germination and pollen tube growth. Much of the present scientific knowledge of the direct in vivo effects of the major air pollutants, SO/sub 2/ and NO/sub 2/, on plant sexual reproduction is a direct result of studies accomplished under this DOE contract. It is our intention to carry this research forward to include similar assessment of a third major air pollutant, ozone.

  16. Comparison of Gas Puff Imaging Data in NSTX with the DEGAS 2 Simulation

    SciTech Connect

    Cao, B.; Stotler, D. P.; Zweben, S. J.; Bell, M.; Diallo, A.; Leblanc, B.

    2012-11-08

    Gas-Puff-Imaging (GPI) is a two dimensional diagnostic which measures the edge Dα light emission from a neutral D2 gas puff nears the outer mid-plane of NSTX. DEGAS 2 is a 3-D Monte Carlo code used to model neutral transport and atomic physics in tokamak plasmas. In this paper we compare measurements of the Dα light emission obtained by GPI on NSTX with DEGAS 2 simulations of Dα light emission for specific experiments. Both the simulated spatial distribution and absolute intensity of the Dα light emission agree well with the experimental data obtained between ELMs in H-mode. __________________________________________________

  17. Comparison of Gas Puff Imaging Data in NSTX with the DEGAS 2 Simulation

    SciTech Connect

    Cao, B.; Stotler, D. P.; Zweben, S. J.; Bell, M.; Diallo, A.; Leblanc, B.

    2012-10-27

    Gas-Puff-Imaging (GPI) is a two dimensional diagnostic which measures the edge Dα light emission from a neutral D2 gas puff nears the outer mid-plane of NSTX. DEGAS 2 is a 3-D Monte Carlo code used to model neutral transport and atomic physics in tokamak plasmas. In this paper we compare measurements of the Dα light emission obtained by GPI on NSTX with DEGAS 2 simulations of Dα light emission for specific experiments. Both the simulated spatial distribution and absolute intensity of the Dα light emission agree well with the experimental data obtained between ELMs in H-mode.

  18. Tracking through laser-induced clutter for air-to-ground directed energy system

    NASA Astrophysics Data System (ADS)

    Belen'kii, Mikhail; Brinkley, Timothy; Hughes, Kevin; Tannenbaum, Allen

    2003-09-01

    The agility and speed with which directed energy can be retargeted and delivered to the target makes a laser weapon highly desirable in tactical battlefield environments. A directed energy system can effectively damage and possibly destroy relatively soft targets on the ground. In order to accurately point a high-energy beam at the target, the directed energy system must be able to acquire and track targets of interest in highly cluttered environments, under different weather, smoke, and camouflage conditions and in the presence of turbulence and thermal blooming. To meet these requirements, we proposed a concept of a multi spectral tracker, which integrates three sensors: SAR radar, a passive MWIR optical tracker, and a range-gated laser illuminated tracker. In this paper we evaluated the feasibility of the integrated optical tracker and arrived to the following conclusions: a) the contrast enhancement by mapping the original pixel distribution to the desired one enhances the target identification capability, b) a reduction of the divergence of the illuminating beam reduces rms pointing error of a laser tracker, c) a clutter removal algorithm based on active contours is capable of capturing targets in highly cluttered environments, d) the daytime rms pointing error caused by anisoplanatism of the track point to the aim point is comparable to the diffraction-limited beam spot size, f) the peak intensity shift from the optical axis caused by thermal blooming at 5 km range for the air-to-ground engagement scenario is on the order of 8 μrad, and it is 10 μrad at 10 km range, and e) the thermal blooming reduces the peak average power in a 2 cm bucket at 5 km range by a factor of 8, and it reduces the peak average power in the bucket at 10 km range by a factor of 22.

  19. Arrival directions of large air showers, low-mu showers and old-age low-mu air showers observed at St. Chacaltaya

    NASA Technical Reports Server (NTRS)

    Hagiwara, K.; Yoshii, H.; Martinic, N.; Siles, L.; Miranda, P.; Kakimoto, F.; Obara, T.; Suga, K.; Kaneko, T.; Inoue, N.

    1985-01-01

    Arrival directions of air showers with primary energies in the range 10 to the 16.5 power eV to 10 to the 18th power eV show the first harmonic in right ascension (RA) with amplitude of 2.7 + or - 1.0% and phase of 13-16h. However, the second harmonic in RA slightly seen for showers in the range 10 to the 18th power eV to 10 to the 19th power eV disappeared by accumulation of observed showers. The distribution of arrival directions of low-mu air showers with primary energies around 10 to the 15th power eV observed at Chacaltaya from 1962 to 1967 is referred to, relating to the above-mentioned first harmonic. Also presented in this paper are arrival directions of old-age low-mu air showers observed at Chacaltaya from 1962 to 1967, for recent interest in gamma-ray air showers.

  20. Direct numerical simulation of auto-ignition of a hydrogen vortex ring reacting with hot air

    SciTech Connect

    Doom, Jeff; Mahesh, Krishnan

    2009-04-15

    Direct numerical simulation (DNS) is used to study chemically reacting, laminar vortex rings. A novel, all-Mach number algorithm developed by Doom et al. [J. Doom, Y. Hou, K. Mahesh, J. Comput. Phys. 226 (2007) 1136-1151] is used. The chemical mechanism is a nine species, nineteen reaction mechanism for H{sub 2}/air combustion proposed by Mueller et al. [M.A. Mueller, T.J. Kim, R.A. Yetter, F.L. Dryer, Int. J. Chem. Kinet. 31 (1999) 113-125]. Diluted H{sub 2} at ambient temperature (300 K) is injected into hot air. The simulations study the effect of fuel/air ratios, oxidizer temperature, Lewis number and stroke ratio (ratio of piston stroke length to diameter). Results show that auto-ignition occurs in fuel lean, high temperature regions with low scalar dissipation at a 'most reactive' mixture fraction, {zeta}{sub MR} (Mastorakos et al. [E. Mastorakos, T.A. Baritaud, T.J. Poinsot, Combust. Flame 109 (1997) 198-223]). Subsequent evolution of the flame is not predicted by {zeta}{sub MR}; a most reactive temperature T{sub MR} is defined and shown to predict both the initial auto-ignition as well as subsequent evolution. For stroke ratios less than the formation number, ignition in general occurs behind the vortex ring and propagates into the core. At higher oxidizer temperatures, ignition is almost instantaneous and occurs along the entire interface between fuel and oxidizer. For stroke ratios greater than the formation number, ignition initially occurs behind the leading vortex ring, then occurs along the length of the trailing column and propagates toward the ring. Lewis number is seen to affect both the initial ignition as well as subsequent flame evolution significantly. Non-uniform Lewis number simulations provide faster ignition and burnout time but a lower maximum temperature. The fuel rich reacting vortex ring provides the highest maximum temperature and the higher oxidizer temperature provides the fastest ignition time. The fuel lean reacting vortex ring has

  1. Direct measurement of the characteristic three-body electron attachment time in the atmospheric air in direct current electric field

    SciTech Connect

    Shutov, A. V.; Smetanin, I. V.; Ionin, A. A.; Levchenko, A. O.; Seleznev, L. V.; Sinitsyn, D. V.; Ustinovskii, N. N.; Zvorykin, V. D.

    2013-07-15

    We report the results of theoretical and experimental study of the characteristic time for three-body attachment of electrons produced by 100 fs UV laser pulse in the atmosphere air in the external DC electric field ranged from 0.2 to 10 kV/cm.

  2. Characterization of the COBRA triple-nozzle gas-puff valve using planar laser induced fluorescence

    NASA Astrophysics Data System (ADS)

    de Grouchy, P. W. L.; Rosenberg, E.; Qi, N.; Kusse, B. R.; Kroupp, E.; Fisher, A.; Maron, Y.; Hammer, D. A.

    2014-12-01

    We present neutral density measurements of argon (Ar) injected into the 70 mm outer diameter, 24 mm axial length, outflow region of the triple-nozzle gas-puff valve fielded for gas-puff z-pinch experiments on the (1 MA, 100-200 ns) COBRA generator at Cornell University. Measurements are obtained by planar laser induced fluorescence of (λ = 266 nm, E = 80 mJ, Δt = 3 ns) frequency-quadrupled Nd:YAG laser light, absorbed by acetone dopant introduced into the Ar at 7% by pressure. Results are acquired 500μs after valve opening, the time of current initiation during z-pinch experiments. Number density plots are obtained across the Outer (O), Inner (I) and Center (C) puffs, with nozzle backing pressures {O:I:C} = {1:3:8}psia and {4:0:10}psia, delivering `uniform' and `hollow' profiles respectively. The total mass per unit length in these puffs is 22±0.4 μgcm-1 and 47±1 μgcm-1. Density measurement precision is ±5×1015 cm-3.

  3. Gas Puff Z-Pinches at 1-MA and 200-ns on COBRA

    NASA Astrophysics Data System (ADS)

    Hammer, David; Qi, Niansheng; Rosenberg, Elliott; Atoyan, Levon; Potter, William; Blesener, Kate; Cahill, Adam; Gourdain, Pierre-Alexandre; Greenly, John; Hoyt, Cad; Kusse, Bruce; Pikuz, Sergei; Schrafel, Peter; Shelkovenko, Tatiana

    2013-10-01

    We report 6-cm diameter, double-shell gas puff Z-pinch experiments at 1 MA on the COBRA pulsed power generator, in which the implosion dynamics in puff-on-puff load configurations with and without a wire on the pinch axis were studied. Diagnostics used included: Planar Laser Induced Fluorescence Analyzer for measuring initial density profiles of the gas puff; a Laser Shearing Interferometer and a Laser Wavefront Analyzer for density profiles in the implosion and pinch phases; fiber-coupled, gated visible-light spectrometers for radially resolved imploding plasma spectra; gated XUV cameras for implosion dynamics; filtered pinhole x-ray cameras for imaging x-ray emission; and a double-crystal x-ray spectrometer for axially resolved pinch plasma densities and temperatures. From these, we derived the implosion velocity, ion charge states and then the imploding plasma temperatures, obtained the time evolution of the imploding plasma sheath structure and Magnetic Rayleigh-Taylor instability, and observed the most stable implosion with light-ions (Ne) imploding on heavy-ions (Ar), unstable implosions with heavy-ions (Ar) imploding on light-ions (Ne), and tighter, denser and less hot pinch plasma with a wire on axis. Details of the results will be presented. Supported by NNSA under DOE Coop. Agreement DE- NA0001836.

  4. Puff-wave transition in an inhomogeneous model for calcium signals

    NASA Astrophysics Data System (ADS)

    Shuai, J. W.; Huang, Y. D.; Rüdiger, S.

    2010-04-01

    In many cell types, calcium ion channels on the endoplasmic reticulum membrane occur in a clustered distribution. The channels generate either localized puffs, each comprising channels of only one cluster, or global calcium waves. In this work we model the calcium system as a two-dimensional lattice of active elements distributed regularly in an otherwise passive space. We address an important feature of the puff-wave transition, which is the difference in lifetime of puffs at a few hundred milliseconds and long-lived global waves with periods of several seconds. We show that such a lifetime difference between puffs and waves can be understood with strongly reduced ordinary differential equations modified by a time-scale factor that takes into account the coupling strength of active and passive regions determined by the Ca2+ diffusion coefficient. Furthermore, we show that the point model can also describe very well the dependence of Ca2+ oscillation characteristics on the cluster-cluster distance in the case of large diffusivity.

  5. High-energy electron acceleration in the gas-puff Z-pinch plasma

    SciTech Connect

    Takasugi, Keiichi; Miyazaki, Takanori; Nishio, Mineyuki

    2014-12-15

    The characteristics of hard x-ray generation were examined in the gas-puff z-pinch experiment. The experiment on reversing the voltage was conducted. In both of the positive and negative discharges, the x-ray was generated only from the anode surface, so it was considered that the electrons were accelerated by the induced electromagnetic force at the pinch time.

  6. A Plasma Opening Switch Based on a Gas-Puff/Axial Wire Configuration

    NASA Astrophysics Data System (ADS)

    Engelbrecht, Joseph; de Grouchy, Philip; Ouart, Nicholas; Qi, Niansheng; Atoyan, Levon; Banasek, Jacob; Potter, William; Hammer, David; Kusse, Bruce; Giuliani, John

    2015-11-01

    We are investigating an idea for switching current from a gas-puff shell to an axial metal wire as a mechanism for generating inductive voltage spikes and x-rays above 10 keV. The outer annulus of a 7 cm. diameter triple-annular gas-puff nozzle is used to inject gas into the electrode gap of the COBRA 1 MA generator, with a single wire on-axis. We show that the current pulse produced by COBRA initially travels through the lower inductance pre-ionized outer shell plasma, generating an azimuthal magnetic field which drives this shell radially inwards. Rayleigh-Taylor instability growth occurs on the outer edge of this imploding plasma, which disrupts the current carrying column, inhibiting the axial flow of current through the gas-puff plasma and possibly causing the current to switch to the higher inductance wire. A disruption to the current through the gas-puff shell caused by instability growth should be measurable as a voltage spike, as the current finds a new path either through the wire or elsewhere in the imploding plasma shell. We investigate this effect as instability conditions are varied, by adjusting the density and species of the injected gas. This work was sponsored by the NNSA Stewardship Sciences Academic Programs under DOE cooperative agreement.

  7. FORMATION OF TRANSIENT PUFFS FROM CONTAINED LIQUID WASTES IN A ROTARY KILN SIMULATOR

    EPA Science Inventory

    The paper gives results of a study of the generation of transient puffs resulting from the batch incineration of liquid waste into a 73 kW rotary kiln incinerator simulator. Liquid wastes investigated included toluene, methylene chloride, carbon tetrachloride, and No. 5 fuel oil....

  8. Simulations of Recent Ar Gas Puff Radiation Sources on the ZR Generator

    NASA Astrophysics Data System (ADS)

    Tangri, Varun; Harvey-Thompson, A. J.; Thornhill, J. W.; Giuliani, J. L.; Ouart, N. D.; Jones, B.; Jennings, C. A.

    2015-11-01

    We present radiation-magnetohydrodynamic simulations of four recent Ar gas puff shots on the refurbished Z generator. The simulations using Mach2-TCRE are calculated in r-z geometry with a tabulated collisional radiative equilibrium model for the non-LTE ionization kinetics and radiation transport. The four shots were designed to study the effects upon the Ar K-shell radiation output due to a change in the initial gas puff distribution. The shots Z2604 and Z2605 had a double shell puff and a central jet. The shots Z2560 and Z2628 did not have a central jet. Calculated yields are close to experimental error-bars. Results will be presented for the impact of the initial gas puff distribution on the K-shell yield. Work supported by the DOE/NNSA. SNL is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's NNSA under contract DE-AC04-94AL85000.

  9. Comparison of True and Smoothed Puff Profile Replication on Smoking Behavior and Mainstream Smoke Emissions

    PubMed Central

    2015-01-01

    To estimate exposures to smokers from cigarettes, smoking topography is typically measured and programmed into a smoking machine to mimic human smoking, and the resulting smoke emissions are tested for relative levels of harmful constituents. However, using only the summary puff data—with a fixed puff frequency, volume, and duration—may underestimate or overestimate actual exposure to smoke toxins. In this laboratory study, we used a topography-driven smoking machine that faithfully reproduces a human smoking session and individual human topography data (n = 24) collected during previous clinical research to investigate if replicating the true puff profile (TP) versus the mathematically derived smoothed puff profile (SM) resulted in differences in particle size distributions and selected toxic/carcinogenic organic compounds from mainstream smoke emissions. Particle size distributions were measured using an electrical low pressure impactor, the masses of the size-fractionated fine and ultrafine particles were determined gravimetrically, and the collected particulate was analyzed for selected particle-bound, semivolatile compounds. Volatile compounds were measured in real time using a proton transfer reaction-mass spectrometer. By and large, TP levels for the fine and ultrafine particulate masses as well as particle-bound organic compounds were slightly lower than the SM concentrations. The volatile compounds, by contrast, showed no clear trend. Differences in emissions due to the use of the TP and SM profiles are generally not large enough to warrant abandoning the procedures used to generate the simpler smoothed profile in favor of the true profile. PMID:25536227

  10. Study of the current-sheath formation during the implosion of multishell gas puffs

    NASA Astrophysics Data System (ADS)

    Labetsky, A. Yu.; Kokshenev, V. A.; Kurmaev, N. E.; Oreshkin, V. I.; Rousskikh, A. G.; Fedyunin, A. V.; Fursov, F. I.; Chaikovsky, S. A.; Shishlov, A. V.; Zhidkova, N. A.

    2008-03-01

    Results are presented from experimental studies of the dynamics of large-diameter multishell gas puffs imploded by microsecond megampere current pulses. The experiments were conducted on the GIT-12 generator in the regime of microsecond implosion ( t imp = 1.1-1.2 μs, I 0 = 3.4-3.7 MA). The influence of the load configuration on the dynamics of current losses and gas-puff radiative characteristics was studied. The correlation between the radial compression ratio (the ratio between the initial and final Z-pinch radii) and the magnitude of the current flowing at the plasma periphery was investigated. The experiments show that, in a multishell gas puff, large-scale instabilities insignificantly affect the gas-puff implosion even over microsecond time intervals and that a compact dense pinch with a relatively high average electron temperature (400-600 eV) forms at the Z-pinch axis. The diameter of the plasma column radiating in the K-shell lines of neon is about 3-4 mm, the K-shell radiation yield being 5-11 kJ/cm. In the final stage of implosion, only a small portion of the current flows through the high-temperature central region of the pinch plasma, whereas the major part of the generator current flows through the residual peripheral plasma.

  11. One-dimensional magnetohydrodynamic calculations of a hydrogen-gas puff

    SciTech Connect

    Maxon, S.; Nielsen, P.D.

    1981-04-20

    A one-dimensional Lagrangian calculation of the implosion of a hydrogen gas puff is presented. At maximum compression, 60% of the mass is located in a density spike .5 mm off the axis with a half width of 40 ..mu..m. The temperature on axis reaches 200 eV.

  12. Development of the gas-puff imaging diagnostic in the TEXTOR tokamak

    SciTech Connect

    Shesterikov, I.; Xu, Y.; Berte, M.; Dumortier, P.; Van Schoor, M.; Vergote, M.; Schweer, B.; Van Oost, G.

    2013-05-15

    Gas puff imaging (GPI) [S. J. Zweben, D. P. Stotler et al., Phys. Plasmas 9, 1981 (2002); R. J. Maqueda, G. A. Wurden et al., Rev. Sci. Instrum. 74, 2020 (2003)] is a powerful diagnostic that permits a two-dimensional measurement of turbulence in the edge region of a fusion plasma and is based on the observation of the local emission of a neutral gas, actively puffed into the periphery of the plasma. The developed in-vessel GPI telescope observes the emission from the puffed gas along local (at the puff) magnetic field lines. The GPI telescope is specially designed to operate in severe TEXTOR conditions and can be treated as a prototype for the GPI systems on next generation machines. Also, the gas puff nozzle is designed to have a lower divergence of the gas flow than previous GPI diagnostics. The resulting images show poloidally and radially propagating structures, which are associated with plasma blobs. We demonstrate that the local gas puff does not disturb plasma properties. Our results indicate also that the neutral gas emission intensity is more sensitive to the electron density than the electron temperature. Here, we present implementation details of the GPI system on TEXTOR and discuss some design and diagnostic issues related to the development of GPI systems in general.

  13. OCCURRENCE OF TRANSIENT PUFFS IN A ROTARY KILN INCINERATOR SIMULATOR. 2. CONTAINED LIQUID WASTES ON SORBENT

    EPA Science Inventory

    The paper gives results of a study of the generation of transient puffs resulting from the batch incineration of liquid waste into a 73 kW rotary kiln incinerator simulator. The liquid was added onto a sorbent, enclosed in cardboard cylinders that are introduced into the combusti...

  14. PARAMETRIC STUDIES DELINEATING THE OCCURRENCE OF TRANSIENT PUFFS IN A ROTARY KILN SIMULATOR

    EPA Science Inventory

    The paper gives results of an experimental investigation into the waste properties and kiln parameters that determine both the instantaneous intensity and total magnitude of transient puffs leaving the kiln. (NOTE: The batch introduction of waste-filled drums or containers into p...

  15. Air-kerma strength determination of a new directional {sup 103}Pd source

    SciTech Connect

    Aima, Manik Reed, Joshua L.; DeWerd, Larry A.; Culberson, Wesley S.

    2015-12-15

    Purpose: A new directional {sup 103}Pd planar source array called a CivaSheet™ has been developed by CivaTech Oncology, Inc., for potential use in low-dose-rate (LDR) brachytherapy treatments. The array consists of multiple individual polymer capsules called CivaDots, containing {sup 103}Pd and a gold shield that attenuates the radiation on one side, thus defining a hot and cold side. This novel source requires new methods to establish a source strength metric. The presence of gold material in such close proximity to the active {sup 103}Pd region causes the source spectrum to be significantly different than the energy spectra of seeds normally used in LDR brachytherapy treatments. In this investigation, the authors perform air-kerma strength (S{sub K}) measurements, develop new correction factors for these measurements based on an experimentally verified energy spectrum, and test the robustness of transferring S{sub K} to a well-type ionization chamber. Methods: S{sub K} measurements were performed with the variable-aperture free-air chamber (VAFAC) at the University of Wisconsin Medical Radiation Research Center. Subsequent measurements were then performed in a well-type ionization chamber. To realize the quantity S{sub K} from a directional source with gold material present, new methods and correction factors were considered. Updated correction factors were calculated using the MCNP 6 Monte Carlo code in order to determine S{sub K} with the presence of gold fluorescent energy lines. In addition to S{sub K} measurements, a low-energy high-purity germanium (HPGe) detector was used to experimentally verify the calculated spectrum, a sodium iodide (NaI) scintillating counter was used to verify the azimuthal and polar anisotropy, and a well-type ionization chamber was used to test the feasibility of disseminating S{sub K} values for a directional source within a cylindrically symmetric measurement volume. Results: The UW VAFAC was successfully used to measure the S

  16. Investigation of statistical parameters of turbulent air flow over waved water surface by direct numerical simulation

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yuliya; Druzhinin, Oleg

    2013-04-01

    Interaction of surface water waves with the wind flow is of primary importance for the wave modeling. The most difficult case for modeling is that of steep waves, when the strongly non-linear effects (e.g. sheltering, flow separation, vortex formation etc.) are encountered in the airflow over waves. Of special interest is also the influence of the wind flow stratification on the wind-wave interaction. In this work the preliminary results of direct numerical simulation (DNS)of structure and statistical characteristics of a turbulent, stably stratified atmospheric boundary layer over waved water surface are presented. In the experiments two-dimensional water waves with different wave age parameters (c/u* = 0-10, where u* is the friction velocity and c is the wave celerity), wave slope ka = 0-0.2 and at a bulk Reynolds number Re = 15000 and different values of the bulk Richardson number Ri (based on the buoyancy jump, bulk velocity and the surface wave length) are considered. The shape of the water wave is prescribed and does not evolve under the action of the wind. The full, 3D Navier-Stokes equations under the Boussinesq approximation are solved in curvilinear coordinates in a frame of reference moving the phase velocity of the wave. The shear driving the flow is created by an upper plane boundary moving horizontally with a bulk velocity in the x-direction. Periodic boundary conditions are considered in the horizontal (x) and lateral (y) directions, and no-slip boundary condition is considered in the vertical z-direction. The grid of nodes in the x, y, and z directions is used. The Adams-Bashforth method is employed to advance the integration in time and the equation for the pressure is solved iteratively by using FFT in the x and y directions and the Gauss method in the z-direction. Ensemble-averaged velocity and pressure fields are evaluated by averaging over time and the spanwise coordinate. Profiles of the mean velocity and turbulent stresses are obtained by

  17. SIMAIR—Evaluation tool for meeting the EU directive on air pollution limits

    NASA Astrophysics Data System (ADS)

    Gidhagen, L.; Johansson, H.; Omstedt, G.

    Almost all Swedish cities need to determine air pollution levels—especially PM10—close to major streets. SIMAIR is an internet tool that can be used by all Swedish municipalities to assess PM10, NO 2, CO and benzene levels and how they compare to the EU directive. SIMAIR is delivered to the municipalities with all required input data pre-loaded and is meant to be used prior to decisions if and where, monitoring campaigns are required. The system includes a road and vehicle database with emission factors and a model to calculate non-tailpipe PM10 emissions. Regional and urban background contributions are pre-calculated and stored as hourly values on a 1×1 km 2 grid. The local contribution is calculated by the user, selecting either an open road or a street canyon environment. A comparison between measured and simulated concentrations in four street locations shows that SIMAIR is able to calculate statistics of yearly mean values, 90-percentile and 98-percentile daily mean values and the number of days exceeding the limit value that are well within ±50% that EU requires for model estimates of yearly mean values. In comparison, all values except one are within ±25% which is the quality objective for fixed measurements according to the EU directive. The SIMAIR model system is also able to separate the percentual contribution of the long-range transport from outside the city, the city contribution and the local contribution from the traffic of an individual street.

  18. Air-breathing direct formic acid microfluidic fuel cell with an array of cylinder anodes

    NASA Astrophysics Data System (ADS)

    Zhu, Xun; Zhang, Biao; Ye, Ding-Ding; Li, Jun; Liao, Qiang

    2014-02-01

    An air-breathing direct formic acid membraneless microfluidic fuel cell using graphite cylinder arrays as the anode is proposed. The three dimensional anode volumetrically extends the reactive surface area and improves fuel utilization. The effects of spacer configuration, fuel and electrolyte concentration as well as reactant flow rate on the species transport and cell performance are investigated. The dynamic behavior of generated CO2 bubbles is visualized and its effect on current generation is discussed. The results show that the absence of two spacers adjacent to the cathode surface improves the cell performance by reducing the proton transfer resistance. The CO2 gas bubbles are constrained within the anode array and expelled by the fluid flow periodically. Proper reactant concentration and flow rate are crucial for cell operation. At optimum conditions, a maximum current density of 118.3 mA cm-3 and a peak power density of 21.5 mW cm-3 are obtained. In addition, benefit from the volumetrically stacked anodes and enhanced fuel transfer, the maximum single pass fuel utilization rate reaches up to 87.6% at the flow rate of 1 mL h-1.

  19. Direct Numerical Simulations of Autoignition in Stratified Dimethyl-ether (DME)/Air Turbulent Mixtures

    SciTech Connect

    Bansal, Gaurav; Mascarenhas, Ajith; Chen, Jacqueline H.

    2014-10-01

    In our paper, two- and three-dimensional direct numerical simulations (DNS) of autoignition phenomena in stratified dimethyl-ether (DME)/air turbulent mixtures are performed. A reduced DME oxidation mechanism, which was obtained using rigorous mathematical reduction and stiffness removal procedure from a detailed DME mechanism with 55 species, is used in the present DNS. The reduced DME mechanism consists of 30 chemical species. This study investigates the fundamental aspects of turbulence-mixing-autoignition interaction occurring in homogeneous charge compression ignition (HCCI) engine environments. A homogeneous isotropic turbulence spectrum is used to initialize the velocity field in the domain. Moreover, the computational configuration corresponds to a constant volume combustion vessel with inert mass source terms added to the governing equations to mimic the pressure rise due to piston motion, as present in practical engines. DME autoignition is found to be a complex three-staged process; each stage corresponds to a distinct chemical kinetic pathway. The distinct role of turbulence and reaction in generating scalar gradients and hence promoting molecular transport processes are investigated. Then, by applying numerical diagnostic techniques, the different heat release modes present in the igniting mixture are identified. In particular, the contribution of homogeneous autoignition, spontaneous ignition front propagation, and premixed deflagration towards the total heat release are quantified.

  20. Recommended direct simulation Monte Carlo collision model parameters for modeling ionized air transport processes

    NASA Astrophysics Data System (ADS)

    Swaminathan-Gopalan, Krishnan; Stephani, Kelly A.

    2016-02-01

    A systematic approach for calibrating the direct simulation Monte Carlo (DSMC) collision model parameters to achieve consistency in the transport processes is presented. The DSMC collision cross section model parameters are calibrated for high temperature atmospheric conditions by matching the collision integrals from DSMC against ab initio based collision integrals that are currently employed in the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) and Data Parallel Line Relaxation (DPLR) high temperature computational fluid dynamics solvers. The DSMC parameter values are computed for the widely used Variable Hard Sphere (VHS) and the Variable Soft Sphere (VSS) models using the collision-specific pairing approach. The recommended best-fit VHS/VSS parameter values are provided over a temperature range of 1000-20 000 K for a thirteen-species ionized air mixture. Use of the VSS model is necessary to achieve consistency in transport processes of ionized gases. The agreement of the VSS model transport properties with the transport properties as determined by the ab initio collision integral fits was found to be within 6% in the entire temperature range, regardless of the composition of the mixture. The recommended model parameter values can be readily applied to any gas mixture involving binary collisional interactions between the chemical species presented for the specified temperature range.

  1. Direct Numerical Simulations of Autoignition in Stratified Dimethyl-ether (DME)/Air Turbulent Mixtures

    DOE PAGESBeta

    Bansal, Gaurav; Mascarenhas, Ajith; Chen, Jacqueline H.

    2014-10-01

    In our paper, two- and three-dimensional direct numerical simulations (DNS) of autoignition phenomena in stratified dimethyl-ether (DME)/air turbulent mixtures are performed. A reduced DME oxidation mechanism, which was obtained using rigorous mathematical reduction and stiffness removal procedure from a detailed DME mechanism with 55 species, is used in the present DNS. The reduced DME mechanism consists of 30 chemical species. This study investigates the fundamental aspects of turbulence-mixing-autoignition interaction occurring in homogeneous charge compression ignition (HCCI) engine environments. A homogeneous isotropic turbulence spectrum is used to initialize the velocity field in the domain. Moreover, the computational configuration corresponds to amore » constant volume combustion vessel with inert mass source terms added to the governing equations to mimic the pressure rise due to piston motion, as present in practical engines. DME autoignition is found to be a complex three-staged process; each stage corresponds to a distinct chemical kinetic pathway. The distinct role of turbulence and reaction in generating scalar gradients and hence promoting molecular transport processes are investigated. Then, by applying numerical diagnostic techniques, the different heat release modes present in the igniting mixture are identified. In particular, the contribution of homogeneous autoignition, spontaneous ignition front propagation, and premixed deflagration towards the total heat release are quantified.« less

  2. Low temperature, atmospheric pressure, direct current microplasma jet operated in air, nitrogen and oxygen

    NASA Astrophysics Data System (ADS)

    Mohamed, A.-A. H.; Kolb, J. F.; Schoenbach, K. H.

    2010-12-01

    Micro-plasma jets in atmospheric pressure molecular gases (nitrogen, oxygen, air) were generated by blowing these gases through direct current microhollow cathode discharges (MHCDs). The tapered discharge channel, drilled through two 100 to 200 μm thick molybdenum electrodes separated by a 200 μm thick alumina layer, is 150 to 450 μm in diameter in the cathode and has an opening of 100 to 300 μm in diameter in the anode. Sustaining voltages are 400 to 600 V, the maximum current is 25 mA. The gas temperature of the microplasma inside the microhollow cathode varies between ~2000 K and ~1000 K depending on current, gas, and flow rate. Outside the discharge channel the temperature in the jet can be reduced by manipulating the discharge current and the gas flow to achieve values close to room temperature. This cold microplasma jet can be used for surface treatment of heat sensitive substances, and for sterilization of contaminated areas.

  3. Jets, Coronal “Puffs,” and a Slow Coronal Mass Ejection Caused by an Opposite-polarity Region within an Active Region Footpoint

    NASA Astrophysics Data System (ADS)

    Alzate, N.; Morgan, H.

    2016-06-01

    During a period of three days beginning 2013 January 17, twelve recurrent reconnection events occur within a small region of opposing flux embedded within one footpoint of an active region, accompanied by flares and jets observed in EUV and fast and faint structureless “puffs” observed by coronagraphs. During the same period a slow structured CME gradually erupts, with one end anchored close to, or within, the jetting region. Four of the jet events occur in pairs—a narrow, primary jet followed within a few tens of minutes by a wider, more massive, jet. All the jets are slow, with an apparent speed of ∼100 km s‑1. The speed of the wide puffs in the coronagraph data is ∼300 km s‑1, and the timing of their appearance rules out a direct association with the EUV jetting material. The jet material propagates along large-scale closed-field loops and does not escape to the extended corona. The rapid reconfiguration of the closed loops following reconnection causes an outwardly propagating disturbance, or wave front, which manifests as puffs in coronagraph data. Furthermore, the newly expanded closed flux tube forms a pressure imbalance, which can result in a secondary jet. The reconnection events, through recurrent field reconfiguration, also leads to the gradual eruption of the structured flux tube appearing as the slow CME. Faint propagating coronal disturbances resulting from flares/jets may be common, but are usually obscured by associated ejections. Occasionally, the associated material ejections are absent, and coronal puffs may be clearly observed.

  4. Event Reconstruction for Atmospheric Releases Employing Urban Puff Model UDM with Stochastic Inversion Methodology

    SciTech Connect

    Neuman, S; Glascoe, L; Kosovic, B; Dyer, K; Hanley, W; Nitao, J; Gordon, R

    2005-11-03

    The rapid identification of contaminant plume sources and their characteristics in urban environments can greatly enhance emergency response efforts. Source identification based on downwind concentration measurements is complicated by the presence of building obstacles that can cause flow diversion and entrainment. While high-resolution computational fluid dynamics (CFD) simulations are available for predicting plume evolution in complex urban geometries, such simulations require large computational effort. We make use of an urban puff model, the Defence Science Technology Laboratory's (Dstl) Urban Dispersion Model (UDM), which employs empirically based puff splitting techniques. UDM enables rapid urban dispersion simulations by combining traditional Gaussian puff modeling with empirically deduced mixing and entrainment approximations. Here we demonstrate the preliminary reconstruction of an atmospheric release event using stochastic sampling algorithms and Bayesian inference together with the rapid UDM urban puff model based on point measurements of concentration. We consider source inversions for both a prototype isolated building and for observations and flow conditions taken during the Joint URBAN 2003 field campaign at Oklahoma City. The Markov Chain Monte Carlo (MCMC) stochastic sampling method is used to determine likely source term parameters and considers both measurement and forward model errors. It should be noted that the stochastic methodology is general and can be used for time-varying release rates and flow conditions as well as nonlinear dispersion problems. The results of inversion indicate the probability of a source being at a particular location with a particular release rate. Uncertainty in observed data, or lack of sufficient data, is inherently reflected in the shape and size of the probability distribution of source term parameters. Although developed and used independently, source inversion with both UDM and a finite-element CFD code can be

  5. Air pollution and climate response to aerosol direct radiative effects: A modeling study of decadal trends across the northern hemisphere

    NASA Astrophysics Data System (ADS)

    Xing, Jia; Mathur, Rohit; Pleim, Jonathan; Hogrefe, Christian; Gan, Chuen-Meei; Wong, David C.; Wei, Chao; Wang, Jiandong

    2015-12-01

    Decadal hemispheric Weather Research and Forecast-Community Multiscale Air Quality simulations from 1990 to 2010 were conducted to examine the meteorology and air quality responses to the aerosol direct radiative effects. The model's performance for the simulation of hourly surface temperature, relative humidity, wind speed, and direction was evaluated through comparison with observations from NOAA's National Climatic Data Center Integrated Surface Data. The inclusion of aerosol direct radiative effects improves the model's ability to reproduce the trend in daytime temperature range which over the past two decades was increasing in eastern China but decreasing in eastern U.S. and Europe. Trends and spatial and diurnal variations of the surface-level gaseous and particle concentrations to the aerosol direct effect were analyzed. The inclusion of aerosol direct radiative effects was found to increase the surface-level concentrations of SO2, NO2, O3, SO42-, NO3-, and particulate matter 2.5 in eastern China, eastern U.S., and Europe by 1.5-2.1%, 1-1.5%, 0.1-0.3%, 1.6-2.3%, 3.5-10.0%, and 2.2-3.2%, respectively, on average over the entire 21 year period. However, greater impacts are noted during polluted days with increases of 7.6-10.6%, 6.2-6.7%, 2.0-3.0%, 7.8-9.5%, 11.1-18.6%, and 7.2-10.1%, respectively. Due to the aerosol direct radiative effects, stabilizing of the atmosphere associated with reduced planetary boundary layer height and ventilation leads to an enhancement of pollution. Consequently, the continual increase of aerosol optical depth (AOD) in eastern China leads to an increasing trend in the air quality feedback which exacerbates air pollution, while emission reductions in eastern U.S. and Europe result in a declining trend in both AODs and feedback which make the air pollution control strategies more effective.

  6. Aire Enforces Immune Tolerance by Directing Autoreactive T Cells into the Regulatory T Cell Lineage.

    PubMed

    Malchow, Sven; Leventhal, Daniel S; Lee, Victoria; Nishi, Saki; Socci, Nicholas D; Savage, Peter A

    2016-05-17

    The promiscuous expression of tissue-restricted antigens in the thymus, driven in part by autoimmune regulator (Aire), is critical for the protection of peripheral tissues from autoimmune attack. Aire-dependent processes are thought to promote both clonal deletion and the development of Foxp3(+) regulatory T (Treg) cells, suggesting that autoimmunity associated with Aire deficiency results from two failed tolerance mechanisms. Here, examination of autoimmune lesions in Aire(-/-) mice revealed an unexpected third possibility. We found that the predominant conventional T cell clonotypes infiltrating target lesions express antigen receptors that were preferentially expressed by Foxp3(+) Treg cells in Aire(+/+) mice. Thus, Aire enforces immune tolerance by ensuring that distinct autoreactive T cell specificities differentiate into the Treg cell lineage; dysregulation of this process results in the diversion of Treg cell-biased clonotypes into pathogenic conventional T cells. PMID:27130899

  7. Monitoring Direct Effects of Delta, Atlas, and Titan Launches from Cape Canaveral Air Station

    NASA Technical Reports Server (NTRS)

    Schmalzer, Paul A.; Boyle, Shannon R.; Hall, Patrice; Oddy, Donna M.; Hensley, Melissa A.; Stolen, Eric D.; Duncan, Brean W.

    1998-01-01

    Launches of Delta, Atlas, and Titan rockets from Cape Canaveral Air Station (CCAS) have potential environmental effects that could arise from direct impacts of the launch exhaust (e.g., blast, heat), deposition of exhaust products of the solid rocket motors (hydrogen chloride, aluminum oxide), or other effects such as noise. Here we: 1) review previous reports, environmental assessments, and environmental impact statements for Delta, Atlas, and Titan vehicles and pad areas to clarity the magnitude of potential impacts; 2) summarize observed effects of 15 Delta, 22 Atlas, and 8 Titan launches; and 3) develop a spatial database of the distribution of effects from individual launches and cumulative effects of launches. The review of previous studies indicated that impacts from these launches can occur from the launch exhaust heat, deposition of exhaust products from the solid rocket motors, and noise. The principal effluents from solid rocket motors are hydrogen chloride (HCl), aluminum oxide (Al2O3), water (H2O), hydrogen (H2), carbon monoxide (CO), and carbon dioxide (CO2). The exhaust plume interacts with the launch complex structure and water deluge system to generate a launch cloud. Fall out or rain out of material from this cloud can produce localized effects from acid or particulate deposition. Delta, Atlas, and Titan launch vehicles differ in the number and size of solid rocket boosters and in the amount of deluge water used. All are smaller and use less water than the Space Shuttle. Acid deposition can cause damage to plants and animals exposed to it, acidify surface water and soil, and cause long-term changes to community composition and structure from repeated exposure. The magnitude of these effects depends on the intensity and frequency of acid deposition.

  8. 78 FR 1735 - Airworthiness Directives; Honeywell International Inc. Air Data Pressure Transducers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... Executive Order 12866, (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR... International Inc. Air Data Pressure Transducers AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... certain Honeywell International Inc. air data pressure transducers as installed on various aircraft....

  9. Influence of pre-drying treatments on physicochemical and organoleptic properties of explosion puff dried jackfruit chips.

    PubMed

    Yi, Jianyong; Zhou, Linyan; Bi, Jinfeng; Chen, Qinqin; Liu, Xuan; Wu, Xinye

    2016-02-01

    The effects of hot air drying (AD), freeze drying (FD), infrared drying (IR), microwave drying (MV), vacuum drying (VD) as pre-drying treatments for explosion puff drying (EPD) on qualities of jackfruit chips were studied. The lowest total color differences (∆E) were found in the FD-, MV- and VD-EPD dried chips. Volume expansion effect (9.2 %) was only observed in the FD-EPD dried chips, which corresponded to its well expanded honeycomb microstructures and high rehydration rate. Compared with AD-, IR-, MV- and VD-EPD, the FD-EPD dried fruit chips exhibited lower hardness and higher crispness, indicative of a crispier texture. FD-EPD dried fruits also obtained high retentions of ascorbic acid, phenolics and carotenoids compared with that of the other puffed products. The results of sensory evaluation suggested that the FD-EPD was a more beneficial combination because it enhanced the overall qualities of jackfruit chips. In conclusion, the FD-EPD could be used as a novel combination drying method for processing valuable and/or high quality fruit chips. PMID:27162392

  10. BIOAVAILABLE AIR PARTICULATE POLLUTION CONSTITUENTS DIRECTLY ALTER CARDIOVASCULAR FUNCTION EX VIVO

    EPA Science Inventory

    Epidemiological studies have reported associations between particulate air pollution exposure and cardiovascular (CV) effects within susceptible individuals. Particle characteristics and biological mechanisms responsible for these observations are not known. We examined whether s...

  11. Template-directed fabrication of porous gas diffusion layer for magnesium air batteries

    NASA Astrophysics Data System (ADS)

    Xue, Yejian; Miao, He; Sun, Shanshan; Wang, Qin; Li, Shihua; Liu, Zhaoping

    2015-11-01

    The uniform micropore distribution in the gas diffusion layers (GDLs) of the air-breathing cathode is very important for the metal air batteries. In this work, the super-hydrophobic GDL with the interconnected regular pores is prepared by a facile silica template method, and then the electrochemical properties of the Mg air batteries containing these GDLs are investigated. The results indicate that the interconnected and uniform pore structure, the available water-breakout pressure and the high gas permeability coefficient of the GDL can be obtained by the application of 30% silica template. The maximum power density of the Mg air battery containing the GDL with 30% regular pores reaches 88.9 mW cm-2 which is about 1.2 times that containing the pristine GDL. Furthermore, the GDL with 30% regular pores exhibits the improved the long term hydrophobic stability.

  12. AIR QUALITY MODELING OF HAZARDOUS POLLUTANTS: CURRENT STATUS AND FUTURE DIRECTIONS

    EPA Science Inventory

    The paper presents a review of current air toxics modeling applications and discusses possible advanced approaches. Many applications require the ability to predict hot spots from industrial sources or large roadways that are needed for community health and Environmental Justice...

  13. Onset conditions for positive direct current corona discharges in air under the action of photoionization

    NASA Astrophysics Data System (ADS)

    Zheng, Yuesheng; Zhang, Bo; He, Jinliang

    2011-12-01

    This paper presents a numerical model for the inception of positive dc corona discharges in air near cylindrical anodes, which plays a bridge role between the classic positive corona onset criterion and the photoionization model considering the effective radiation wavelength. The predicted onset voltages agree well with Peek's experimental data in a wide range of conductor radii and relative air densities. The influence of the collisional quenching of emitting excited states on the surface onset field is significant with low air density or small conductor radius. Within the effective radiation wavelength, numerical expressions for the photon absorption coefficient in air and Townsend's second coefficient due to photoionization are deduced on the basis of the new model. A different perspective on the classic coefficients is given.

  14. TH-C-17A-09: Direct Visualization and Monitoring of Medical Radiation Beams in Air

    SciTech Connect

    Fahimian, B; Ceballos, A; Turkcan, S; Kapp, D; Pratx, G

    2014-06-15

    Purpose: Radiation therapy errors are rare but potentially catastrophic. Recent fatal incidents could have been avoided by utilizing real-time methods of monitoring delivery of radiation during treatment. However, few existing methods are practical enough to be used routinely. The study presents the first experimental demonstration of a novel non-perturbing method of monitoring radiation therapy through the phenomena of air scintillation. Methods: Monitoring of radiation delivery was devised by leveraging the phenomena of nitrogen excitation in air by ionizing radiation. The excitation induced weak luminescence in the 300–400 nm range, a process called air scintillation. An electron-multiplication charge-coupled device camera (f/0.95 lens; 440 nm shortpass) was set-up in a clinical treatment vault and was used to capture air scintillation images of kilovoltage and megavoltage beams. Monte Carlo simulations were performed to determine the correlation of radiation dose to air scintillation. Results: Megavoltage beams from a Varian Clinac 21EX and kilovoltage beams from an orthovoltage unit (50 kVp, 30 mA) were visualized with a relatively short exposure time (10 s). Cherenkov luminescence produced in a plastic transparent phantom did not interfere with detection of air scintillation. The image intensity displayed an inverse intensity falloff (r{sup 2} = 0.89) along the central axis and was proportional to dose rate (r{sup 2} = 0.9998). As beam energy increased, the divergence of the imaged beam decreased. Last, air scintillation was visualized during a simulated total skin irradiation electron treatment. Conclusion: Air scintillation can be clinically detected to monitor a radiation beam in an inexpensive and non-perturbing manner. This new method is advantageous in monitoring for gross delivery and uniquely capable of wide area in a single acquisition, such as the case for online verification of total body / skin / lymphoid irradiation treatments.

  15. Seeing the invisible: Direct visualization of therapeutic radiation beams using air scintillation

    SciTech Connect

    Fahimian, Benjamin; Türkcan, Silvan; Kapp, Daniel S.; Pratx, Guillem; Ceballos, Andrew

    2014-01-15

    Purpose: To assess whether air scintillation produced during standard radiation treatments can be visualized and used to monitor a beam in a nonperturbing manner. Methods: Air scintillation is caused by the excitation of nitrogen gas by ionizing radiation. This weak emission occurs predominantly in the 300–430 nm range. An electron-multiplication charge-coupled device camera, outfitted with an f/0.95 lens, was used to capture air scintillation produced by kilovoltage photon beams and megavoltage electron beams used in radiation therapy. The treatment rooms were prepared to block background light and a short-pass filter was utilized to block light above 440 nm. Results: Air scintillation from an orthovoltage unit (50 kVp, 30 mA) was visualized with a relatively short exposure time (10 s) and showed an inverse falloff (r{sup 2} = 0.89). Electron beams were also imaged. For a fixed exposure time (100 s), air scintillation was proportional to dose rate (r{sup 2} = 0.9998). As energy increased, the divergence of the electron beam decreased and the penumbra improved. By irradiating a transparent phantom, the authors also showed that Cherenkov luminescence did not interfere with the detection of air scintillation. In a final illustration of the capabilities of this new technique, the authors visualized air scintillation produced during a total skin irradiation treatment. Conclusions: Air scintillation can be measured to monitor a radiation beam in an inexpensive and nonperturbing manner. This physical phenomenon could be useful for dosimetry of therapeutic radiation beams or for online detection of gross errors during fractionated treatments.

  16. The effect of microscale urban canyon flow on mesoscale puff dispersion

    SciTech Connect

    Brown, M.J.; Muller, C.

    1997-06-01

    When modeling mesoscale plume or puff transport over distances of one to ten kilometers, the initial small-scale near-source effects are often ignored or parameterized in a crude way. If the release is in an urban environment, buildings and other urban structures can significantly impact the local plume dispersion (e.g., Davidson et al., 1995). In this paper, the authors investigate whether the building-scale effects are important on the longer time-scale mesoscale dispersion process.

  17. Detection of direct-acting mutagens in ambient air: A comparison of two highly sensitive mutagenicity assays

    SciTech Connect

    Houk, V.S.; Goto, S.; Endo, O.; Claxton, L.D.; Lewtas, J.; Matsushita, H. )

    1992-01-01

    Ambient air has been shown to contain numerous hazardous pollutants, many of which are known or suspected carcinogens and mutagens. Bioassays play a prominent role in the characterization of these genotoxic pollutants, and as new test methods are developed, it is incumbent upon researchers to evaluate assay performance and report relative merits. In this study, two Salmonella test methods (the spiral and preincubation assays) were assessed to determine their usefulness as screening methods for monitoring direct-acting mutagens in ambient air. The spiral assay automates the conventional plate-incorporation assay and has been shown to reduce the labor, materials, and sample mass required to perform mutagenicity testing. The preincubation assay has been shown to enhance test sensitivity for certain classes of compound, thereby reducing the amount of sample required for dose-response analysis. Both assays were used to test organic extracts of airborne particulate matter collected in Tokyo during the winters of 1988 and 1990. In addition to the conventional tester strains TA98 and TA100, two newly developed YG strains were evaluated. Strains YG1024 and YG1029-derived from TA98 and TA100, respectively-contain an acetyltransferase plasmid that confers upon the strains greater sensitivity towards nitroarenes. Results from this study indicated that both assays were able to detect direct-acting mutagens in the Tokyo air samples. The mutagenic activity associated with the samples was directly related to the particle mass present in a given volume of air. Mutagenic response was greater in the spiral assay relative to the preincubation assay, especially when YG tester strains were used. The YG strains were significantly more sensitive to mutation than the TA strains in both assays, which suggests that nitroaromatics are an important class of genotoxic contaminant present in Tokyo air.

  18. Field test of two high-pressure, direct-contact downhole steam generators. Volume I. Air/diesel system

    SciTech Connect

    Marshall, B.W.

    1983-05-01

    As a part of the Project DEEP STEAM to develop technology to more efficiently utilize steam for the recovery of heavy oil from deep reservoirs, a field test of a downhole steam generator (DSG) was performed. The DSG burned No. 2 diesel fuel in air and was a direct-contact, high pressure device which mixed the steam with the combustion products and injected the resulting mixture directly into the oil reservoir. The objectives of the test program included demonstration of long-term operation of a DSG, development of operational methods, assessment of the effects of the steam/combustion gases on the reservoir and comparison of this air/diesel DSG with an adjacent oxygen/diesel direct contact generator. Downhole operation of the air/diesel DSG was started in June 1981 and was terminated in late February 1982. During this period two units were placed downhole with the first operating for about 20 days. It was removed, the support systems were slightly modified, and the second one was operated for 106 days. During this latter interval the generator operated for 70% of the time with surface air compressor problems the primary source of the down time. Thermal contact, as evidenced by a temperature increase in the production well casing gases, and an oil production increase were measured in one of the four wells in the air/diesel pattern. Reservoir scrubbing of carbon monoxide was observed, but no conclusive data on scrubbing of SO/sub x/ and NO/sub x/ were obtained. Corrosion of the DSG combustor walls and some other parts of the downhole package were noted. Metallurgical studies have been completed and recommendations made for other materials that are expected to better withstand the downhole combustion environment. 39 figures, 8 tables.

  19. Comparison of unextruded air slip direct chill cast 6061 ingot with bar stock extruded from conventional direct chill cast 6061 ingot

    NASA Astrophysics Data System (ADS)

    Bergsma, S. C.; Kassner, M. E.

    1997-08-01

    Air Slip direct chill cast 6061 small diameter ingots (Direct Forge) were compared with 6061 extruded bar stock. The T6 mechanical properties were compared for both the Direct Forge ingot and the extruded bar stock, as well as cold impact extruded cylinders produced from Direct Forge small diameter ingot and extruded stock. It was found that the tensile and fatigue properties of Direct Forge ingot and cylinders from this ingot were significantly superior to those of extruded stock and cylinder produced from this stock. The improved properties are a result of higher solidification rates leading to smaller alloy-constituent dispersed particles and, thus, the production of smaller and more stable grain sizes. Direct Forge has the additional advantages of (a) not requiring hot or cold work prior to forming impacted extruded or forged parts, (b) being utilized in the T6 temper without any prior deformation, (c) having isotropic and consistent properties, (d) not requiring machining to remove surface segregation or defects, and (e) having more consistent and refined grain sizes.

  20. MESOI Version 2. 0: an interactive mesoscale Lagrangian puff dispersion model with deposition and decay

    SciTech Connect

    Ramsdell, J.V.; Athey, G.F.; Glantz, C.S.

    1983-11-01

    MESOI Version 2.0 is an interactive Lagrangian puff model for estimating the transport, diffusion, deposition and decay of effluents released to the atmosphere. The model is capable of treating simultaneous releases from as many as four release points, which may be elevated or at ground-level. The puffs are advected by a horizontal wind field that is defined in three dimensions. The wind field may be adjusted for expected topographic effects. The concentration distribution within the puffs is initially assumed to be Gaussian in the horizontal and vertical. However, the vertical concentration distribution is modified by assuming reflection at the ground and the top of the atmospheric mixing layer. Material is deposited on the surface using a source depletion, dry deposition model and a washout coefficient model. The model also treats the decay of a primary effluent species and the ingrowth and decay of a single daughter species using a first order decay process. This report is divided into two parts. The first part discusses the theoretical and mathematical bases upon which MESOI Version 2.0 is based. The second part contains the MESOI computer code. The programs were written in the ANSI standard FORTRAN 77 and were developed on a VAX 11/780 computer. 43 references, 14 figures, 13 tables.

  1. Efficient neutron production from a novel configuration of deuterium gas-puff z-pinch.

    PubMed

    Klir, D; Kubes, P; Rezac, K; Cikhardt, J; Kravarik, J; Sila, O; Shishlov, A V; Kovalchuk, B M; Ratakhin, N A; Kokshenev, V A; Labetsky, A Yu; Cherdizov, R K; Fursov, F I; Kurmaev, N E; Dudkin, G N; Nechaev, B A; Padalko, V N; Orcikova, H; Turek, K

    2014-03-01

    A novel configuration of a deuterium z pinch has been used to generate fusion neutrons. Injecting an outer hollow cylindrical plasma shell around an inner deuterium gas puff, neutron yields from DD reactions reached Y(n)=(2.9 ± 0.3) × 10(12) at 700 ns implosion time and 2.7 MA current. Such a neutron yield means a tenfold increase in comparison with previous deuterium gas puff experiments at the same current generator. The increase of beam-target yields was obtained by a larger amount of current assembled on the z-pinch axis, and subsequently by higher induced voltage and higher energies of deuterons. A stack of CR-39 track detectors on the z-pinch axis showed hydrogen ions up to 38 MeV. Maximum neutron energies of 15 and 22 MeV were observed by radial and axial time-of-flight detectors, respectively. The number of DD neutrons per one joule of stored plasma energy approached 5 × 10(7). This implies that deuterium gas puff z pinches belong to the most efficient plasma-based sources of DD neutrons. PMID:24655260

  2. On the behaviour of a stressed cotton canopy in a direct air stream

    NASA Technical Reports Server (NTRS)

    Schutt, J. B.; Newcomb, W. W.

    1986-01-01

    Reflectance variations of a stressed cotton canopy were conducted in the presence of a fan-generated air stream to investigate the effects of air movement and the resulting temperature changes on remotely-sensed data. The initial drop in reflectance after application of the air stream was found to be greatest in the morning because leaf turgor was at a maximum, enabling leaves on the windward side of the canopy to assume surprisingly stable vertical positions. By afternoon, a reduction in leaf turgor was responsible for less stem displacement and consequently a reduction in light-trapping capability. However, reflectance oscillations were greater because the leaves had become sufficiently limp to flutter at the edges and about the petioles exposing both adaxial and abaxial surfaces to the incident light.

  3. Carcinogenicity of ambient air pollution: use of biomarkers, lessons learnt and future directions

    PubMed Central

    Vineis, Paolo

    2015-01-01

    The association between ambient air pollution (AAP) exposure and lung cancer risk has been investigated in prospective studies and the results are generally consistent, indicating that long-term exposure to air pollution can cause lung cancer. Biomarkers can enhance research on the health effects of air pollution by improving exposure assessment, increasing the understanding of mechanisms, and enabling the investigation of individual susceptibility. In this review, we assess DNA adducts as biomarkers of exposure to AAP and early biological effect, and DNA methylation as biomarker of early biological change and discuss critical issues arising from their incorporation in AAP health impact evaluations, such as confounding, individual susceptibilities, timing, intensity and duration of exposure, and investigated tissue. DNA adducts and DNA methylation are treated as paradigms. However, the lessons, learned from their use in the examination of AAP carcinogenicity, can be applied to investigations of other biomarkers involved in AAP carcinogenicity. PMID:25694819

  4. Overview of 12-cm-Diameter, Argon Gas-Puff Experiments and Analyses with >200-ns Implosion Times at 3- to 6-MA Peak Currents

    SciTech Connect

    Commisso, R. J.; Apruzese, J. P.; Davis, J.; Murphy, D. P.; Thornhill, J. W.; Velikovich, A. L.; Weber, B. V.; Jackson, S. L.; Mosher, D.; Young, F. C.; Coverdale, C. A.; Jones, B.

    2009-01-21

    This paper reviews the motivation for, results from, and analyses of 12-cm-diameter argon gas-puff experiments carried out over the last four years on three generators at 3.2- to 6.5-MA peak currents, all with implosion times {>=}200 ns. Using the argon K-shell yield as a metric of implosion quality, high-quality implosions are obtained for an appropriate initial radial mass distribution, i.e., a distribution that is peaked on axis. Higher compressed densities and smaller final radii are observed compared to shell-like initial mass distributions. Theory and data suggest that these distributions mitigate the magnetic Rayleigh-Taylor instability. An energy analysis shows that (1) significant electrical energy is directly coupled to the pinch during the K-shell radiation pulse and (2) conversion of radially-directed kinetic energy into thermal energy is not the dominant mechanism responsible for the pinch K-shell radiation.

  5. 14 CFR 380.34a - Substitution of direct air carrier's security or depository agreement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... participant payments (including those for ground accommodations and services) and for the fulfillment of all...: (1) Payments by or on behalf of charter participants shall be allocated to the flight accounts... charter cost of the participant's air transportation on that flight. The portion of each payment...

  6. New Directions: Understanding Interactions of Air Quality and Climate Change at Regional Scales

    EPA Science Inventory

    The estimates of the short-lived climate forcers’ (SLCFs) impacts and mitigation effects on the radiation balance have large uncertainty because the current global model set-ups and simulations contain simplified parameterizations and do not completely cover the full range of air...

  7. 76 FR 9495 - Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    ..., amendment 39-16412 (75 FR 52255, August 25, 2010), for all Air Tractor Models AT-802 and AT- 802A airplanes... statutes, to fit regulatory and informational requirements to the scale of the businesses, organizations... actions. The RFA covers a wide range of small entities, including small businesses,...

  8. BIOASSAY-DIRECTED FRACTIONATION OF THE ORGANIC EXTRACT OF SRM 1649 URBAN AIR PARTICULATE MATTER

    EPA Science Inventory

    Separation of 2 grams of the methylene chloride extract of NIST SRM 1649 (Washington, D.C. urban air particulate matter) into six compound class fractions by acid-base partitioning and silica gel column chromatography is demonstrated here. ecoveries of organic mass and Salmonella...

  9. 76 FR 34011 - Airworthiness Directives; Viking Air Limited (Type Certificate No. A-815 Formerly Held by...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ... 2011-05-02, Amendment 39-16611 (76 FR 10220, February 24, 2011), for certain Viking Air Limited (Type...-05-02, Amendment 39-16611 (76 FR 10220, February 24, 2011), and adding the following new AD: Viking... a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February...

  10. Comparative study of 3D numerical and puff models for dense air pollutants

    SciTech Connect

    Chang, N.B.; Wei, Y.L.; Tseng, C.C.; Kao, C.Y.J.

    1999-02-01

    To prepare for a chemical emergency response program in those industrial cities that might involve a release of chemical contaminants to the atmosphere, the authors have adopted a series of source emission models and a three-dimensional atmospheric model along with its companion diffusion module for predicting the dispersion and concentrations of these hazardous chemicals with various types of release scenarios. The three-dimensional atmospheric model predicts the wind, temperature, and turbulence fields in which the physical processes associated with terrain, clouds, radiation, and surface vegetation are included. The analytical framework is designed by the fact that the diffusion module uses the estimated release rate from a source emission model and the predicted winds and turbulence conditions from the atmospheric model to compute particle trajectories, concentrations, and dosages in the area of a release. In addition, the model results have been coupled with the geographical information system, which may be used for risk assessment at the urban industrial area of south Taiwan by emergency planners.

  11. Characteristics of air puffs produced in English "pa": experiments and simulations.

    PubMed

    Derrick, Donald; Anderson, Peter; Gick, Bryan; Green, Sheldon

    2009-04-01

    Three dimensional large eddy simulations, microphone "pop" measurements, and high-speed videos of the airflow and lip opening associated with the syllable "pa" are presented. In the simulations, the mouth is represented by a narrow static ellipse with a back pressure dropping to 110th of its initial value within 60 ms of the release. The simulations show a jet penetration rate that falls within range of the pressure front of microphone pop. The simulations and high-speed video experiments were within 20% agreement after 40 ms, with the video experiments showing a slower penetration rate than the simulations during the first 40 ms. Kinematic measurements indicate that rapid changes in lip geometry during the first 40 ms underlie this discrepancy. These findings will be useful for microphone manufacturers, sound engineers, and researchers in speech aerodynamics modeling and articulatory speech synthesis. PMID:19354402

  12. Acceleration of Deuterons to Multi-MeV Energies in Deuterium Gas-Puff Z-Pinch

    NASA Astrophysics Data System (ADS)

    Klir, D.; Cikhardt, J.; Cikhardtova, B.; Kravarik, J.; Kubes, P.; Rezac, K.; Sila, O.; Shishlov, A.; Cherdizov, R.; Fursov, F.; Kokshenev, V.; Kovalchuk, B.; Kurmaev, N.; Labetsky, A.; Ratakhin, N.; Krasa, J.; Turek, K.

    2015-11-01

    A novel configuration of a deuterium gas-puff z-pinch has been used to generate a short (approx. 20 ns) pulse of multi-MeV ions and neutrons. Even though ion acceleration in z-pinches has not been researched to such an extent as in laser-based sources, obtained results show that z-pinches can reach values comparable to those of state-of-the-art lasers. On the 3 MA GIT-12 generator, the peak neutron yield was 3.6x1012. When a neutron-producing sample was placed onto the axis below a cathode mesh, the neutron yield was increased up to 1013. The emission time of 20 ns implied the neutron production rate of 5x1020 n/s. Neutron energies reached the maximum value of 33 MeV. The comprehensive set of ion diagnostics provided unique information about ion acceleration mechanism. The ion emission was highly anisotropic. Deuterons were trapped in the radial direction whereas a lot of fast ions escaped the z-pinch along the axis. On the axis, the total number of >1 MeV and >25 MeV deuterons was 1016 and 5x1012, respectively. Utilizing these ions offers a real possibility of various applications including the production of short-lived isotopes or fast neutron radiography. This work was supported by the MSMT grants LH13283, LD14089.

  13. Instructions for observing air temperature, humidity, and direction and force of wind

    USGS Publications Warehouse

    U.S. Geological Survey

    1892-01-01

    Description of instruments.-The temperature and humidity of the air are obtained from the simultaneous observation of a pair of mercurial thermometers termed the dry and the wet bulb. The air temperature is given by the dry-bulb thermometer, and the humidity is obtained from the combined readings of both. The wet-bulb thermometer differs from the dry-bulb thermometer only in having its bulb covered with thin muslin, which is wetted in pure water at each observation.The two thermometers are fastened in a light metal 'or wooden frame. To this frame is to be attached a stout cord for the whirling of the thermometers, which is an essential part of every observation.

  14. Retrieval of Mid-tropospheric CO2 Directly from AIRS Measurements

    NASA Technical Reports Server (NTRS)

    Olsen, Edward T.; Chahine, Moustafa T.; Chen, Luke L.; Pagano, Thomas S.

    2008-01-01

    We apply the method of Vanishing Partial Derivatives (VPD) to AIRS spectra to retrieve daily the global distribution of CO2 at a nadir geospatial resolution of 90 km x 90 km without requiring a first-guess input beyond the global average. Our retrievals utilize the 15 (micro)m band radiances, a complex spectral region. This method may be of value in other applications, in which spectral signatures of multiple species are not well isolated spectrally from one another.

  15. Perspective use of direct human blood as an energy source in air-breathing hybrid microfluidic fuel cells

    NASA Astrophysics Data System (ADS)

    Dector, A.; Escalona-Villalpando, R. A.; Dector, D.; Vallejo-Becerra, V.; Chávez-Ramírez, A. U.; Arriaga, L. G.; Ledesma-García, J.

    2015-08-01

    This work presents a flexible and light air-breathing hybrid microfluidic fuel cell (HμFC) operated under biological conditions. A mixture of glucose oxidase, glutaraldehyde, multi-walled carbon nanotubes and vulcan carbon (GOx/VC-MWCNT-GA) was used as the bioanode. Meanwhile, integrating an air-exposed electrode (Pt/C) as the cathode enabled direct oxygen delivery from air. The microfluidic fuel cell performance was evaluated using glucose obtained from three different sources as the fuel: 5 mM glucose in phosphate buffer, human serum and human blood. For the last fuel, an open circuit voltage and maximum power density of 0.52 V and 0.20 mW cm-2 (at 0.38 V) were obtained respectively; meanwhile the maximum current density was 1.1 mA cm-2. Furthermore, the stability of the device was measured in terms of recovery after several polarization curves, showing excellent results. Although this air-breathing HμFC requires technological improvements before being tested in a biomedical device, it represents the best performance to date for a microfluidic fuel cell using human blood as glucose source.

  16. Hybrid Li-air battery cathodes with sparse carbon nanotube arrays directly grown on carbon fiber papers

    SciTech Connect

    Li, YF; Huang, ZP; Huang, K; Carnahan, D; Xing, YC

    2013-11-01

    Sparsely populated, vertically aligned nitrogen doped carbon nanotube arrays (CNTAs) with dislocated-graphene stacking were grown directly on carbon fiber papers and investigated as hierarchical air cathodes in hybrid Li-air batteries with aqueous catholytes. The CNTAs were made with electrodeposited Ni nanocatalysts, followed by plasma-enhanced chemical vapor deposition. The thus obtained CNTAs can reach a population number density as low as similar to 10(7) per cm(2) on the carbon fibers, achieving an extremely high porosity of over 99% for the active layer in the cathode. The sparse CNTAs not only provide effective pathways for the reacting species, but also show a significantly high catalytic activity, which is found to be comparable to that of a supported Pt electrocatalyst. The high activity of the CNTAs is attributed to the rich graphene edges exposed on the CNT surface and nitrogen doping. Hybrid Li-air batteries with such cathodes have shown a consistent discharging capacity of 710 mA h g(-1) and a specific energy of 2057 W h kg(-1) at 0.5 mA cm(-2). Stable charge-discharge cycling at 0.5 mA cm(-2) showed an average potential difference of 1.35 V, indicative of a relatively small overpotential and high round trip efficiency (71%). Furthermore, the hybrid Li-air battery based on the hierarchical cathode can reach a power density as high as 10.4 mW cm(-2).

  17. Air-directed attachment of coccoid bacteria to the surface of superhydrophobic lotus-like titanium.

    PubMed

    Truong, V K; Webb, H K; Fadeeva, E; Chichkov, B N; Wu, A H F; Lamb, R; Wang, J Y; Crawford, R J; Ivanova, E P

    2012-01-01

    Superhydrophobic titanium surfaces fabricated by femtosecond laser ablation to mimic the structure of lotus leaves were assessed for their ability to retain coccoid bacteria. Staphylococcus aureus CIP 65.8T, S. aureus ATCC 25923, S. epidermidis ATCC 14990T and Planococcus maritimus KMM 3738 were retained by the surface, to varying degrees. However, each strain was found to preferentially attach to the crevices located between the microscale surface features. The upper regions of the microscale features remained essentially cell-free. It was hypothesised that air entrapped by the topographical features inhibited contact between the cells and the titanium substratum. Synchrotron SAXS revealed that even after immersion for 50 min, nano-sized air bubbles covered 45% of the titanium surface. After 1 h the number of cells of S. aureus CIP 65.8T attached to the lotus-like titanium increased to 1.27×10(5) mm(-2), coinciding with the replacement of trapped air by the incubation medium. PMID:22686938

  18. Capillarity-induced directed self-assembly of patchy hexagram particles at the air-water interface.

    PubMed

    Kang, Sung-Min; Choi, Chang-Hyung; Kim, Jongmin; Yeom, Su-Jin; Lee, Daeyeon; Park, Bum Jun; Lee, Chang-Soo

    2016-07-01

    Directed self-assembly can produce ordered or organized superstructures from pre-existing building blocks through pre-programmed interactions. Encoding desired information into building blocks with specific directionality and strength, however, poses a significant challenge for the development of self-assembled superstructures. Here, we demonstrate that controlling the shape and patchiness of particles trapped at the air-water interface can represent a powerful approach for forming ordered macroscopic complex structures through capillary interactions. We designed hexagram particles using a micromolding method that allowed for precise control over the shape and, more importantly, the chemical patchiness of the particles. The assembly behaviors of these hexagram particles at the air-water interface were strongly affected by chemical patchiness. In particular, two-dimensional millimeter-scale ordered structures could be formed by varying the patchiness of the hexagram particles, and we attribute this effect to the delicate balance between the attractive and repulsive interactions among the patchy hexagram particles. Our results provide important clues for encoding information into patchy particles to achieve macroscopic assemblies via a simple molding technique and potentially pave a new pathway for the programmable assembly of particles at the air-water interface. PMID:27328067

  19. Fabrication of a polyvinylidene difluoride fiber with a metal core and its application as directional air flow sensor

    NASA Astrophysics Data System (ADS)

    Bian, Yixiang; Liu, Rongrong; Hui, Shen

    2016-09-01

    We fabricated a sensitive air flow detector that mimic the sensing mechanism found at the tail of some insects. [see Y. Yang, A. Klein, H. Bleckmann and C. Liu, Appl. Phys. Lett. 99(2) (2011); J. J. Heys, T. Gedeon, B. C. Knott and Y. Kim, J. Biomech. 41(5), 977 (2008); J. Tao and X. Yu, Smart Mat. Struct. 21(11) (2012)]. Our bionic airflow sensor uses a polyvinylidene difluoride (PVDF) microfiber with a molybdenum core which we produced with the hot extrusion tensile method. The surface of the fiber is partially coated with conductive silver adhesive that serve as surface electrodes. A third electrode, the metal core is used to polarize polyvinylidene difluoride (PVDF) under the surface electrodes. The cantilever beam structure of the prepared symmetric electrodes of metal core piezoelectric fiber (SMPF) is used as the artificial hair airflow sensor. The surface electrodes are used to measure output voltage. Our theoretical and experimental results show that the SMPF responds fast to air flow changes, the output charge has an exponential correlation with airflow velocity and a cosine relation with the direction of airflow. Our bionic airflow sensor with directional sensing ability can also measure air flow amplitude. [see H. Droogendijk, R. G. P. Sanders and G. J. M. Krijnen, New J. Phys. 15 (2013)]. By using two surface electrodes, our sensing circuit further improves sensitivity.

  20. Inactivation of Staphylococcus aureus and Enterococcus faecalis by a direct-current, cold atmospheric-pressure air plasma microjet☆

    PubMed Central

    Tian, Ye; Sun, Peng; Wu, Haiyan; Bai, Na; Wang, Ruixue; Zhu, Weidong; Zhang, Jue; Liu, Fuxiang

    2010-01-01

    Objective A direct-current, cold atmospheric-pressure air plasma microjet (PMJ) was performed to inactivate Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis) in air. The process of sterilization and morphology of bacteria was observed. We wish to know the possible inactivation mechanisms of PMJ and explore a potential application in dental and other temperature sensitive treatment. Methods In this study, we employed a direct current, atmospheric pressure, cold air PMJ to inactivate bacterias. Scanning electron microscopy was employed to evaluate the morphology of S. aureus and showed rupture of cell walls after the plasma treatment and Optical emission spectrum (OES) were used to understand the possible inactivation mechanisms of PMJ. Results The inactivation rates could reach 100% in 5 min. When the distance between the exit nozzle of the PMJ device and Petri dish was extended from 1 cm to 3 cm, effective inactivation was also observed with a similar inactivation curve. Conclusion The inactivation of bacteria is attributed to the abundant reactive oxygen and nitrogen species, as well as ultroviolet radiation in the plasma. Different life spans and defensibilities of these killing agents may hold the key to understanding the different inactivation curves at different treatment distances. PMID:23554639

  1. Air Abrasion

    MedlinePlus

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  2. Modeling 3D conjugate heat and mass transfer for turbulent air drying of Chilean papaya in a direct contact dryer

    NASA Astrophysics Data System (ADS)

    Lemus-Mondaca, Roberto A.; Vega-Gálvez, Antonio; Zambra, Carlos E.; Moraga, Nelson O.

    2016-03-01

    A 3D model considering heat and mass transfer for food dehydration inside a direct contact dryer is studied. The k- ɛ model is used to describe turbulent air flow. The samples thermophysical properties as density, specific heat, and thermal conductivity are assumed to vary non-linearly with temperature. FVM, SIMPLE algorithm based on a FORTRAN code are used. Results unsteady velocity, temperature, moisture, kinetic energy and dissipation rate for the air flow are presented, whilst temperature and moisture values for the food also are presented. The validation procedure includes a comparison with experimental and numerical temperature and moisture content results obtained from experimental data, reaching a deviation 7-10 %. In addition, this turbulent k- ɛ model provided a better understanding of the transport phenomenon inside the dryer and sample.

  3. Impact of low-trans fat compositions on the quality of conventional and fat-reduced puff pastry.

    PubMed

    Silow, Christoph; Zannini, Emanuele; Arendt, Elke K

    2016-04-01

    Four vegetable fat blends (FBs) with low trans-fatty acid (TFA ≤ 0.6 %) content with various ratios of palm stearin (PS) and rapeseed oil (RO) were characterised and examined for their application in puff pastry production. The amount of PS decreased from FB1 to FB4 and simultaneously the RO content increased. A range of analytical methods were used to characterise the FBs, including solid fat content (SFC), differential scanning calorimetry (DSC), cone penetrometry and rheological measurements. The internal and external structural quality parameters of baked puff pastry were investigated using texture analyser equipped with an Extended Craft Knife (ECK), VolScan and C-Cell image system. Puff pastry containing FB1 and FB2 achieved excellent baking results for full fat and fat-reduced puff pastry; hence these FBs contained adequate shortening properties. A fat reduction by 40 % using FB2 and a reduction of saturated fatty acids (SAFA) by 49 %, compared to the control, did not lead to adverse effects in lift and specific volume. The higher amount of RO and the lower SAFA content compared to FB1 coupled with the satisfying baking results makes FB2 the fat of choice in this study. FB3 and FB4 were found to be unsuitable for puff pastry production because of their melting behaviour. PMID:27413242

  4. Long-Implosion-Time Z-pinch Experiments with Deuterium Gas-Puffs on the GIT-12 Generator

    NASA Astrophysics Data System (ADS)

    Klir, D.; Kubes, P.; Rezac, K.; Cikhardt, J.; Kravarik, J.; Shishlov, A.; Labetsky, A.; Fursov, F.; Kokshenev, V.; Kovalchuk, B.; Kurmaev, N.; Ratakhin, N.

    2012-10-01

    Experiments with deuterium triple shell gas-puffs have been carried out on the GIT-12 generator at the IHCE in Tomsk. Outer, middle, and inner nozzle diameters were 160 mm, 80 mm and 30 mm, respectively. The influence of the mass of deuterium shells on neutron emission times, neutron yields and neutron spectra was studied. The linear mass density of deuterium varied between 50 and 270 μg/cm. Gas puffs imploded onto the axis before the peak of a generator current at 700-1100 ns. The first neutron peak occurred during the stagnation. Most of the neutrons were emitted during the second neutron pulse after the development of instabilities. In lower mass gas puffs, neutron energies of up to 4.4 MeV gave the evidence of 1 MeV deuterons. The peak neutron yield from D(d,n)^3He reactions reached 3x10^11 on a current level of 2.5 MA. Secondary DT neutrons were measured by BDS-10000 bubble detectors. An average neutron yield ratio Y>10 MeV/Y2.5 MeV exceeded (6±3)x10-4. Ne-Ne-D2 and Ne-D2-D2 gas puffs produced 3 times lower neutron yields but the first neutron pulse during the stagnation was nearly the same as with D2-D2-D2 gas puffs.

  5. Research Update: Direct conversion of amorphous carbon into diamond at ambient pressures and temperatures in air

    SciTech Connect

    Narayan, Jagdish Bhaumik, Anagh

    2015-10-01

    We report on fundamental discovery of conversion of amorphous carbon into diamond by irradiating amorphous carbon films with nanosecond lasers at room-temperature in air at atmospheric pressure. We can create diamond in the form of nanodiamond (size range <100 nm) and microdiamond (>100 nm). Nanosecond laser pulses are used to melt amorphous diamondlike carbon and create a highly undercooled state, from which various forms of diamond can be formed upon cooling. The quenching from the super undercooled state results in nucleation of nanodiamond. It is found that microdiamonds grow out of highly undercooled state of carbon, with nanodiamond acting as seed crystals.

  6. Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production

    PubMed Central

    Rau, Greg H.; Carroll, Susan A.; Bourcier, William L.; Singleton, Michael J.; Smith, Megan M.; Aines, Roger D.

    2013-01-01

    We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 105-fold increase in OH− concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na2SO4 solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After electrolysis, full equilibration of the alkalized solution with air led to a significant pH reduction and as much as a 45-fold increase in dissolved inorganic carbon concentration. This demonstrated significant spontaneous air CO2 capture, chemical conversion, and storage as a bicarbonate, predominantly as NaHCO3. The excess OH− initially formed in these experiments apparently resulted via neutralization of the anolyte acid, H2SO4, by reaction with the base mineral silicate at the anode, producing mineral sulfate and silica. This allowed the NaOH, normally generated at the cathode, to go unneutralized and to accumulate in the bulk electrolyte, ultimately reacting with atmospheric CO2 to form dissolved bicarbonate. Using nongrid or nonpeak renewable electricity, optimized systems at large scale might allow relatively high-capacity, energy-efficient (<300 kJ/mol of CO2 captured), and inexpensive (<$100 per tonne of CO2 mitigated) removal of excess air CO2 with production of carbon-negative H2. Furthermore, when added to the ocean, the produced hydroxide and/or (bi)carbonate could be useful in reducing sea-to-air CO2 emissions and in neutralizing or offsetting the effects of ongoing ocean acidification. PMID:23729814

  7. Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production.

    PubMed

    Rau, Greg H; Carroll, Susan A; Bourcier, William L; Singleton, Michael J; Smith, Megan M; Aines, Roger D

    2013-06-18

    We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 10(5)-fold increase in OH(-) concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na2SO4 solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After electrolysis, full equilibration of the alkalized solution with air led to a significant pH reduction and as much as a 45-fold increase in dissolved inorganic carbon concentration. This demonstrated significant spontaneous air CO2 capture, chemical conversion, and storage as a bicarbonate, predominantly as NaHCO3. The excess OH(-) initially formed in these experiments apparently resulted via neutralization of the anolyte acid, H2SO4, by reaction with the base mineral silicate at the anode, producing mineral sulfate and silica. This allowed the NaOH, normally generated at the cathode, to go unneutralized and to accumulate in the bulk electrolyte, ultimately reacting with atmospheric CO2 to form dissolved bicarbonate. Using nongrid or nonpeak renewable electricity, optimized systems at large scale might allow relatively high-capacity, energy-efficient (<300 kJ/mol of CO2 captured), and inexpensive (<$100 per tonne of CO2 mitigated) removal of excess air CO2 with production of carbon-negative H2. Furthermore, when added to the ocean, the produced hydroxide and/or (bi)carbonate could be useful in reducing sea-to-air CO2 emissions and in neutralizing or offsetting the effects of ongoing ocean acidification. PMID:23729814

  8. Thermal analysis and two-directional air flow thermal management for lithium-ion battery pack

    NASA Astrophysics Data System (ADS)

    Yu, Kuahai; Yang, Xi; Cheng, Yongzhou; Li, Changhao

    2014-12-01

    Thermal management is a routine but crucial strategy to ensure thermal stability and long-term durability of the lithium-ion batteries. An air-flow-integrated thermal management system is designed in the present study to dissipate heat generation and uniformize the distribution of temperature in the lithium-ion batteries. The system contains of two types of air ducts with independent intake channels and fans. One is to cool the batteries through the regular channel, and the other minimizes the heat accumulations in the middle pack of batteries through jet cooling. A three-dimensional anisotropic heat transfer model is developed to describe the thermal behavior of the lithium-ion batteries with the integration of heat generation theory, and validated through both simulations and experiments. Moreover, the simulations and experiments show that the maximum temperature can be decreased to 33.1 °C through the new thermal management system in comparison with 42.3 °C through the traditional ones, and temperature uniformity of the lithium-ion battery packs is enhanced, significantly.

  9. Neutron production in deuterium gas-puff implosions on the refurbished Z accelerator.

    SciTech Connect

    Flicker, Dawn G.; Coverdale, Christine Anne; Velikovich, Aleksandr Lazarevich; Clark, R. W.; Chong, Y. K.; Davis, J.; Giuliani, J. L.

    2010-06-01

    It has been experimentally demonstrated that deuterium gas-puff implosions at >15 MA are powerful sources of fusion neutrons. Analysis of these experiments indicates that a substantial fraction of the obtained DD fusion neutron yields {approx} 3 x 10{sup 13}, about 50%, might have been of thermonuclear origin. The goal of our study is to estimate the scaling of the thermonuclear neutron yield from deuterium gas-puff implosions with higher load currents available after the refurbishment of Z, both in the short-pulse ({approx}100 ns) and in the long-pulse ({approx}300 ns) implosion regimes. We report extensive ID and 2D radiation-hydrodynamic simulations of such implosions. The mechanisms of ion heating to the fusion temperatures of 7-10 keV are essentially the same as used in structured gas-puff loads to generate high Ar K-shell yields: shock thermalization of the implosion kinetic energy and subsequent adiabatic heating of the on-axis plasma. We investigate the role of high-atomic-number gas that can be added to the outer shell to improve both energy coupling of the imploded mass to the generator and energy transfer to the inner part of the load, due to radiative losses that make the outer shell thin. We analyze the effect of imposed axial magnetic field {approx}30-100 kG, which can contribute both to stabilization of the implosion and to Joule heating of the imploded plasma. Our estimates indicate that thermonuclear DD neutron yields approaching 10 are within the reach on refurbished Z.

  10. Breeding Super-Earths and Birthing Super-Puffs in Transitional Disks

    NASA Astrophysics Data System (ADS)

    Lee, Eve J.; Chiang, Eugene

    2015-12-01

    The riddle posed by super-Earths (1--4 Earth radii, 2--20 Earth masses) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earthsformed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many orders of magnitude, and super-Earths can robustly emerge with percent-by-weight atmospheres after ~0.1--1 Myr. We propose that 1) close-in super-Earths form in situ, because their cores necessarily coagulate in gas-poor environments—gas dynamical friction must be weakened sufficiently to allow constituent protocores to cross orbits and merge; 2) super- Earths acquire their atmospheres from ambient wisps of gas that are supplied from a diffusing outer disk. The formation environment is reminiscent of the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also 3) address the inverse problem presented by super-puffs: an uncommon class of short- period planets seemingly too voluminous for their small masses (4--10 Earth radii, 2--6 Earth masses). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ~1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content.

  11. First Argon Gas Puff Experiments With 500 ns Implosion Time On Sphinx Driver

    SciTech Connect

    Zucchini, F.; Calamy, H.; Lassalle, F.; Loyen, A.; Maury, P.; Grunenwald, J.; Georges, A.; Morell, A.; Bedoch, J.-P.; Ritter, S.; Combes, P.; Smaniotto, O.; Lample, R.; Coleman, P. L.; Krishnan, M.

    2009-01-21

    Experiments have been performed at the SPHINX driver to study potential of an Argon Gas Puff load designed by AASC. We present here the gas Puff hardware and results of the last shot series.The Argon Gas Puff load used is injected thanks to a 20 cm diameter nozzle. The nozzle has two annuli and a central jet. The pressure and gas type in each of the nozzle plena can be independently adjusted to tailor the initial gaz density distribution. This latter is selected as to obtain an increasing radial density from outer shell towards the pinch axis in order to mitigate the RT instabilities and to increase radiating mass on axis. A flashboard unit produces a high intensity UV source to pre-ionize the Argon gas. Typical dimensions of the load are 200 mm in diameter and 40 mm height. Pressures are adjusted to obtain an implosion time around 550 ns with a peak current of 3.5 MA.With the goal of improving k-shell yield a mass scan of the central jet was performed and implosion time, mainly given by outer and middle plena settings, was kept constant. Tests were also done to reduce the implosion time for two configurations of the central jet. Strong zippering of the radiation production was observed mainly due to the divergence of the central jet over the 40 mm of the load height. Due to that feature k-shell radiation is mainly obtained near cathode. Therefore tests were done to mitigate this effect first by adjusting local pressure of middle and central jet and second by shortening the pinch length.At the end of this series, best shot gave 5 kJ of Ar k-shell yield. PCD detectors showed that k-shell x-ray power was 670 GW with a FWHM of less than 10 ns.

  12. First Argon Gas Puff Experiments With 500 ns Implosion Time On Sphinx Driver

    NASA Astrophysics Data System (ADS)

    Zucchini, F.; Calamy, H.; Lassalle, F.; Loyen, A.; Maury, P.; Grunenwald, J.; Georges, A.; Morell, A.; Bedoch, J.-P.; Ritter, S.; Combes, P.; Smaniotto, O.; Lample, R.; Coleman, P. L.; Krishnan, M.

    2009-01-01

    Experiments have been performed at the SPHINX driver to study potential of an Argon Gas Puff load designed by AASC. We present here the gas Puff hardware and results of the last shot series. The Argon Gas Puff load used is injected thanks to a 20 cm diameter nozzle. The nozzle has two annuli and a central jet. The pressure and gas type in each of the nozzle plena can be independently adjusted to tailor the initial gaz density distribution. This latter is selected as to obtain an increasing radial density from outer shell towards the pinch axis in order to mitigate the RT instabilities and to increase radiating mass on axis. A flashboard unit produces a high intensity UV source to pre-ionize the Argon gas. Typical dimensions of the load are 200 mm in diameter and 40 mm height. Pressures are adjusted to obtain an implosion time around 550 ns with a peak current of 3.5 MA. With the goal of improving k-shell yield a mass scan of the central jet was performed and implosion time, mainly given by outer and middle plena settings, was kept constant. Tests were also done to reduce the implosion time for two configurations of the central jet. Strong zippering of the radiation production was observed mainly due to the divergence of the central jet over the 40 mm of the load height. Due to that feature k-shell radiation is mainly obtained near cathode. Therefore tests were done to mitigate this effect first by adjusting local pressure of middle and central jet and second by shortening the pinch length. At the end of this series, best shot gave 5 kJ of Ar k-shell yield. PCD detectors showed that k-shell x-ray power was 670 GW with a FWHM of less than 10 ns.

  13. Comparison of Puff Volume With Cigarettes per Day in Predicting Nicotine Uptake Among Daily Smokers.

    PubMed

    Krebs, Nicolle M; Chen, Allshine; Zhu, Junjia; Sun, Dongxiao; Liao, Jason; Stennett, Andrea L; Muscat, Joshua E

    2016-07-01

    The role of inhalation behaviors as predictors of nicotine uptake was examined in the Pennsylvania Adult Smoking Study (2012-2014), a study of 332 adults whose cigarette smoking was measured in a naturalistic environment (e.g., at home) with portable handheld topography devices. Piecewise regression analyses showed that levels of salivary cotinine, trans-3'-hydroxycotinine, and total salivary nicotine metabolites (cotinine + trans-3'-hydroxycotinine) increased linearly up to a level of about 1 pack per day (20 cigarettes per day (CPD)) (P < 0.01). Total daily puff volume (TDPV; in mL) (P < 0.05) and total daily number of puffs (P < 0.05), but not other topographical measures, increased linearly with CPD up to a level of about 1 pack per day. The mean level of cotinine per cigarette did not change above 20 CPD and was 36% lower in heavy smokers (≥20 CPD) than in lighter smokers (<20 CPD) (15.6 ng/mL vs. 24.5 ng/mL, respectively; P < 0.01). Mediation models showed that TDPV accounted for 43%-63% of the association between CPD and nicotine metabolites for smokers of <20 CPD. TDPV was the best predictor of nicotine metabolite levels in light-to-moderate smokers (1-19 CPD). In contrast, neither CPD, total daily number of puffs, nor TDPV predicted nicotine metabolite levels above 20 CPD (up to 40 CPD). Finally, although light smokers are traditionally considered less dependent on nicotine, these findings suggest that they are exposed to more nicotine per cigarette than are heavy smokers due to more frequent, intensive puffing. PMID:27313218

  14. Numerical modeling on air quality in an urban environment with changes of the aspect ratio and wind direction.

    PubMed

    Yassin, Mohamed F

    2013-06-01

    Due to heavy traffic emissions within an urban environment, air quality during the last decade becomes worse year by year and hazard to public health. In the present work, numerical modeling of flow and dispersion of gaseous emissions from vehicle exhaust in a street canyon were investigated under changes of the aspect ratio and wind direction. The three-dimensional flow and dispersion of gaseous pollutants were modeled using a computational fluid dynamics (CFD) model which was numerically solved using Reynolds-averaged Navier-Stokes (RANS) equations. The diffusion flow field in the atmospheric boundary layer within the street canyon was studied for different aspect ratios (W/H=1/2, 3/4, and 1) and wind directions (θ=90°, 112.5°, 135°, and 157.5°). The numerical models were validated against wind tunnel results to optimize the turbulence model. The numerical results agreed well with the wind tunnel results. The simulation demonstrated that the minimum concentration at the human respiration height within the street canyon was on the windward side for aspect ratios W/H=1/2 and 1 and wind directions θ=112.5°, 135°, and 157.5°. The pollutant concentration level decreases as the wind direction and aspect ratio increase. The wind velocity and turbulence intensity increase as the aspect ratio and wind direction increase. PMID:23192299

  15. Simulations of gas puff effects on edge density and ICRF coupling in ASDEX upgrade using EMC3-Eirene

    SciTech Connect

    Zhang, W.; Lunt, T.; Bobkov, V.; Coster, D.; Brida, D.; Noterdaeme, J.-M.; Jacquet, P.; Feng, Y.

    2015-12-10

    Simulations were carried out with the 3D plasma transport code EMC3-EIRENE, to study the deuterium gas (D{sub 2}) puff effects on edge density and the coupling of Ion Cyclotron Range of Frequency (ICRF) power in ASDEX Upgrade. Firstly we simulated an inter-ELM phase of an H-mode discharge with a moderate (1.2 × 10{sup 22} electrons/s) lower divertor gas puff. Then we changed the gas source positions to the mid-plane or top of machine while keeping other conditions the same. Cases with different mid-plane or top gas valves are investigated. Our simulations indicate that compared to lower divertor gas puffing, the mid-plane gas puff can enhance the local density in front of the antennas most effectively, while a rather global (toroidally uniform) but significantly smaller enhancement is found for top gas puffing. Our results show quantitative agreement with the experiments.

  16. Synthesis of ammonia directly from air and water at ambient temperature and pressure

    PubMed Central

    Lan, Rong; Irvine, John T. S.; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol−1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10−5 mol m−2 s−1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future. PMID:23362454

  17. Cross-directional interlocking of rolls in an air press of a papermaking machine

    DOEpatents

    Beck, David A.; Gorshe, Thomas

    2003-05-13

    An air press for pressing a paper web is composed of a plurality of rolls including at least a first roll and a second roll. The first roll and the second roll are positioned adjacent one another and form a first nip therebetween. Further, the first roll and the second roll each have a roll end, the roll end of the first roll adjoining the roll end of the second roll. A bevel plate is attached to the roll end of the first roll, the bevel plate having at least a first angled plate face. A seal ring is positioned adjacent the roll end of the second roll, the seal ring being juxtaposed to the bevel plate. The seal ring has at least a first angled ring face, and the first angled ring face mates with the first angled plate face.

  18. 78 FR 59258 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Withdrawal of Direct...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-26

    ...-approved Motor Vehicle Emissions Budgets (MVEBs) for nitrogen oxides (NO X ) and volatile organic compounds.... DATES: The direct final rule published at 78 FR 48323 on August 8, 2013, is withdrawn as of September 26... 40 CFR 52.2043 and 40 CFR 52.2052, published on August 8, 2013 (78 FR 48323), are withdrawn as...

  19. 78 FR 18533 - Airworthiness Directives; Lindstrand Hot Air Balloons Ltd Appliances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-27

    ..., 2013. The effective date for AD 2013-03-10; Amendment 39-17345 (78 FR 9785, February 12, 2013) remains...: Airworthiness Directive 2013-03-10; Amendment 39-17345 (78 FR 9785, February 12, 2013), requires inspecting the... indicate confusion as to the way the applicability of AD 2013-03- 10; Amendment 39-17345 (78 FR...

  20. 76 FR 62605 - Airworthiness Directives; Viking Air Limited Model DHC-3 (Otter) Airplanes With Supplemental Type...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... . SUPPLEMENTARY INFORMATION: Airworthiness Directive 2011-12-02, Amendment 39-16709 (76 FR 31800, June 2, 2011... 2, 2011, AD 2011-12-02; Amendment 39-16709 (76 FR 31800, June 2, 2011), is corrected as follows: On...-02; Amendment 39- 16709 (76 FR 31800, June 2, 2011), on page 31802, paragraphs (e) and (f)(2) of...

  1. 75 FR 70106 - Airworthiness Directives; Viking Air Limited (Type Certificate Previously Held by Bombardier, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... NPRM was published in the Federal Register on July 23, 2010, (75 FR 43092). That NPRM proposed to... Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant economic impact, positive or... 2009-NM-236-AD; Amendment 39-16510; AD 2010-23-21] RIN 2120-AA64 Airworthiness Directives; Viking...

  2. 75 FR 56487 - Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64F Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... April 11, 2000 (65 FR 19477-78). Examining the Docket You may examine the docket that contains the... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Erickson...

  3. 76 FR 66617 - Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64F Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-27

    .... That NPRM was published in the Federal Register on September 16, 2010 (75 FR 56487). That NPRM proposed... Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant economic impact, positive or...-026-AD; Amendment 39-16835; AD 2011-21-12] RIN 2120-AA64 Airworthiness Directives; Erickson...

  4. Fully kinetic particle-in-cell simulations of a deuterium gas puff z pinch.

    PubMed

    Welch, D R; Rose, D V; Clark, R E; Mostrom, C B; Stygar, W A; Leeper, R J

    2009-12-18

    We present the first fully kinetic, collisional, and electromagnetic simulations of the complete time evolution of a deuterium gas puff z pinch. Recent experiments with 15-MA current pinches have suggested that the dominant neutron-production mechanism is thermonuclear. We observe distinct differences between the kinetic and magnetohydrodynamic simulations in the pinch evolution with the kinetic simulations producing both thermonuclear and beam-target neutrons. The kinetic approach demonstrated in this Letter represents a viable alternative for performing future plasma physics calculations. PMID:20366259

  5. Interactive Mesoscale Lagrangian Puff Dispersion Model with Deposition and Decay. See CCC-677/MESORAD.

    1986-06-15

    Version: 00 MESOI Version 2.0 is a third generation Lagrangian puff transport and diffusion model based on the earlier MESODIF model. It explicitly treats physical processes affecting material released to the atmosphere which were not treated in the earlier versions. It is an interactive model for estimating the transport, diffusion, deposition and decay of effluents released to the atmosphere. It is capable of treating simultaneous releases from as many as four release points which maymore » be elevated or at ground level.« less

  6. Gas-puff liner implosion in the configuration with helical current return rods

    SciTech Connect

    Sorokin, S. A.

    2013-02-15

    Results of experiments with double-shell gas-puff liners carried out on a high-current MIG generator (2 MA, 80 ns) are presented. To stabilize the process of liner implosion and increase the efficiency of energy transfer from the generator to the liner plasma, a current return in the form of a multifilar helix was used. The effect of the configuration of the current return on the parameters of the generated pulses of argon and neon K-shell radiation (with photon energies of 3-5 and 0.9-1.5 keV, respectively) and the neutron yield from a deuterium liner were studied.

  7. Investigation of Metal Puff Z pinch Based on Multichannel Vacuum Arcs

    NASA Astrophysics Data System (ADS)

    Rousskikh, A. G.; Oreshkin, V. I.; Zhigalin, A. S.; Chaikovsky, S. A.; Baksht, R. B.; Mitrofanov, K. N.

    2015-11-01

    The performance of a metal double puff Z-pinch system has been studied experimentally. In this type of system, the outer and inner cylindrical shells were produced by ten plasma guns. Each gun initiates a vacuum arc operating between aluminum electrodes. The net current of the guns was 80 kA. The arc-produced plasma shells were compressed by using a 450-kA, 450-ns driver, and as a result, a plasma column 0.2 cm in diameter was formed. The power of the Al K-line radiation emitted by the plasma for 7 ns was 800 MW/cm.

  8. C02 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Mark Kovar; Scott Wehner

    1998-01-31

    The principal objective of this CO2 Huf-n-Puff (H-n-P) project is to determine the feasibility and practicality of the technology in a waterflooded shallow shelf carbonate environment. The results of parametric simulation of the CO2 H-n-P process, coupled with reservoir characterization components are to be used to determine if this process is technically and economically feasible for field implementation. The technology transfer objective of the project is to disseminate the knowledge gained through an innovative plan of increasing oil production and deferring abandonment of shallow shelf carbonate reservoirs.

  9. Comparison of Gas Puff Imaging Data in NSTX with the DEGAS 2 Simulation

    SciTech Connect

    Cao, B.; Stotler, D. P.; Zweben, S. J.; Bell, M.; Diallo, A.; LeBlanc, B.

    2013-04-10

    Gas-Pu -Imaging (GPI) is a two dimensional diagnostic which measures the edge Dα light emission from a neutral Dα gas puff near the outer mid- plane of the National Spherical Torus Experiment (NSTX). DEGAS 2 is a 3-D Monte Carlo code used to model neutral transport and plasma-neutral interactions in fusion plasmas. In this paper, we compare the measured and modeled Dα light emission for speci c NSTX experiments. Both the simulated spatial distribution and radiance of the Dα light emission agree well with the experimental data obtained between Edge Localized Modes (ELMs) in ELMy H-modes.

  10. Numerical analysis of MHD instability suppression in a double gas puff

    SciTech Connect

    Glazyrin, Igor V.; Diyankov, Oleg V.; Karlykhanov, Nikolai G.; Koshelev, Sergei V.

    1997-05-05

    The process of double gas-puff implosion is numerically analyzed. Various liner configurations are considered: 1) the outer cascade is ten times lighter then the inner one, 2) the masses of cascades are equal, 3) the outer cascade is ten times heavier then the inner one. The mechanism of liner implosions stabilization is discussed. The comparison of two-cascade and single-cascade schemes is performed. The role of magnetic field penetration at the initial time into liner's body is also discussed.

  11. Apportionment of air pollution sources with directional sampling size segregation and soluble/total elemental determination of air particlates in Hong Kong

    SciTech Connect

    Fung, Y.S.; Cheung, H.K.

    1996-12-31

    With an aim to improve the identification of pollution sources, to enhance the ability to resolve source types and to assist the interpretation of results, a computer controlled sampling station has been developed for directional sampling and size segregation of air particulates collected using a High Volume Sampler running at a flow rate of 40 cfm. A given set of criteria was monitored by the microcomputer to stop sampling during raining and calm period (<0.5 ms{sup -1}), and to start the pump when more than 60% of the wind direction data are within the designated sector. Two size fractions of the particulates were collected (coarse, 3.0-10 um, and fine, M 3.0 um) daily with a net sampling time of 16-24 hours. Elemental analysis was performed on the particulates sampled for their total and soluble contents using FTIR for the PAHs, Capillary Electrophoresis and DC Arc Plasma Emission Spectroscopy for soluble and total anion and cation analysis.

  12. Directed self-assembly of diblock copolymers in cylindrical confinement: effect of underfilling and air-polymer interactions on configurations

    NASA Astrophysics Data System (ADS)

    Carpenter, Corinne L.; Delaney, Kris T.; Laachi, Nabil; Fredrickson, Glenn H.

    2015-03-01

    Directed self-assembly (DSA) of block copolymers has attracted attention for its use as a simple, cost- effective patterning tool for creating vertical interconnect access (VIA) channels in nanoelectronic devices.1, 2 This technique supplements existing lithographic technologies to allow for the creation of high-resolution cylindrical holes whose diameter and placement can be precisely controlled. In this study, we use self-consistent field theory (SCFT) simulations to investigate the equilibrium configurations of under-filled DSA systems with air-polymer interactions. We report on a series of SCFT simulations of our three species (PMMA-b-PS diblock and air) model in cylindrical confinement to explore the role of template diameter, under-fill fraction (i.e. volume fraction of air), air-polymer surface interaction and polymer-side wall/substrate interactions on equilibrium morphologies in an under-filled template with a free top surface. We identify parameters and system configurations where a meniscus appears and explore cases with PMMA-attractive, PS-attractive, and all-neutral walls to understand the effects of wall properties on meniscus geometry and DSA morphology. An important outcome is an understanding of the parameters that control the contact angle of the meniscus with the wall, as it is one of the simplest quantitative measures of the meniscus shape. Ultimately, we seek to identify DSA formulations, templates, and surface treatments with predictable central cylinder diameter and a shallow contact angle, as these factors would facilitate broad process windows and ease of manufacturing.

  13. Direct measurement of methyl radicals in a methane/air flame at atmospheric pressure by radar REMPI.

    PubMed

    Wu, Yue; Bottom, Andrew; Zhang, Zhili; Ombrello, Timothy M; Katta, Viswanath R

    2011-11-21

    We report the direct measurements of methyl radicals (CH(3)) in methane/air flames at atmospheric pressure by using coherent microwave Rayleigh scattering (Radar) from Resonance Enhanced Multi-Photon Ionization (REMPI), also known as the Radar REMPI technique. A tunable dye laser was used to selectively induce the (2 + 1) REMPI ionization of methyl radicals (CH(3), 3p(2)A(2)('')0(0)(0) band) in a near adiabatic and premixed laminar methane/air flame, generated by a Hencken burner. In situ measurements of the REMPI electrons were made by non-intrusively using a microwave homodyne transceiver detection system. The REMPI spectrum of the CH(3) radical was obtained and a spatial distribution of the radicals limited by focused laser beam geometry, approximately 20 µm normal to the flame front and 2.4 mm parallel to the flame, was determined. The measured CH(3) was in good agreement with numerical simulations performed using the detailed kinetic mechanism of GRI-3.0. To the authors' knowledge, these experiments represent the first directly-measured spatially-resolved CH(3) in a flame at atmospheric pressure. PMID:22109424

  14. Control of IP3-mediated Ca2+ puffs in Xenopus laevis oocytes by the Ca2+-binding protein parvalbumin

    PubMed Central

    John, Linu M; Mosquera-Caro, Monica; Camacho, Patricia; Lechleiter, James D

    2001-01-01

    Elementary events of Ca2+ release (Ca2+ puffs) can be elicited from discrete clusters of inositol 1,4,5 trisphosphate receptors (IP3Rs) at low concentrations of IP3. Ca2+ puffs have rarely been observed unless elicited by either hormone treatment or introduction of IP3 into the cell. However, cells appear to have sufficient concentrations of IP3 (0.1-3.0 μM) to induce Ca2+ release under resting conditions. Here, we investigated Ca2+ puff activity in non-stimulated Xenopus oocytes using confocal microscopy. The fluorescent Ca2+ dye indicators Calcium Green 1 and Oregon Green 488 BAPTA-2 were injected into oocytes to monitor basal Ca2+ activity. In this preparation, injection or overexpression of parvalbumin, an EF-hand Ca2+-binding protein (CaBP), induced Ca2+ puffs in resting Xenopus oocytes. This activity was inhibited by heparin, an IP3R channel blocker, and by mutation of the Ca2+-binding sites in parvalbumin. Ca2+ puff activity was also evoked by injection of low concentrations of the Ca2+ chelator EGTA, but not by calbindin D28k, another member of the EF-hand CaBP superfamily. BAPTA and the Ca2+ indicator dye Oregon Green 488 BAPTA-1 evoked Ca2+ puff activity, while the dextran conjugate of Oregon Green 488 BAPTA-1 did not. These data indicate that a Ca2+ buffer must be mobile in order to increase Ca2+ puff activity. Together, the data indicate that some IP3Rs spontaneously release Ca2+ under resting concentrations of IP3. These elementary Ca2+ events appear to be below the level of detection of current imaging techniques. We suggest that parvalbumin evokes Ca2+ puffs by coordinating the activity of elementary IP3R channel openings. We conclude that Ca2+ release can be evoked not only by hormone-induced increases in IP3, but also by expression of mobile cytosolic CaBPs under resting concentrations of IP3. PMID:11507154

  15. New Directions: GEIA’s 2020 Vision for Better Air Emissions Information

    SciTech Connect

    Frost, G. J.; Middleton, Paulette; Tarrason, Leonor; Granier, Claire; Guenther, Alex B.; Cardenas, B.; Denier van der Gon, Hugo; Janssens-Maenhout, Greet; Kaiser, Johannes W.; Keating, Terry; Klimont, Z.; Lamarque, Jean-Francois; Liousse, Catherine; Nickovic, S.; Ohara, Toshimasa; Schultz, Martin; Skiba, Ute; Wang, Y.

    2013-12-01

    We are witnessing a crucial change in how we quantify and understand emissions of greenhouse gases and air pollutants, with an increasing demand for science-based transparent emissions information produced by robust community efforts. Today’s scientific capabilities, with near-real-time in-situ and remote sensing observations combined with forward and inverse models and a better understanding of the controlling processes, are contributing to this transformation and providing new approaches to derive, verify, and forecast emissions (Tong et al., 2011; Frost et al., 2012) and to quantify their impacts on the environment (e.g., Bond et al., 2013). At the same time, the needs for emissions information and the demands for their accuracy and consistency have grown. Changing economies, demographics, agricultural practices, and energy sources, along with mandates to evaluate emissions mitigation efforts, demonstrate compliance with legislation, and verify treaties, are leading to new challenges in emissions understanding. To quote NOAA Senior Technical Scientist David Fahey, "We are in the Century of Accountability. Emissions information is critical not only for environmental science and decision-making, but also as an instrument of foreign policy and international diplomacy." Emissions quantification represents a key step in explaining observed variability and trends in atmospheric composition and in attributing these observed changes to their causes. Accurate emissions data are necessary to identify feasible controls that reduce adverse impacts associated with air quality and climate and to track the success of implemented policies. To progress further, the international community must improve the understanding of drivers and contributing factors to emissions, and it must strengthen connections among and within different scientific disciplines that characterize our environment and entities that protect the environment and influence further emissions. The Global

  16. The study of droplet-laden turbulent air-flow over waved water surface by direct numerical simulation

    NASA Astrophysics Data System (ADS)

    Druzhinin, Oleg A.; Troitskaya, Yuliya I.; Zilitinkevich, Sergej S.

    2016-04-01

    The detailed knowledge of the interaction of wind with surface water waves is necessary for correct parameterization of turbulent exchange at the air-sea interface in prognostic models. At sufficiently strong winds, sea-spray-generated droplets interfere with the wind-waves interaction. The results of field experiments and laboratory measurements (Andreas et al., JGR 2010) show that mass fraction of air-borne spume water droplets increases with the wind speed and their impact on the carrier air-flow may become significant. Phenomenological models of droplet-laden marine atmospheric boundary layer (Kudryavtsev & Makin, Bound.-Layer Met. 2011) predict that droplets significantly increase the wind velocity and suppress the turbulent air stress. The results of direct numerical simulation (DNS) of a turbulent particle-laden Couette flow over a flat surface show that inertial particles may significantly reduce the carrier flow vertical momentum flux (Richter & Sullivan, GRL 2013). The results also show that in the range of droplet sizes typically found near the air-sea interface, particle inertial effects are significant and dominate any particle-induced stratification effects. However, so far there has been no attempt to perform DNS of a droplet-laden air-flow over waved water surface. In this report, we present results of DNS of droplet-laden, turbulent Couette air-flow over waved water surface. The carrier, turbulent Couette-flow configuration in DNS is similar to that used in previous numerical studies (Sullivan et al., JFM 2000, Shen et al., JFM 2010, Druzhinin et al., JGR 2012). Discrete droplets are considered as non-deformable solid spheres and tracked in a Lagrangian framework, and their impact on the carrier flow is modeled with the use of a point-force approximation. The droplets parameters in DNS are matched to the typical known spume-droplets parameters in laboratory and field experiments. The DNS results show that both gravitational settling of droplets and

  17. Direct AFM force measurements between air bubbles in aqueous monodisperse sodium poly(styrene sulfonate) solutions.

    PubMed

    Browne, Christine; Tabor, Rico F; Grieser, Franz; Dagastine, Raymond R

    2015-08-01

    Structural forces play an important role in the rheology, processing and stability of colloidal systems and complex fluids, with polyelectrolytes representing a key class of structuring colloids. Here, we explore the interactions between soft colloids, in the form of air bubbles, in solutions of monodisperse sodium poly(styrene sulfonate) as a model polyelectrolyte. It is found that by self-consistently modelling the force oscillations due to structuring of the polymer chains along with deformation of the bubbles, it is possible to precisely predict the interaction potential between approaching bubbles. In line with polyelectrolyte scaling theory, two distinct regimes of behaviour are seen, corresponding to dilute and semi-dilute polymer solutions. It is also seen that by blending monodisperse systems to give a bidisperse sample, the interaction forces between soft colloids can be controlled with a high degree of precision. At increasing bubble collision velocity, it is revealed that hydrodynamic flow overwhelms oscillatory structural interactions, showing the important disparity between equilibrium behaviour and dynamic interactions. PMID:25881266

  18. The direct and inverse problems of an air-saturated porous cylinder submitted to acoustic radiation

    NASA Astrophysics Data System (ADS)

    Ogam, Erick; Depollier, Claude; Fellah, Z. E. A.

    2010-09-01

    Gas-saturated porous skeleton materials such as geomaterials, polymeric and metallic foams, or biomaterials are fundamental in a diverse range of applications, from structural materials to energy technologies. Most polymeric foams are used for noise control applications and knowledge of the manner in which the energy of sound waves is dissipated with respect to the intrinsic acoustic properties is important for the design of sound packages. Foams are often employed in the audible, low frequency range where modeling and measurement techniques for the recovery of physical parameters responsible for energy loss are still few. Accurate acoustic methods of characterization of porous media are based on the measurement of the transmitted and/or reflected acoustic waves by platelike specimens at ultrasonic frequencies. In this study we develop an acoustic method for the recovery of the material parameters of a rigid-frame, air-saturated polymeric foam cylinder. A dispersion relation for sound wave propagation in the porous medium is derived from the propagation equations and a model solution is sought based on plane-wave decomposition using orthogonal cylindrical functions. The explicit analytical solution equation of the scattered field shows that it is also dependent on the intrinsic acoustic parameters of the porous cylinder, namely, porosity, tortuosity, and flow resistivity (permeability). The inverse problem of the recovery of the flow resistivity and porosity is solved by seeking the minima of the objective functions consisting of the sum of squared residuals of the differences between the experimental and theoretical scattered field data.

  19. PlanetVac: Sample Return with a Puff of Gas

    NASA Astrophysics Data System (ADS)

    Zacny, K.; Mueller, R.; Betts, B. H.

    2014-12-01

    PlanetVac is a regolith sample acquisition mission concept that uses compressed gas to blow material from the surface up a pneumatic tube and directly into a sample return container. The PlanetVac sampling device is built into the lander legs to eliminate cost and complexity associated with robotic arms and scoops. The pneumatic system can effectively capture fine and coarse regolith, including small pebbles. It is well suited for landed missions to Mars, asteroids, or the Moon. Because of the low pressures on all those bodies, the technique is extremely efficient. If losses are kept to minimum, 1 gram of compressed gas could efficiently lift 6000 grams of soil. To demonstrate this approach, the PlanetVac lander with four legs and two sampling tubes has been designed, integrated, and tested. Vacuum chamber testing was performed using two well-known planetary regolith simulants: Mars Mojave Simulant (MMS) and lunar regolith simulant JSC-1A. One of the two sampling systems was connected to a mockup of an earth return rocket while the second sampling system was connected to a lander deck mounted instrument (clear box for easy viewing). The tests included a drop from a height of approximately 50 cm onto the bed of regolith, deployment of sampling tubes into the regolith, pneumatic acquisition of sample into an instrument (sample container) and the rocket, and the launch of the rocket. The demonstration has been successful and can be viewed here: https://www.youtube.com/watch?v=DjJXvtQk6no. In most of the tests, 20 grams or more of sample was delivered to the 'instrument' and approximately 5 grams of regolith was delivered into a sampling chamber within the rocket. The gas lifting efficiency was calculated to be approximately 1000:1; that is 1 gram of gas lofted 1000 grams of regolith. Efficiencies in lower gravity environments are expected to be much higher. This successful, simple and lightweight sample capture demonstration paves the way to using such sampling system

  20. Analytical estimation of neutron yield in a micro gas-puff X pinch

    SciTech Connect

    Derzon, M. S.; Galambos, P. C.; Hagen, E. C.

    2012-12-01

    In this paper, we present the basic concepts for developing a micro x pinch as a small-scale neutron source. For compact sources, these concepts offer repetitive function at higher yields and pulsing rates than competing methods. The uniqueness of these concepts arises from the use of microelectronic technology to reduce the size of the target plasma and to efficiently heat the target gas. The use of repetitive microelectromechanical systems (MEMs) gas puff technology, as compared to cryogenic wires or solid targets (for the beam-target alternatives), has the potential to be robust and have a long lifetime because the plasma is not created from solid surfaces. The modeling suggests that a 50 J at the wall plug pulse could provide >10{sup 5} tritium (DT) neutrons and 10{sup 3} deuterium (DD) neutrons at temperatures of a few keV. At 1 kHz, this would be >10{sup 8} and 10{sup 6} neutrons per second, DT and DD, respectively, with a 250 {mu}m anode-cathode gap. DT gas puff devices may provide >10{sup 12} neutrons/s operating at 1 kHz and requiring 100 kW. The MEMs approach offers potentially high pulse rates and yields.

  1. K-shell Radiation Source of a Low Z Puff on a High Z Jet

    NASA Astrophysics Data System (ADS)

    Giuliani, J. L.; Dasgupta, A.; Velikovich, A. L.; Commisso, R. J.; Tangri, V.; Harvey-Thompson, A. J.; Ampleford, D. J.; Jennings, C. A.

    2015-11-01

    We examine a Z-pinch gas puff load wherein the JxB coupled energy from the generator is coupled to the ion thermal and kinetic energy of an outer, imploding low Z pusher. The central jet is the target K-shell emitter of larger Z. At assembly on axis, the kinetic energy of the pusher is dissipated, and during the strong compression, the excess ion thermal energy of the pusher is transferred to the electrons of the jet producing excitation and radiation from the high Z target. An analysis of the dynamics is first presented through a 0-D snowplow model to show that with a centrally peaked initial density profile the kinetic energy of implosion can be half of the total JxB energy. Next we present 2-D Mach2-TCRE simulations for the ZR generator of a Ne puff onto a central Kr jet. The capability of this load design for producing K-shell emission from Kr will be examined. Work supported by the DOE/NNSA. SNL is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's NNSA under contract DE-AC04-94AL85000.

  2. An ambusher's arsenal: chemical crypsis in the puff adder (Bitis arietans).

    PubMed

    Miller, Ashadee Kay; Maritz, Bryan; McKay, Shannon; Glaudas, Xavier; Alexander, Graham J

    2015-12-22

    Ambush foragers use a hunting strategy that places them at risk of predation by both visual and olfaction-oriented predators. Resulting selective pressures have driven the evolution of impressive visual crypsis in many ambushing species, and may have led to the development of chemical crypsis. However, unlike for visual crypsis, few studies have attempted to demonstrate chemical crypsis. Field observations of puff adders (Bitis arietans) going undetected by several scent-orientated predator and prey species led us to investigate chemical crypsis in this ambushing species. We trained dogs (Canis familiaris) and meerkats (Suricata suricatta) to test whether a canid and a herpestid predator could detect B. arietans using olfaction. We also tested for chemical crypsis in five species of active foraging snakes, predicted to be easily detectable. Dogs and meerkats unambiguously indicated active foraging species, but failed to correctly indicate puff adder, confirming that B. arietans employs chemical crypsis. This is the first demonstration of chemical crypsis anti-predatory behaviour, though the phenomenon may be widespread among ambushers, especially those that experience high mortality rates owing to predation. Our study provides additional evidence for the existence of an ongoing chemically mediated arms race between predator and prey species. PMID:26674950

  3. Can one puff really make an adolescent addicted to nicotine? A critical review of the literature

    PubMed Central

    2010-01-01

    Rationale In the past decade, there have been various attempts to understand the initiation and progression of tobacco smoking among adolescents. One line of research on these issues has made strong claims regarding the speed in which adolescents can become physically and mentally addicted to smoking. According to these claims, and in contrast to other models of smoking progression, adolescents can lose autonomy over their smoking behavior after having smoked one puff in their lifetime and never having smoked again, and can become mentally and physically "hooked on nicotine" even if they have never smoked a puff. Objectives To critically examine the conceptual and empirical basis for the claims made by the "hooked on nicotine" thesis. Method We reviewed the major studies on which the claims of the "hooked on nicotine" research program are based. Results The studies we reviewed contained substantive conceptual and methodological flaws. These include an untenable and idiosyncratic definition of addiction, use of single items or of very lenient criteria for diagnosing nicotine dependence, reliance on responders' causal attributions in determining physical and mental addiction to nicotine and biased coding and interpretation of the data. Discussion The conceptual and methodological problems detailed in this review invalidate many of the claims made by the "hooked on nicotine" research program and undermine its contribution to the understanding of the nature and development of tobacco smoking in adolescents. PMID:21067587

  4. Applicability of solvent based Huff-and-Puff Method to enhance heavy oil recovery

    NASA Astrophysics Data System (ADS)

    Qazvini Firouz, Alireza

    Over and above solvent based processes, specifically, the cyclic solvent injection well known as "Huff-and-Puff', has demonstrated a significant potential to enhance heavy oil recovery. Solvent and CO2 Huff-and-Puff are analogies to cyclic steam stimulation; however, in this method, steam is replaced with CO2, hydrocarbon solvent or mixture of the two. This study attempts to validate the feasibility of the Solvent Based Huff-and-Puff Method with respect to enhancing heavy oil recovery and to investigate the effect of fluid, operation, and reservoir parameters on its' performance. Thus, both experimental and reservoir simulation approaches were applied and, the impact of the aforementioned parameters on the performance of the process was investigated. All experiments were conducted in a Berea core with the dimensions of 30.48 cm by 5.07 cm. The core has a permeability of 1800 md and a porosity of 24% which was mounted in a high pressure, stainless steel core holder. Before conducting each Huff-and-Puff Test, the core was saturated with an oil sample representative of Saskatchewan heavy oil reservoirs and exhibited a viscosity of 952 mPa.s, at a temperature of 28°C. Prior to the tests, a complete phase behavior (PVT) analysis of the oil sample and solvents mixture was conducted using CMG- WinProp(TM) software. Over 12 sets of Huff-and-Puff Experiments, utilizing the pure solvent of carbon dioxide, methane, and mixtures of CO2 and propane, were performed at different operating pressures. A soaking time period of 24 hrs and a cut-off pressure of 276 kPa were considered for all cycles. In addition, all Huff-and-Puff Cycles were continued for each operating pressure until production dropped below one percent of the original oil in place. The production trend and recovery factor for each experiment were determined. The final oil recoveries, at the highest operating pressure of 7239 kPa for pure CO2 and, at 6895 kPa for pure methane, were 71 and 50 % OOIP, respectively

  5. High-Z Pusher Experiments on the Cobra Triple Nozzle Gas-Puff Z-Pinch

    NASA Astrophysics Data System (ADS)

    de Grouchy, Philip; Qi, Niansheng; Kusse, Bruce; Seyler, Charles; Atoyan, Levon; Byvank, Tom; Cahill, Adam; Greenly, John; Hoyt, Cad; Pikuz, Sergei; Shelkovenko, Tania; Hammer, David

    2014-10-01

    For inertial confinement fusion application and as efficient hard x-ray sources, the imploding sheath of a gas-puff z-pinch or thin liner must be accelerated to the highest possible velocity before hydrodynamic instabilities significantly disrupt the implosion symmetry. Much recent work has focused on increasing implosion stability using radially structured mass-density profiles produced by multi-nozzle gas-puff valves. The introduction of a high-Z element such as xenon into the outer gas shells in such experiments can modify radiation output during the implosion phase as well as at stagnation. In these experiments xenon is introduced into the triple-nozzle gas valve fielded on the (1 MA, 200 ns) COBRA z-pinch machine at Cornell University. The xenon is introduced only in the outer shell, only in the inner shell or in both, to investigate the radiative effects on implosion hydrodynamics and x-ray yield. Results are compared to those obtained during pure argon implosions with the same mass-density profile. Sheath thicknesses and stability are recorded using laser interferometry (532 nm) and multi-frame imaging systems. The distribution of flow velocities and of high-Z material across the pinch is investigated using a (5 GW, 527 nm) Thomson scattering probe. Work supported by DOE Grant No. DE-NA0001836.

  6. Argon gas-puff radius optimiaztion for Saturn operating in the long-pulse mode.

    SciTech Connect

    Apruzese, John P.; Jackson, S. L.; Commisso, Robert J.; Weber, Bruce V.; Mosher, Daniel A.

    2010-06-01

    Argon gas puff experiments using the long pulse mode of Saturn (230-ns rise time) have promise to increase the coupled energy and simplify operations because the voltage is reduced in vacuum and the forward-going energy is higher for the same Marx charge. The issue addressed in this work is to determine if the 12-cm-diameter triple nozzle used in Saturn long-pulse-mode experiments to date provides maximum K-shell yield, or if a different-radius nozzle provides additional radiation. Long-pulse implosions are modeled by starting with measured density distributions from the existing 12-cm-diameter nozzle, and then varying the outer radius in an implosion-energy-conserving self-similar manner to predict the gas-puff diameter that results in the maximum K-shell yield. The snowplow-implosions and multi-zone radiation transport models used in the analysis are benchmarked against detailed measurements from the 12-cm-diameter experiments. These calculations indicate that the maximum K-shell emission is produced with very nearly the existing nozzle radius.

  7. A Novel Method making direct use of AIRS and IASI Calibrated Radiances for Measuring Trends in Surface Temperatures

    NASA Astrophysics Data System (ADS)

    Aumann, H. H.; Ruzmaikin, A.

    2014-12-01

    Making unbiased measurements of trends in the surface temperatures, particularly on a gobal scale, is challenging: While the non-frozen oceans temperature measurements are plentiful and accurate, land and polar areas are much less accurately or fairly sampled. Surface temperature deduced from infrared radiometers on polar orbiting satellites (e.g. the Atmospheric Infrared Sounder (AIRS) at 1:30PM, the Interferometer Atmosphere Sounding Interferometer (IASI) at 9:30 AM and the MODerate resolution Imaging Spectro-radiometer (MODIS) at 1:30PM), can produce what appear to be well sampled data, but dealing with clouds either by cloud filtering (MODIS, IASI) or cloud-clearing (AIRS) can create sampling bias. We use a novel method: Random Nadir Sampling (RNS) combined with Probability Density Function (PDF) analysis. We analyze the trend in the PDF of st1231, the water vapor absorption corrected brightness temperatures measured in the 1231 cm-1 atmospheric window channel. The advantage of this method is that trends can be directly traced to the known, less than 3 mK/yr trend for AIRS, in st1231. For this study we created PDFs from 22,000 daily RNS from the AIRS and IASI data. We characterized the PDFs by its daily 90%tile value, st1231p90, and analysed the statistical properties of the this time series between 2002 and 2014. The method was validated using the daily NOAA SST (RTGSST) from the non-frozen oceans: The mean, seasonal variability and anomaly trend of st1231p90 agree with the corrsponding values from the RTGSST and the anomaly correlation is larger than 0.9. Preliminary results (August 2014) confirm the global hiatus in the increase of the globally averaged surface temperatures between 2002 and 2014, with a change of less than 10 mK/yr. This uncertainty is dominated by the large interannual variability related to El Niño events. Further insite is gained by analyzing land/ocean, day/night, artic and antarctic trends. We observe a massive warming trend in the

  8. Numerical study of turbulence-influence mechanism on arc characteristics in an air direct current circuit breaker

    NASA Astrophysics Data System (ADS)

    Wu, Mingliang; Yang, Fei; Rong, Mingzhe; Wu, Yi; Qi, Yang; Cui, Yufei; Liu, Zirui; Guo, Anxiang

    2016-04-01

    This paper focuses on the numerical investigation of arc characteristics in an air direct current circuit breaker (air DCCB). Using magneto-hydrodynamics (MHD) theory, 3D laminar model and turbulence model are constructed and calculated. The standard k-epsilon model is utilized to consider the turbulence effect in the arc chamber of the DCCB. Several important phenomena are found: the arc column in the turbulence-model case is more extensive, moves much more slowly than the counterpart in the laminar-model case, and shows stagnation at the entrance of the chamber, unlike in the laminar-model case. Moreover, the arc voltage in the turbulence-model case is much lower than in the laminar-model case. However, the results in the turbulence-model case show a much better agreement with the results of the breaking experiments under DC condition than in the laminar-model case, which is contradictory to the previous conclusions from the arc researches of both the low-voltage circuit breaker and the sulfur hexafluoride (SF6) nozzle. First, in the previous air-arc research of the low-voltage circuit breaker, it is assumed that the air plasma inside the chamber is in the state of laminar, and the laminar-model application gives quite satisfactory results compared with the experiments, while in this paper, the laminar-model application works badly. Second, the turbulence-model application in the arc research of the SF6-nozzle performs much better and gives higher arc voltage than the laminar-model application does, whereas in this paper, the turbulence-model application predicts lower arc voltage than the laminar-model application does. Based on the analysis of simulation results in detail, the mechanism of the above phenomena is revealed. The transport coefficients are strongly changed by turbulence, which will enhance the arc diffusion and make the arc volume much larger. Consequently, the arc appearance and the distribution of Lorentz force in the turbulence-model case

  9. Consistent treatment of transport properties for five-species air direct simulation Monte Carlo/Navier-Stokes applications

    NASA Astrophysics Data System (ADS)

    Stephani, K. A.; Goldstein, D. B.; Varghese, P. L.

    2012-07-01

    A general approach for achieving consistency in the transport properties between direct simulation Monte Carlo (DSMC) and Navier-Stokes (CFD) solvers is presented for five-species air. Coefficients of species diffusion, viscosity, and thermal conductivities are considered. The transport coefficients that are modeled in CFD solvers are often obtained by expressions involving sets of collision integrals, which are obtained from more realistic intermolecular potentials (i.e., ab initio calculations). In this work, the self-consistent effective binary diffusion and Gupta et al.-Yos tranport models are considered. The DSMC transport coefficients are approximated from Chapman-Enskog theory in which the collision integrals are computed using either the variable hard sphere (VHS) and variable soft sphere (VSS) (phenomenological) collision cross section models. The VHS and VSS parameters are then used to adjust the DSMC transport coefficients in order to achieve a best-fit to the coefficients computed from more realistic intermolecular potentials over a range of temperatures. The best-fit collision model parameters are determined for both collision-averaged and collision-specific pairing approaches using the Nelder-Mead simplex algorithm. A consistent treatment of the diffusion, viscosity, and thermal conductivities is presented, and recommended sets of best-fit VHS and VSS collision model parameters are provided for a five-species air mixture.

  10. Similarity laws for cathode-directed streamers in gaps with an inhomogeneous field at elevated air pressures

    SciTech Connect

    Bolotov, O. V.; Golota, V. I.; Kadolin, B. B.; Karas', V. I.; Ostroushko, V. N.; Zavada, L. M.; Shulika, A. Yu.

    2010-11-15

    Results are presented from experimental studies of cathode-directed streamers in the gap closure regime without a transition into spark breakdown. Spatiotemporal, electrodynamic, and spectroscopic characteristics of streamer discharges in air at different pressures were studied. Similarity laws for streamer discharges were formulated. These laws allow one to compare the discharge current characteristics and streamer propagation dynamics at different pressures. Substantial influence of gas photoionization on the deviations from the similarity laws was revealed. The existence of a pressure range in which the discharges develop in a similar way was demonstrated experimentally. In particular, for fixed values of the product pd and discharge voltage U, the average streamer velocity is also fixed. It is found that, although the similarity laws are violated in the interstreamer pause of the discharge, the average discharge current and the product of the pressure and the streamer repetition period remain the same at different pressures. The radiation spectra of the second positive system of nitrogen (the C{sup 3{Pi}}{sub u}-B{sup 3{Pi}}{sub g} transitions) in a wavelength range of 300-400 nm at air pressures of 1-3 atm were recorded. It is shown that, in the entire pressure range under study, the profiles of the observed radiation bands practically remain unchanged and the relative intensities of the spectral lines corresponding to the {sup 3{Pi}}{sub u}-B{sup 3{Pi}}{sub g} transitions are preserved.

  11. The electrolyte challenge for a direct methanol-air polymer electrolyte fuel cell operating at temperatures up to 200 C

    NASA Technical Reports Server (NTRS)

    Savinell, Robert; Yeager, Ernest; Tryk, Donald; Landau, Uziel; Wainright, Jesse; Gervasio, Dominic; Cahan, Boris; Litt, Morton; Rogers, Charles; Scherson, Daniel

    1993-01-01

    Novel polymer electrolytes are being evaluated for use in a direct methanol-air fuel cell operating at temperatures in excess of 100 C. The evaluation includes tests of thermal stability, ionic conductivity, and vapor transport characteristics. The preliminary results obtained to date indicate that a high temperature polymer electrolyte fuel cell is feasible. For example, Nafion 117 when equilibrated with phosphoric acid has a conductivity of at least 0.4 Omega(exp -1)cm(exp -1) at temperatures up to 200 C in the presence of 400 torr of water vapor and methanol vapor cross over equivalent to 1 mA/cm(exp 2) under a one atmosphere methanol pressure differential at 135 C. Novel polymers are also showing similar encouraging results. The flexibility to modify and optimize the properties by custom synthesis of these novel polymers presents an exciting opportunity to develop an efficient and compact methanol fuel cell.

  12. Direct observation of a resolvable spin separation in the spin Hall effect of light at an air-glass interface

    SciTech Connect

    Ren, Jin-Li; Wang, Bo; Xiao, Yun-Feng; Gong, Qihuang; Li, Yan

    2015-09-14

    We theoretically and experimentally demonstrate that it is possible to directly observe the resolvable spin separation in the spin Hall effect of light at an air-glass interface by choosing optimal parameters. When a P-polarized light with a beam waist of 10 μm is incident around Brewster's angle, the two spin components of the reflected beam can be completely separated by eliminating the influence of the in-plane wavevector spread. This not only obviously reveals the strong impacts of the polarization state, the incident angle, the beam waist, and the in-plane wavevector spread, but also intuitively visualizes the observation of the spin Hall effect of light.

  13. Frequency and Relative Prevalence of Calcium Blips and Puffs in a Model of Small IP3R Clusters

    PubMed Central

    Qi, Hong; Huang, Yandong; Rüdiger, Sten; Shuai, Jianwei

    2014-01-01

    In this work, we model the local calcium release from clusters with a few inositol 1,4,5-trisphosphate receptor (IP3R) channels, focusing on the stochastic process in which an open channel either triggers other channels to open (as a puff) or fails to cause any channel to open (as a blip). We show that there are linear relations for the interevent interval (including blips and puffs) and the first event latency against the inverse cluster size. However, nonlinearity is found for the interpuff interval and the first puff latency against the inverse cluster size. Furthermore, the simulations indicate that the blip fraction among all release events and the blip frequency are increasing with larger basal [Ca2+], with blips in turn giving a growing contribution to basal [Ca2+]. This result suggests that blips are not just lapses to trigger puffs, but they may also possess a biological function to contribute to the initiation of calcium waves by a preceding increase of basal [Ca2+] in cells that have small IP3R clusters. PMID:24896114

  14. Impact of California's Air Pollution Laws on Black Carbon and their Implications for Direct Radiative Forcing

    NASA Astrophysics Data System (ADS)

    Bahadur, R.; Feng, Y.; Russell, L. M.; Ramanathan, V.

    2010-12-01

    We examine the temporal and the spatial trends in the concentrations of black carbon (BC) - recorded by the IMPROVE monitoring network for the past 20 years - in California. Annual average BC concentrations in California have decreased by about 50% from 0.46 μg m-3 in 1989 to 0.24 μgm-3 in 2008 compared to a corresponding reductions in diesel BC emissions (also about 50%) from a peak of 0.013 Tg Yr-1 in 1990 to 0.006 Tg Yr-1 by 2008. We attribute the observed negative trends to the deployment of diesel particulate filters. Our conclusion that the reduction in diesel emissions is the primary cause of the observed BC reduction is also substantiated by a significant decrease in the ratio of BC to non-BC aerosols. The absorption efficiency of aerosols at visible wavelengths - determined from the observed scattering coefficient and the observed BC - also decreased by about 50% leading to a model-inferred negative direct radiative forcing (a cooling effect) of -1.4 Wm-2 (±60%) over California. Figure 1 (a) Annual means of measured Black Carbon (left axis) and BC fossil fuel emissions (right axis) in California from 1985 to 2008. Error bars correspond to standard deviation between measurements at each station. Dashed lines indicate a linear fit. Aerosol measurements from the IMPROVE network, emission inventories from (1) CARB, (2) [Ito and Penner, 2005] (b) Annual means of BC measured in Southern (South of 35 N), Northern (North of 38 N), and Central California (c) Annual means of measured Sulfate, Nitrate, and OC from IMPROVE network.

  15. Intra-puff CO and CO 2 measurements of cigarettes with iron oxide cigarette paper using quantum cascade laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Crawford, Danielle R.; Parrish, Milton E.; Gee, Diane L.; Harward, Charles N.

    2007-05-01

    The objective of this research was to apply Fourier transform infrared spectroscopy (FTIR) and tunable infrared laser differential absorption spectroscopy (TILDAS) for measuring selected gaseous constituents in mainstream (MS) and sidestream (SS) smoke for experimental cigarettes designed to reduce MS CO using iron oxide cigarette papers. These two complimentary analytical techniques are well suited for providing per puff smoke deliveries and intra-puff evolution profiles in cigarette smoke respectively. The quad quantum cascade (QC) laser high resolution infrared spectroscopy system has the necessary temporal and spectral resolution and whole smoke analysis capabilities to provide detailed information for CO and CO 2 as they are being formed in both MS and SS smoke. The QC laser system has an optimal data rate of 20 Hz and a unique puffing system, with a square wave shaped puff, that allows whole smoke to enter an 18 m, 0.3 L multi-pass gas cell in real time (0.1 s cell response time) requiring no syringe or Cambridge filter pad. Another similar multi-pass gas cell with a 36 m pathlength simultaneously monitors the sidestream cigarette smoke. The smoke from experimental cigarettes manufactured with two types of iron oxide papers were compared to the smoke from cigarettes manufactured similarly without iron oxide in the paper using both instrument systems. The delivery per puff determined by the QC laser method agreed with FTIR results. MS CO intra-puff evolution profiles for iron oxide prototype cigarettes demonstrated CO reduction when compared to cigarettes without iron oxide paper. Additionally, both CO and CO 2 intra-puff evolution profiles of the cigarettes with iron oxide paper showed a significant reduction at the initial portion of the 2 s puff not observed in the non-iron oxide prototype cigarettes. This effect also was observed for ammonia and ethylene, suggesting that physical parameters such as paper porosity and burn rate are important. The SS CO and

  16. Meeting 2006, outdoor noise directive (OND) noise levels for a diesel engine driven air compressor: A case study in noise reduction

    NASA Astrophysics Data System (ADS)

    Rowe, David F.

    2005-09-01

    In January 2006, the noise limits for many products in the European Union will drop by 2-3 dBA, as directed by 2000/14/EC ``Noise Emission in the Environment by Equipment Used Outdoors,'' commonly called the ``Outdoor Noise Directive,'' or ``OND.'' Air compressors are among the products addressed by this directive. At Ingersoll-Rand, significant effort has been directed at meeting the challenge of reducing noise on a variety of diesel engine driven air compressor platforms, ranging from 15 to 350 kW diesel engine power ratings. This paper presents a case study of the noise reduction on a 750 cfm (21 m3/min) air compressor operating at 300 psig (21 bar), to meet the 2006 OND noise limit of 100 LwA.

  17. A direct sensitivity approach to predict hourly ozone resulting from compliance with the National Ambient Air Quality Standard.

    PubMed

    Simon, Heather; Baker, Kirk R; Akhtar, Farhan; Napelenok, Sergey L; Possiel, Norm; Wells, Benjamin; Timin, Brian

    2013-03-01

    In setting primary ambient air quality standards, the EPA's responsibility under the law is to establish standards that protect public health. As part of the current review of the ozone National Ambient Air Quality Standard (NAAQS), the US EPA evaluated the health exposure and risks associated with ambient ozone pollution using a statistical approach to adjust recent air quality to simulate just meeting the current standard level, without specifying emission control strategies. One drawback of this purely statistical concentration rollback approach is that it does not take into account spatial and temporal heterogeneity of ozone response to emissions changes. The application of the higher-order decoupled direct method (HDDM) in the community multiscale air quality (CMAQ) model is discussed here to provide an example of a methodology that could incorporate this variability into the risk assessment analyses. Because this approach includes a full representation of the chemical production and physical transport of ozone in the atmosphere, it does not require assumed background concentrations, which have been applied to constrain estimates from past statistical techniques. The CMAQ-HDDM adjustment approach is extended to measured ozone concentrations by determining typical sensitivities at each monitor location and hour of the day based on a linear relationship between first-order sensitivities and hourly ozone values. This approach is demonstrated by modeling ozone responses for monitor locations in Detroit and Charlotte to domain-wide reductions in anthropogenic NOx and VOCs emissions. As seen in previous studies, ozone response calculated using HDDM compared well to brute-force emissions changes up to approximately a 50% reduction in emissions. A new stepwise approach is developed here to apply this method to emissions reductions beyond 50% allowing for the simulation of more stringent reductions in ozone concentrations. Compared to previous rollback methods, this

  18. X-ray results from a modified nozzle and double gas puff z pinch

    SciTech Connect

    Chang, T.; Fisher, A.; Van Drie, A. )

    1991-03-15

    The nozzle and the anode of the UCI (University of California, Irvine) {ital z}-pinch facility were modified to study the influence of the anode-cathode geometrical structure on the stability of the pinch and the x-ray yield of the pinch. The anode was modified from a honey-comb to a hollow cylinder with a 4-cm diameter and a {similar to}3.5-mm wall thickness, placed 2 cm below the cathode. The cavity in the center of the cathode was enlarged from 6-mm diameter to 36 mm. The design of the cathode and the anode showed a marked improvement of the pinch stability over the previous design. Both zirconium and carbon-carbon nozzle were used for the Kr and Ne {ital z} pinches. After a few tens of shots the Zr nozzle was melted at the edge and the pinch degraded, while the carbon-carbon nozzle did not sustain any damage for more than 300 shots. Some shots showed the {ital di}/{ital dt} at the implosion is {similar to}5 times higher than the {ital di}/{ital dt} at the beginning of the discharge, this has never been obtained at UCI before. This ratio of the initial {ital di}/{ital dt} to pinch {ital di}/{ital dt} is a measure of the pinch quality. By serendipity it was found that double gas puff {ital z} pinch increased the hard x-ray ({gt}1 keV) output by about an order of magnitude. The nozzle was then modified to allow double puff operation. A 3.4-mm-diam hole was opened at the center of the nozzle and a plunger was inserted from the top to control the mass of the gas entering the hole. The diagnostics include {ital di}/{ital dt} coil, soft, and hard x-ray diodes. Soft and hard x-ray emission are both enhanced by the double gas puff {ital z} pinch.

  19. Breeding Super-Earths and Birthing Super-puffs in Transitional Disks

    NASA Astrophysics Data System (ADS)

    Lee, Eve J.; Chiang, Eugene

    2016-02-01

    The riddle posed by super-Earths (1-4R⊕, 2-20M⊕) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustly emerge after ˜0.1-1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4-10R⊕, 2-6M⊕). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ˜1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions.

  20. Field-testing a new directional passive air sampler for fugitive dust in a complex industrial source environment.

    PubMed

    Ferranti, E J S; Fryer, M; Sweetman, A J; Garcia, M A Solera; Timmis, R J

    2014-01-01

    Quantifying the sources of fugitive dusts on complex industrial sites is essential for regulation and effective dust management. This study applied two recently-patented Directional Passive Air Samplers (DPAS) to measure the fugitive dust contribution from a Metal Recovery Plant (MRP) located on the periphery of a major steelworks site. The DPAS can collect separate samples for winds from different directions (12 × 30° sectors), and the collected dust may be quantified using several different measurement methods. The DPASs were located up and down-prevailing-wind of the MRP processing area to (i) identify and measure the contribution made by the MRP processing operation; (ii) monitor this contribution during the processing of a particularly dusty material; and (iii) detect any changes to this contribution following new dust-control measures. Sampling took place over a 12-month period and the amount of dust was quantified using photographic, magnetic and mass-loading measurement methods. The DPASs are able to effectively resolve the incoming dust signal from the wider steelworks complex, and also different sources of fugitive dust from the MRP processing area. There was no confirmable increase in the dust contribution from the MRP during the processing of a particularly dusty material, but dust levels significantly reduced following the introduction of new dust-control measures. This research was undertaken in a regulatory context, and the results provide a unique evidence-base for current and future operational or regulatory decisions. PMID:24296778

  1. Deuterium gas-puff Z-pinch implosions on the Z accelerator

    SciTech Connect

    Coverdale, C. A.; Deeney, C.; Ruiz, C. L.; Velikovich, A. L.; Davis, J.; Clark, R. W.; Chong, Y. K.; Apruzese, J. P.; Chittenden, J.; Chantrenne, S.; Franklin, J.; LePell, P. D.; Cooper, G. W.; Nelson, A. J.; Levine, J.; Banister, J.

    2007-05-15

    Experiments on the Z accelerator with deuterium gas-puff implosions have produced up to 3.7x10{sup 13} ({+-}20%) neutrons at 2.34 MeV ({+-}0.10 MeV). Although the mechanism for generating these neutrons was not definitively identified, this neutron output is 100 times more than previously observed from neutron-producing experiments at Z. Dopant gases in the deuterium (argon and chlorine) were used to study implosion characteristics and stagnated plasma conditions through x-ray yield measurements and spectroscopy. Magnetohydrodynamic (MHD) calculations have suggested that the dopants improved the neutron output through better plasma compression, which has been studied in experiments increasing the dopant fraction. Scaling these experiments, and additional MHD calculations, suggest that {approx}5x10{sup 14} deuterium-deuterium (DD) neutrons could be generated at the 26-MA refurbished Z facility.

  2. Neutron production and implosion characteristics of a deuterium gas-puff Z pinch

    SciTech Connect

    Coverdale, C. A.; Deeney, C.; Velikovich, A. L.; Clark, R. W.; Chong, Y. K.; Davis, J.; Chittenden, J.; Ruiz, C. L.; Cooper, G. W.; Nelson, A. J.; Franklin, J.; LePell, P. D.; Apruzese, J. P.; Levine, J.; Banister, J.; Qi, N.

    2007-02-15

    Experiments on the Z accelerator with deuterium gas puff implosions have produced up to 3.9x10{sup 13} ({+-}20%) neutrons at 2.34 MeV ({+-}0.10 MeV). Experimentally, the mechanism for generating these neutrons has not been definitively identified through isotropy measurements, but activation diagnostics suggest multiple mechanisms may be responsible. One-, two-, and three-dimensional magnetohydrodynamic (MHD) calculations have indicated that thermonuclear outputs from Z could be expected to be in the (0.3-1.0)x10{sup 14} range. X-ray diagnostics of plasma conditions, fielded to look at dopant materials in the deuterium, have shown that the stagnated deuterium plasma achieved electron temperatures of 2.2 keV and ion densities of 2x10{sup 20} cm{sup -3}, in agreement with the MHD calculations.

  3. Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode.

    PubMed

    Poehlmann, Flavio R; Cappelli, Mark A; Rieker, Gregory B

    2010-12-01

    Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma deflagration. The effects of varying the bank capacitance, transmission line inductance, and applied electrode voltage were studied over the range from 14 to 112 μF, 50 to 200 nH, and 1 to 3 kV, respectively. PMID:21267082

  4. Computational modeling of Krypton gas puffs with tailored mass density profiles on Z

    SciTech Connect

    Jennings, C. A.; Ampleford, D. J.; Lamppa, D. C.; Hansen, S. B.; Jones, B.; Harvey-Thompson, A. J.; Jobe, M.; Strizic, T.; Reneker, J.; Rochau, G. A.; Cuneo, M. E.

    2015-05-15

    Large diameter multi-shell gas puffs rapidly imploded by high current (∼20 MA, ∼100 ns) on the Z generator of Sandia National Laboratories are able to produce high-intensity Krypton K-shell emission at ∼13 keV. Efficiently radiating at these high photon energies is a significant challenge which requires the careful design and optimization of the gas distribution. To facilitate this, we hydrodynamically model the gas flow out of the nozzle and then model its implosion using a 3-dimensional resistive, radiative MHD code (GORGON). This approach enables us to iterate between modeling the implosion and gas flow from the nozzle to optimize radiative output from this combined system. Guided by our implosion calculations, we have designed gas profiles that help mitigate disruption from Magneto-Rayleigh–Taylor implosion instabilities, while preserving sufficient kinetic energy to thermalize to the high temperatures required for K-shell emission.

  5. Application of bio-huff-`n`-puff technology at Jilin oil field

    SciTech Connect

    Xiu-Yuan Wang; Yan-Fed Xue; Gang Dai; Ling Zhao

    1995-12-31

    An enriched culture 48, capable of adapting to the reservoir conditions and fermenting molasses to produce gas and acid, was used as an inoculum for bio- huff-`n`-puff tests at Fuyu oil area of Jilin oil field. The production well was injected with water containing 4-6% (v/v) molasses and inoculum, and then shut in. After 15-21 days, the well was placed back in operation. A total of 44 wells were treated, of which only two wells showed no effects. The daily oil production of treated wells increased by 33.3-733.3%. Up to the end of 1994, the oil production was increased by 204 tons per well on average. Results obtained from various types of production wells were discussed.

  6. Computational modeling of Krypton gas puffs with tailored mass density profiles on Z

    SciTech Connect

    Jennings, Christopher A.; Ampleford, David J.; Lamppa, Derek C.; Hansen, Stephanie B.; Jones, Brent Manley; Harvey-Thompson, Adam James; Jobe, Marc Ronald Lee; Reneker, Joseph; Rochau, Gregory A.; Cuneo, Michael Edward; Strizic, T.

    2015-05-18

    Large diameter multi-shell gas puffs rapidly imploded by high current (~20 MA, ~100 ns) on the Z generator of Sandia National Laboratories are able to produce high-intensity Krypton K-shell emission at ~13 keV. Efficiently radiating at these high photon energies is a significant challenge which requires the careful design and optimization of the gas distribution. To facilitate this, we hydrodynamically model the gas flow out of the nozzle and then model its implosion using a 3-dimensional resistive, radiative MHD code (GORGON). This approach enables us to iterate between modeling the implosion and gas flow from the nozzle to optimize radiative output from this combined system. Furthermore, guided by our implosion calculations, we have designed gas profiles that help mitigate disruption from Magneto-Rayleigh–Taylor implosion instabilities, while preserving sufficient kinetic energy to thermalize to the high temperatures required for K-shell emission.

  7. Use of vacuum arc plasma guns for a metal puff Z-pinch system

    SciTech Connect

    Rousskikh, A. G.; Zhigalin, A. S.; Oreshkin, V. I.; Chaikovsky, S. A.; Labetskaya, N. A.; Baksht, R. B.

    2011-09-15

    The performance of a metal puff Z-pinch system has been studied experimentally. In this type of system, the initial cylindrical shell 4 cm in diameter was produced by ten plasma guns. Each gun initiates a vacuum arc operating between magnesium electrodes. The net current of the guns was 80 kA. The arc-produced plasma shell was compressed by using a 450-kA, 450-ns driver, and as a result, a plasma column 0.3 cm in diameter was formed. The electron temperature of the plasma reached 400 eV at an average ion concentration of 1.85 {center_dot} 10{sup 18} cm{sup -3}. The power of the Mg K-line radiation emitted by the plasma for 15-30 ns was 300 MW/cm.

  8. Cross-Section Covariance Data Processing with the AMPX Module PUFF-IV

    SciTech Connect

    Wiarda, Dorothea; Leal, Luiz C; Dunn, Michael E

    2011-01-01

    The ENDF community is endeavoring to release an updated version of the ENDF/B-VII library (ENDF/B-VII.1). In the new release several new evaluations containing covariance information have been added, as the community strives to add covariance information for use in programs like the TSUNAMI (Tools for Sensitivity and Uncertainty Analysis Methodology Implementation) sequence of SCALE (Ref 1). The ENDF/B formatted files are processed into libraries to be used in transport calculations using the AMPX code system (Ref 2) or the NJOY code system (Ref 3). Both codes contain modules to process covariance matrices: PUFF-IV for AMPX and ERRORR in the case of NJOY. While the cross section processing capability between the two code systems has been widely compared, the same is not true for the covariance processing. This paper compares the results for the two codes using the pre-release version of ENDF/B-VII.1.

  9. Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode

    NASA Astrophysics Data System (ADS)

    Poehlmann, Flavio R.; Cappelli, Mark A.; Rieker, Gregory B.

    2010-12-01

    Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma deflagration. The effects of varying the bank capacitance, transmission line inductance, and applied electrode voltage were studied over the range from 14 to 112 μF, 50 to 200 nH, and 1 to 3 kV, respectively.

  10. Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode

    PubMed Central

    Poehlmann, Flavio R.; Cappelli, Mark A.; Rieker, Gregory B.

    2010-01-01

    Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma deflagration. The effects of varying the bank capacitance, transmission line inductance, and applied electrode voltage were studied over the range from 14 to 112 μF, 50 to 200 nH, and 1 to 3 kV, respectively. PMID:21267082

  11. Computational modeling of Krypton gas puffs with tailored mass density profiles on Z

    DOE PAGESBeta

    Jennings, Christopher A.; Ampleford, David J.; Lamppa, Derek C.; Hansen, Stephanie B.; Jones, Brent Manley; Harvey-Thompson, Adam James; Jobe, Marc Ronald Lee; Reneker, Joseph; Rochau, Gregory A.; Cuneo, Michael Edward; et al

    2015-05-18

    Large diameter multi-shell gas puffs rapidly imploded by high current (~20 MA, ~100 ns) on the Z generator of Sandia National Laboratories are able to produce high-intensity Krypton K-shell emission at ~13 keV. Efficiently radiating at these high photon energies is a significant challenge which requires the careful design and optimization of the gas distribution. To facilitate this, we hydrodynamically model the gas flow out of the nozzle and then model its implosion using a 3-dimensional resistive, radiative MHD code (GORGON). This approach enables us to iterate between modeling the implosion and gas flow from the nozzle to optimize radiativemore » output from this combined system. Furthermore, guided by our implosion calculations, we have designed gas profiles that help mitigate disruption from Magneto-Rayleigh–Taylor implosion instabilities, while preserving sufficient kinetic energy to thermalize to the high temperatures required for K-shell emission.« less

  12. Sequestration of flue gas CO₂ by direct gas-solid carbonation of air pollution control system residues.

    PubMed

    Tian, Sicong; Jiang, Jianguo

    2012-12-18

    Direct gas-solid carbonation reactions of residues from an air pollution control system (APCr) were conducted using different combinations of simulated flue gas to study the impact on CO₂ sequestration. X-ray diffraction analysis of APCr determined the existence of CaClOH, whose maximum theoretical CO₂ sequestration potential of 58.13 g CO₂/kg APCr was calculated by the reference intensity ratio method. The reaction mechanism obeyed a model of a fast kinetics-controlled process followed by a slow product layer diffusion-controlled process. Temperature is the key factor in direct gas-solid carbonation and had a notable influence on both the carbonation conversion and the CO₂ sequestration rate. The optimal CO₂ sequestrating temperature of 395 °C was easily obtained for APCr using a continuous heating experiment. CO₂ content in the flue gas had a definite influence on the CO₂ sequestration rate of the kinetics-controlled process, but almost no influence on the final carbonation conversion. Typical concentrations of SO₂ in the flue gas could not only accelerate the carbonation reaction rate of the product layer diffusion-controlled process, but also could improve the final carbonation conversion. Maximum carbonation conversions of between 68.6% and 77.1% were achieved in a typical flue gas. Features of rapid CO₂ sequestration rate, strong impurities resistance, and high capture conversion for direct gas-solid carbonation were proved in this study, which presents a theoretical foundation for the applied use of this encouraging technology on carbon capture and storage. PMID:23181908

  13. Direct Writing of Resist Patterns Using a Wire Nozzle Newly Developed for an Air-Pressure Dispenser

    NASA Astrophysics Data System (ADS)

    Shinichiro Ohtsuka,; Toshiyuki Horiuchi,

    2010-06-01

    Direct writing of resist patterns using an air-pressure dispenser is expected as a low-cost patterning method for fabricating various microdevices. However, it was difficult to smoothly delineate fine resist patterns with a width of less than 100 μm when a commercial air-pressure dispenser system was used, because high-viscosity resists block fine dispenser nozzles, and low-viscosity resists spread after they are dispensed. For this reason, a new wire-nozzle dispenser was developed to write fine resist patterns with a width of less than 100 μm. The technology is especially suitable for customized small-scale productions. In the experiments, patterns were delineated onto wafers and copper-clad plastic substrates using the new wire-nozzle dispenser with an inner diameter of 100 μm and a wire diameter of 30 μm. As a result, straight line patterns with a minimum width of 50 μm were successfully delineated using a resist PMER P-LA900PM with a viscosity of 1500 mPa\\cdots. Patterns circularly curved with a radius of 1 mm and a width of 130 μm were also smoothly delineated. In addition, microreactor patterns including a joint point and curved shapes were successfully written. Although the linewidths at the curved parts slightly differed from those at the straight parts, all the patterns were smoothly stitched. Moreover, complicated patterns with variously curved routes were also successfully delineated. It was verified that the newly developed wire nozzle was useful as a new dispenser tool.

  14. Direct Writing of Resist Patterns Using a Wire Nozzle Newly Developed for an Air-Pressure Dispenser

    NASA Astrophysics Data System (ADS)

    Ohtsuka, Shinichiro; Horiuchi, Toshiyuki

    2010-06-01

    Direct writing of resist patterns using an air-pressure dispenser is expected as a low-cost patterning method for fabricating various microdevices. However, it was difficult to smoothly delineate fine resist patterns with a width of less than 100 µm when a commercial air-pressure dispenser system was used, because high-viscosity resists block fine dispenser nozzles, and low-viscosity resists spread after they are dispensed. For this reason, a new wire-nozzle dispenser was developed to write fine resist patterns with a width of less than 100 µm. The technology is especially suitable for customized small-scale productions. In the experiments, patterns were delineated onto wafers and copper-clad plastic substrates using the new wire-nozzle dispenser with an inner diameter of 100 µm and a wire diameter of 30 µm. As a result, straight line patterns with a minimum width of 50 µm were successfully delineated using a resist PMER P-LA900PM with a viscosity of 1500 mPa·s. Patterns circularly curved with a radius of 1 mm and a width of 130 µm were also smoothly delineated. In addition, microreactor patterns including a joint point and curved shapes were successfully written. Although the linewidths at the curved parts slightly differed from those at the straight parts, all the patterns were smoothly stitched. Moreover, complicated patterns with variously curved routes were also successfully delineated. It was verified that the newly developed wire nozzle was useful as a new dispenser tool.

  15. Evaluation of a regional air-quality model with bi-directional NH3 exchange coupled to an agro-ecosystem model

    NASA Astrophysics Data System (ADS)

    Bash, J. O.; Cooter, E. J.; Dennis, R. L.; Walker, J. T.; Pleim, J. E.

    2012-08-01

    Atmospheric ammonia (NH3) is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurements indicate that the air-surface exchange of NH3 is bi-directional. However, the effects of bi-directional exchange, soil biogeochemistry and human activity are not parameterized in air quality models. The US Environmental Protection Agency (EPA)'s Community Multiscale Air-Quality (CMAQ) model with bi-directional NH3 exchange has been coupled with the United States Department of Agriculture (USDA)'s Environmental Policy Integrated Climate (EPIC) agro-ecosystem model's nitrogen geochemistry algorithms. CMAQ with bi-directional NH3 exchange coupled to EPIC connects agricultural cropping management practices to emissions and atmospheric concentrations of reduced nitrogen and models the biogeochemical feedback on NH3 air-surface exchange. This coupled modeling system reduced the biases and error in NHx (NH3 + NH4+) wet deposition and in ambient aerosol concentrations in an annual 2002 Continental US (CONUS) domain simulation when compared to a 2002 annual simulation of CMAQ without bi-directional exchange. Fertilizer emissions estimated in CMAQ 5.0 with bi-directional exchange exhibits markedly different seasonal dynamics than the US EPA's National Emissions Inventory (NEI), with lower emissions in the spring and fall and higher emissions in July.

  16. Mediatorless glucose biosensor and direct electron transfer type glucose/air biofuel cell enabled with carbon nanodots.

    PubMed

    Zhao, Mei; Gao, Yue; Sun, Junyong; Gao, Feng

    2015-03-01

    Utilization of carbon nanodots (CNDs), newcomers to the world of carbonaceous nanomaterials, in the electrochemistry realm has rarely been reported so far. In this study, CNDs were used as immobilization supports and electron carriers to promote direct electron transfer (DET) reactions of glucose oxidase (GOx) and bilirubin oxidase (BOD). At the CNDs electrode entrapped with GOx, a high rate constant (k(s)) of 6.28 ± 0.05 s(-1) for fast DET and an apparent Michaelis-Menten constant (K(M)(app)) as low as 0.85 ± 0.03 mM for affinity to glucose were found. By taking advantage of its excellent direct bioelectrocatalytic performances to glucose oxidation, a DET-based biosensor for glucose detection ranging from 0 to 0.64 mM with a high sensitivity of 6.1 μA mM(-1) and a limit of detection (LOD) of 1.07 ± 0.03 μM (S/N = 3) was proposed. Additionally, the promoted DET of BOD immobilized on CNDs was also observed and effectively catalyzed the reduction of oxygen to water at the onset potential of +0.51 V (vs Ag/AgCl). On the basis of the facilitated DET of these two enzymes at CNDs electrodes, a mediator-free DET-type glucose/air enzymatic biofuel cell (BFC), in which CNDs electrodes entrapped with GOx and BOD were employed for oxidizing glucose at the bioanode and reducing oxygen at the biocathode, respectively, was successfully fabricated. The constructed BFC displayed an open-circuit voltage (OCV) as high as 0.93 V and a maximum power density of 40.8 μW cm(-2) at 0.41 V. These important features of CNDs have implied to be promising materials for immobilizing enzymes and efficient platforms for elaborating bioelectrochemical devices such as biosensors and BFCs. PMID:25666266

  17. Characterization of argon direct-current glow discharge with a longitudinal electric field applied at ambient air

    PubMed Central

    Jiang, Weiman; Tang, Jie; Wang, Yishan; Zhao, Wei; Duan, Yixiang

    2014-01-01

    A direct-current-driven plasma jet is developed by applying a longitudinal electric field on the flowing argon at ambient air. This plasma shows a torch shape with its cross-section increased from the anode to the cathode. Comparison with its counterparts indicates that the gas flow plays a key role in variation of the plasma structure and contributes much to enlarging the plasma volume. It is also found that the circular hollow metal base promotes generation of plasma with a high-power volume density in a limited space. The optical emission spectroscopy (OES) diagnosis indicates that the plasma comprises many reactive species, such as OH, O, excited N2, and Ar metastables. Examination of the rotational and vibrational temperature indicates that the plasma is under nonequilibrium condition and the excited species OH(A 2Σ+), O(5P), and N2(C 3Πu) are partly generated by energy transfer from argon metastables. The spatially resolved OES of plasma reveals that the negative glow, Faraday dark space, and positive column are distributed across the gas gap. The absence of the anode glow is attributed to the fact that many electrons in the vicinity of the anode follow ions into the positive column due to the ambipolar diffusion in the flowing gas. PMID:25205176

  18. Characterization of argon direct-current glow discharge with a longitudinal electric field applied at ambient air.

    PubMed

    Jiang, Weiman; Tang, Jie; Wang, Yishan; Zhao, Wei; Duan, Yixiang

    2014-01-01

    A direct-current-driven plasma jet is developed by applying a longitudinal electric field on the flowing argon at ambient air. This plasma shows a torch shape with its cross-section increased from the anode to the cathode. Comparison with its counterparts indicates that the gas flow plays a key role in variation of the plasma structure and contributes much to enlarging the plasma volume. It is also found that the circular hollow metal base promotes generation of plasma with a high-power volume density in a limited space. The optical emission spectroscopy (OES) diagnosis indicates that the plasma comprises many reactive species, such as OH, O, excited N2, and Ar metastables. Examination of the rotational and vibrational temperature indicates that the plasma is under nonequilibrium condition and the excited species OH(A (2)Σ(+)), O((5)P), and N2(C (3)Πu) are partly generated by energy transfer from argon metastables. The spatially resolved OES of plasma reveals that the negative glow, Faraday dark space, and positive column are distributed across the gas gap. The absence of the anode glow is attributed to the fact that many electrons in the vicinity of the anode follow ions into the positive column due to the ambipolar diffusion in the flowing gas. PMID:25205176

  19. Deemed Savings Estimates for Legacy Air Conditioning and WaterHeating Direct Load Control Programs in PJM Region

    SciTech Connect

    Goldman, Charles

    2007-03-01

    During 2005 and 2006, the PJM Interconnection (PJM) Load Analysis Subcommittee (LAS) examined ways to reduce the costs and improve the effectiveness of its existing measurement and verification (M&V) protocols for Direct Load Control (DLC) programs. The current M&V protocol requires that a PURPA-compliant Load Research study be conducted every five years for each Load-Serving Entity (LSE). The current M&V protocol is expensive to implement and administer particularly for mature load control programs, some of which are marginally cost-effective. There was growing evidence that some LSEs were mothballing or dropping their DLC programs in lieu of incurring the expense associated with the M&V. This project had several objectives: (1) examine the potential for developing deemed savings estimates acceptable to PJM for legacy air conditioning and water heating DLC programs, and (2) explore the development of a collaborative, regional, consensus-based approach for conducting monitoring and verification of load reductions for emerging load management technologies for customers that do not have interval metering capability.

  20. New Directions: Questions surrounding suspended particle mass used as a surrogate for air quality and for regulatory control of ambient urban air pollution

    NASA Astrophysics Data System (ADS)

    Hoare, John L.

    2014-07-01

    The original choice of particulate matter mass (PM) as a realistic surrogate for gross air pollution has gradually evolved into routine use nowadays of epidemiologically-based estimates of the monetary and other benefits expected from regulating urban air quality. Unfortunately, the statistical associations facilitating such calculations usually are based on single indices of air pollution whereas the health effects themselves are more broadly based causally. For this and other reasons the economic benefits of control tend to be exaggerated. Primarily because of their assumed inherently inferior respirability, particles ≥10 μm are generally excluded from such considerations. Where the particles themselves are chemically heterogeneous, as in an urban context, this may be inappropriate. Clearly all air-borne particles, whether coarse or fine, are susceptible to inhalation. Hence, the possibility exists for any adhering potentially harmful semi-volatile substances to be subsequently de-sorbed in vivo thereby facilitating their transport deeper into the lungs. Consequently, this alone may be a sufficient reason for including rather than rejecting during air quality monitoring the relatively coarse 10-100 μm particle fraction, ideally in conjunction with routine estimation of the gaseous co-pollutants thereby facilitating a multi-pollutant approach apropos regulation.

  1. Demonstration of a neonlike argon soft-x-ray laser with a picosecond-laser-irradiated gas puff target.

    PubMed

    Fiedorowicz, H; Bartnik, A; Dunn, J; Smith, R F; Hunter, J; Nilsen, J; Osterheld, A L; Shlyaptsev, V N

    2001-09-15

    We demonstrate a neonlike argon-ion x-ray laser, using a short-pulse laser-irradiated gas puff target. The gas puff target was formed by pulsed injection of gas from a high-pressure solenoid valve through a nozzle in the form of a narrow slit and irradiated with a combination of long, 600-ps and short, 6-ps high-power laser pulses with a total of 10 J of energy in a traveling-wave excitation scheme. Lasing was observed on the 3p (1)S(0)?3s (1)P(1) transition at 46.9 nm and the 3d (1)P(1)?3p (1)P(1) transition at 45.1 nm. A gain of 11 cm(-1) was measured on these transitions for targets up to 0.9 cm long. PMID:18049619

  2. Generation and characterization of plasma channels in gas puff targets using soft X-ray radiography technique

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Bartnik, A.; Jarocki, R.; Fok, T.; Wegrzyński, Ł.; Kostecki, J.; Szczurek, M.; Jabczyński, J.; Fiedorowicz, H.

    2014-10-01

    We present our recent results of a formation and characterization of plasma channels in elongated krypton and xenon gas puff targets. The study of their formation and temporal expansion was carried out using a combination of a soft X-ray radiography (shadowgraphy) and pinhole camera imaging. Two high-energy short laser pulses were used to produce the channels. When a pumping laser pulse was shaped into a line focus, using cylindrical and spherical lenses, the channels were not produced because much smaller energy density was deposited in the gas puff target. However, when a point focus was obtained, using just a spherical lens, the plasma channels appeared. The channels were up to 9 mm in length, had a quite uniform density profile, and expanded in time with velocities of about 2 cm/μs.

  3. Generation and characterization of plasma channels in gas puff targets using soft X-ray radiography technique

    SciTech Connect

    Wachulak, P. W. Bartnik, A.; Jarocki, R.; Fok, T.; Węgrzyński, Ł.; Kostecki, J.; Szczurek, M.; Jabczyński, J.; Fiedorowicz, H.

    2014-10-15

    We present our recent results of a formation and characterization of plasma channels in elongated krypton and xenon gas puff targets. The study of their formation and temporal expansion was carried out using a combination of a soft X-ray radiography (shadowgraphy) and pinhole camera imaging. Two high-energy short laser pulses were used to produce the channels. When a pumping laser pulse was shaped into a line focus, using cylindrical and spherical lenses, the channels were not produced because much smaller energy density was deposited in the gas puff target. However, when a point focus was obtained, using just a spherical lens, the plasma channels appeared. The channels were up to 9 mm in length, had a quite uniform density profile, and expanded in time with velocities of about 2 cm/μs.

  4. On the possibility of neutron generation in an imploding TiD{sub 2} puff Z pinch

    SciTech Connect

    Baksht, Rina B.; Oreshkin, Vladimir I.; Rousskikh, Alexander G.

    2013-08-15

    Simulation of implosion of a TiD{sub 2} puff Z pinch is reported. The Z pinch is supposed to be produced by the plasma flow generated by a vacuum arc, as described by Rousskikh et al.[Phys. Plasmas 18, 092707 (2011)]. To simulate the implosion, a one-dimensional two-temperature radiative magnetohydrodynamics code was used. The simulation has shown that neutrons are generated during the implosion of a TiD{sub 2} puff Z pinch due to thermalization of the pinch plasma stagnated on axis. It has been shown that the necessary condition for neutron generation is that the ion temperature must be substantially higher than the electron temperature. For a pinch current of 1 MA, the predicted yield of 'thermal' neutrons is 2.5 × 10{sup 9} neutrons/shot.

  5. Design and initial results from a kilojoule level dense plasma focus with hollow anode and cylindrically symmetric gas puff

    SciTech Connect

    Ellsworth, J. L. Falabella, S.; Tang, V.; Schmidt, A.; Guethlein, G.; Hawkins, S.; Rusnak, B.

    2014-01-15

    We have designed and built a Dense Plasma Focus (DPF) Z-pinch device using a kJ-level capacitor bank and a hollow anode, and fueled by a cylindrically symmetric gas puff. Using this device, we have measured peak deuteron beam energies of up to 400 keV at 0.8 kJ capacitor bank energy and pinch lengths of ∼6 mm, indicating accelerating fields greater than 50 MV/m. Neutron yields of on the order of 10{sup 7} per shot were measured during deuterium operation. The cylindrical gas puff system permitted simultaneous operation of DPF with a radiofrequency quadrupole accelerator for beam-into-plasma experiments. This paper describes the machine design, the diagnostic systems, and our first results.

  6. Performance/Design Requirements and Detailed Technical Description for a Computer-Directed Training Subsystem for Integration into the Air Force Phase II Base Level System.

    ERIC Educational Resources Information Center

    Butler, A. K.; And Others

    The performance/design requirements and a detailed technical description for a Computer-Directed Training Subsystem to be integrated into the Air Force Phase II Base Level System are described. The subsystem may be used for computer-assisted lesson construction and has presentation capability for on-the-job training for data automation, staff, and…

  7. Assessment of Volatile Organic Compound and Hazardous Air Pollutant Emissions from Oil and Natural Gas Well Pads using Mobile Remote and On-site Direct Measurements

    EPA Science Inventory

    Emissions of volatile organic compounds (VOC) and hazardous air pollutants (HAP) from oil and natural gas production were investigated using direct measurements of component-level emissions on well pads in the Denver-Julesburg (DJ) Basin and remote measurements of production pad-...

  8. Development of the High-Order Decoupled Direct Method in Three Dimensions for Particulate Matter: Enabling Advanced Sensitivity Analysis in Air Quality Models

    EPA Science Inventory

    The high-order decoupled direct method in three dimensions for particular matter (HDDM-3D/PM) has been implemented in the Community Multiscale Air Quality (CMAQ) model to enable advanced sensitivity analysis. The major effort of this work is to develop high-order DDM sensitivity...

  9. Efficient generation of fast neutrons by magnetized deuterons in an optimized deuterium gas-puff z-pinch

    NASA Astrophysics Data System (ADS)

    Klir, D.; Shishlov, A. V.; Kokshenev, V. A.; Kubes, P.; Labetsky, A. Yu; Rezac, K.; Cherdizov, R. K.; Cikhardt, J.; Cikhardtova, B.; Dudkin, G. N.; Fursov, F. I.; Garapatsky, A. A.; Kovalchuk, B. M.; Kravarik, J.; Kurmaev, N. E.; Orcikova, H.; Padalko, V. N.; Ratakhin, N. A.; Sila, O.; Turek, K.; Varlachev, V. A.

    2015-04-01

    Z-pinch experiments with deuterium gas puffs have been carried out on the GIT-12 generator at 3 MA currents. Recently, a novel configuration of a deuterium gas-puff z-pinch was used to accelerate deuterons and to generate fast neutrons. In order to form a homogeneous, uniformly conducting layer at a large initial radius, an inner deuterium gas puff was surrounded by an outer hollow cylindrical plasma shell. The plasma shell consisting of hydrogen and carbon ions was formed at the diameter of 350 mm by 48 plasma guns. A linear mass of the plasma shell was about 5 µg cm-1 whereas a total linear mass of deuterium gas in single or double shell gas puffs was about 100 µg cm-1. The implosion lasted 700 ns and seemed to be stable up to a 5 mm radius. During stagnation, m = 0 instabilities became more pronounced. When a disruption of necks occurred, the plasma impedance reached 0.4 Ω and high energy (>2 MeV) bremsstrahlung radiation together with high energy deuterons were produced. Maximum neutron energies of 33 MeV were observed by axial time-of-flight detectors. The observed neutron spectra could be explained by a suprathermal distribution of deuterons with a high energy tail f≤ft({{E}\\text{d}}\\right)\\propto E\\text{d}-(1.8+/- 0.2) . Neutron yields reached 3.6 × 1012 at a 2.7 MA current. A high neutron production efficiency of 6 × 107 neutrons per one joule of plasma energy resulted from the generation of high energy deuterons and from their magnetization inside plasmas.

  10. Emission of High-Energy Ions in the SHOTGUN III Divergent Gas-Puff Z-Pinch Experiment

    NASA Astrophysics Data System (ADS)

    TAKASUGI, Keiichi; IWATA, Masayuki; NISHIO, Mineyuki

    2016-03-01

    Ion pinhole measurements of high-energy ions were conducted on the divergent gas-puff z-pinch plasma. Two types of ions, 1.7 - 2.5 MeV and 0.1 - 0.7 MeV, were observed. The former was observed only on the axis. The latter showed quite different characteristics between positive and negative discharges. These ions were considered to be accelerated by inductive electric field generated by the pinch.

  11. Characterization of neutron emission from mega-ampere deuterium gas puff Z-pinch at microsecond implosion times

    NASA Astrophysics Data System (ADS)

    Klir, D.; Shishlov, A. V.; Kokshenev, V. A.; Kubes, P.; Labetsky, A. Yu; Rezac, K.; Cikhardt, J.; Fursov, F. I.; Kovalchuk, B. M.; Kravarik, J.; Kurmaev, N. E.; Ratakhin, N. A.; Sila, O.; Stodulka, J.

    2013-08-01

    Experiments with deuterium (D2) triple shell gas puffs were carried out on the GIT-12 generator at a 3 MA current level and microsecond implosion times. The outer, middle and inner nozzle diameters were 160 mm, 80 mm and 30 mm, respectively. The influence of the mass of deuterium shells on neutron emission times, neutron yields and neutron energy spectra was studied. The injected linear mass of deuterium varied between 50 and 255 µg cm-1. Gas puffs imploded onto the axis before the peak of generator current at 700-1100 ns. Most of the neutrons were emitted during the second neutron pulse after the development of instabilities. Despite higher currents, heavier gas puffs produced lower neutron yields. Optimal mass and a short time delay between the valve opening and the generator triggering were more important than the better coincidence of stagnation with peak current. The peak neutron yield from D(d, n)3He reactions reached 3 × 1011 at 2.8 MA current, 90 µg cm-1 injected linear mass and 37 mm anode-cathode gap. In the case of lower mass shots, a large number of 10 MeV neutrons were produced either by secondary DT reactions or by DD reactions of deuterons with energies above 7 MeV. The average neutron yield ratio Y>10 MeV/Y2.5 MeV reached (6 ± 3) × 10-4. Such a result can be explained by a power law distribution for deuterons as \\rmd N_d/\\rmd E_d\\propto E_d^{-3} . The optimization of a D2 gas puff Z-pinch and similarities to a plasma focus and its drive parameter are described.

  12. EPA'S INDOOR AIR QUALITY AND WORK ENVIRONMENT STUDY: RELATIONSHIPS OF EMPLOYEE'S SELF-REPORTED HEALTHY SYMPTOMS WITH DIRECT INDOOR AIR QUALITY MEASUREMENTS

    EPA Science Inventory

    In recent years, employees at the three headquarters buildings of the U.S. Environmental Protection Agency (EPA) in the Washington, D.C. area have expressed concerns about air quality and work environment discomforts. s part of a large-scale study of health and comfort concerns, ...

  13. Initial magnetic field compression studies using gas-puff Z-pinches and thin liners on COBRA

    NASA Astrophysics Data System (ADS)

    Gourdain, P.-A.; Concepcion, R. J.; Evans, M. T.; Greenly, J. B.; Hammer, D. A.; Hoyt, C. L.; Kroupp, E.; Kusse, B. R.; Maron, Y.; Novick, A. S.; Pikuz, S. A.; Qi, N.; Rondeau, G.; Rosenberg, E.; Schrafel, P. C.; Seyler, C. E.; Shelkovenko, T. C.

    2013-08-01

    This magnetic compression of cylindrical liners filled with DT gas has promise as an efficient way to achieve fusion burn using pulsed-power machines. However, to avoid rapid cooling of the fuel by transfer of heat to the liner an axial magnetic field is required. This field has to be compressed during the implosion since the thermal insulation is more demanding as the compressed DT plasma becomes hotter and its volume smaller. This compression of the magnetic field is driven both by the imploding liner and plasma. To highlight how this magnetic field compression by the plasma and liner evolves we have separately studied Z-pinch implosions generated by gas puff and liner loads. The masses of the gas puff and liner loads were adjusted to match COBRA's current rise times. Our results have shown that Ne gas-puff implosions are well described by a snowplow model where electrical currents are predominately localized to the outer surface of the imploding plasma and the magnetic field is external to the imploding plasma. Liner implosions are dominated by the plasma ablation process on the inside surface of the liner and the electrical currents and magnetic fields are advected into the inner plasma volume; the sharp radial gradient associated with the snowplow process is not present.

  14. Spectroscopic Studies of the Soft X-Ray Radiation from Gas-Puff Z-Pinches on Cobra

    NASA Astrophysics Data System (ADS)

    Shelkovenko, T. A.; Pikuz, S. A.; de Grouchy, P. W. L.; Qi, N.; Atoyan, L.; Kusse, B. R.; Hammer, D. A.

    2015-11-01

    Gas-puff Z-pinch experiments have been conducted on the 0.8-1.2 MA, 100-240 ns pulse duration COBRA pulsed power generator. Triple nozzle gas-puff loads consisting of Ne, Ar and Kr gases in different combination and pressures with pre-ionization were used in the most recent experiments. Photo-conducting diodes (PCDs) and pinhole cameras with different filters were used to study the X-ray timing, intensity and spatial distribution in different energy bands. Spectrographs with spatial and temporal resolution were used to study the soft x-ray radiation from the gas-puff Z-pinches. One spectrograph with two spherically bent mica crystals was used to study radiation with 200 micron spatial resolution and high spectral resolution. An x-ray streak camera with one spherically bent quartz crystal was used to study the x-ray radiation with up to 10 ps temporal resolution. The x-ray spectra were used to estimate spatial and temporal distributions of plasma parameters and determine the intensity of the line and continuum radiation from the Z-pinches plasma. Work supported by the National Nuclear Security Administration Stewardship Sciences Academic Programs under Department of Energy Cooperative Agreement No. DE-NA0001836.

  15. Aerosol Optical Depth over Europe: Evaluation of the CALIOPE air quality modelling system with direct-sun AERONET observations

    NASA Astrophysics Data System (ADS)

    Basart, Sara; Pay, María. Teresa; Pérez, Carlos; Cuevas, Emilio; Jorba, Oriol; Piot, Matthias; María Baldasano, Jose

    2010-05-01

    In the frame of the CALIOPE project (Baldasano et al., 2008), the Barcelona Supercomputing Center (BSC-CNS) currently operates a high-resolution air quality forecasting system based on daily photochemical forecasts in Europe (12km x 12km resolution) with the WRF-ARW/HERMES/CMAQ modelling system (http://www.bsc.es/caliope) and desert dust forecasts over Southern Europe with BSC-DREAM8b (Pérez et al., 2006; http://www.bsc.es/projects/earthscience/DREAM). High resolution simulations and forecasts are possible through their implementation on MareNostrum supercomputer at BSC-CNS. As shown in previous air quality studies (e.g. Rodríguez et al., 2001; Jiménez-Guerrero et al., 2008), the contribution of desert dust on particulate matter levels in Southern Europe is remarkable due to its proximity to African desert dust sources. When considering only anthropogenic emissions (Baldasano et al., 2008) and the current knowledge about aerosol physics and chemistry, chemistry-transport model simulations underestimate the PM10 concentrations by 30-50%. As a first approach, the natural dust contribution from BSC-DREAM8b is on-line added to the anthropogenic aerosol output of CMAQ. The aim of the present work is the quantitative evaluation of the WRF-ARW/HERMES/ CMAQ/BSC-DREAM8b forecast system to simulate the Aerosol Optical Depth (AOD) over Europe. The performance of the modelled AOD has been quantitatively evaluated with discrete and categorical (skill scores) statistics by a comparison to direct-sun AERONET observations for 2004. The contribution of different types of aerosols will be analyzed by means of the O'Neill fine mode AOD products (O'Neill et al., 2001). A previous aerosol characterization of AERONET data was performed (Basart et al., 2009) in order to discriminate the different aerosol source contributions within the study region. The results indicate a remarkable improvement in the discrete and skill-scores evaluation (accuracy, critical success index and

  16. Do questions reflecting indoor air pollutant exposure from a questionnaire predict direct measure of exposure in owner-occupied houses?

    PubMed

    Loo, C K Jennifer; Foty, Richard G; Wheeler, Amanda J; Miller, J David; Evans, Greg; Stieb, David M; Dell, Sharon D

    2010-08-01

    Home characteristic questions are used in epidemiological studies and clinical settings to assess potentially harmful exposures in the home. The objective of this study was to determine whether questionnaire-reported home characteristics can predict directly measured pollutants. Sixty home inspections were conducted on a subsample of the 2006 population-based Toronto Child Health Evaluation Questionnaire. Indoor/outdoor air and settled dust samples were analyzed. Mean Fel d 1 was higher (p < 0.0001) in homes with a cat (450.58 μg/g) versus without (22.28 μg/g). Mean indoor NO(2) was higher (p = 0.003) in homes with gas stoves (14.98 ppb) versus without (8.31 ppb). Self-reported musty odours predicted higher glucan levels (10554.37 μg/g versus 6308.58 μg/g, p = 0.0077). Der f 1 was predicted by the home's age, but not by reports of carpets, and was higher in homes with mean relative humidity > 50% (61.30 μg/g, versus 6.24 μg/g, p = 0.002). Self-reported presence of a cat, a gas stove, musty odours, mice, and the home's age and indoor relative humidity over 50% predicted measured indoor levels of cat allergens, NO(2), fungal glucan, mouse allergens and dust mite allergens, respectively. These results are helpful for understanding the significance of indoor exposures ascertained by self-reporting in large epidemiological studies and also in the clinical setting. PMID:20948960

  17. A Direct sensitivity approach to predict hourly ozone resulting from compliance with the National Ambient Air Quality Standard

    EPA Science Inventory

    In setting primary ambient air quality standards, the EPA’s responsibility under the law is to establish standards that protect public health. As part of the current review of the ozone National Ambient Air Quality Standard (NAAQS), the US EPA evaluated the health exposure and ...

  18. R-Z Density Mapping and CFD Simulation of Gas Puff Nozzle Flow

    NASA Astrophysics Data System (ADS)

    McKee, Erik; Valenzuela, Julio; Krasheninnikov, Igor; Frazier, Alister; Covington, Aaron; Beg, Farhat; Darling, Tim; Nevada Terawatt Facility Team; University of San Diego Team

    2015-11-01

    Laser induced fluorescence (LIF) is a technique in which a tracer is added to the gas flow for measurement of its spatial and temporal density profile. The Nd:YAG EKSPLA laser 20mJ/150ps at the fourth harmonic 266nm wavelength is focused down to a <1mm pencil beam to excite the acetone tracer. The use of anr ICCD gating camera is necessary because the 4ns short-lived fluorescence state is an order-of-magnitude dimmer than the 200us long-lived phosphorescence state. Mapping the density profile in time and space requires multiple shots. Once the temporal and spatial density profile is obtained, it can be used and benchmarked for two independent CFD software programs using transient solvers: OpenFOAM and FLUENT. The measurements and simulations serve as the initial conditions for (i) Gas Puff experiments that utilize special nozzle contours to inject the gas load between the electrode gap on pulsed-power machines and (ii) use with future MHD modeling efforts. Support for this work is provided by DOE/NNSA grant DE-NA0002075 and funded by the US Department of Energy, ARPA-E, Control Number 1184-1527.

  19. Implosion dynamics and radiative characteristics of a high yield structured gas puff load

    SciTech Connect

    Levine, J. S.; Banister, J. W.; Failor, B. H.; Qi, N.; Sze, H. M.; Velikovich, A. L.; Commisso, R. J.; Davis, J.; Lojewski, D.

    2006-08-15

    A large diameter gas puff nozzle, designed to produce a radial mass profile with a substantial fraction of the injected mass on the axis, has demonstrated an increase in K shell yield by nearly a factor of 2, to 21 kJ, in an argon Z pinch at 3.5 MA peak current and 205 ns implosion time [H. Sze, J. Banister, B. H. Failor, J. S. Levine, N. Qi, A. L. Velikovich, J. Davis, D. Lojewski, and P. Sincerny, Phys. Rev. Lett. 95, 105001 (2005)] and 80 kJ at 6 MA and 227 ns implosion time. The initial gas distribution produced by this nozzle has been determined and related to measured plasma dynamics during the implosion run-in phase. The role of two gas shells and the center jet are elucidated by the inclusion of a tracer element sequentially into each of the three independent plenums and by evacuating each plenum. The implosion dynamics and radiative characteristics of the Z pinches are presented.

  20. Diagnostics of deuterium gas-puff z-pinch experiments on the GIT-12 generator

    NASA Astrophysics Data System (ADS)

    Cikhardt, J.; Klir, D.; Rezac, K.; Kubes, P.; Kravarik, J.; Batobolotova, B.; Sila, O.; Turek, K.; Shishlov, A.; Labetsky, A.; Kokshenev, V.; Chedizov, R.; Ratakhin, N.; Varlachev, V.; Garapatsky, A.; Dudkin, G.; Padalko, V.; GIT-12 Team

    2014-10-01

    Z-pinch experiments with a deuterium gas-puff and an outer plasma shell generated by plasma guns were carried out on the GIT-12 generator at the IHCE in Tomsk. Using this novel configuration of the load, the neutron yields from the DD reaction were significantly increased from 2×1011 up to 3×1012 neutrons per shot at the current level of about 3 MA. In addition to recent experiments, the threshold activation detectors were used in order to get the information about the energy spectrum of the generated neutrons. The copper, indium, and lead samples were irradiated by the pulse of the neutrons generated during the experimental shot. The decay radiation of the products from the reactions 63Cu(n,2n)62Cu, 115In(n, γ) 116 mIn and 206Pb (n,3n)204mPb was observed using gamma spectrometer. According to the used neutron ToF scintillation detectors, the energy of neutrons reaches up to 20 MeV. The work was supported by the MSMT of the Czech Republic research Programs No. ME090871, No. LG13029, by the GACR Grant No. P205/12/0454, Grant CRA IAEA No. 17088 and RFBR research Project No. 13-08-00479-a.

  1. Upgrade to the Gas Puff Imaging Diagnostic that Views Alcator C-Mod's Inboard Edge

    NASA Astrophysics Data System (ADS)

    Sierchio, J. M.; Terry, J. L.

    2012-10-01

    We describe an upgrade of Alcator C-Mod's Gas Puff Imaging system which views the inboard plasma edge and SOL along lines-of-sight that are approximately parallel to the local magnetic field. The views are arranged in a 2D (R,Z) array with ˜2.8 cm radial coverage and ˜2.4 cm poloidal coverage. 23 of 54 available views were coupled via fibers to individual interference filters and PIN photodiode detectors. We are in the process of upgrading the system in order to increase the sensitivity of the system by replacing the PIN photodiodes with a 4x8 array of Avalanche Photo-Diodes (APD). Light from 30 views is coupled to the single-chip APD array through a single interference filter. We expect an improvement in signal-to-noise ratio of more than 10x. The frequency response of the system will increase from ˜400 kHz to 1MHz. The dynamic range of the new system is manipulated by changing the high-voltages on the APDs. Test results of the detectors' channel-to-channel cross-talk, frequency response, and gain curves will be presented, along with schematics of the experimental setup. The upgraded system allows for more study of inboard edge fluctuations, including whether the quasi-coherent fluctuations observed in the outboard edge also exist inboard.

  2. Preliminary Results of an Examination of Electronic Cigarette User Puff Topography: The Effect of a Mouthpiece-Based Topography Measurement Device on Plasma Nicotine and Subjective Effects

    PubMed Central

    Spindle, Tory R.; Breland, Alison B.; Karaoghlanian, Nareg V.; Shihadeh, Alan L.

    2015-01-01

    Introduction: Electronic cigarettes (ECIGs) heat a nicotine-containing solution; the resulting aerosol is inhaled by the user. Nicotine delivery may be affected by users’ puffing behavior (puff topography), and little is known about the puff topography of ECIG users. Puff topography can be measured using mouthpiece-based computerized systems. However, the extent to which a mouthpiece influences nicotine delivery and subjective effects in ECIG users is unknown. Methods: Plasma nicotine concentration, heart rate, and subjective effects were measured in 13 experienced ECIG users who used their preferred ECIG and liquid (≥12mg/ml nicotine) during 2 sessions (with or without a mouthpiece). In both sessions, participants completed an ECIG use session in which they were instructed to take 10 puffs with 30-second inter-puff intervals. Puff topography was recorded in the mouthpiece condition. Results: Almost all measures of the effects of ECIG use were independent of topography measurement. Collapsed across session, mean plasma nicotine concentration increased by 16.8ng/ml, and mean heart rate increased by 8.5 bpm (ps < .05). Withdrawal symptoms decreased significantly after ECIG use. Participants reported that the mouthpiece affected awareness and made ECIG use more difficult. Relative to previously reported data for tobacco cigarette smokers using similar topography measurement equipment, ECIG-using participants took larger and longer puffs with lower flow rates. Conclusions: In experienced ECIG users, measuring ECIG topography did not influence ECIG-associated nicotine delivery or most measures of withdrawal suppression. Topography measurement systems will need to account for the low flow rates observed for ECIG users. PMID:25239957

  3. CO2 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Kovar, Mark; Wehner, Scott

    1998-01-13

    The application of cyclic CO2, often referred to as the CO2 Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 Huff-n-Puff process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital-intensive miscible projects. Texaco Exploration & Production Inc. and the U. S. Department of Energy have teamed up in an attempt to develop the CO2 Huff-n-Puff process in the Grayburg and San Andres formations which are light oil, shallow shelf carbonate reservoirs that exist throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected sites for this demonstration project are the Central Vacuum Unit waterflood in Lea County, New Mexico and the Sundown Slaughter Field in Hockley County, Texas. Miscible CO2 flooding is the process of choice for enhancing recovery of light oils and already accounts for over 12% of the Permian Basin's daily production. There are significant probable reserves associated with future miscible CO2 projects. However, many are marginally economic at current market conditions due to large up-front capital commitments for a peak response, which may be several years in the future. The resulting negative cash-flow is sometimes too much for an operator to absorb. The CO2 Huff-n-Puff process is being investigated as a near

  4. A membraneless air-breathing hydrogen biofuel cell based on direct wiring of thermostable enzymes on carbon nanotube electrodes.

    PubMed

    Lalaoui, Noémie; de Poulpiquet, Anne; Haddad, Raoudha; Le Goff, Alan; Holzinger, Michael; Gounel, Sébastien; Mermoux, Michel; Infossi, Pascale; Mano, Nicolas; Lojou, Elisabeth; Cosnier, Serge

    2015-05-01

    A biocathode was designed by the modification of a carbon nanotube (CNT) gas-diffusion electrode with bilirubin oxidase from Bacillus pumilus, achieving high current densities up to 3 mA cm(-2) for the reduction of O2 from air. A membraneless air-breathing hydrogen biofuel cell was designed by combination of this cathode with a functionalized CNT-based hydrogenase anode. PMID:25845356

  5. EPA's indoor-air-quality and work-environment survey: Relationships of employees' self-reported health symptoms with direct indoor-air-quality measurements

    SciTech Connect

    Nelson, C.J.; Clayton, C.A.; Wallace, L.A.; Highsmith, V.R.; Kollander, M.

    1991-06-07

    In recent years, employees at the three headquarters buildings of the U.S. Environmental Protection Agency (EPA) in the Washington, D.C. area have expressed concerns about air quality and work environment discomforts. As part of a large-scale study of health and comfort concerns, environmental monitoring was carried out in March 1989 at approximately 100 sites (rooms) within these buildings. Employees in the vicinity of the monitors were administered a brief questionnaire to elicit information regarding their work environment, comfort levels, odors noticed, health symptoms, mood states, and perceptions of overall air quality. Statistical analyses were carried out for the 191 males and the 192 females for whom both questionnaire and monitoring data were available. The analyses entailed estimation of linear regression and logistic regression models aimed at testing for associations between the employees' responses and the environmental measurements, which included temperature, humidity, carbon dioxide, and particlate concentrations (100 sites), and various microbiologic and volatile organic compound concentrations (subset of 56 sites). Principal component analyses were used to develop some of the outcome and explanatory variables used in the models. In the paper, the authors describe the study design, the study limitations, the statistical models and methods, and the results and implications of the data analysis.

  6. Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants

    SciTech Connect

    McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

    2007-02-01

    Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media

  7. Simulation of effects of direction and air flow speed on temperature distribution in the room covered by various roof materials

    NASA Astrophysics Data System (ADS)

    Sukanto, H.; Budiana, E. P.; Putra, B. H. H.

    2016-03-01

    The objective of this research is to get a comparison of the distribution of the room temperature by using three materials, namely plastic-rubber composite, clay, and asbestos. The simulation used Ansys Fluent to get the temperature distribution. There were two conditions in this simulations, first the air passing beside the room and second the air passing in front of the room. Each condition will be varied with the air speed of 1 m/s, 2 m/s, 3 m/s, 4 m/s, 5 m/s for each material used. There are three heat transfers in this simulation, namely radiation, convection, and conduction. Based on the ANSI/ ASHRAE Standard 55-2004, the results of the simulation showed that the best temperature distribution was the roof of plastic-rubber composites.

  8. A Series of Jets that Drove Streamer-Puff CMEs from Giant Active Region of 2014

    NASA Technical Reports Server (NTRS)

    Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

    2016-01-01

    We investigate characteristics of solar coronal jets that originated from active region NOAA 12192 and produced coronal mass ejections (CMEs). This active region produced many non-jet major flare eruptions (X and M class) that made no CME. A multiitude of jets occurred from the southeast edge of the active region, and in contrast to the major-flare eruptions in the core, six of these jets resulted in CMEs. Our jet observations are from multiple SDO/AIA EUV channels, including 304, 171 and 193 Angstrom, and CME observations are taken from SOHO/LASCO C2 coronograph. Each jet-driven CME was relatively slow-moving (approximately 200 - 300 km s(sup-1) compared to most CMEs; had angular width (20deg - 50deg) comparable to that of the streamer base; and was of the "streamer-puff" variety, whereby a preexisting streamer was transiently inflated but not removed (blown out) by the passage of the CME. Much of the chromospheric-temperature plasma of the jets producing the CMEs escaped from the Sun, whereas relatively more of the chromospheric plasma in the non-CME-producing jets fell back to the solar surface. We also found that the CME-producing jets tended to be faster in speed and longer in duration than the non-CME-producing jets. We expect that the jets result from eruptions of mini-filaments. We further propose that the CMEs are driven by magnetic twist injected into streamer-base coronal loops when erupting twisted mini-filament field reconnects with the ambient field at the foot of those loops.

  9. A Series of Jets that Drove Streamer-Puff CMEs from Giant Active Region of 2014

    NASA Technical Reports Server (NTRS)

    Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

    2016-01-01

    We investigate characteristics of solar coronal jets that originated from active region NOAA 12192 and produced coronal mass ejections (CMEs). This active region produced many non­-jet major flare eruptions (X and M class) that made no CME. A multitude of jets occurred from the southeast edge of the active region, and in contrast to the major-­flare eruptions in the core, six of these jets resulted in CMEs. Our jet observations are from SDO/AIA EUV channels and from Hinode/XRT, and CME observations are from the SOHO/LASCO C2 coronograph. Each jet-­driven CME was relatively slow-­moving (approx. 200 - 300 km/s) compared to most CMEs; had angular width (20deg - 50deg) comparable to that of the streamer base; and was of the "streamer­-puff" variety, whereby a pre-existing streamer was transiently inflated but not removed (blown out) by the passage of the CME. Much of the chromospheric-­temperature plasma of the jets producing the CMEs escaped from the Sun, whereas relatively more of the chromospheric plasma in the non-CME-producing jets fell back to the solar surface. We also found that the CME-producing jets tended to be faster in speed and longer in duration than the non-CME-­producing jets. We expect that the jets result from eruptions of mini-filaments. We further propose that the CMEs are driven by magnetic twist injected into streamer-­base coronal loops when erupting twisted mini-filament field reconnects with the ambient field at the foot of those loops.

  10. Gas Puff Radiation Performance As a Function of Radial Mass Distribution

    NASA Astrophysics Data System (ADS)

    Coleman, Philip L.; Krishnan, Mahadevan; Prasad, Rahul; Qi, Niansheng; Waisman, Eduardo; Failor, B. H.; Levine, J. S.; Sze, H.

    2002-12-01

    The basic concept of a z-pinch, that JxB forces implode a shell of mass, creating a hot dense plasma on-axis, is coming under closer scrutiny. Wire arrays may start with an initial cold mass in a near "ideal" shell, but in fact they appear to develop complex radial mass distributions well before the final x-ray output [1,2]. We consider here the situation for gas puff z-pinches. While the ideal of a gas "shell" has been the nominal objective for many years, detailed measurements of gas flow show that nozzles used for plasma radiation sources (PRS) also have complex radial distributions. In particular, there are significant data [3] showing that the best x-ray yield comes from the least shell-like distributions. Recent experiments on the Double Eagle generator with argon have further enhanced this view [4]. For those tests with a double "shell" nozzle, there was a factor of almost 4 increase in yield when the relative mass (outer:inner) in the two shells was changed from 2:1 to less than 1:1. We suggest the following explanation. A configuration with most of its mass at large radii is subject to severe disruption by instabilities during the implosion. A more continuous radial mass distribution with dρ/dr < 0 may mitigate instability development (via the "snowplow stabilization" [5] mechanism) and thus enhance the thermalization of the kinetic energy of the imploding mass. In addition, the appropriate balance of outer to inner mass maximizes the formation of a strong shock in the core of the pinch that heats the plasma and leads to x-ray emission.

  11. A Series of Streamer-Puff CMEs Driven by Solar Homologous Jets

    NASA Astrophysics Data System (ADS)

    Panesar, N. K.; Sterling, A. C.; Moore, R. L.

    2015-12-01

    Solar coronal jets are magnetically channeled narrow eruptions often observed in the solar atmosphere, typically in EUV and X-ray emission, and occurring in various solar environments including active regions and coronal holes. Their driving mechanism is still under discussion, but facts that we know about jets include: (a) they are ejected from or near sites of compact magnetic explosions (compact ejective solar flares), (b) they sometimes carry chromospheric material high into the corona along with coronal-temperature plasma, (c) the cool-material jet velocities can reach 100 km s-1 or more, and (d) some active-region jets produce coronal mass ejections (CMEs). Here we investigate characteristics of EUV jets that originated from active region NOAA 12192 and produced CMEs. This active region produced many non-jet major flare eruptions (X and M class) that made no CME. A multitude of jets also occurred in the region, and in contrast to the major-flare eruptions, seven of these jets resulted in CMEs. Our jet observations are from multiple SDO/AIA EUV channels, including 304, 171, 193 and 94 Å, and our CME observations are from SOHO/LASCO C2 images. Each jet-driven CME was relatively slow-moving; had angular width (30° - 70°) comparable to that of the streamer base; and was of the "streamer-puff" variety, whereby a preexisting streamer was transiently inflated but not removed (blown out) by the passage of the CME. Much of the chromospheric-temperature plasma of the jets producing the CMEs escaped from the Sun, whereas relatively more of the chromospheric plasma in the non-CME-producing jets fell back to the solar surface. We also found that the CME-producing jets tended to be faster in speed and longer in duration than the non-CME-producing jets. This research was supported by funding from NASA's LWS program.

  12. Heat transfer and pressure drop measurements in an air/molten salt direct-contact heat exchanger

    SciTech Connect

    Bohn, M.S.

    1988-11-01

    This paper presents a comparison of experimental data with a recently published model of heat exchange in irrigated packed beds. Heat transfer and pressure drop were measured in a 150 mm (ID) column with a 610-mm bed of metal Pall rings. Molten nitrate salt and preheated air were the working fluids with a salt inlet temperature of approximately 440{degree}C and air inlet temperatures of approximately 230{degree}C. A comparison between the experimental data and the heat transfer model is made on the basis of heat transfer from the salt. For the range of air and salt flow rates tested, 0.3 to 1.2 kg/m{sup 2} s air flow and 6 to 18 kg/m{sup 2} s salt flow, the data agree with the model within 22% standard deviation. In addition, a model for the column pressure drop was validated, agreeing with the experimental data within 18% standard deviation over the range of column pressure drop from 40 to 1250 Pa/m. 25 refs., 7 figs., 2 tabs.

  13. Exposure Information in Environmental Health Research: Current Opportunities and Future Directions for Particulate Matter, Ozone, and Toxic Air Pollutants

    EPA Science Inventory

    In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in ord...

  14. Waterpipe Tobacco and Cigarette Smoking Direct Comparison of Toxicant Exposure

    PubMed Central

    Eissenberg, Thomas; Shihadeh, Alan

    2009-01-01

    Background Waterpipe (hookah, shisha) tobacco smoking has spread worldwide. Many waterpipe smokers believe that, relative to cigarettes, waterpipes are associated with lower smoke toxicant levels and fewer health risks. For physicians to address these beliefs credibly, waterpipe and cigarette must be compared directly. Purpose The purpose of this study is to provide the first controlled, direct laboratory comparison of the toxicant exposure associated with waterpipe tobacco and cigarette smoking Methods Participants (N=31; mean=21.4 years, SD=2.3) reporting monthly waterpipe use (mean 5.2 uses/month, SD=4.0) and weekly cigarette smoking (mean= 9.9 cigarettes/day, SD=6.4) completed a crossover study in which they each smoked a waterpipe for a maximum of 45 minutes or a single cigarette. Outcomes included expired air carbon monoxide (CO) 5 minutes after session’s end, and blood carboxyhemoglobin (COHb), plasma nicotine, heart rate, and puff topography. Data were collected in 2008–2009 and analyzed in 2009. Results CO increased, on average, by 23.9 ppm for waterpipe (SD=19.8) and 2.7 ppm for cigarette (SD=1.8) while peak waterpipe COHb levels (mean=3.9%, SD=2.5) were three times those observed for the cigarette (mean=1.3%, SD=0.5; Ps<0.001). Peak nicotine levels did not differ (mean ng/ml waterpipe=10.2, SD=7.0; cigarette=10.6, SD=7.7). Significant heart rate increases relative to pre-smoking were observed 5, 10, 15, 20, 25, and 35 minutes during the cigarette session and at every 5-minute interval during the waterpipe session (Ps<0.001). Mean total puff volume was 48.6 liters for waterpipe as compared to 1.0 liters for cigarette (P<0.001). Conclusions Relative to a cigarette, waterpipe use is associated with greater CO, similar nicotine, and dramatically more smoke exposure. Physicians should consider advising their patients that waterpipe tobacco smoking exposes them to some of the same toxicants as cigarette smoking and therefore the two tobacco smoking methods

  15. A comparison of contaminant plume statistics from a Gaussian puff and urban CFD model for two large cities

    NASA Astrophysics Data System (ADS)

    Pullen, Julie; Boris, Jay P.; Young, Theodore; Patnaik, Gopal; Iselin, John

    This paper quantitatively assesses the spatial extent of modeled contaminated regions resulting from hypothetical airborne agent releases in major urban areas. We compare statistics from a release at several different sites in Washington DC and Chicago using a Gaussian puff model (SCIPUFF, version 1.3, with urban parameter settings) and a building-resolving computational fluid dynamics (CFD) model (FAST3D-CT). For a neutrally buoyant gas source term with urban meteorology, we compare near-surface dosage values within several kilometers of the release during the first half hour, before the gas is dispersed beyond the critical lethal level. In particular, using "fine-grain" point-wise statistics such as fractional bias, spatial correlations and the percentage of points lying within a factor of two, we find that dosage distributions from the Gaussian puff and CFD model share few features in common. Yet the "coarse-grain" statistic that compares areas contained within a given contour level reveals that the differences between the models are less pronounced. Most significant among these distinctions is the rapid lofting, leading to enhanced vertical mixing, and projection downwind of the contaminant by the interaction of the winds with the urban landscape in the CFD model. This model-to-model discrepancy is partially ameliorated by supplying the puff model with more detailed information about the urban boundary layer that evolves on the CFD grid. While improving the correspondence of the models when using the "coarse-grain" statistic, the additional information does not lead to quite as substantial an overall agreement between the models when the "fine-grain" statistics are compared. The taller, denser and more variable building landscape of Chicago created increased sensitivity to release site and led to greater divergence in FAST3D-CT and SCIPUFF results relative to the flatter, sparser and more uniform urban morphology of Washington DC.

  16. Prolonged gray matter disease without demyelination caused by Theiler's murine encephalomyelitis virus with a mutation in VP2 puff B.

    PubMed

    Tsunoda, I; Wada, Y; Libbey, J E; Cannon, T S; Whitby, F G; Fujinami, R S

    2001-08-01

    Theiler's murine encephalomyelitis virus (TMEV) is divided into two subgroups based on neurovirulence. During the acute phase, DA virus infects cells in the gray matter of the central nervous system (CNS). Throughout the chronic phase, DA virus infects glial cells in the white matter, causing demyelinating disease. Although GDVII virus also infects neurons in the gray matter, infected mice developed a severe polioencephalomyelitis, and no virus is detected in the white matter or other areas in the CNS in rare survivors. Several sequence differences between the two viruses are located in VP2 puff B and VP1 loop II, which are located near each other, close to the proposed receptor binding site. We constructed a DA virus mutant, DApBL2M, which has the VP1 loop II of GDVII virus and a mutation at position 171 in VP2 puff B. While DApBL2M virus replicated less efficiently than DA virus during the acute phase, DApBL2M-induced acute polioencephalitis was comparable to that in DA virus infection. Interestingly, during the chronic phase, DApBL2M caused prolonged gray matter disease in the brain without white matter involvement in the spinal cord. This is opposite what is observed during wild-type DA virus infection. Our study is the first to demonstrate that conformational differences via interaction of VP2 puff B and VP1 loop II between GDVII and DA viruses can play an important role in making the transition of infection from the gray matter in the brain to the spinal cord white matter during TMEV infection. PMID:11462022

  17. Modeling of ns and ps laser-induced soft X-ray sources using nitrogen gas puff target

    SciTech Connect

    Vrba, P.; Vrbova, M.; Zakharov, S. V.

    2014-07-15

    Gas puff laser plasma is studied as a source of water window radiation with 2.88 nm wavelength, corresponding to quantum transition 1s{sup 2} → 1s2p of helium-like nitrogen ions. Spatial development of plasma induced by Nd:YAG laser beam is simulated by 2D Radiation-Magneto-Hydro-Dynamic code Z*. The results for nitrogen gas layer (0.72 mm thickness, 1 bar pressure) and two different laser pulses (600 mJ/7 ns and 525 mJ/170 ps), corresponding to the experiments done in Laser Laboratory Gottingen are presented.

  18. Measurement of acrolein and 1,3-butadiene in a single puff of cigarette smoke using lead-salt tunable diode laser infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Thweatt, W. Dave; Harward, Charles N., Sr.; Parrish, Milton E.

    2007-05-01

    Acrolein and 1,3-butadiene in cigarette smoke generally are measured using two separate analytical methods, a carbonyl derivative HPLC method for acrolein and a volatile organic compound (VOC) GC/MS method for 1,3-butadiene. However, a single analytical method having improved sensitivity and real-time per puff measurement will offer more specific information for evaluating experimental carbon filtered cigarettes designed to reduce the smoke deliveries of these constituents. This paper describes an infrared technique using two lead-salt tunable diode lasers (TDLs) operating with liquid nitrogen cooling with emissions at 958.8 cm -1 and 891.0 cm -1 respectively for the simultaneous measurement of acrolein and 1,3-butadiene, respectively, in each puff of mainstream cigarette smoke in real time. The dual TDL system uses a 3.1 l volume, 100 m astigmatic multiple pass absorption gas cell. Quantitation is based on a spectral fit that uses previously determined infrared molecular line parameters generated in our laboratory, including line positions, line strengths and nitrogen-broadened half-widths for these species. Since acrolein and ethylene absorption lines overlap and 1,3-butadiene, ethylene and propylene absorption lines overlap, the per puff deliveries of ethylene and propylene were determined since their overlapping absorption lines must be taken into account by the spectral fit. The acrolein and 1,3-butadiene total cigarette deliveries for the 1R5F Kentucky Reference cigarette were in agreement with the HPLC and GC/MS methods, respectively. The limit of detection (LOD) for 1,3-butadiene and acrolein was 4 ng/puff and 24 ng/puff, respectively, which is more than adequate to determine at which puff they break through the carbon filter. The retention and breakthrough behavior for the two primary smoke constituents depend on the cigarette design and characteristics of the carbon filter being evaluated.

  19. CLOUDS, AEROSOLS, RADIATION AND THE AIR-SEA INTERFACE OF THE SOUTHERN OCEAN: ESTABLISHING DIRECTIONS FOR FUTURE RESEARCH

    SciTech Connect

    Wood, Robert; Bretherton, Chris; McFarquhar, Greg; Protat, Alain; Quinn, Patricia; Siems, Steven; Jakob, Christian; Alexander, Simon; Weller, Bob

    2014-09-29

    A workshop sponsored by the Department of Energy was convened at the University of Washington to discuss the state of knowledge of clouds, aerosols and air-sea interaction over the Southern Ocean and to identify strategies for reducing uncertainties in their representation in global and regional models. The Southern Ocean plays a critical role in the global climate system and is a unique pristine environment, yet other than from satellite, there have been sparse observations of clouds, aerosols, radiation and the air-sea interface in this region. Consequently, much is unknown about atmospheric and oceanographic processes and their linkage in this region. Approximately 60 scientists, including graduate students, postdoctoral fellows and senior researchers working in atmospheric and oceanic sciences at U.S. and foreign universities and government laboratories, attended the Southern Ocean Workshop. It began with a day of scientific talks, partly in plenary and partly in two parallel sessions, discussing the current state of the science for clouds, aerosols and air-sea interaction in the Southern Ocean. After the talks, attendees broke into two working groups; one focused on clouds and meteorology, and one focused on aerosols and their interactions with clouds. This was followed by more plenary discussion to synthesize the two working group discussions and to consider possible plans for organized activities to study clouds, aerosols and the air-sea interface in the Southern Ocean. The agenda and talk slides, including short summaries of the highlights of the parallel session talks developed by the session chars, are available at http://www.atmos.washington.edu/socrates/presentations/SouthernOceanPresentations/.

  20. Comparison of 192Ir air kerma calibration coefficients derived at ARPANSA using the interpolation method and at the National Physical Laboratory using a direct measurement.

    PubMed

    Butler, D; Haworth, A; Sander, T; Todd, S

    2008-12-01

    The reference air kerma rate from 192Ir High Dose Rate (HDR) brachytherapy sources can be measured using a suitably calibrated Farmer chamber and an appropriate in-air calibration jig. When a primary standard for 192Ir gamma rays is available, a calibration coefficient for the chamber and jig combination can be determined directly. In Australia, due to the absence of such a standard, the chamber must be calibrated by interpolation of the response in 60Co and in a kilovoltage x-ray beam. Corrections for the effect of the jig, scatter and beam non-uniformity must then be measured or calculated before the reference air kerma rate can be determined. We compare the air-kerma calibration coefficient of a PTW 30010 PMMA/A1 Farmer chamber (referred to as Farmer chamber throughout this report) obtained from the 192Ir primary standard at the National Physical Laboratory in the UK with the corresponding coefficient obtained by interpolating Australian calibrations using 60Co and 250 kV x-rays and determining suitable correction factors. The resulting chamber/jig calibration coefficients differ by 0.2% which is well within the combined standard uncertainties of 1.2% and 0.6% reported by ARPANSA and NPL respectively. PMID:19239060

  1. Source area identification with observation from limited monitor sites for air pollution episodes in industrial parks

    NASA Astrophysics Data System (ADS)

    Huang, Zihan; Wang, Yuan; Yu, Qi; Ma, Weichun; Zhang, Yan; Chen, Limin

    2015-12-01

    Air pollution episodes of unknown origins are often detected by online equipment for air quality monitoring in industrial parks in China. The number of monitors available to provide observation data, as well as the source information, is often very limited. In such case, the identification of a potential source area is more practical than the precise back-calculation of the real source. The potential source area which can be deduced from the observation data from limited monitors was concerned in this paper. In order to do the source area identification, two inverse methods, a direct method and a statistical sampling method, were applied with a Gaussian puff model as the forward modeling method. The characteristic of the potential source area was illustrated by case studies. Both synthetic and real cases were presented. The distribution of the source locations and its variation with the other unknown source parameters were mainly focused in the case study. As a screening method, source area identification can be applied not only when the number of effective monitors is limited but also when an ideal number of monitors are available as long as the source information is almost uncertain.

  2. Energy Efficient Removal of Volatile Organic Compounds (VOCs) and Organic Hazardous Air Pollutants (o-HAPs) from Industrial Waste Streams by Direct Electron Oxidation

    SciTech Connect

    Testoni, A. L.

    2011-10-19

    This research program investigated and quantified the capability of direct electron beam destruction of volatile organic compounds and organic hazardous air pollutants in model industrial waste streams and calculated the energy savings that would be realized by the widespread adoption of the technology over traditional pollution control methods. Specifically, this research determined the quantity of electron beam dose required to remove 19 of the most important non-halogenated air pollutants from waste streams and constructed a technical and economic model for the implementation of the technology in key industries including petroleum refining, organic & solvent chemical production, food & beverage production, and forest & paper products manufacturing. Energy savings of 75 - 90% and green house gas reductions of 66 - 95% were calculated for the target market segments.

  3. Development of the gas puff charge exchange recombination spectroscopy (GP-CXRS) technique for ion measurements in the plasma edge

    SciTech Connect

    Churchill, R. M.; Theiler, C.; Lipschultz, B.; Dux, R.; Pütterich, T.; Viezzer, E.; Collaboration: Alcator C-Mod Team; ASDEX Upgrade Team

    2013-09-15

    A novel charge-exchange recombination spectroscopy (CXRS) diagnostic method is presented, which uses a simple thermal gas puff for its donor neutral source, instead of the typical high-energy neutral beam. This diagnostic, named gas puff CXRS (GP-CXRS), is used to measure ion density, velocity, and temperature in the tokamak edge/pedestal region with excellent signal-background ratios, and has a number of advantages to conventional beam-based CXRS systems. Here we develop the physics basis for GP-CXRS, including the neutral transport, the charge-exchange process at low energies, and effects of energy-dependent rate coefficients on the measurements. The GP-CXRS hardware setup is described on two separate tokamaks, Alcator C-Mod and ASDEX Upgrade. Measured spectra and profiles are also presented. Profile comparisons of GP-CXRS and a beam based CXRS system show good agreement. Emphasis is given throughout to describing guiding principles for users interested in applying the GP-CXRS diagnostic technique.

  4. CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir

    SciTech Connect

    1998-06-01

    The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration and Production Inc. and the US Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg and San Andres formations, a light oil, shallow shelf carbonate reservoir that exists throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. The goals of the project are the development of guidelines for cost-effective selection of candidate reservoirs and wells, along with estimating recovery potential. This project has two defined budget periods. The first budget period primarily involves tasks associated with reservoir analysis and characterization, characterizing existing producibility problems, and reservoir simulation of the proposed technology. The final budget period covers the actual field demonstration of the proposed technology. Technology transfer spans the entire course of the project. This report covers the concluding tasks performed under the second budget period.

  5. Demonstration of a directional sonic prism in two dimensions using an air-acoustic leaky wave antenna

    SciTech Connect

    Naify, Christina J. Rohde, Charles A.; Calvo, David C.; Orris, Gregory J.; Guild, Matthew D.

    2015-09-28

    Analysis and experimental demonstration of a two-dimensional acoustic leaky wave antenna is presented for use in air. The antenna is comprised of a two-dimensional waveguide patterned with radiating acoustic shunts. When excited using a single acoustic source within the waveguide, the antenna acts as a sonic prism that exhibits frequency steering. This design allows for control of acoustic steering angle using only a single source transducer and a patterned aperture. Aperture design was determined using transmission line analysis and finite element methods. The designed antenna was fabricated and the steering angle measured. The performance of the measured aperture was within 9% of predicted angle magnitudes over all examined frequencies.

  6. Demonstration of a directional sonic prism in two dimensions using an air-acoustic leaky wave antenna

    NASA Astrophysics Data System (ADS)

    Naify, Christina J.; Guild, Matthew D.; Rohde, Charles A.; Calvo, David C.; Orris, Gregory J.

    2015-09-01

    Analysis and experimental demonstration of a two-dimensional acoustic leaky wave antenna is presented for use in air. The antenna is comprised of a two-dimensional waveguide patterned with radiating acoustic shunts. When excited using a single acoustic source within the waveguide, the antenna acts as a sonic prism that exhibits frequency steering. This design allows for control of acoustic steering angle using only a single source transducer and a patterned aperture. Aperture design was determined using transmission line analysis and finite element methods. The designed antenna was fabricated and the steering angle measured. The performance of the measured aperture was within 9% of predicted angle magnitudes over all examined frequencies.

  7. Simultaneous determination of nicotine and 3-vinylpyridine in single cigarette tobacco smoke and in indoor air using direct extraction to solid phase.

    PubMed

    Koszowski, Bartosz; Goniewicz, Maciej Lukasz; Czogala, Jan; Zymelka, Anna; Sobczak, Andrzej

    2009-01-01

    The aim of the present study was to develop a new analytical method of chromatographic determination of two important markers of ETS exposure: nicotine and 3-vinylpyridine (3-ethenylpyridine, 3-EP) in mainstream (MS) and sidestream (SS) smoke of one single cigarette and in indoor air using direct solid phase extraction combined with gas chromatography. The method can be utilised for both nicotine and 3-EP determination in SS and MS of one single cigarette as well as it allows for a precise determination of compound distribution in indoor air. The application of the same analytical method for both kinds of samples allows anticipating indoor air distribution of both analysed compounds in a very precise way. The precision of the method (calculated as a relative standard deviation) was 9.78% for nicotine and 2.67% for 3-EP; whereas the accuracy (evaluated by a recovery study conducted at three different levels) was 70.1 and 87.3%, respectively. The limit of detection was 0.06 µg per cigarette for both nicotine and 3-EP. The method was evaluated by determining the compounds of interest in two commercially available brands of cigarettes as well as in the reference cigarettes 3R4F and also in indoor air polluted with tobacco smoke. Determined levels of compounds of interest in MS varied from 586 to 772 (nicotine) µg per cigarette and from 3.5 to 10.7 (3-EP) µg per cigarette. In SS smoke the level varied from 14,370 to 22,590 (nicotine) µg per cigarette and from 185 to 550 (3-EP) µg per cigarette, whereas levels in indoor air polluted with tobacco smoke varied from 50.1 to 157.3 (nicotine) µg m(-3) and from 7.7 to 20.8 (3-EP) µg m(-3). PMID:19662106

  8. Ozone generation by negative direct current corona discharges in dry air fed coaxial wire-cylinder reactors

    SciTech Connect

    Yehia, Ashraf; Mizuno, Akira

    2013-05-14

    An analytical study was made in this paper for calculating the ozone generation by negative dc corona discharges. The corona discharges were formed in a coaxial wire-cylinder reactor. The reactor was fed by dry air flowing with constant rates at atmospheric pressure and room temperature, and stressed by a negative dc voltage. The current-voltage characteristics of the negative dc corona discharges formed inside the reactor were measured in parallel with concentration of the generated ozone under different operating conditions. An empirical equation was derived from the experimental results for calculating the ozone concentration generated inside the reactor. The results, that have been recalculated by using the derived equation, have agreed with the experimental results over the whole range of the investigated parameters, except in the saturation range for the ozone concentration. Therefore, the derived equation represents a suitable criterion for expecting the ozone concentration generated by negative dc corona discharges in dry air fed coaxial wire-cylinder reactors under any operating conditions in range of the investigated parameters.

  9. New directions: Time for a new approach to modeling surface-atmosphere exchanges in air quality models?

    NASA Astrophysics Data System (ADS)

    Saylor, Rick D.; Hicks, Bruce B.

    2016-03-01

    Just as the exchange of heat, moisture and momentum between the Earth's surface and the atmosphere are critical components of meteorological and climate models, the surface-atmosphere exchange of many trace gases and aerosol particles is a vitally important process in air quality (AQ) models. Current state-of-the-art AQ models treat the emission and deposition of most gases and particles as separate model parameterizations, even though evidence has accumulated over time that the emission and deposition processes of many constituents are often two sides of the same coin, with the upward (emission) or downward (deposition) flux over a landscape depending on a range of environmental, seasonal and biological variables. In this note we argue that the time has come to integrate the treatment of these processes in AQ models to provide biological, physical and chemical consistency and improved predictions of trace gases and particles.

  10. Demonstration of Air-Power-Assist Engine Technology for Clean Combustion and Direct Energy Recovery in Heavy Duty Application

    SciTech Connect

    Hyungsuk Kang; Chun Tai

    2010-05-01

    The first phase of the project consists of four months of applied research, starting from September 1, 2005 and was completed by December 31, 2005. During this time, the project team heavily relied on highly detailed numerical modeling techniques to evaluate the feasibility of the APA technology. Specifically, (i) A GT-Power{sup TM}engine simulation model was constructed to predict engine efficiency at various operating conditions. Efficiency was defined based on the second-law thermodynamic availability. (ii) The engine efficiency map generated by the engine simulation was then fed into a simplified vehicle model, which was constructed in the Matlab/Simulink environment, to predict fuel consumption of a refuse truck on a simple collection cycle. (iii) Design and analysis work supporting the concept of retrofitting an existing Sturman Industries Hydraulic Valve Actuation (HVA) system with the modifications that are required to run the HVA system with Air Power Assist functionality. A Matlab/Simulink model was used to calculate the dynamic response of the HVA system. Computer aided design (CAD) was done in Solidworks for mechanical design and hydraulic layout. At the end of Phase I, 11% fuel economy improvement was predicted. During Phase II, the engine simulation group completed the engine mapping work. The air handling group made substantial progress in identifying suppliers and conducting 3D modelling design. Sturman Industries completed design modification of the HVA system, which was reviewed and accepted by Volvo Powertrain. In Phase II, the possibility of 15% fuel economy improvement was shown with new EGR cooler design by reducing EGR cooler outlet temperature with APA engine technology from Air Handling Group. In addition, Vehicle Simulation with APA technology estimated 4 -21% fuel economy improvement over a wide range of driving cycles. During Phase III, the engine experimental setup was initiated at VPTNA, Hagerstown, MD. Air Handling system and HVA

  11. USE OF BIOASSAY-DIRECTED CHEMICAL ANALYSIS FOR IDENTIFYING MUTAGENIC COMPOUNDS IN URBAN AIR AND COMBUSTION EMISSIONS

    EPA Science Inventory

    Bioassay-directed chemical analysis fractionation has been used for 30 years to identify mutagenic classes of compounds in complex mixtures. Most studies have used the Salmonella (Ames) mutagenicity assay, and we have recently applied this methodology to two standard reference sa...

  12. Model-measurement comparison of ammonia bi-directional air-surface exchange fluxes over agricultural fields

    EPA Science Inventory

    Modeling of the bi-directional fluxes (BDFs) of ammonia (NH3) over fertilized soybean and corn canopies was evaluated for three intensive sampling periods: the first, during the summer of 2002 in Warsaw, North Carolina (NC), USA; and the second and third during the summer of 2007...

  13. Fundamental Study of a Single Point Lean Direct Injector. Part I: Effect of Air Swirler Angle and Injector Tip Location on Spray Characteristics

    NASA Technical Reports Server (NTRS)

    Tedder, Sarah A.; Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

    2015-01-01

    Lean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 degrees is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.

  14. Aerosol Direct Radiative Forcing in the Southern Appalachian Mountains: Initial Results from the Appalachian Atmospheric Interdisciplinary Research (AppalAIR) Facility

    NASA Astrophysics Data System (ADS)

    Taubman, B.; Sherman, J.; Sheridan, P. J.; Perry, L. B.; Neufeld, H.; Emanuel, R. E.; Tashakkori, R.; Bowman, D.; Long, C.

    2009-12-01

    AppalAIR (Appalachian Atmospheric Interdisciplinary Research, http://appalair.appstate.edu/) is a new interdisciplinary, atmospheric research facility located on the campus of Appalachian State University (1076 m; 36.2° N, 81.7° W) in the southern Appalachian Mountains. The facility was designed to investigate air pollution formation and transport, the relationships among biogenic and anthropogenic inputs to a changing climate, and the effects of these factors on regional ecosystems. AppalAIR is a collaborating member of the NOAA Earth System Research Laboratory Global Monitoring Division (NOAA/ESRL GMD) Collaborative Global Aerosol Network (http://www.esrl.noaa.gov/gmd/aero/net/app/index.html). Measurements are made from a 34 m tower and include aerosol light scattering (3-λ nephelometer) and absorption (3-λ PSAP, 7-λ aethalometer, 6-λ UV aethalometer), particle number concentration (CPC), and aerosol chemistry, size, and morphology using SPME/GC-MS and SEM analyses on 24 h filter samples. Initial results indicate alternating periods of small, highly absorptive (ssa < 0.90) fractal agglomerates and large, highly scattering (ssa > 0.95) spherical particles that are strongly dependent upon the highly variably meteorological patterns that have occurred over the summertime (JJA) in the southeastern U.S. By quantifying the aerosol direct radiative forcing during discrete meteorological patterns as defined by statistical cluster analysis as well as from specific aerosol chemical sources, we are able to extrapolate the results beyond the immediate region.

  15. Fundamental Study of a Single Point Lean Direct Injector. Part I: Effect of Air Swirler Angle and Injector Tip Location on Spray Characteristics

    NASA Technical Reports Server (NTRS)

    Tedder, Sarah A.; Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

    2014-01-01

    Lean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 deg is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.

  16. Spatially-Resolved Argon and Neon K-Shell X-Ray Spectra from Triple-Nozzle Gas-Puff Z-Pinches on Cobra

    NASA Astrophysics Data System (ADS)

    Qi, Niansheng; de Grouchy, Philip; Hoyt, Cad; Shelkovenko, Tania; Pikuz, Sergei; Atoyan, Levon; Potter, William; Cahill, Adam; Greenly, John; Kusse, Bruce; Hammer, David

    2014-10-01

    We present the x-ray spectra obtained during Ar/Ne gas puff z-pinch experiments on the 1MA, 200ns COBRA pulsed power generator at Cornell University. A triple-nozzle gas-puff, which produces two annular (``outer'' and ``inner'') gas puffs and a high density center jet, is used to tailor the radial mass density distribution. Argon and/or neon plasmas are imploded. Filtered x-ray photo-conducting detectors are used for timing the neon and argon K-shell emission and a filtered x-ray pinhole camera images the K-shell x-ray source size. A spectrometer with three spherical mica crystals is used to capture the K-shell x-ray emission. Our objective is to diagnose the Ar and Ne pinch plasma densities (1019-1020 cm-3) and temperatures (0.5-2 keV) with 0.1 mm axial and/or radial spatial resolution from the K-shell X-ray spectra. The He-like resonance to intercombination line ratio will be used to estimate the electron density and the He-like resonance to Li-like satellite line ratio will be used to estimate the electron temperature. We will also add Cl as a dopant in either the center Ar gas jet or inner annular puff for K-shell x-ray spectrum studies. Work supported by DOE Grant No. DE-NA0001836.

  17. Synthesis of free-standing carbon nanohybrid by directly growing carbon nanotubes on air-sprayed graphene oxide paper and its application in supercapacitor

    SciTech Connect

    Wei, Li; Jiang, Wenchao; Yuan, Yang; Goh, Kunli; Yu, Dingshan; Wang, Liang; Chen, Yuan

    2015-04-15

    We report the synthesis of a free-standing two dimensional carbon nanotube (CNT)-reduced graphene oxide (rGO) hybrid by directly growing CNTs on air-sprayed GO paper. As a result of the good integration between CNTs and thermally reduced GO film during chemical vapor deposition, excellent electrical conductivity (2.6×10{sup 4} S/m), mechanical flexibility (electrical resistance only increases 1.1% after bent to 90° for 500 times) and a relatively large surface area (335.3 m{sup 2}/g) are achieved. Two-electrode supercapacitor assembled using the CNT–rGO hybrids in ionic liquid electrolyte (1-ethyl-3-methylimidazolium tetrafluoroborate) shows excellent stability upon 500 bending cycles with the gravimetric energy density measuring 23.7 Wh/kg and a power density of 2.0 kW/kg. Furthermore, it shows an impedance phase angle of −64.4° at a frequency of 120 Hz, suggesting good potentials for 120 Hz alternating current line filtering applications. - Graphical abstract: Flexible and highly conductive carbon nanotube-reduced graphene oxide nanohybrid. - Highlights: • Direct growth of carbon nanotubes by chemical vapor deposition on air-sprayed graphene oxide paper. • Two-dimensional carbon nanohybrid with excellent conductivity and mechanical flexibility. • Supercapacitor with excellent performance stability upon mechanical deformation for flexible electronics applications. • Supercapacitor with high impedance phase angle for 120 Hz alternating current line filtering applications.

  18. In Vitro Exposures in Diesel Exhaust Atmospheres: Resuspension of PM from Filters Verses Direct Deposition of PM from Air

    PubMed Central

    Lichtveld, Kim M.; Ebersviller, Seth M.; Sexton, Kenneth G.; Vizuete, William; Jaspers, Ilona; Jeffries, Harvey E.

    2012-01-01

    One of the most widely used in vitro particulate matter (PM) exposures methods is the collection of PM on filters, followed by resuspension in a liquid medium, with subsequent addition onto a cell culture. To avoid disruption of equilibria between gases and PM, we have developed a direct in vitro sampling and exposure method (DSEM) capable of PM-only exposures. We hypothesize that the separation of phases and post-treatment of filter-collected PM significantly modifies the toxicity of the PM compared to direct deposition, resulting in a distorted view of the potential PM health effects. Controlled test environments were created in a chamber that combined diesel exhaust with an urban-like mixture. The complex mixture was analyzed using both the DSEM and concurrently-collected filter samples. The DSEM showed that PM from test atmospheres produced significant inflammatory response, while the resuspension exposures at the same exposure concentration did not. Increasing the concentration of resuspended PM sixteen times was required to yield measurable IL-8 expression. Chemical analysis of the resuspended PM indicated a total absence of carbonyl compounds compared to the test atmosphere during the direct-exposures. Therefore, collection and resuspension of PM into liquid modifies its toxicity and likely leads to underestimating toxicity. PMID:22834915

  19. The direct problem of acoustic diffraction of an audible probe radiation by an air-saturated porous cylinder

    NASA Astrophysics Data System (ADS)

    Ogam, Erick; Depollier, Claude; Fellah, Z. E. A.

    2010-12-01

    Gas-saturated, solid skeleton, porous media like geomaterials, polymeric and metallic foams or biomaterials are fundamental in a diverse range of applications, from structural materials to energy technologies. Most polymeric foams are used for noise control applications and knowledge of the manner in which the energy of sound waves is dissipated with respect to the intrinsic acoustic properties is important for the design of sound packages. Foams are often employed in the audible, low frequency range where modeling and measurement techniques for the recovery of physical parameters responsible for energy loss, are still few. Accurate acoustic methods for the characterization of porous media are based on the measurement of the transmitted and/or reflected acoustic waves by platelike specimens at ultrasonic frequencies. In this study we have developed a method based on the theory and experiment of diffraction of acoustic waves by a rigid-frame, air-saturated polymeric foam in cylindrical form in the audible frequency regime. A dispersion relation for sound wave propagation in the porous medium is derived from the propagation equations and a model solution is sought based on plane-wave decomposition using orthogonal cylindrical functions. The explicit analytical solution equation of the scattered field show that it is also dependent on the intrinsic microstructural parameters of the porous cylinder namely, porosity, tortuosity, and the flow resistivity (related to permeability).

  20. A compact UHV package for microfabricated ion-trap arrays with direct electronic air-side access

    NASA Astrophysics Data System (ADS)

    Wilpers, Guido; See, Patrick; Gill, Patrick; Sinclair, Alastair G.

    2013-04-01

    We have demonstrated a new apparatus for operating microfabricated ion-trap arrays in a compact ultra-high-vacuum setup with excellent optical and electrical access. The approach uses conventional components, materials and techniques in a unique fashion. The microtrap chip is mounted on a modified ceramic leadless chip carrier, the conductors of which serve as the vacuum feedthrough. The chip carrier is indium-sealed to stainless-steel components to form vacuum seals, resulting in short electrical path lengths of ≤20 mm from the trap electrodes under vacuum to air side. The feedthrough contains conductors for the radio-frequency trap drive, as well as 42 conductors for DC electrodes. Vacuum pressures of ˜1 × 10-11 mbar are achieved, and ions have been confined and laser cooled in a microtrap chip. The apparatus enables accurate measurements of radio-frequency voltage amplitudes on the trap electrodes, yielding an excellent agreement between measured and modelled trap efficiencies. This feature is of significant use in establishing initial operation of new devices. The principle of the connectivity scheme presented here is applicable to larger ceramic chip carriers containing many more conductors.

  1. The study of the properties of turbulent stably stratified air flow over water surface by direct numerical simulation

    NASA Astrophysics Data System (ADS)

    Druzhinin, Oleg; Troitskaya, Yuliya; Zilitinkevich, Sergej

    2014-05-01

    Parameterization of turbulent momentum and heat fluxes in a turbulent, stably stratified boundary layer flow over water surface is important for numerical climate modeling and weather prediction. In this work, the detailed structure and statistical characteristics of a turbulent, stably stratified atmospheric boundary layer flow over water surface is studied by direct numerical simulation (DNS). The most difficult case for modeling is that of flows at high Reynolds numbers and sufficiently steep surface waves, when strongly non-linear effects (e.g. sheltering, boundary layer separation, vortex formation etc.) are encountered. Of special interest is the influence of the wind flow stratification on the properties of boundary-layer turbulence and the turbulent momentum and heat fluxes. In DNS a two-dimensional water wave with different wave age parameters (c/u*, where u* is the friction velocity and c is the wave celerity), wave slope ka varying from 0 to 0.2 and bulk Reynolds number Re (from 15000 to 80000) and different Richardson numbers are considered. The shape of the water wave is prescribed and does not evolve under the action of the wind. The full, 3D Navier-Stokes equations under the Boussinesq approximation are solved in curvilinear coordinates in a frame of reference moving the phase velocity of the wave. The shear driving the flow is created by an upper plane boundary moving horizontally with a bulk velocity in the x-direction. Periodic boundary conditions are considered in the horizontal (x) and lateral (y) directions, and no-slip boundary condition is considered in the vertical z-direction. The grid of 360 x 240 x 360 nodes in the x, y, and z directions is used. The Adams-Bashforth method is employed to advance the integration in time and the equation for the pressure is solved iteratively. Ensemble-averaged velocity and pressure fields are evaluated by averaging over time and the spanwise coordinate. Profiles of the mean velocity and turbulent stresses

  2. Efficient Radiation Production in Long Implosions of Structured Gas-Puff Z Pinch Loads from Large Initial Radius

    SciTech Connect

    Sze, H.; Banister, J.; Failor, B.H.; Levine, J.S.; Qi, N.; Sincerny, P.; Velikovich, A.L.; Davis, J.; Lojewski, D.

    2005-09-02

    We have proposed and demonstrated successfully a new approach for generating high-yield K-shell radiation with large-diameter gas-puff Z pinches. The novel load design consists of an outer region plasma that carries the current and couples energy from the driver, an inner region plasma that stabilizes the implosion, and a high-density center jet plasma that radiates. It increased the Ar K-shell yield at 3.46 MA in 200 ns implosions from 12 cm initial diameter by a factor of 2, to 21 kJ, matching the yields obtained earlier on the same accelerator with 100 ns implosions. A new ''pusher-stabilizer-radiator'' physical model is advanced to explain this result.

  3. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

    SciTech Connect

    Loebner, Keith T. K. Underwood, Thomas C.; Cappelli, Mark A.

    2015-06-15

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  4. A Radiative Performance Investigation of the PLIF Experimental and Theoretical Large Diameter Argon Gas Puff Nozzle Profiles on DQ

    NASA Astrophysics Data System (ADS)

    Chong, Y. K.; Thornhill, J. W.; Davis, J.; Qi, N.; Frese, M. H.; Frese, S. D.

    2004-11-01

    Theoretical and experimental results for the dynamics and the K-shell radiation emission characteristics of large diameter argon double-puff loads driven by the Decade Quad (DQ) pulsed power generator are compared. The theoretical results are generated using a version of the MACH2 two dimensional MHD code that incorporates a tabular collisional radiative equilibrium (TCRE) model. The TCRE model is needed to self-consistently treat the non-LTE radiation and ionization dynamics. The initial gas density profiles used in the calculations are taken from the measured PLIF (planar laser induced fluorescence) data. Based on the results of this experimental/theoretical comparison, it may be possible to create a theoretical tool for designing future nozzles. This can be done by combining the capabilities of our radiation MHD code with one that does a reasonable job of predicting the initial density profile for a given nozzle such as the Navier Stokes nozzle design code at AEDC.

  5. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

    NASA Astrophysics Data System (ADS)

    Loebner, Keith T. K.; Underwood, Thomas C.; Cappelli, Mark A.

    2015-06-01

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  6. Application of the Kolmogorov-Zurbenko filter and the decoupled direct 3D method for the dynamic evaluation of a regional air quality model

    NASA Astrophysics Data System (ADS)

    Kang, Daiwen; Hogrefe, Christian; Foley, Kristen L.; Napelenok, Sergey L.; Mathur, Rohit; Trivikrama Rao, S.

    2013-12-01

    Regional air quality models are being used in a policy-setting to assess the changes in air pollutant concentrations from changes in emissions and meteorology. Dynamic evaluation entails examination of a retrospective case(s) to examine whether an air quality model has properly predicted the air quality response to known changes in emissions and/or meteorology. In this study, the Kolmogorov-Zurbenko (KZ) filter has been used to spectrally decompose pollutant time series into different forcings that are controlled by different atmospheric processes influencing the predicted and observed pollutant concentrations. Through analyses of the different components influenced by different forcings as part of dynamic model evaluation, we can discern which of the component(s) or scale(s) of forcing are simulated well by the model and the component(s) or scale(s) of forcing needing further improvement in the model. The KZ filter has been applied to both the observed and Community Multiscale Air Quality (CMAQ) model-predicted summertime ozone (O3) time series in years 2002 and 2005. The 2002-2005 time period is a good candidate for the dynamic evaluation case study because of the large changes in NOx emissions as a result of the U.S. Environmental Protection Agency's (USEPA) NOx State Implementation Plan (SIP) call together with a gradual decline in mobile emissions. Results suggest that the CMAQ model performs similarly for both years in terms of capturing the observed synoptic-scale forcing. However, the changes in the observed ozone baseline component (i.e. longer-term variations) are not properly captured by the model at some locations. The factors contributing to the ozone baseline include emissions loading, boundary conditions, and other parameters that vary slowly over time. Analysis using a reduced form model developed from the sensitivity coefficients calculated from the decoupled direct method in three dimensions (DDM-3D) reveals that ground-level NOx emissions

  7. Magnetic Rayleigh-Taylor instability mitigation and efficient radiation production in gas puff Z-pinch implosions

    SciTech Connect

    Sze, H.; Levine, J. S.; Banister, J.; Failor, B. H.; Qi, N.; Steen, P.; Velikovich, A. L.; Davis, J.; Wilson, A.

    2007-05-15

    Large radius Z-pinches are inherently susceptible to the magnetic Rayleigh-Taylor (RT) instability because of their relatively long acceleration path. This has been reflected in a significant reduction of the argon K-shell yield as was observed when the diameter of the load was increased from 2.5 to >4 cm. Recently, an approach was demonstrated to overcome the challenge with a structured gas puff load that mitigates the RT instability, enhances the energy coupling, and leads to a high compression, high yield Z-pinch. The novel load consists of a 'pusher', outer region plasma that carries the current and couples energy from the driver, a 'stabilizer', inner region plasma that mitigates the RT growth, and a ''radiator,'' high-density center jet plasma that is heated and compressed to radiate. In 3.5-MA, 200-ns, 12-cm initial diameter implosions, the Ar K-shell yield has increased by a factor of 2, to 21 kJ, matching the yields obtained on the same accelerator with 100-ns, 2.5-cm-diam implosions. Further tests of such structured Ar gas load on {approx}6 MA, 200-ns accelerators have achieved >80 kJ. From laser diagnostics and measurements of the K-shell and extreme ultraviolet emission, initial gas distribution and implosion trajectories were obtained, illustrating the RT suppression and stabilization of the imploding plasma, and identifying the radiation source region in a structured gas puff load. Magnetohydrodynamic simulations, started from actual initial density profiles, reproduce many features of the measurements both qualitatively and quantitatively.

  8. Direct Measurement of Air-Sea Exchange of N2O5 and ClNO2 at a Polluted Coastal Site (Invited)

    NASA Astrophysics Data System (ADS)

    Bertram, T. H.; Kim, M.; Ryder, O. S.; Farmer, D.

    2013-12-01

    The reactive uptake of N2O5 at aqueous interfaces can serve as both an efficient NOx removal mechanism and regionally significant halogen activation process through the production of photo-labile ClNO2 molecules. Both the reaction rate and ClNO2 product yield are a complex function of the chemical composition and chloride molarity of the reactive surface. To date, analysis of the impact of N2O5 chemistry on oxidant loadings in the marine boundary layer has been limited to reactions occurring on aerosol particles, with little attention paid to reactions occurring at the air-sea interface. Here, we report the first direct measurements of the air-sea flux of N2O5 and ClNO2 made via eddy covariance in the polluted marine boundary layer in La Jolla, CA. We observe rapid N2O5 deposition to the ocean surface, while ClNO2 deposition rates were significantly lower and fastest during the first three hours following sunset. The results are interpreted using a time-dependent box-model, suggesting that under conditions characterized by shallow marine boundary layer heights (< 100 m) and representative aerosol reactive uptake coefficients (< 0.01), N2O5 deposition to the ocean surface can account for over 50% of the total N2O5 loss rate.

  9. Direct determination of total sulfur in wine using a continuum-source atomic-absorption spectrometer and an air-acetylene flame.

    PubMed

    Huang, Mao Dong; Becker-Ross, Helmut; Florek, Stefan; Heitmann, Uwe; Okruss, Michael

    2005-08-01

    Determination of sulfur in wine is an important analytical task, particularly with regard to food safety legislation, wine trade, and oenology. Hitherto existing methods for sulfur determination all have specific drawbacks, for example high cost and time consumption, poor precision or selectivity, or matrix effects. In this paper a new method, with low running costs, is introduced for direct, reliable, rapid, and accurate determination of the total sulfur content of wine samples. The method is based on measurement of the molecular absorption of carbon monosulfide (CS) in an ordinary air-acetylene flame by using a high-resolution continuum-source atomic-absorption spectrometer including a novel high-intensity short-arc xenon lamp. First results for total sulfur concentrations in different wine samples were compared with data from comparative ICP-MS measurements. Very good agreement within a few percent was obtained. PMID:15999269

  10. System for time-discretized vacuum ultraviolet spectroscopy of spark breakdown in air

    SciTech Connect

    Ryberg, D.; Fierro, A.; Dickens, J.; Neuber, A.

    2014-10-15

    A system for time-discretized spectroscopic measurements of the vacuum ultraviolet (VUV) emission from spark discharges in the 60-160 nm range has been developed for the study of early plasma-forming phenomena. The system induces a spark discharge in an environment close to atmospheric conditions created using a high speed puff value, but is otherwise kept at high vacuum to allow for the propagation of VUV light. Using a vertical slit placed 1.5 mm from the discharge the emission from a small cross section of the discharge is allowed to pass into the selection chamber consisting of a spherical grating, with 1200 grooves/mm, and an exit slit set to 100 μm. Following the exit slit is a photomultiplier tube with a sodium salicylate scintillator that is used for the time discretized measurement of the VUV signal with a temporal resolution limit of 10 ns. Results from discharges studied in dry air, Nitrogen, SF{sub 6}, and Argon indicate the emission of light with wavelengths shorter than 120 nm where the photon energy begins to approach the regime of direct photoionization.

  11. The study of the effect of the surface wave on turbulent stably-stratified boundary layer air-flow by direct numerical simulation

    NASA Astrophysics Data System (ADS)

    Druzhinin, Oleg; Troitskaya, Yliya; Zilitinkevich, Sergej

    2015-04-01

    Detailed knowledge of the interaction of surface water waves with the wind flow is of primary importance for correct parameterization of turbulent momentum and heat fluxes which define the energy and momentum transfer between the atmosphere and hydrosphere. The objective of the present study is to investigate the properties of the stably stratified turbulent boundary-layer (BL) air-flow over waved water surface by direct numerical simulation (DNS) at a bulk Reynolds number varying from 15000 to 80000 and the surface-wave slope up to ka = 0.2. The DNS results show that the BL-flow remains in the statistically stationary, turbulent regime if the Reynolds number (ReL) based on the Obukhov length scale and friction velocity is sufficiently large (ReL > 100). In this case, mean velocity and temperature vertical profiles are well predicted by log-linear asymptotic solutions following from the Monin-Obukhov similarity theory provided the velocity and temperature roughness parameters, z0U and z0T, are appropriately prescribed. Both z0U and z0T increase for larger surface-wave slope. DNS results also show that turbulent momentum and heat fluxes and turbulent velocity and temperature fluctuations are increased for larger wave slope (ka) whereas the mean velocity and temperature derivatives remain practically the same for different ka. Thus, we conclude that the source of turbulence enhancement in BL-flow are perturbations induced by the surface wave, and not the shear instability of the bulk flow. On the other hand, if stratification is sufficiently strong, and the surface-wave slope is sufficiently small, the BL-flow over waved surface relaminarizes in the bulk of the domain. However, if the surface-wave slope exceeds a threshold value, the velocity and temperature fluctuations remain finite in the vicinity of the critical-layer level, where the surface-wave phase velocity coincides with the mean flow velocity. We call this new stably-stratified BL-flow regime observed in

  12. The Clean Air Game.

    ERIC Educational Resources Information Center

    Avalone-King, Deborah

    2000-01-01

    Introduces the Clean Air game which teaches about air quality and its vital importance for life. Introduces students to air pollutants, health of people and environment, and possible actions individuals can take to prevent air pollution. Includes directions for the game. (YDS)

  13. The size dependence of the average transverse momentum of hadrons with respect to the shower axis direction in extensive air showers observed at sea level

    NASA Astrophysics Data System (ADS)

    Ashton, F.; Nejabat, H.

    The simplest way of studying whether the characteristics of a nucleon-nucleon interaction change with increasing energy is to observe whether the mean value of hadron energy at the orthogonal core distance depends on shower size. Ashton et al. (1977) used a high-energy hadron detector as a master trigger and measured the core position and shower size of any accompanying air shower; results showed that the average transverse momentum of hadrons with respect to the shower axis direction increases with shower size. These results are checked, but with the following experimental changes: (1) the master trigger is now either an electron density inner ring trigger or an electron density outer ring trigger of the Durham EAS array; (2) the orthogonal core distances between measured hadron interactions and the shower axis direction are found; and (3) the charged or neutral state of a sample of detected hadrons is determined. The previously obtained results are confirmed by the experiment, and a change in the character of the nucleon-nucleon interaction is indicated for energies greater than 2 x 10 to the 14th eV.

  14. Quantitative measurements of one-dimensional OH absolute concentration profiles in a methane/air flat flame by bi-directional laser-induced fluorescence

    NASA Astrophysics Data System (ADS)

    Yu, Xin; Yang, Zhen; Peng, Jiang-Bo; Zhang, Lei; Ma, Yu-Fei; Yang, Chao-Bo; Li, Xiao-Hui; Sun, Rui

    2015-11-01

    The one-dimensional (1D) spatial distributions of OH absolute concentration in methane/air laminar premixed flat flame under different equivalence ratios at atmospheric pressure are investigated by using bi-directional laser-induced fluorescence (LIF) detection scheme combined with the direct absorption spectroscopy. The effective peak absorption cross section and the average temperature at a height of 2 mm above the burner are obtained by exciting absorption on the Q1(8) rotational line in the A2Σ+ (ʋ‧ = 0) ← X2Π (ʋ″ = 0) at 309.240 nm. The measured values are 1.86×10-15 cm2 and 1719 K, respectively. Spatial filtering and frequency filtering methods of reducing noise are used to deal with the experimental data, and the smoothing effects are also compared using the two methods. The spatial distribution regularities of OH concentration are obtained with the equivalence ratios ranging from 0.8 to 1.3. The spatial resolution of the measured result is 84 μm. Finally, a comparison is made between the experimental result of this paper and other relevant study results. Project supported by the National Key Scientific Instrument and Equipment Development Projects of China (Grant No. 2012YQ040164), the National Natural Science Foundation of China (Grant Nos. 61275127 and 91441130), the China Postdoctoral Science Foundation (Grant No. 2014M560262), and the Postdoctoral Fellowship in Heilongjiang Province, China (Grant No. LBH-Z14074).

  15. Primary zone air proportioner

    DOEpatents

    Cleary, Edward N. G.

    1982-10-12

    An air proportioner is provided for a liquid hydrocarbon fueled gas turbine of the type which is convertible to oil gas fuel and to coal gas fuel. The turbine includes a shell for enclosing the turbine, an air duct for venting air in said shell to a gasifier, and a fuel injector for injecting gasified fuel into the turbine. The air proportioner comprises a second air duct for venting air from the air duct for mixing with fuel from the gasifier. The air can be directly injected into the gas combustion basket along with the fuel from the injector or premixed with fuel from the gasifier prior to injection by the fuel injector.

  16. Recent advancements in the "water-window" microscopy with laser-plasma SXR source based on a double stream gas-puff target

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.

    2016-09-01

    An overview of our recent developments, regarding "water-window" soft X-ray (SXR) microscopy based on a laser-plasma double stream gas puff target sources is presented. The work, presented herein, describes two approaches to SXR microscopy. The first one is a low spatial resolution, achromatic SXR microscopy, employing Wolter type-I objective. The second one is a nanometer spatial resolution SXR microscopy, with the use of a Fresnel zone plate objective, for imaging various objects with quasimonochromatic light, emitted from a double stream gas puff target based short wavelength source. The developments regarding both systems are presented, as well as the possible applications, for which the SXR microscope was already employed. Such compact, table-top size, laboratory type microscopy setups may be employed in the near future for complementary-like studies to other, often used, microscopy techniques.

  17. The effect of gradients at stagnation on K-shell x-ray line emission in high-current Ar gas-puff implosions

    SciTech Connect

    Jones, B. Harvey-Thompson, A. J.; Ampleford, D. J.; Jennings, C. A.; Hansen, S. B.; Moore, N. W.; Lamppa, D. C.; Johnson, D.; Jones, M. C.; Waisman, E. M.; Coverdale, C. A.; Cuneo, M. E.; Rochau, G. A.; Apruzese, J. P.; Giuliani, J. L.; Thornhill, J. W.; Ouart, N. D.; Chong, Y. K.; Velikovich, A. L.; Dasgupta, A.; and others

    2015-02-15

    Argon gas puffs have produced 330 kJ ± 9% of x-ray radiation above 3 keV photon energy in fast z-pinch implosions, with remarkably reproducible K-shell spectra and power pulses. This reproducibility in x-ray production is particularly significant in light of the variations in instability evolution observed between experiments. Soft x-ray power measurements and K-shell line ratios from a time-resolved spectrum at peak x-ray power suggest that plasma gradients in these high-mass pinches may limit the K-shell radiating mass, K-shell power, and K-shell yield from high-current gas puffs.

  18. “Water window” compact, table-top laser plasma soft X-ray sources based on a gas puff target

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Bartnik, A.; Fiedorowicz, H.; Rudawski, P.; Jarocki, R.; Kostecki, J.; Szczurek, M.

    2010-05-01

    We have developed compact, high repetition, table-top soft-X-ray sources, based on a gas puff target, emitting in "water window" spectral range at λ = 2.88 nm from nitrogen gas target or, in 2-4 nm range of wavelengths, from argon gas target. Double stream gas puff target was pumped optically by commercial Nd:YAG laser, energy 0.74 J, pulse time duration 4 ns. Spatial distribution of laser-produced plasma was imaged using a pinhole camera. Using transmission grating spectrometer, argon and nitrogen emission spectra were obtained, showing strong emission in the "water window" spectral range. Using AXUV100 detector the flux measurements of the soft-X-ray pulses were carried out and are presented. These debris free sources are table-top alternative for free electron lasers and synchrotron installations. They can be successfully employed in microscopy, spectroscopy and metrology experiments among others.

  19. Experiments with a Gas-Puff-On-Wire-Array Load on the GIT-12 Generator for Al K-shell Radiation Production at Microsecond Implosion Times

    NASA Astrophysics Data System (ADS)

    Shishlov, Alexander V.; Baksht, Rina B.; Chaikovsky, Stanislav A.; Fedunin, Anatoly V.; Fursov, Fedor I.; Kovalchuk, Boris M.; Kokshenev, Vladimir A.; Kurmaev, Nikolai E.; Labetsky, Aleksey Yu.; Oreshkin, Vladimir I.; Rousskikh, Alexander G.; Lassalle, Francis; Bayol, Frederic

    2006-01-01

    Results of the experiments carried out on the GIT-12 generator at the current level of 3.5 MA and the Z-pinch implosion times from 700 ns to 1.1 μs are presented. A multi-shell (triple-shell) load configuration with the outer gas puffs (neon) and the inner wire array (aluminum) was used in the experiments. In the course of the research, implosion dynamics of the triple-shell z-pinch was studied, and the radiation yield in the spectral range of neon and aluminum K-lines have been measured. Optimization of the inner wire array parameters aimed at obtaining the maximum aluminum K-shell radiation yield has been carried out. As a result of optimization of the gas-puff-on-wire-array Z-pinch load, the aluminum K-shell radiation yield (hv> 1.55 keV) up to 4 kJ/cm in the radiation pulse with FWHM less than 30 ns has been obtained. Comparison of the experimental results with the results of preliminary 1D RMHD simulations allows a conclusion that at least 2/3 of the generator current is switched from a gas puff to an aluminum wire array. The radiation yield in the spectral range of neon K-lines (0.92-1.55 keV) increases considerably in the shots with the inner wire array in comparison with the shots carried out with the outer gas puffs only. The radiation yield in the spectral range above 1 keV registered in the experiments reached 10 kJ/cm. The presence of a high portion of the neon plasma inside an inner wire array can limit the radiation yield in the spectral range above 1.55 keV.

  20. Application of Kolomogorov-Zurbenko Filter and the decoupled direct 3D method for the dynamic evaluation of a regional air quality model

    EPA Science Inventory

    Regional air quality models are being used in a policy-setting to estimate the response of air pollutant concentrations to changes in emissions and meteorology. Dynamic evaluation entails examination of a retrospective case(s) to assess whether an air quality model has properly p...

  1. Air temperature, wind speed, and wind direction in the National Petroleum Reserve—Alaska and the Arctic National Wildlife Refuge, 1998–2011

    USGS Publications Warehouse

    Urban, Frank E.; Clow, Gary D.

    2013-01-01

    This report provides air temperature, wind speed, and wind direction data collected on Federal lands in Arctic Alaska over the period August 1998 to July 2011 by the U.S. Department of the Interior's climate monitoring array, part of the Global Terrestrial Network for Permafrost. In addition to presenting data, this report also describes monitoring, data collection, and quality control methodology. This array of 16 monitoring stations spans 68.5°N to 70.5°N and 142.5°W to 161°W, an area of roughly 150,000 square kilometers. Climate summaries are presented along with provisional quality-controlled data. Data collection is ongoing and includes several additional climate variables to be released in subsequent reports, including ground temperature and soil moisture, snow depth, rainfall, up- and downwelling shortwave radiation, and atmospheric pressure. These data were collected by the U.S. Geological Survey in close collaboration with the Bureau of Land Management and the U.S. Fish and Wildlife Service.

  2. Direct quantification of PM{sub 2.5} fossil and biomass carbon within the Northern Front Range Air Quality Study's domain

    SciTech Connect

    Klinedinst, D.B.; Currie, L.A.

    1999-12-01

    Radiocarbon ({sup 14}C) analyses of PM{sub 2.5} (particulate matter with an aerodynamic diameter of 2.5 {micro}m or less) of both ambient and source samples from the Northern Front Range Air Quality Study (NFRAQS) in Colorado were performed. The {sup 14}C analyses were undertaken to provide direct fossil vs modern (biomass) carbon source discrimination data for a subset of summer and winter 1996--1997 samples collected within the Denver metropolitan area. Samples were prepared for {sup 14}C accelerator mass spectrometry measurements using techniques specially developed for small samples, i.e., {lt}100 {mu}g C. For the days and sampling periods analyzed the median and interquartile range of the winter blank corrected fraction of modern carbon was 23% (16--34%) at Welby and 27% (25--37%) at Brighton. The summer samples exhibited a more mixed signature with a median and interquartile range of 47% (9--70%). Source samples yielded {sup 14}C signatures consistent with expectation. The authors conclude fossil-derived sources contribute substantially in both seasons and at both locations; however, the biomass carbon component dominates episodically in the summer.

  3. Direct AFM force measurements between air bubbles in aqueous polydisperse sodium poly(styrene sulfonate) solutions: effect of collision speed, polyelectrolyte concentration and molar mass.

    PubMed

    Browne, Christine; Tabor, Rico F; Grieser, Franz; Dagastine, Raymond R

    2015-07-01

    Interactions between colliding air bubbles in aqueous solutions of polydisperse sodium poly(styrene sulfonate) (NaPSS) using direct force measurements were studied. The forces measured with deformable interfaces were shown to be more sensitive to the presence of the polyelectrolytes when compared to similar measurements using rigid interfaces. The experimental factors that were examined were NaPSS concentration, bubble collision velocity and polyelectrolyte molar mass. These measurements were then compared with an analytical model based on polyelectrolyte scaling theory in order to explain the effects of concentration and bubble deformation on the interaction between bubbles. Typically structural forces from the presence of monodisperse polyelectrolyte between interacting surfaces may be expected, however, it was found that the polydispersity in molar mass resulted in the structural forces to be smoothed and only a depletion interaction was able to be measured between interacting bubbles. It was found that an increase in number density of NaPSS molecules resulted in an increase in the magnitude of the depletion interaction. Conversely this interaction was overwhelmed by an increase in the fluid flow in the system at higher bubble collision velocities. Polymer molar mass dispersity plays a significant role in the interactions present between the bubbles and has implications that also affect the polyelectrolyte overlap concentration of the solution. Further understanding of these implications can be expected to play a role in the improvement in operations in such fields as water treatment and mineral processing where polyelectrolytes are used extensively. PMID:25596872

  4. Synthesis of free-standing carbon nanohybrid by directly growing carbon nanotubes on air-sprayed graphene oxide paper and its application in supercapacitor

    NASA Astrophysics Data System (ADS)

    Wei, Li; Jiang, Wenchao; Yuan, Yang; Goh, Kunli; Yu, Dingshan; Wang, Liang; Chen, Yuan

    2015-04-01

    We report the synthesis of a free-standing two dimensional carbon nanotube (CNT)-reduced graphene oxide (rGO) hybrid by directly growing CNTs on air-sprayed GO paper. As a result of the good integration between CNTs and thermally reduced GO film during chemical vapor deposition, excellent electrical conductivity (2.6×104 S/m), mechanical flexibility (electrical resistance only increases 1.1% after bent to 90° for 500 times) and a relatively large surface area (335.3 m2/g) are achieved. Two-electrode supercapacitor assembled using the CNT-rGO hybrids in ionic liquid electrolyte (1-ethyl-3-methylimidazolium tetrafluoroborate) shows excellent stability upon 500 bending cycles with the gravimetric energy density measuring 23.7 Wh/kg and a power density of 2.0 kW/kg. Furthermore, it shows an impedance phase angle of -64.4° at a frequency of 120 Hz, suggesting good potentials for 120 Hz alternating current line filtering applications.

  5. Two-dimensional two-phase mass transport model for methanol and water crossover in air-breathing direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Ye, Dingding; Zhu, Xun; Liao, Qiang; Li, Jun; Fu, Qian

    A two-dimensional two-phase mass transport model has been developed to predict methanol and water crossover in a semi-passive direct methanol fuel cell with an air-breathing cathode. The mass transport in the catalyst layer and the discontinuity in liquid saturation at the interface between the diffusion layer and catalyst layer are particularly considered. The modeling results agree well with the experimental data of a home-assembled cell. Further studies on the typical two-phase flow and mass transport distributions including species, pressure and liquid saturation in the membrane electrode assembly are investigated. Finally, the methanol crossover flux, the net water transport coefficient, the water crossover flux, and the total water flux at the cathode as well as their contributors are predicted with the present model. The numerical results indicate that diffusion predominates the methanol crossover at low current densities, while electro-osmosis is the dominator at high current densities. The total water flux at the cathode is originated primarily from the water generated by the oxidation reaction of the permeated methanol at low current densities, while the water crossover flux is the main source of the total water flux at high current densities.

  6. Direct measurements of HONO and NO2 by tunable infrared differential absorption spectroscopy; Results from two field campaigns sampling aircraft exhaust and ambient urban air

    NASA Astrophysics Data System (ADS)

    Lee, B. H.; Santoni, G.; Herndon, S. C.; Wood, E. C.; Miake-Lye, R. C.; Munger, J. W.; Wofsy, S. C.; Zahniser, M. S.; McManus, J. B.; Nelson, D. D.

    2009-12-01

    Nitrous acid (HONO) is an important source of hydroxyl radicals (OH), the main oxidizing agent in the atmosphere. However, gaseous HONO has historically proven difficult to measure accurately and to date there is no standard technique. We describe a new instrument capable of high-frequency measurements of HONO and nitrogen dioxide (NO2) mixing ratios by tunable infrared differential absorption spectrometry. Mid-infrared light from two continuous-wave mode quantum cascade lasers traverse a 210 m path through a multi-pass astigmatic cell at reduced pressures for the direct detection of HONO (1660 cm-1) and NO2 (1604 cm-1). We achieve an absorbance precision less than 3×10-6 Hz-1 in one second, which translates to detection limits (S/N=3) of 300 and 30 ppt for HONO and NO2, respectively, in one second. Both lasers and the detector are thermoelectrically cooled, facilitating long-term unattended measurements. We also report preliminary results from two field campaigns; the Alternative Aviation Fuels Experiment (AAFEX) and the Study of Houston Air Radical Precursors (SHARP). At AAFEX, HONO emission ratios relative to CO2 and NOy observed in commercial aircraft exhaust are larger than in most other combustion sources and likely to play a significant role in regional HOx chemistry. Preliminary analysis from the SHARP campaign shows good agreement in HONO and NO2 levels between various measurement techniques.

  7. Effects of dieting status and cigarette deprivation on progressive ratio responding for cigarette puffs by young women smokers.

    PubMed

    Jenks, Rebecca A; Higgs, Suzanne

    2011-04-01

    There is evidence from self-report measures which suggests that young women dieters find cigarette smoking less rewarding than non-dieters. We aimed to further elucidate differences between dieters and non-dieters in their evaluation of smoking using a behavioural measure of drug reward. Thirty female undergraduates attended two sessions (cigarette deprived and non-deprived). A computer-based progressive ratio operant procedure was employed to assess the amount of effort that participants were willing to expend to gain a puff on a cigarette. The point at which responding ceased was taken as a measure of drug reward (breakpoint). Self-report measures of sensory/hedonic aspects of smoking were also completed. The breakpoints of both dieters and non-dieters were greater under deprived than non-deprived conditions but the breakpoints of dieters were significantly lower than those of the non-dieting smokers under both conditions. Self-reported enjoyment of smoking was lower for dieters than non-dieters and reports for non-dieters but not dieters were affected by deprivation level. Both behavioural and self-report measures of rewarding aspects of smoking suggest that young women dieters find smoking less rewarding than non-dieters, but self-report measures are more resistant to deprivation effects for dieters. This is consistent with the suggestion that subjective and behavioural measures assess different dimensions of the rewarding effects of smoking. PMID:21169394

  8. Neutron Diagnostics of a Deuterium Gas-Puff Z-pinch on the Level of 3 MA

    NASA Astrophysics Data System (ADS)

    Rezac, Karel; Klir, Daniel; Kubes, Pavel; Kravarik, Jozef; Shishlov, Alexander; Labetsky, Aleksey; Ratakhin, Nicolai; GIT-12 Team

    2011-10-01

    The diagnostics of a deuterium gas-puff Z-pinch (outer shell with diam. of 100 or 80 mm, inner annular with diam. of 30 mm or solid-fill shell with diam. of 20 mm with linear mass varied in each shell in the range of 25 - 40 μg/cm) is presented. The experiments were carried out on the GIT-12 generator at IHCE in Tomsk (2.5 MJ bank energy, load current of 2.8 MA with the rise time of 250 ns) during the April-May campaign in 2011. Results from the neutron time-of-flight diagnostics including the determination of the neutron production time and reconstructed radial energy spectra are shown. Several methods which provided measurement of the total neutron yield indicated the number of neutrons in order of 1011 per one shot. The time correlations with other diagnostics such as electrical characteristics, soft X-rays, hard X-rays and a visible streak camera are also presented. Work supported by MEYS research programs No. LA08024, No. ME09087, No. LC528, by GACR grants No. 202-08-H057 and grant CRA IAEA No. 14817.

  9. Deuterium Gas-Puff Z-pinch as a Source of Fast Ions Producing Intensive Pulse of Neutrons

    NASA Astrophysics Data System (ADS)

    Rezac, K.; Cikhardt, J.; Cikhardtova, B.; Klir, D.; Kravarik, J.; Kubes, P.; Sila, O.; Shishlov, A.; Cherdizov, R.; Fursov, F.; Kokshenev, V.; Kovalchuk, B.; Kurmaev, N.; Labetsky, A.; Ratakhin, N.; Turek, K.

    2015-11-01

    A deuterium gas-puff with outer plasma shell has been examined on GIT-12 generator (on the current level of 3 MA) since 2013. Such a configuration caused more stable implosion at final stage of z-pinch. The consequence of this was a production of intensive pulses of fast ions. During last 4 campaigns in 2013-2015, fast ions were examined by several in-chamber diagnostics such as: stack detector (ion energy), pinhole camera (location of ion source), multi-pinhole camera (asymmetry and anisotropy of ion emission), and ion beam detector (dynamics of ion pulses). A CR-39 track detectors and also GAFCHROMIC HD-V2 films from these diagnostics will be presented. On the basis of obtained results, the solid sample for increasing of neutron yield up to 1e13 could be placed below the cathode mesh. Except of neutron yield, other properties such as: neutron energies (up to 33 MeV), neutron emission time (about 20 ns), and emission anisotropy of neutrons were measured. Such a short and intensive neutron pulse provides various applications. This work was supported by the MSMT project LH13283.

  10. Design and optimization of a gas-puff nozzle for staged Z-pinch experiments using computational fluid dynamics simulations

    NASA Astrophysics Data System (ADS)

    Valenzuela, J. C.; Krasheninnikov, I.; Beg, F. N.; Wessel, F.; Rahman, H.; Ney, P.; Presura, R.; McKee, E.; Darling, T.; Covington, A.

    2015-11-01

    Previous experimental work on staged Z-pinches demonstrated that gas liners can efficiently couple energy and implode uniformly a target-plasma. A 1.5 MA, 1 μs current driver was used to implode a magnetized, Kr liner onto a D + target, producing 1010 neutrons per shot and providing clear evidence of enhanced pinch stability. Time-of-flight data suggest that primary and secondary neutrons were produced. MHD simulations show that in Zebra, a 1.5MA and 100ns rise-time current driver, high fusion gain can be attained when the optimum liner and plasma target conditions are used. In this work we present the design and optimization of a liner-on-target nozzle to be fielded in Zebra and demonstrate high fusion gain at 1 MA current level. The nozzle is composed of an annular high atomic number gas-puff and an on-axis plasma gun that will deliver the ionized deuterium target. The nozzle optimization was carried out using the computational fluid dynamics (CFD) code fluent and the MHD code Mach2. The CFD simulation produces density and temperature profiles, as a function of the nozzle shapes and gas conditions, which are then used in Mach2 to find the optimum plasma liner implosion-pinch conditions. Funded by the US Department of Energy, ARPA-E, Control Number 1184-1527.

  11. Neutron production in deuterium gas-puff z-pinch with outer plasma shell at current of 3 MA

    NASA Astrophysics Data System (ADS)

    Cikhardt, J.; Klir, D.; Rezac, K.; Cikhardtova, B.; Kravarik, J.; Kubes, P.; Sila, O.; Shishlov, A. V.; Cherdizov, R. K.; Frusov, F. I.; Kokshenev, V. A.; Kurmaev, N. E.; Labetsky, A. Yu.; Ratakhin, N. A.; Dudkin, G. N.; Garapatsky, A. A.; Padalko, V. N.; Varlachev, V. A.; Turek, K.; Krasa, J.

    2015-11-01

    Z-pinch experiments at the current of about 3 MA were carried out on the GIT-12 generator. The outer plasma shell of deuterium gas-puff was generated by the system of 48 plasma guns. This configuration exhibits a high efficiency of the production of DD fusion neutrons with the yield of above 1012 neutrons produced in a single shot with the duration of about 20 ns. The maximum energy of the neutrons produced in this pulse exceeded 30 MeV. The neutron radiation was measured using scintillation TOF detectors, CR-39 nuclear track detectors, bubble detectors BD-PND and BDS-10000 and by several types of nuclear activation detectors. These diagnostic tools were used to measure the anisotropy of neutron fluence and neutron energy spectra. It allows us to estimate the total number of DD neutrons, the contribution of other nuclear reactions, the amount of scattered neutrons, and other parameters of neutron production. This work was supported by the MSMT grants LH13283, LD14089.

  12. A comparative assessment of cigarette smoke aerosols using an in vitro air-liquid interface cytotoxicity test.

    PubMed

    Thorne, David; Dalrymple, Annette; Dillon, Deborah; Duke, Martin; Meredith, Clive

    2015-01-01

    This study describes the evaluation of a modified air-liquid interface BALB/c 3T3 cytotoxicity method for the assessment of smoke aerosols in vitro. The functionality and applicability of this modified protocol was assessed by comparing the cytotoxicity profiles from eight different cigarettes. Three reference cigarettes, 1R5F, 3R4F and CORESTA Monitor 7 were used to put the data into perspective and five bespoke experimental products were manufactured, ensuring a balanced and controlled study. Manufactured cigarettes were matched for key variables such as nicotine delivery, puff number, pressure drop, ventilation, carbon monoxide, nicotine free dry particulate matter and blend, but significantly modified for vapor phase delivery, via the addition of two different types and quantities of adsorptive carbon. Specifically manufacturing products ensures comparisons can be made in a consistent manner and allows the research to ask targeted questions, without confounding product variables. The results demonstrate vapor-phase associated cytotoxic effects and clear differences between the products tested and their cytotoxic profiles. This study has further characterized the in vitro vapor phase biological response relationship and confirmed that the biological response is directly proportional to the amount of available vapor phase toxicants in cigarette smoke, when using a Vitrocell® VC 10 exposure system. This study further supports and strengthens the use of aerosol based exposure options for the appropriate analysis of cigarette smoke induced responses in vitro and may be especially beneficial when comparing aerosols generated from alternative tobacco aerosol products. PMID:26339773

  13. Subsurface evaluation of the west parking lot and landfill 3 areas of Air Force Plant 4, Fort Worth, Texas, using two-dimensional direct-current resistivity profiling

    USGS Publications Warehouse

    Braun, Christopher L.; Jones, Sonya A.

    2002-01-01

    During September 1999, the U.S. Geological Survey made 10 two-dimensional direct-current resistivity profile surveys in the west parking lot and landfill 3 areas of Air Force Plant 4, Fort Worth, Texas, to identify subsurface areas of anomalously high or low resistivity that could indicate potential contamination, contaminant pathways, or anthropogenic structures. Six of the 10 surveys (transects) were in the west parking lot. Each of the inverted sections of these transects had anomalously high resistivities in the terrace alluvium/fill (the surficial subsurface layer) that probably were caused by highly resistive fill material. In addition, each of these transects had anomalously low resistivities in the Walnut Formation (a bedrock layer immediately beneath the alluvium/fill) that could have been caused by saturation of fractures within the Walnut Formation. A high-resistivity anomaly in the central part of the study area probably is associated with pea gravel fill used in construction of a French drain. Another high resistivity anomaly in the west parking lot, slightly southeast of the French drain, could be caused by dense nonaqueous-phase liquid in the Walnut Formation. The inverted sections of the four transects in the landfill 3 area tended to have slightly higher resistivities in both the alluvium/fill and the Walnut Formation than the transects in the west parking lot. The higher resistivities in the alluvium/fill could have been caused by drier conditions in grassy areas relative to conditions in the west parking lot. Higher resistivities in parts of the Walnut Formation also could be a function of drier conditions or variations in the lithology of the Walnut Formation. In addition to the 10 vertical sections, four horizontal sections at 2-meteraltitude intervals show generally increasing resistivity with decreasing altitude that most likely results from the increased influence of the Walnut Formation, which has a higher resistivity than the terrace

  14. Analytical results from ground-water sampling using a direct-push technique at the Dover National Test Site, Dover Air Force Base, Delaware, June-July 2001

    USGS Publications Warehouse

    Guertal, William R.; Stewart, Marie; Barbaro, Jeffrey R.; McHale, Timthoy J.

    2004-01-01

    A joint study by the Dover National Test Site and the U.S. Geological Survey was conducted from June 27 through July 18, 2001 to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site at Dover Air Force Base, Delaware. The study was conducted to support a planned enhanced bio-remediation demonstration and to assist the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. This report presents the analytical results from ground-water samples collected during the direct-push ground-water sampling study. A direct-push drill rig was used to quickly collect 115 ground-water samples over a large area at varying depths. The ground-water samples and associated quality-control samples were analyzed for volatile organic compounds and methyl tert-butyl ether by the Dover National Test Site analytical laboratory. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloroethene, 1.14 micrograms per liter of trichloroethene, 2.65 micrograms per liter of tetrachloroethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest methyl tert-butyl ether concentrations were found in the surficial aquifer from -4.6 to 6.4 feet mean sea level, however, methyl tert-butyl ether was detected as deep as -9.5 feet mean sea level. Increased methane concentrations and decreased dissolved oxygen concentrations were found in

  15. Air Sensor Guidebook

    EPA Science Inventory

    This Air Sensor Guidebook has been developed by the U.S. EPA to assist those interested in potentially using lower cost air quality sensor technologies for air quality measurements. Its development was in direct response to a request for such a document following a recent scienti...

  16. OTM 33 Geospatial Measurement of Air Pollution, Remote Emissions Quantification (GMAP-REQ) and OTM33A Geospatial Measurement of Air Pollution-Remote Emissions Quantification-Direct Assessment (GMAP-REQ-DA)

    EPA Science Inventory

    Background: Next generation air measurement (NGAM) technologies are enabling new regulatory and compliance approaches that will help EPA better understand and meet emerging challenges associated with fugitive and area source emissions from industrial and oil and gas sectors. In...

  17. Demonstration of the ITER Power Exhaust Solution Using the Puff and Pump Technique on DIII-D

    SciTech Connect

    Wade, M.R.; West, W.P.; Hill, D.N.; Allen, S.L.; Boedo, J.A.; Brooks, N.H.; Fenstermacher, M.E.; Hogan, J.T.; Isler, R.C.; Jayakumar, R.J.; Lasnier, C.J.; Lehmer, R.; Leonard, A.W.; Maingi, R.; Moyer, R.A.; Petrie, T.W.; Schaffer, M.J.; Watkins, J.G.; Whyte, D.G.; Wood, R.D.

    1999-07-01

    In future, high power density fusion devices, the need to prevent excessive local deposition of the plasma energy efflux on the first-wall surfaces is a critical design consideration in order to maintain the integrity of such surfaces. This requirement must be met without significant impact on plasma purity or overall plasma confinement. For the International Thermonuclear Experimental Reactor (ITER), these constraints have led to the following design criteria [1] P{sub rad}/(P{sub input} + P{sub {alpha}}) = 83%, P{sub rad,core}/(P{sub input} + P{sub {alpha}}) = 33%, P{sub target}/P{sub loss} = 17%, Z{sub eff} < 1.8, and {tau}{sub E}/{tau}{sub E,ITER93H} > 0.85. Here, P{sub loss} is the power flowing out of the core (i.e., P{sub input} + P{sub {alpha}} - P{sub rad,core})and P{sub target} is the power conducted to the target plate. These criteria represent a compromise between obtaining sufficient radiation to reduce the target heat load to a tolerable level, minimizing core fuel dilution, and maintaining sufficient power flow through the edge plasma to maintain H-mode confinement. Past experiments have had difficulty achieving these conditions simultaneously when using seeded impurities, and therefore there has been some concern regarding the viability of the ITER design. However, recent experiments in DIII-D using the puff and pump technique with argon as the seeded impurity have demonstrated the compatibility of these design constraints. In particular, steady-state plasma conditions have been achieved with P{sub rad}/P{sub input} = 72%, P{sub rad,core}/P{sub input} = 16%, P{sub target}/P{sub loss} = 17%, Z{sub eff} = 1.85, and {tau}{sub E}/{tau}{sub E,ITER93H} = 1.05.

  18. CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. 1994 Annual report

    SciTech Connect

    Wehner, S.C.

    1995-05-01

    It is anticipated that this project will show that the application of the CO{sub 2} Huff-n-Puff process in shallow shelf carbonates can be economically implemented to recover appreciable volumes of light oil. The goals of the project are the development of guidelines for cost-effective selection of candidate reservoirs and wells, along with estimating recovery potential. The selected site for the demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Work is nearing completion on the reservoir characterization components of the project. The near-term emphasis is to, (1) provide an accurate distribution of original oil-in-place on a waterflood pattern entity level, (2) evaluate past recovery efficiencies, (3) perform parametric simulations, and (4) forecast performance for a site specific field demonstration of the proposed technology. Macro zonation now exists throughout the study area and cross-sections are available. The Oil-Water Contact has been defined. Laboratory capillary pressure data was used to define the initial water saturations within the pay horizon. The reservoir`s porosity distribution has been enhanced with the assistance of geostatistical software. Three-Dimensional kriging created the spatial distributions of porosity at interwell locations. Artificial intelligence software was utilized to relate core permeability to core porosity, which in turn was applied to the 3-D geostatistical porosity gridding. An Equation-of-State has been developed and refined for upcoming compositional simulation exercises. Options for local grid-refinement in the model are under consideration. These tasks will be completed by mid-1995, prior to initiating the field demonstrations in the second budget period.

  19. Scanning Lidar Measurements of the Full-Scale RDD Field Trial Puff Plumes.

    PubMed

    Cao, Xiaoying; Roy, Gilles

    2016-05-01

    A vertically scanning lidar (light/radar) was used to measure the time evolution of clouds generated by a small explosive device. Vertical sweeps were performed at a downwind distance of 105 m from the detonation. The measured quantity obtained from the lidar was the light extinction coefficient. This quantity is directly proportional to the aerosol concentration. The background aerosol value was set to 0.0001 m (-1) (assuming a visibility of 40 km), and assuming the scattering properties of the explosively generated cloud is the same as the background aerosol, the authors found that the instantaneous maximal local concentration of aerosol in the cloud did not exceed 500 times the background aerosol value, and the instantaneous concentration was typically less than five times the background aerosol value. In the two trials that were done, the volumes of the clouds were reasonably close at 2,700 m(3) and 4,000 m(3), respectively. PMID:27023031

  20. Characterization and optimization of images acquired by a compact soft X-ray microscope based on a double stream gas-puff target source

    NASA Astrophysics Data System (ADS)

    Torrisi, A.; Wachulak, P.; Fahad Nawaz, M.; Bartnik, A.; Węgrzyński, L.; Jancarek, A.; Fiedorowicz, H.

    2016-04-01

    Using a table-top size soft X-ray (SXR) microscope, based on a laser plasma source with a double stream gas-puff target and a Fresnel zone plate objective, series of images of test samples were acquired. Characterization and optimization of the acquisition parameters were studied and evaluated in terms of signal to noise ratio (SNR). Conclusions for the optimization of SXR imaging were reached. Similar SNR measurements might be performed to characterize other SXR imaging systems as well. Software enabling live calculation of the SNR during the image acquisition might be introduced in future in the compact imaging systems for optimal image acquisition or for benchmarking purposes.

  1. Magnetic Rayleigh-Taylor instability mitigation in large-diameter gas puff Z-pinch implosions

    SciTech Connect

    Qi, N.; Sze, H.; Failor, B. H.; Banister, J.; Levine, J. S.; Riordan, J. C.; Steen, P.; Sincerny, P.; Lojewski, D.

    2008-02-15

    Recently, a new approach for efficiently generating K-shell x-rays in large-diameter, long-implosion time, structured argon gas Z-pinches has been demonstrated based on a 'pusher-stabilizer-radiator' model. In this paper, direct observations of the Rayleigh-Taylor instability mitigation of a 12-cm diameter, 200-ns implosion time argon Z-pinch using a laser shearing interferometer (LSI) and a laser wavefront analyzer (LWA) are presented. Using a zero-dimensional snowplow model, the imploding plasma trajectories are calculated with the driver current waveforms and the initial mass distributions measured using the planar laser induced fluorescence method. From the LSI and LWA images, the plasma density and trajectory during the implosion are measured. The measured trajectory agrees with the snowplow calculations. The suppression of hydromagnetic instabilities in the ''pusher-stabilizer-radiator'' structured loads, leading to a high-compression ratio, high-yield Z-pinch, is discussed. For comparison, the LSI and LWA images of an alternative load (without stabilizer) show the evolution of a highly unstable Z-pinch.

  2. In Vitro Toxic Effects of Puff Adder (Bitis arietans) Venom, and Their Neutralization by Antivenom

    PubMed Central

    Fernandez, Steven; Hodgson, Wayne; Chaisakul, Janeyuth; Kornhauser, Rachelle; Konstantakopoulos, Nicki; Smith, Alexander Ian; Kuruppu, Sanjaya

    2014-01-01

    This study investigated the in vitro toxic effects of Bitis arietans venom and the ability of antivenom produced by the South African Institute of Medical Research (SAIMR) to neutralize these effects. The venom (50 µg/mL) reduced nerve-mediated twitches of the chick biventer muscle to 19% ± 2% of initial magnitude (n = 4) within 2 h. This inhibitory effect of the venom was significantly attenuated by prior incubation of tissues with SAIMR antivenom (0.864 µg/µL; 67% ± 4%; P < 0.05; n = 3–5, unpaired t-test). Addition of antivenom at t50 failed to prevent further inhibition or reverse the inhibition of twitches and responses to agonists. The myotoxic action of the venom (50 µg/mL) was evidenced by a decrease in direct twitches (30% ± 6% of the initial twitch magnitude) and increase in baseline tension (by 0.7 ± 0.3 g within 3 h) of the chick biventer. Antivenom failed to block these effects. Antivenom however prevented the venom induced cytotoxic effects on L6 skeletal muscle cells. Venom induced a marginal but significant reduction in plasma clotting times at concentrations above 7.8 µg/100 µL of plasma, indicating poor procoagulant effects. In addition, the results of western immunoblotting indicate strong immunoreactivity with venom proteins, thus warranting further detailed studies on the neutralization of the effects of individual venom toxins by antivenom. PMID:24854547

  3. Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

    PubMed

    Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

    2010-02-01

    Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers. PMID:20050661

  4. A reassessment study of multi-material-shell gas puff z-pinches as a pulsed neutron source on the sandia ZR

    NASA Astrophysics Data System (ADS)

    Chong, Y. K.; Velikovich, A. L.; Thornhil, J. W.; Giuliani, J. L.; Knapp, P.; Jennings, C.

    2013-10-01

    Over the last few years, numerous 1D and 2D MHD simulation studies of deuterium (D) based double-shell gas-puff Z-pinch implosions driven by the Sandia ZR accelerator have been carried out to assess the Z-pinch as a pulsed thermal fusion neutron source. In these studies, an ad-hoc time-dependent shunt impedance model was used within the external driving circuit model in order to account for the unresolved current loss in the MITL and the load. In this study, we incorporate an improved ZR circuit model recently formulated based on the recent Sandia argon gas-puff experiment circuit data into the multi-material version of the Mach +DDTCRE RMHD code. We reinvestigate the effects of multidimensional structure and nonuniform gradients as well as the outer- and inner-shell material interaction on the implosion physics and dynamics of both D-on-D and argon-on-D Z-pinch loads using the model. Then, we characterize the neutron production performance of the Z-pinch loads as a function of total mass, mass ratio and/or radius toward their optimization as a pulsed thernonuclear neutron source. Work supported by DOE/NNSA. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's NNSA under contract DE-AC04-94AL85000.

  5. Multicolor, time-gated, soft x-ray pinhole imaging of wire array and gas puff Z pinches on the Z and Saturn pulsed power generators

    SciTech Connect

    Jones, B.; Coverdale, C. A.; Nielsen, D. S.; Jones, M. C.; Deeney, C.; Serrano, J. D.; Nielsen-Weber, L. B.; Meyer, C. J.; Apruzese, J. P.; Clark, R. W.; Coleman, P. L.

    2008-10-15

    A multicolor, time-gated, soft x-ray pinhole imaging instrument is fielded as part of the core diagnostic set on the 25 MA Z machine [M. E. Savage et al., in Proceedings of the Pulsed Power Plasma Sciences Conference (IEEE, New York, 2007), p. 979] for studying intense wire array and gas puff Z-pinch soft x-ray sources. Pinhole images are reflected from a planar multilayer mirror, passing 277 eV photons with <10 eV bandwidth. An adjacent pinhole camera uses filtration alone to view 1-10 keV photons simultaneously. Overlaying these data provides composite images that contain both spectral as well as spatial information, allowing for the study of radiation production in dense Z-pinch plasmas. Cu wire arrays at 20 MA on Z show the implosion of a colder cloud of material onto a hot dense core where K-shell photons are excited. A 528 eV imaging configuration has been developed on the 8 MA Saturn generator [R. B. Spielman et al., and A. I. P. Conf, Proc. 195, 3 (1989)] for imaging a bright Li-like Ar L-shell line. Ar gas puff Z pinches show an intense K-shell emission from a zippering stagnation front with L-shell emission dominating as the plasma cools.

  6. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    SciTech Connect

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-07-15

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions.

  7. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode.

    PubMed

    Rieker, G B; Poehlmann, F R; Cappelli, M A

    2013-07-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions. PMID:23983449

  8. CO2 Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Annual report, January 1, 1995--December 31, 1995

    SciTech Connect

    Wehner, S.C.; Boomer, R.J.; Cole, R.; Preiditus, J.; Vogt, J.

    1996-09-01

    The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg/San Andres formation; a light oil, shallow shelf carbonate reservoir within the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico.

  9. Comparison of Deuterium-Deuterium-Deuterium and Neon-Deuterium-Deuterium Triple Shell Gas-Puff Z-pinch on the Level of 3 MA

    NASA Astrophysics Data System (ADS)

    Rezac, K.; Klir, Daniel; Kubes, P.; Kravarik, J.; Shishlov, A.; Labetsky, A.; Ratakhin, N.

    2012-10-01

    The experiments of a triple shell gas-puff Z-pinch were carried out on the GIT-12 generator at IHCE in Tomsk during the April-May-June campaign in 2012. We diagnosed 17 Z-pinch shots where the triple D2-D2-D2 (with the linear mass in the range of 50 - 255 μg/cm) and Ne-D2-D2 (with the linear mass in the range of 110 - 285 μg/cm) gas-puffs with diameter of 160 mm / 80 mm / 30 mm were mostly used as loads. This contribution is focused on the comparison of the results obtained by X-ray and neutron diagnostics, especially to the difference in reconstructed neutron energy spectra and obtained neutron yields (with the maximum of 3.3 x10^11 neutrons/shot on a current level of 2.5 MA). The time correlations with other diagnostics such as electrical characteristics, a visible streak camera and MCP frames are also presented.

  10. Acceleration of Hydrogen Ions up to 30 MeV and Generation of 3 × 1012 Neutrons in Megaampere Deuterium Gas-Puff Z-Pinch

    NASA Astrophysics Data System (ADS)

    Klir, D.; Cikhardt, J.; Kravarik, J.; Kubes, P.; Rezac, K.; Sila, O.; Shishlov, A.; Cherdizov, R.; Fursov, F.; Kokshenev, V.; Kovalchuk, B.; Kurmaev, N.; Labetsky, A.; Ratakhin, N.; Orcikova, H.; Turek, K.

    2013-10-01

    Fusion neutrons were produced with a deuterium gas-puff z-pinch on the GIT-12 generator at the Institute of High Current Electronics in Tomsk. The peak neutron yield from DD reactions reached Yn = (2 . 9 +/- 0 . 3) ×1012 at 100 μg/cm linear mass density of deuterium, 700 ns implosion time and 2.7 MA current. Such a neutron yield means that the scaling law of deuterium z-pinches Yn ~I4 was extended to 3 MA currents. The further increase of neutron yields up to (3 . 7 +/- 0 . 4) ×1012 was achieved by placing a deuterated polyethylene catcher onto the axis. Maximum neutron energies of 15 and 22 MeV were observed by radial and axial nToF detectors, respectively. A stack of CR-39 track detectors showed up to 40 MeV deuterons (or 30 MeV protons) on the z-pinch axis. Since the energy input into plasmas was 70 kJ, the number of DD neutrons per one joule of stored plasma energy exceeded the value of 5 ×107 . This value implies that deuterium gas-puff z-pinches belong to the most efficient plasma-based sources of DD neutrons. This work was partially supported by the GACR grant No. P205/12/0454 and by the RFBR research project No. 13-08-00479-a.

  11. Genetic analysis of the Drosophila 63F early puff. Characterization of mutations in E63-1 and maggie, a putative Tom22.

    PubMed Central

    Vaskova, M; Bentley, A M; Marshall, S; Reid, P; Thummel, C S; Andres, A J

    2000-01-01

    The 63F early puff in the larval salivary gland polytene chromosomes contains the divergently transcribed E63-1 and E63-2 ecdysone-inducible genes. E63-1 encodes a member of the EF-hand family of Ca(2+)-binding proteins, while E63-2 has no apparent open reading frame. To understand the functions of the E63 genes, we have determined the temporal and spatial patterns of E63-1 protein expression, as well as undertaken a genetic analysis of the 63F puff. We show that E63-1 is expressed in many embryonic and larval tissues, but the third-instar larval salivary gland is the only tissue where increases in protein levels correlate with increases in ecdysone titer. Furthermore, the subcellular distribution of E63-1 protein changes dynamically in the salivary glands at the onset of metamorphosis. E63-1 and E63-2 null mutations, however, have no effect on development or fertility. We have characterized 40 kb of the 63F region, defined as the interval between Ubi-p and E63-2, and have identified three lethal complementation groups that correspond to the dSc-2, ida, and mge genes. We show that mge mutations lead to first-instar larval lethality and that Mge protein is similar to the Tom22 mitochondrial import proteins of fungi, suggesting that it has a role in mitochondrial function. PMID:10978288

  12. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    PubMed Central

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-01-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions. PMID:23983449

  13. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    NASA Astrophysics Data System (ADS)

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-07-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions.

  14. Genetic analysis of the Drosophila 63F early puff. Characterization of mutations in E63-1 and maggie, a putative Tom22.

    PubMed

    Vaskova, M; Bentley, A M; Marshall, S; Reid, P; Thummel, C S; Andres, A J

    2000-09-01

    The 63F early puff in the larval salivary gland polytene chromosomes contains the divergently transcribed E63-1 and E63-2 ecdysone-inducible genes. E63-1 encodes a member of the EF-hand family of Ca(2+)-binding proteins, while E63-2 has no apparent open reading frame. To understand the functions of the E63 genes, we have determined the temporal and spatial patterns of E63-1 protein expression, as well as undertaken a genetic analysis of the 63F puff. We show that E63-1 is expressed in many embryonic and larval tissues, but the third-instar larval salivary gland is the only tissue where increases in protein levels correlate with increases in ecdysone titer. Furthermore, the subcellular distribution of E63-1 protein changes dynamically in the salivary glands at the onset of metamorphosis. E63-1 and E63-2 null mutations, however, have no effect on development or fertility. We have characterized 40 kb of the 63F region, defined as the interval between Ubi-p and E63-2, and have identified three lethal complementation groups that correspond to the dSc-2, ida, and mge genes. We show that mge mutations lead to first-instar larval lethality and that Mge protein is similar to the Tom22 mitochondrial import proteins of fungi, suggesting that it has a role in mitochondrial function. PMID:10978288

  15. One- and two-dimensional modeling of argon K-shell emission from gas-puff Z-pinch plasmas

    NASA Astrophysics Data System (ADS)

    Thornhill, J. W.; Chong, Y. K.; Apruzese, J. P.; Davis, J.; Clark, R. W.; Giuliani, J. L.; Terry, R. E.; Velikovich, A. L.; Commisso, R. J.; Whitney, K. G.; Frese, M. H.; Frese, S. D.; Levine, J. S.; Qi, N.; Sze, H.; Failor, B. H.; Banister, J. W.; Coleman, P. L.; Coverdale, C. A.; Jones, B.; Deeney, C.

    2007-06-01

    In this paper, a theoretical model is described and demonstrated that serves as a useful tool for understanding K-shell radiating Z-pinch plasma behavior. Such understanding requires a self-consistent solution to the complete nonlocal thermodynamic equilibrium kinetics and radiation transport in order to realistically model opacity effects and the high-temperature state of the plasma. For this purpose, we have incorporated into the MACH2 two-dimensional magnetohydrodynamic (MHD) code [R. E. Peterkin et al., J. Comput. Phys. 140, 148 (1998)] an equation of state, called the tabular collisional radiative equilibrium (TCRE) model [J. W. Thornhill et al., Phys. Plasmas 8, 3480 (2001)], that provides reasonable approximations to the plasma's opacity state. MACH2 with TCRE is applied toward analyzing the multidimensional implosion behavior that occurred in Decade Quad (DQ) [D. Price et al., Proceedings of the 12th IEEE Pulsed Power Conference, Monterey, CA, edited by C. Stallings and H. Kirbie (IEEE, New York, 1999), p. 489] argon gas puff experiments that employed a 12cm diameter nozzle with and without a central gas jet on axis. Typical peak drive currents and implosion times in these experiments were ˜6MA and ˜230ns. By using Planar Laser Induced Fluorescence measured initial density profiles as input to the calculations, the effect these profiles have on the ability of the pinch to efficiently produce K-shell emission can be analyzed with this combined radiation-MHD model. The calculated results are in agreement with the experimental result that the DQ central-jet configuration is superior to the no-central-jet experiment in terms of producing more K-shell emission. These theoretical results support the contention that the improved operation of the central-jet nozzle is due to the better suppression of instabilities and the higher-density K-shell radiating conditions that the central-jet configuration promotes. When we applied the model toward projecting argon K

  16. One- and two-dimensional modeling of argon K-shell emission from gas-puff Z-pinch plasmas

    SciTech Connect

    Thornhill, J. W.; Chong, Y. K.; Apruzese, J. P.; Davis, J.; Clark, R. W.; Giuliani, J. L. Jr.; Terry, R. E.; Velikovich, A. L.; Commisso, R. J.; Whitney, K. G.; Frese, M. H.; Frese, S. D.; Levine, J. S.; Qi, N.; Sze, H.; Failor, B. H.; Banister, J. W.; Coleman, P. L.; Coverdale, C. A.; Jones, B.

    2007-06-15

    In this paper, a theoretical model is described and demonstrated that serves as a useful tool for understanding K-shell radiating Z-pinch plasma behavior. Such understanding requires a self-consistent solution to the complete nonlocal thermodynamic equilibrium kinetics and radiation transport in order to realistically model opacity effects and the high-temperature state of the plasma. For this purpose, we have incorporated into the MACH2 two-dimensional magnetohydrodynamic (MHD) code [R. E. Peterkin et al., J. Comput. Phys. 140, 148 (1998)] an equation of state, called the tabular collisional radiative equilibrium (TCRE) model [J. W. Thornhill et al., Phys. Plasmas 8, 3480 (2001)], that provides reasonable approximations to the plasma's opacity state. MACH2 with TCRE is applied toward analyzing the multidimensional implosion behavior that occurred in Decade Quad (DQ) [D. Price et al., Proceedings of the 12th IEEE Pulsed Power Conference, Monterey, CA, edited by C. Stallings and H. Kirbie (IEEE, New York, 1999), p. 489] argon gas puff experiments that employed a 12 cm diameter nozzle with and without a central gas jet on axis. Typical peak drive currents and implosion times in these experiments were {approx}6 MA and {approx}230 ns. By using Planar Laser Induced Fluorescence measured initial density profiles as input to the calculations, the effect these profiles have on the ability of the pinch to efficiently produce K-shell emission can be analyzed with this combined radiation-MHD model. The calculated results are in agreement with the experimental result that the DQ central-jet configuration is superior to the no-central-jet experiment in terms of producing more K-shell emission. These theoretical results support the contention that the improved operation of the central-jet nozzle is due to the better suppression of instabilities and the higher-density K-shell radiating conditions that the central-jet configuration promotes. When we applied the model toward

  17. Laser surface texturing of 316L stainless steel in air and water: A method for increasing hydrophilicity via direct creation of microstructures

    NASA Astrophysics Data System (ADS)

    Razi, Sepehr; Madanipour, Khosro; Mollabashi, Mahmoud

    2016-06-01

    Laser processing of materials in water contact is sometimes employed for improving the machining, cutting or welding quality. Here, we demonstrate surface patterning of stainless steel grade 316L by nano-second laser processing in air and water. Suitable adjustments of laser parameters offer a variety of surface patterns on the treated targets. Furthermore alterations of different surface features such as surface chemistry and wettability are investigated in various processing circumstances. More than surface morphology, remarkable differences are observed in the surface oxygen content and wettability of the samples treated in air and water at the same laser processing conditions. Mechanisms of the changes are discussed extensively.

  18. Performance evaluation of AERMOD, CALPUFF, and legacy air dispersion models using the Winter Validation Tracer Study dataset

    NASA Astrophysics Data System (ADS)

    Rood, Arthur S.

    2014-06-01

    The performance of the steady-state air dispersion models AERMOD and Industrial Source Complex 2 (ISC2), and Lagrangian puff models CALPUFF and RATCHET were evaluated using the Winter Validation Tracer Study dataset. The Winter Validation Tracer Study was performed in February 1991 at the former Rocky Flats Environmental Technology Site near Denver, Colorado. Twelve, 11-h tests were conducted where a conservative tracer was released and measured hourly at 140 samplers in concentric rings 8 km and 16 km from the release point. Performance objectives were unpaired maximum one- and nine-hour average concentration, location of plume maximum, plume impact area, arc-integrated concentration, unpaired nine-hour average concentration, and paired ensemble means. Performance objectives were aimed at addressing regulatory compliance, and dose reconstruction assessment questions. The objective of regulatory compliance is not to underestimate maximum concentrations whereas for dose reconstruction, the objective is an unbiased estimate of concentration in space and time. Performance measures included the fractional bias, normalized mean square error, geometric mean, geometric mean variance, correlation coefficient, and fraction of observations within a factor of two. The Lagrangian puff models tended to exhibit the smallest variance, highest correlation, and highest number of predictions within a factor of two compared to the steady-state models at both the 8-km and 16-km distance. Maximum one- and nine-hour average concentrations were less likely to be under-predicted by the steady-state models compared to the Lagrangian puff models. The characteristic of the steady-state models not to under-predict maximum concentrations make them well suited for regulatory compliance demonstration, whereas the Lagrangian puff models are better suited for dose reconstruction and long range transport.

  19. Development of an Agricultural Fertilizer Modeling System for Bi-Directional Ammonia Fluxes in the Community Multiscale Air Quality (CMAQ) Model

    EPA Science Inventory

    Atmospheric ammonia (NH3) plays an important role in fine-mode aerosol formation. Accurate estimates of ammonia from both human and natural emissions can reduce uncertainties in air quality modeling. The majority of ammonia anthropogenic emissions come from the agricul...

  20. CHARACTERIZATION OF AN AQUITARD AND DIRECT DETECTION OF LNAPL AT HILL AIR FORCE BASE USING GPR AVO AND MIGRATION VELOCITY ANALYSES

    EPA Science Inventory

    Large quantities of non-aqueous phase liquids (NAPL) contaminate the near surface sediments at Operable Unit 1 (OU1), Hill Air Force Base (HAFB), Utah. In October 2000, a 3D, multi-offset GPR survey was acquired at OU1 with two objectives: 1) to i...

  1. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, ... a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  2. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  3. The influence of intraocular pressure and air jet pressure on corneal contactless tonometry tests.

    PubMed

    Simonini, Irene; Pandolfi, Anna

    2016-05-01

    The air puff is a dynamic contactless tonometer test used in ophthalmology clinical practice to assess the biomechanical properties of the human cornea and the intraocular pressure due to the filling fluids of the eye. The test is controversial, since the dynamic response of the cornea is governed by the interaction of several factors which cannot be discerned within a single measurement. In this study we describe a numerical model of the air puff tests, and perform a parametric analysis on the major action parameters (jet pressure and intraocular pressure) to assess their relevance on the mechanical response of a patient-specific cornea. The particular cornea considered here has been treated with laser reprofiling to correct myopia, and the parametric study has been conducted on both the preoperative and postoperative geometries. The material properties of the cornea have been obtained by means of an identification procedure that compares the static biomechanical response of preoperative and postoperative corneas under the physiological IOP. The parametric study on the intraocular pressure suggests that the displacement of the cornea׳s apex can be a reliable indicator for tonometry, and the one on the air jet pressure predicts the outcomes of two or more distinct measurements on the same cornea, which can be used in inverse procedures to estimate the material properties of the tissue. PMID:26282384

  4. Novel Air Stimulation MR-Device for Intraoral Quantitative Sensory Cold Testing

    PubMed Central

    Brönnimann, Ben; Meier, Michael L.; Hou, Mei-Yin; Parkinson, Charles; Ettlin, Dominik A.

    2016-01-01

    The advent of neuroimaging in dental research provides exciting opportunities for relating excitation of trigeminal neurons to human somatosensory perceptions. Cold air sensitivity is one of the most frequent causes of dental discomfort or pain. Up to date, devices capable of delivering controlled cold air in an MR-environment are unavailable for quantitative sensory testing. This study therefore aimed at constructing and evaluating a novel MR-compatible, computer-controlled cold air stimulation apparatus (CASA) that produces graded air puffs. CASA consisted of a multi-injector air jet delivery system (AJS), a cold exchanger, a cooling agent, and a stimulus application construction. Its feasibility was tested by performing an fMRI stimulation experiment on a single subject experiencing dentine cold sensitivity. The novel device delivered repetitive, stable air stimuli ranging from room temperature (24.5°C ± 2°C) to −35°C, at flow rates between 5 and 17 liters per minute (l/min). These cold air puffs evoked perceptions similar to natural stimuli. Single-subject fMRI-analysis yielded brain activations typically associated with acute pain processing including thalamus, insular and cingulate cortices, somatosensory, cerebellar, and frontal brain regions. Thus, the novel CASA allowed for controlled, repetitive quantitative sensory testing by using air stimuli at graded temperatures (room temperature down to −35°C) while simultaneously recording brain responses. No MR-compatible stimulation device currently exists that is capable of providing non-contact natural-like stimuli at a wide temperature range to tissues in spatially restricted areas such as the mouth. The physical characteristics of this novel device thus holds promise for advancing the field of trigeminal and spinal somatosensory research, namely with respect to comparing therapeutic interventions for dentine hypersensitivity. PMID:27445771

  5. Novel Air Stimulation MR-Device for Intraoral Quantitative Sensory Cold Testing.

    PubMed

    Brönnimann, Ben; Meier, Michael L; Hou, Mei-Yin; Parkinson, Charles; Ettlin, Dominik A

    2016-01-01

    The advent of neuroimaging in dental research provides exciting opportunities for relating excitation of trigeminal neurons to human somatosensory perceptions. Cold air sensitivity is one of the most frequent causes of dental discomfort or pain. Up to date, devices capable of delivering controlled cold air in an MR-environment are unavailable for quantitative sensory testing. This study therefore aimed at constructing and evaluating a novel MR-compatible, computer-controlled cold air stimulation apparatus (CASA) that produces graded air puffs. CASA consisted of a multi-injector air jet delivery system (AJS), a cold exchanger, a cooling agent, and a stimulus application construction. Its feasibility was tested by performing an fMRI stimulation experiment on a single subject experiencing dentine cold sensitivity. The novel device delivered repetitive, stable air stimuli ranging from room temperature (24.5°C ± 2°C) to -35°C, at flow rates between 5 and 17 liters per minute (l/min). These cold air puffs evoked perceptions similar to natural stimuli. Single-subject fMRI-analysis yielded brain activations typically associated with acute pain processing including thalamus, insular and cingulate cortices, somatosensory, cerebellar, and frontal brain regions. Thus, the novel CASA allowed for controlled, repetitive quantitative sensory testing by using air stimuli at graded temperatures (room temperature down to -35°C) while simultaneously recording brain responses. No MR-compatible stimulation device currently exists that is capable of providing non-contact natural-like stimuli at a wide temperature range to tissues in spatially restricted areas such as the mouth. The physical characteristics of this novel device thus holds promise for advancing the field of trigeminal and spinal somatosensory research, namely with respect to comparing therapeutic interventions for dentine hypersensitivity. PMID:27445771

  6. Environment International, Special Issue, "Future Directions in Air Quality Research Ecological, Atmospheric, Regulatory/Policy/Economic, and Educational Issues", Volume 29, #2-3. June 2003. ISSN 0160 4120

    SciTech Connect

    Alcock, Ruth E; Heck, Walter W; Chappelka, Arthur H; Hunt, William F; Innes, John L; and Unsworth, Michael

    2003-06-01

    The Air Resources Consortium sponsored a Conference entitled "Future Directions in Air Quality Research". The Conference was held on February 12-15, 2001 at the Sheraton Imperial Hotel and Conference Center in the Research Triangle Park, NC. This was an international conference that had wide interest in both the scientific and regulatory communities at both State and Federal levels in the U.S. and in the international community. Attendance over the four days of the Conference was over 200 with excellent international participation. The primary purpose of the Conference was to highlight future directions in air quality research based on our current knowledge and ongoing research. Three atmospheric contaminates (ozone, carbon dioxide and species of nitrogen) as the primary focus for the Conference, since they would likely be of continuing concern to the international community over the next several decades. Speakers focused on ways that research could support regulatory, policy and environmental needs of federal, state and local government as well as the concerns of both industrial and environmental groups. Economic impacts were considered when covering policy implications. The program was developed around ecological effects, atmospheric processes and their relationships. Conference speakers were asked to develop their papers for inclusion in a Conference Proceedings. The proceedings were published in the Journal "Environment International" as Volume 29, Numbers 2-3, in June of 2003. Copies of the Proceedings have been sent to DOE.

  7. Interfacial redox reaction-directed synthesis of silver@cerium oxide core-shell nanocomposites as catalysts for rechargeable lithium-air batteries

    NASA Astrophysics Data System (ADS)

    Liu, Ying; Wang, Man; Cao, Lu-Jie; Yang, Ming-Yang; Ho-Sum Cheng, Samson; Cao, Chen-Wei; Leung, Kwan-Lan; Chung, Chi-Yuen; Lu, Zhou-Guang

    2015-07-01

    A facile oxidation-reduction reaction method has been implemented to prepare pomegranate-like Ag@CeO2 multicore-shell structured nanocomposites. Under Ar atmosphere, redox reaction automatically occurs between AgNO3 and Ce(NO3)3 in an alkaline solution, where Ag+ is reduced to Ag nanopartilces and Ce3+ is simultaneously oxidized to form CeO2, followed by the self-assembly to form the pomegranate-like multicore-shell structured Ag@CeO2 nanocomposites driven by thermodynamic equilibrium. No other organic amines or surfactants are utilized in the whole reaction system and only NaOH instead of organic reducing agent is used to prevent the introduction of a secondary reducing byproduct. The as-obtained pomegranate-like Ag@CeO2 multicore-shell structured nanocomposites have been characterized as electro-catalysts for the air cathode of lithium-air batteries operated in a simulated air environment. Superior electrochemical performance with high discharge capacity of 3415 mAh g-1 at 100 mA g-1, stable cycling and small charge/discharge polarization voltage is achieved, which is much better than that of the CeO2 or simple mixture of CeO2 and Ag. The enhanced properties can be primarily attributed to the synergy effect between the Ag core and the CeO2 shell resulting from the unique pomegranate-like multicore-shell nanostructures possessing plenty of active sites to promote the facile formation and decomposition of Li2O2.

  8. Photoinduced Directional Motions of Microparticles at Air-Liquid-Crystal Interfaces of Azobenzene-Doped Liquid-Crystal Films with Homeotropic or Homogeneous Alignment Structures

    NASA Astrophysics Data System (ADS)

    Yamamoto, Takahiro; Yoshida, Masaru

    2012-10-01

    We investigated the effects of liquid-crystal (LC) alignments on photoinduced motions of microparticles at air-LC interfaces of azobenzene-doped LC films. In homeotropically aligned LC films, the lattice spacings of pseudo-hexagonal structures of microparticles site-selectively exhibited reversible expansion or contraction on alternating irradiation with ultraviolet and visible light. The particle motions were probably driven by photochemical deformation of LC surfaces. In homogeneously aligned films, alternating irradiation induced macroscopic convective flows followed by rapid gathering or dispersion of linear chains of microparticles. Particle motions were significantly influenced by LC alignments as well as the light wavelength.

  9. AIR RADIOACTIVITY MONITOR

    DOEpatents

    Bradshaw, R.L.; Thomas, J.W.

    1961-04-11

    The monitor is designed to minimize undesirable background buildup. It consists of an elongated column containing peripheral electrodes in a central portion of the column, and conduits directing an axial flow of radioactively contaminated air through the center of the column and pure air through the annular portion of the column about the electrodes. (AEC)

  10. Effect of resistivity profile on current decay time of initial phase of current quench in neon-gas-puff inducing disruptions of JT-60U

    NASA Astrophysics Data System (ADS)

    Kawakami, S.; Shibata, Y.; Watanabe, K. Y.; Ohno, N.; Isayama, A.; Takizuka, T.; Kawano, Y.; Okamoto, M.

    2013-11-01

    According to an early work [Y. Shibata et al., Nucl. Fusion 50, 025015 (2010)] on the behavior of the plasma current decay in the JT-60U disruptive discharges caused by the radiative collapse with a massive neon-gas-puff, the increase of the internal inductance mainly determined the current decay time of plasma current during the initial phase of current quench. To investigate what determines the increase of the internal inductance, we focus attention on the relationship between the electron temperature (or the resistivity) profile and the time evolution of the current density profile and carry out numerical calculations. As a result, we find the reason of the increase of the internal inductance: The current density profile at the start of the current quench is broader than an expected current density profile in the steady state, which is determined by the temperature (or resistivity) profile. The current density profile evolves into peaked one and the internal inductance is increasing.

  11. A comparison of planar, laser-induced fluorescence, and high-sensitivity interferometry techniques for gas-puff nozzle density measurements

    SciTech Connect

    Jackson, S. L.; Weber, B. V.; Mosher, D.; Phipps, D. G.; Stephanakis, S. J.; Commisso, R. J.; Qi, N.; Failor, B. H.; Coleman, P. L.

    2008-10-15

    The distribution of argon gas injected by a 12-cm-diameter triple-shell nozzle was characterized using both planar, laser-induced fluorescence (PLIF) and high-sensitivity interferometry. PLIF is used to measure the density distribution at a given time by detecting fluorescence from an acetone tracer added to the gas. Interferometry involves making time-dependent, line-integrated gas density measurements at a series of chordal locations that are then Abel inverted to obtain the gas density distribution. Measurements were made on nominally identical nozzles later used for gas-puff Z-pinch experiments on the Saturn pulsed-power generator. Significant differences in the mass distributions obtained by the two techniques are presented and discussed, along with the strengths and weaknesses of each method.

  12. Effect of resistivity profile on current decay time of initial phase of current quench in neon-gas-puff inducing disruptions of JT-60U

    SciTech Connect

    Kawakami, S.; Ohno, N.; Shibata, Y.; Isayama, A.; Kawano, Y.; Watanabe, K. Y.; Takizuka, T.; Okamoto, M.

    2013-11-15

    According to an early work [Y. Shibata et al., Nucl. Fusion 50, 025015 (2010)] on the behavior of the plasma current decay in the JT-60U disruptive discharges caused by the radiative collapse with a massive neon-gas-puff, the increase of the internal inductance mainly determined the current decay time of plasma current during the initial phase of current quench. To investigate what determines the increase of the internal inductance, we focus attention on the relationship between the electron temperature (or the resistivity) profile and the time evolution of the current density profile and carry out numerical calculations. As a result, we find the reason of the increase of the internal inductance: The current density profile at the start of the current quench is broader than an expected current density profile in the steady state, which is determined by the temperature (or resistivity) profile. The current density profile evolves into peaked one and the internal inductance is increasing.

  13. Investigating the double-peaked K-shell pulse emitted by the Xe-doped Ar gas-puff shot Z 2603

    NASA Astrophysics Data System (ADS)

    Apruzese, J. P.; Giuliani, J. L.; Ouart, N. D.; Tangri, V.; Harvey-Thompson, A. J.; Jones, B.; Jennings, C. A.

    2015-11-01

    A recent series of Ar gas-puff experiments on Sandia National Laboratories' Z generator achieved K-shell yields in excess of 300 kJ. However, when a Xe dopant of 0.8% by number was added to the central jet, the K-shell yield was reduced by a factor of 3, and, only on this shot, it appeared in two distinct, nearly equal peaks. We investigate possible causes of this phenomenon in terms of the evolving properties of the pinch, and the temperature sensitivity of Ar K-shell emissivity. Work supported by DOE/NNSA and by Sandia National Laboratories under DOE Contract No. DE-AC04-94AL85000.

  14. CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Quarterly technical progress report, July--September, 1995

    SciTech Connect

    Cole, R.; Prieditis, J.; Vogt, J. Wehner, S.

    1995-10-15

    The principal objective of the Central Vacuum Unit (CVU) CO{sub 2} Huff-n-Puff (H-n-P) project is to determine the feasibility and practicality of the technology in a waterflooded shallow shelf carbonate environment. The results of parametric simulation of the CO{sub 2} H-n-P process, coupled with the CVU reservoir characterization components will determine if this process is technically and economically feasible for field implementation. The technology transfer objective of the project is to disseminate the knowledge gained through an innovative plan in support of the Department of Energy`s (DOE) objective of increasing domestic oil production and deferring the abandonment of shallow shelf carbonate (SSC) reservoirs. Tasks associated with this objective are carried out in what is considered a timely effort for near-term goals.

  15. Direct correlation and strong reduction of native point defects and microwave dielectric loss in air-annealed (Ba,Sr)TiO{sub 3}

    SciTech Connect

    Zeng, Z. Q.; Podpirka, A.; Kirchoefer, S. W.; Asel, T. J.; Brillson, L. J.

    2015-05-04

    We report on the native defect and microwave properties of 1 μm thick Ba{sub 0.50}Sr{sub 0.50}TiO{sub 3} (BST) films grown on MgO (100) substrates by molecular beam epitaxy (MBE). Depth-resolved cathodoluminescence spectroscopy (DRCLS) showed high densities of native point defects in as-deposited BST films, causing strong subgap emission between 2.0 eV and 3.0 eV due to mixed cation V{sub C} and oxygen Vo vacancies. Post growth air anneals reduce these defects with 2.2, 2.65, and 3.0 eV V{sub O} and 2.4 eV V{sub C} intensities decreasing with increasing anneal temperature and by nearly two orders of magnitude after 950 °C annealing. These low-defect annealed BST films exhibited high quality microwave properties, including room temperature interdigitated capacitor tunability of 13% under an electric bias of 40 V and tan δ of 0.002 at 10 GHz and 40 V bias. The results provide a feasible route to grow high quality BST films by MBE through post-air annealing guided by DRCLS.

  16. CO{sub 2} huff-n-puff process in a light oil shallow carbonate reservoir. Annual report, January 1, 1996--December 31, 1996

    SciTech Connect

    Prieditis, J.; Wehner, S.

    1998-01-01

    The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg and San Andres formations; a light oil, shallow shelf carbonate reservoir that exists throughout the Permian Basin. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Miscible CO{sub 2} flooding is the process of choice for enhancing recovery of light oils and already accounts for over 12% of the Permian Basin`s daily production. There are significant probable reserves associated with future miscible CO{sub 2} projects. However, many are marginally economic at current market conditions due to large up-front capital commitments for a peak response which may be several years in the future. The resulting negative cash-flow is sometimes too much for an operator to absorb. The CO{sub 2} H-n-P process is being investigated as a near-term option to mitigate the negative cash-flow situation--allowing acceleration of inventoried miscible CO{sub 2} projects when coupled together.

  17. Hepa room air purifier

    SciTech Connect

    Davis, G.B.

    1986-12-16

    This patent describes a portable air purification apparatus comprising a housing including a base portion and cover means, the base portion including an air deflection means and a plate means mounted in spaced relationship to the air deflection means so as to create a substantially continuous air exhaust opening therebetween. A centrifugal fan means is disposed between the plate means and the air deflection means and is mounted so as to direct air radially outwardly therefrom through the air exhaust opening, at least one opening through the plate means to permit air flow therethrough to the centrifugal fan means. The motor means carried by the base portion and extends upwardly with respect to the opening in the plate means, the motor means having drive shaft means for driving the centrifugal fan means. An air filter means is mounted between the base portion and the cover means so that air is drawn therethrough toward the centrifugal fan means, and a means for secures the cover means relative to the base means to thereby retain the air filter means therebetween.

  18. A noncontact intraocular pressure measurement device using a micro reflected air pressure sensor for the prediagnosis of glaucoma

    NASA Astrophysics Data System (ADS)

    Kim, Kyoung Hwan; Kim, Byeong Hee; Seo, Young Ho

    2012-03-01

    This study investigates a novel, portable tonometer using a micro reflected air pressure sensor for the prediagnosis of glaucoma. Because glaucoma progresses slowly and is not painful, glaucoma patients require a portable prediagnosis system to periodically measure intraocular pressure at home. Conventionally, intraocular pressure is measured by an air-puff tonometer whereby the cornea is deformed by a short pulse of air pressure and the magnitude of the corneal deformation is measured by optic systems such as a combination of laser- and photodiodes. In this study, a micro reflected air pressure sensor was designed, fabricated, and tested in order to measure the magnitude of corneal deformation without optic systems. In an experimental study, artificial eyes with different internal pressures were fabricated and these pressures were measured by the aforementioned system.

  19. Shock-swallowing air sensor

    NASA Technical Reports Server (NTRS)

    Nugent, J.; Sakamoto, G. M.; Webb, L. D.; Couch, L. M.

    1979-01-01

    An air-data probe allows air to flow through it so that supersonic and hypersonic shock waves form behind pressure measuring orifices and tube instead of directly on them. Measured pressures are close to those in free-flowing air and are used to determine mach numbers of flying aircraft.

  20. Cytogenetic analysis of the 2B1-2-2B9-10 region of the X chromosome of Drosophila melanogaster. V. Changes in the pattern of polypeptide synthesis in salivary glands caused by mutations located in the 2B5 puff

    SciTech Connect

    Dubrovskii, E.B.; Zhimulev, I.F.

    1986-02-01

    The authors have investigated the role of the 2B5 puff in the synthesis of ecdysone-inducible proteins. They showed that in mutants for the overlapping complementation complex (occ) located in the 2B5 puff the synthesis of these proteins is impaired: in mutants 1t336 and 1t366 to a lesser extent and in mutant t143 to a greater extent. Similarly to the deletion of the 2B5 puff, mutation t435 completely blocks the synthesis of ecdysone-inducible proteins. An increase in the dose of the 2B5 puff leads to an increase in the level of synthesis of two ecdysone-inducible polypeptides, for which evidence is available that they are encoded in the region of another ecdysone puff. The results obtained, together with the findings that the tissues of larvae mutant for the occ locus are not sensitive to the action of 20-hydroxy ecdysone and that the normal course of development of ecdysone-dependent puffing is impaired in the chromosomes of salivary glands of these mutants, suggest the presence of a key regulatory role of the 2B5 puff in metamorphosis.

  1. Determination of 43 polycyclic aromatic hydrocarbons in air particulate matter by use of direct elution and isotope dilution gas chromatography/mass spectrometry.

    PubMed

    Li, Zheng; Pittman, Erin N; Trinidad, Debra A; Romanoff, Lovisa C; Mulholland, James; Sjödin, Andreas

    2010-02-01

    We are reporting a method for measuring 43 polycyclic aromatic hydrocarbons (PAH) and their methylated derivatives (Me-PAHs) in air particulate matter (PM) samples using isotope dilution gas chromatography/high-resolution mass spectrometry (GC/HRMS). In this method, PM samples were spiked with internal standards, loaded into solid phase extraction cartridges, and eluted by dichloromethane. The extracts were concentrated, spiked with a recovery standard, and analyzed by GC/HRMS at 10,000 resolution. Sixteen (13)C-labeled PAHs and two deuterated Me-PAHs were used as internal standards to account for instrument variability and losses during sample preparation. Recovery of labeled internal standards was in the range of 86-115%. The proposed method is less time-consuming than commonly used extraction methods, such as sonication and accelerated solvent extraction (ASE), and it eliminates the need for a filtration step required after the sonication extraction method. Limits of detection ranged from 41 to 332 pg/sample for the 43 analytes. This method was used to analyze reference materials from the National Institute of Standards and Technology. The results were consistent with those from ASE and sonication extraction, and these results were also in good agreement with the certified or reference concentrations. The proposed method was then used to measure PAHs on PM(2.5) samples collected at three sites (urban, suburban, and rural) in Atlanta, GA. The results showed distinct seasonal and spatial variation and were consistent with an earlier study measuring PM(2.5) samples using an ASE method, further demonstrating the compatibility of this method and the commonly used ASE method. PMID:19936717

  2. A mutation in the puff region of VP2 attenuates the myocarditic phenotype of an infectious cDNA of the Woodruff variant of coxsackievirus B3.

    PubMed Central

    Knowlton, K U; Jeon, E S; Berkley, N; Wessely, R; Huber, S

    1996-01-01

    Coxsackievirus B3 (CVB3) infections induce myocarditis in humans and mice. Little is known about the molecular characteristics of CVB3 that activate the cellular immunity responsible for cardiac inflammation. Previous experiments have identified an antibody escape mutant (H310A1) of a myocarditic variant of CVB3 (H3) that attenuates the myocarditic potential of the virus in mice in spite of ongoing viral replication in the heart. We have cloned full-length infectious cDNA copies of the viral genome of both the wild-type myocarditic H3 variant of CVB3 and the antibody escape mutant H310A1. Progeny viruses maintained the myocarditic and attenuated myocarditic potential of the parent viruses, H3 and H310A1. The full sequence of the H3 viral cDNA is reported and compared with those of previously published CVB3 variants. Comparison of the full sequences of H3 and H310A1 viruses identified a single nonconserved mutation (A to G) in the P1 polyprotein region at nucleotide 1442 resulting in an asparagine-to-aspartate mutation in amino acid 165 of VP2. This mutation is in a region that corresponds to the puff region of VP2. Nucleotide 1442 of the H3 and H310A1 cDNA copies of the viral genome was mutated to change amino acid 165 of VP2 to aspartate and asparagine, respectively. The presence of asparagine at amino acid 165 of VP2 is associated with the myocarditic phenotype, while an aspartate at the same site reduces the myocarditic potential of the virus. In addition, high-level production of tumor necrosis factor alpha by infected BALB/c monocytes is associated with asparagine at amino acid 165 of VP2 as has been previously demonstrated for the H3 virus. These findings identify potentially important differences between the H3 variant of CVB3 and other previously published CVB3 variants. In addition, the data demonstrate that a point mutation in the puff region of VP2 can markedly alter the ability of CVB3 to induce myocarditis in mice and tumor necrosis factor alpha

  3. Precise Detection of Direct Glomerular Input Duration by the Olfactory Bulb

    PubMed Central

    Li, Anan; Gire, David H.; Bozza, Thomas

    2014-01-01

    Sensory neuron input to the olfactory bulb (OB) was activated precisely for different durations with blue light in mice expressing channelrhodopsin-2 in olfactory sensory neurons. Behaviorally the mice discriminated differences of 10 ms in duration of direct glomerular activation. In addition, a subset of mitral/tufted cells in the OB of awake mice responded tonically therefore conveying information on stimulus duration. Our study provides evidence that duration of the input to glomeruli not synchronized to sniffing is detected. This potent cue may be used to obtain information on puffs in odor plumes. PMID:25429146

  4. Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 1, Methodology

    SciTech Connect

    Not Available

    1993-11-01

    The Energy Policy and Conservation Act (P.L. 94-163), as amended, establishes energy conservation standards for 12 of the 13 types of consumer products specifically covered by the Act. The legislation requires the Department of Energy (DOE) to consider new or amended standards for these and other types of products at specified times. DOE is currently considering amending standards for seven types of products: water heaters, direct heating equipment, mobile home furnaces, pool heaters, room air conditioners, kitchen ranges and ovens (including microwave ovens), and fluorescent light ballasts and is considering establishing standards for television sets. This Technical Support Document presents the methodology, data, and results from the analysis of the energy and economic impacts of the proposed standards. This volume presents a general description of the analytic approach, including the structure of the major models.

  5. Use of radiation sources with mercury isotopes for real-time highly sensitive and selective benzene determination in air and natural gas by differential absorption spectrometry with the direct Zeeman effect.

    PubMed

    Revalde, Gita; Sholupov, Sergey; Ganeev, Alexander; Pogarev, Sergey; Ryzhov, Vladimir; Skudra, Atis

    2015-08-01

    A new analytical portable system is proposed for the direct determination of benzene vapor in the ambient air and natural gas, using differential absorption spectrometry with the direct Zeeman effect and innovative radiation sources: capillary mercury lamps with different isotopic compositions ((196)Hg, (198)Hg, (202)Hg, (204)Hg, and natural isotopic mixture). Resonance emission of mercury at a wavelength of 254 nm is used as probing radiation. The differential cross section of benzene absorption in dependence on wavelength is determined by scanning of magnetic field. It is found that the sensitivity of benzene detection is enhanced three times using lamp with the mercury isotope (204)Hg in comparison with lamp, filled with the natural isotopic mixture. It is experimentally demonstrated that, when benzene content is measured at the Occupational Exposure Limit (3.2 mg/m(3) for benzene) level, the interference from SO2, NO2, O3, H2S and toluene can be neglected if concentration of these gases does not exceed corresponding Occupational Exposure Limits. To exclude the mercury effect, filters that absorb mercury and let benzene pass in the gas duct are proposed. Basing on the results of our study, a portable spectrometer is designed with a multipath cell of 960 cm total path length and detection limit 0.5 mg/m(3) at 1 s averaging and 0.1 mg/m(3) at 30 s averaging. The applications of the designed spectrometer to measuring the benzene concentration in the atmospheric air from a moving vehicle and in natural gas are exemplified. PMID:26320799

  6. Air resources

    SciTech Connect

    1995-10-01

    This section describes the ambient (surrounding) air quality of the TVA region, discusses TVA emission contributions to ambient air quality, and identifies air quality impacts to human health and welfare. Volume 2 Technical Document 2, Environmental Consequences, describes how changes in TVA emissions could affect regional air quality, human health, environmental resources, and materials. The primary region of the affected environment is broadly defined as the state of Tennessee, as well as southern Kentucky, western Virginia, southern West Virginia, western North Carolina, and northern Georgia, Alabama, and Mississippi. This area represents the watershed of the Tennessee River and the 201 counties of the greater TVA service area. Emissions from outside the Tennessee Valley region contribute to air quality in the Valley. Also, TVA emissions are transported outside the Valley and have some impact on air quality beyond the primary study area. Although the study area experiences a number of air quality problems, overall air quality is good.

  7. Radial lean direct injection burner

    DOEpatents

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  8. Seasonal changes in ground-water quality and ground-water levels and directions of ground-water movement in southern Elmore County, southwestern Idaho, including Mountain Home Air Force Base, 1990-1991

    USGS Publications Warehouse

    Young, H.W.; Parliman, D.J.; Jones, Michael L.

    1992-01-01

    The study area is located in southern Elmore County, southwestern Idaho, and includes the Mountain Home Air Force Base located approximately 10 mi southwest of the city of Mountain Home. Chemical analyzes have been made periodically since the late 1940's on water samples from supply wells on the Air Force Base. These analyses indicate increases in specific conductance and in concentrations of nitrogen compounds, chloride, and sulfate. The purposes of this report, which was prepared in cooperation with the Department of the Air Force, are to describe the seasonal changes in water quality and water levels and to depict the directions of ground-water movement in the regional aquifer system and perched-water zones. Although data presented in this report are from both the regional ground-water system and perched-water zones, the focus is on the regional system. A previous study by the U.S. Geological Survey (Parliman and Young, 1990) describes the areal changes in water quality and water levels during the fall of 1989. During March, July, and October 1990, 141 wells were inventoried and depth to water was measured. Continuous water-level recorders were installed on 5 of the wells and monthly measurements of depth to water were made in 17 of the wells during March 1990 through February 1991. Water samples from 33 wells and 1 spring were collected during the spring and fall of 1990 for chemical analyses. Samples also were collected monthly from 11 of those wells during April to September 1990 (table 1). Selected well-construction and water-use data and measurements of depth to water for 141 wells are given in table 2 (separated sheets in envelope). Directions of ground-water movement and selected hydrographs showing seasonal fluctuations of water levels in the regional ground-water system and perched-water zones are shown on sheet 2. Changes in water levels in the regional ground-water system during March to October 1990 are shown on sheet 2.

  9. Olefin metathesis in air

    PubMed Central

    Piola, Lorenzo; Nahra, Fady

    2015-01-01

    Summary Since the discovery and now widespread use of olefin metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments concerning catalytic systems directed towards water and air tolerance. PMID:26664625

  10. Air Pollution.

    ERIC Educational Resources Information Center

    Gilpin, Alan

    A summary of one of our most pressing environmental problems, air pollution, is offered in this book by the Director of Air Pollution Control for the Queensland (Australia) State Government. Discussion of the subject is not restricted to Queensland or Australian problems and policies, however, but includes analysis of air pollution the world over.…

  11. K-shell and extreme ultraviolet spectroscopic signatures of structured Ar puff Z-pinch loads with high K-shell x-ray yield

    SciTech Connect

    Failor, B. H.; Sze, H. M.; Banister, J. W.; Levine, J. S.; Qi, N.; Apruzese, J. P.; Lojewski, D. Y.

    2007-02-15

    Structured 12-cm-diam Ar gas-puff loads have recently produced Z-pinch implosions with reduced Rayleigh-Taylor instability growth and increased K-shell x-ray yield [H. Sze, J. Banister, B. H. Failor, J. S. Levine, N. Qi, A. L. Velikovich, J. Davis, D. Lojewski, and P. Sincerny, Phys. Rev. Lett. 95, 105001 (2005)]. To better understand the dynamics of these loads, we have measured the extreme ultraviolet (XUV) emission resolved radially, spectrally, and axially. Radial measurements indicated a compressed diameter of {approx_equal}3 mm, consistent with the observed load inductance change and an imploded-mass consisting of a {approx_equal}1.5-mm-diam, hot, K-shell-emitting core and a cooler surrounding blanket. Spectral measurements indicate that, if the load is insufficiently heated, then radiation from the core will rapidly photoheat the outer blanket, producing a strong increase in XUV emission. Also, adding a massive center jet ({>=}20% of load mass) increases the rise and fall times of the XUV emission to {>=}40 ns, consistent with a more adiabatic compression and heating of the load. Axial measurements show that, despite differences in the XUV and K-shell emission time histories, the K-shell x-ray yield is insensitive to axial variations in load mass.

  12. Heuristic drift-based model of the power scrape-off width in low-gas-puff H-mode tokamaks

    NASA Astrophysics Data System (ADS)

    Goldston, R. J.

    2012-01-01

    A heuristic model for the plasma scrape-off width in low-gas-puff tokamak H-mode plasmas is introduced. Grad B and curv B drifts into the scrape-off layer (SOL) are balanced against near-sonic parallel flows out of the SOL, to the divertor plates. The overall particle flow pattern posited is a modification for open field lines of Pfirsch-Schlüter flows to include order-unity sinks to the divertors. These assumptions result in an estimated SOL width of ~2aρp/R. They also result in a first-principles calculation of the particle confinement time of H-mode plasmas, qualitatively consistent with experimental observations. It is next assumed that anomalous perpendicular electron thermal diffusivity is the dominant source of heat flux across the separatrix, investing the SOL width, derived above, with heat from the main plasma. The separatrix temperature is calculated based on a two-point model balancing power input to the SOL with Spitzer-Härm parallel thermal conduction losses to the divertor. This results in a heuristic closed-form prediction for the power scrape-off width that is in reasonable quantitative agreement both in absolute magnitude and in scaling with recent experimental data. Further work should include full numerical calculations, including all magnetic and electric drifts, as well as more thorough comparison with experimental data.

  13. High energy axial ion beam generated by deuterium gas-puff Z-pinch at the current level of 3 MA

    NASA Astrophysics Data System (ADS)

    Rezac, K.; Klir, D.; Kubes, P.; Cikhardt, J.; Batobolotova, B.; Kravarik, J.; Orcikova, H.; Turek, K.; Shishlov, A.; Labetsky, A.; Kokshenev, V.; Ratakhin, N.; GIT-12 Team

    2014-10-01

    The contribution presents results from Z-pinch experiments with a plasma shell on deuterium gas-puff (with deuterium linear mass of about 100 μg/cm) carried out on the GIT-12 generator at IHCE in Tomsk at the current level slightly below 3 MA. The first purpose of experiments was to study the influence of different parameters on the production of neutrons. Neutron yield up to 5 ×1012 neutrons/shot was measured in the shot with LiF catcher. The second purpose was the examination of high-energy ions generated on the Z-pinch axis using RCF and CR-39. Very interesting results were provided by ion pinhole camera, where the influence of magnetic field on the ion beam could be studied. One of the conclusions is that the ions with energy below 10 MeV were significantly deflected by magnetic field. Work supported by MEYS CR research Programs No. ME090871, No. LG13029, by GACR Grant No. P205/12/0454, Grant CRA IAEA No. 17088 and RFBR Grant No. 13-08-00479-a.

  14. High-Compression-Ratio; Atkinson-Cycle Engine Using Low-Pressure Direct Injection and Pneumatic-Electronic Valve Actuation Enabled by Ionization Current and Foward-Backward Mass Air Flow Sensor Feedback

    SciTech Connect

    Harold Schock; Farhad Jaberi; Ahmed Naguib; Guoming Zhu; David Hung

    2007-12-31

    This report describes the work completed over a two and one half year effort sponsored by the US Department of Energy. The goal was to demonstrate the technology needed to produce a highly efficient engine enabled by several technologies which were to be developed in the course of the work. The technologies included: (1) A low-pressure direct injection system; (2) A mass air flow sensor which would measure the net airflow into the engine on a per cycle basis; (3) A feedback control system enabled by measuring ionization current signals from the spark plug gap; and (4) An infinitely variable cam actuation system based on a pneumatic-hydraulic valve actuation These developments were supplemented by the use of advanced large eddy simulations as well as evaluations of fuel air mixing using the KIVA and WAVE models. The simulations were accompanied by experimental verification when possible. In this effort a solid base has been established for continued development of the advanced engine concepts originally proposed. Due to problems with the valve actuation system a complete demonstration of the engine concept originally proposed was not possible. Some of the highlights that were accomplished during this effort are: (1) A forward-backward mass air flow sensor has been developed and a patent application for the device has been submitted. We are optimistic that this technology will have a particular application in variable valve timing direct injection systems for IC engines. (2) The biggest effort on this project has involved the development of the pneumatic-hydraulic valve actuation system. This system was originally purchased from Cargine, a Swedish supplier and is in the development stage. To date we have not been able to use the actuators to control the exhaust valves, although the actuators have been successfully employed to control the intake valves. The reason for this is the additional complication associated with variable back pressure on the exhaust valves when

  15. Quantitative planar laser-induced fluorescence imaging of multi-component fuel/air mixing in a firing gasoline-direct-injection engine: Effects of residual exhaust gas on quantitative PLIF

    SciTech Connect

    Williams, Ben; Ewart, Paul; Wang, Xiaowei; Stone, Richard; Ma, Hongrui; Walmsley, Harold; Cracknell, Roger; Stevens, Robert; Richardson, David; Fu, Huiyu; Wallace, Stan

    2010-10-15

    A study of in-cylinder fuel-air mixing distributions in a firing gasoline-direct-injection engine is reported using planar laser-induced fluorescence (PLIF) imaging. A multi-component fuel synthesised from three pairs of components chosen to simulate light, medium and heavy fractions was seeded with one of three tracers, each chosen to co-evaporate with and thus follow one of the fractions, in order to account for differential volatility of such components in typical gasoline fuels. In order to make quantitative measurements of fuel-air ratio from PLIF images, initial calibration was by recording PLIF images of homogeneous fuel-air mixtures under similar conditions of in-cylinder temperature and pressure using a re-circulation loop and a motored engine. This calibration method was found to be affected by two significant factors. Firstly, calibration was affected by variation of signal collection efficiency arising from build-up of absorbing deposits on the windows during firing cycles, which are not present under motored conditions. Secondly, the effects of residual exhaust gas present in the firing engine were not accounted for using a calibration loop with a motored engine. In order to account for these factors a novel method of PLIF calibration is presented whereby 'bookend' calibration measurements for each tracer separately are performed under firing conditions, utilising injection into a large upstream heated plenum to promote the formation of homogeneous in-cylinder mixtures. These calibration datasets contain sufficient information to not only characterise the quantum efficiency of each tracer during a typical engine cycle, but also monitor imaging efficiency, and, importantly, account for the impact of exhaust gas residuals (EGR). By use of this method EGR is identified as a significant factor in quantitative PLIF for fuel mixing diagnostics in firing engines. The effects of cyclic variation in fuel concentration on burn rate are analysed for different

  16. Variation of polycyclic aromatic hydrocarbons in atmospheric PM2.5 during winter haze period around 2014 Chinese Spring Festival at Nanjing: Insights of source changes, air mass direction and firework particle injection.

    PubMed

    Kong, Shaofei; Li, Xuxu; Li, Li; Yin, Yan; Chen, Kui; Yuan, Liang; Zhang, Yingjie; Shan, Yunpeng; Ji, Yaqin

    2015-07-01

    Daily PM2.5 samples were collected at a suburban site of Nanjing around 2014 Chinese Spring Festival (SF) and analyzed for 18 kinds of polycyclic aromatic hydrocarbons (PAHs) by GC-MS. Comparison of PAH concentrations during different periods, with different air mass origins and under different pollution situations was done. Sources were analyzed by diagnostics ratios and principal component analysis (PCA). The threat of PAHs was assessed by BaP equivalent concentrations (BaPeq) and incremental lifetime cancer risk (ILCR). The averaged PAHs for pre-SF, SF and after SF periods were 50.6, 17.2 and 29 ng m(-3), indicating the variations of PAH sources, with reduced traffic, industrial and construction activities during SF and gradually re-starting of them after-SF. According to PAH mass concentrations, their relative abundance to particles, ratio of PAHs (3-ring+4-ring)/PAHs(5-ring+6-ring), mass concentrations of combustion-derived and carcinogenic PAHs, fireworks burning is an important source for PAHs during SF. The ILCR values for Chinese New Year day were 0.68 and 3.3 per 100,000 exposed children and adults. It suggested the necessity of controlling fireworks burning during Chinese SF period which was always companied with serious regional haze pollution. PAH concentrations exhibited decreasing trend when air masses coming from the following directions as North China Plain (63.9 ng m(-3))>Central China (53.0 ng m(-3))>Shandong Peninsula (46.6 ng m(-3))>Northwest China (18.8 ng m(-3))>Sea (15.8 ng m(-3)). For different pollution situations, they decreased as haze (44.5 ng m(-3))>fog-haze (28.4 ng m(-3))>clear (12.2 ng m(-3))>fog day (9.2 ng m(-3)). Coal combustion, traffic emission, industrial processes and petroleum (only for non-SF holiday periodss) were the main sources of PM2.5 associated PAHs. Fireworks burning contributed 14.0% of PAHs during SF period. Directly measurement of PAHs from fireworks burning is urgently needed for source apportionment studies in

  17. 14 CFR 212.7 - Direct sales.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and... direct sales Public Charters by a foreign air carrier upon a finding that such action is necessary in the... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Direct sales. 212.7 Section...

  18. 14 CFR 212.7 - Direct sales.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and... direct sales Public Charters by a foreign air carrier upon a finding that such action is necessary in the... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Direct sales. 212.7 Section...

  19. 14 CFR 212.7 - Direct sales.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and... direct sales Public Charters by a foreign air carrier upon a finding that such action is necessary in the... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Direct sales. 212.7 Section...

  20. High-resolution time and spatial imaging of tobacco and its pyrolysis products during a cigarette puff by microprobe sampling photoionisation mass spectrometry.

    PubMed

    Hertz-Schünemann, R; Ehlert, S; Streibel, T; Liu, C; McAdam, K; Baker, R R; Zimmermann, R

    2015-03-01

    The time- and space-resolved chemical signatures of gases and vapours formed in solid-state combustion processes are difficult to examine using recent analytical techniques. A machine-smoked cigarette represents a very reproducible model system for dynamic solid-state combustion. By using a special sampling system (microprobe unit) that extracts the formed gases from inside of the burning cigarette, which is coupled to a photoionisation mass spectrometer, it was possible to study the evolution of organic gases during a 2-s cigarette puff. The concentrations of various pyrolysis and combustion products such as 1,3-butadiene, toluene, acetaldehyde and phenol were monitored on-line at different sampling points within cigarettes. A near-microscopic-scale spatial resolution and a 200-ms time resolution were achieved. Finally, the recorded information was combined to generate time-resolved concentration maps, showing the formation and destruction zones of the investigated compounds in the burning cigarette. The combustion zone at the tip of cigarette, where e.g. 1,3-butadiene is predominately formed, was clearly separable from the pyrolysis zones. Depending on the stability of the precursor (e.g. lignin or cellulose), the position of pyrolytic formation varies. In conclusion, it was demonstrated that soft photoionisation mass spectrometry in conjunction with a microprobe sampling device can be used for time- and space-resolved analysis of combustion and pyrolysis reactions. In addition to studies on the model cigarette, further model systems may be studied with this approach. This may include further studies on the combustion of biomass or coal chunks, on heterogeneously catalysed reactions or on spray, dust and gas combustion processes. PMID:25627787

  1. Direct heating surface combustor

    NASA Technical Reports Server (NTRS)

    Beremand, D. G.; Shire, L. I.; Mroz, T. S. (Inventor)

    1978-01-01

    The combustor utilizes a non-adiabatic flame to provide low-emission combustion for gas turbines. A fuel-air mixture is directed through a porous wall, the other side of which serves as a combustion surface. A radiant heat sink disposed adjacent to and spaced from the combustion surface controls the combustor flame temperature in order to prevent the formation of oxides of nitrogen. A secondary air flow cools the heat sink. Additionally, up to 100% of secondary air flow is mixed with the combustion products at the direct heating surface combustor to dilute such products thereby reducing exit temperature. However, if less than 100% secondary air is mixed to the combustor, the remainder may be added to the combustion products further downstream.

  2. Understanding Our Environment: Air.

    ERIC Educational Resources Information Center

    DiSpezio, Michael

    Part of the Understanding Our Environment project that is designed to engage students in investigating specific environmental problems through concrete activities and direct experience, this unit uses the contemporary dilemma of acid rain as a vehicle for teaching weather and the characteristics of air and atmosphere. The project involves a…

  3. Air Pollution.

    ERIC Educational Resources Information Center

    Fox, Donald L.

    1989-01-01

    Materials related to air pollution are reviewed for the period January 1987, to October 1988. The topics are pollution monitoring, air pollution, and environmental chemistry. The organization consists of two major analytical divisions: (1) gaseous methods; and (2) aerosol and particulate methods. (MVL)

  4. Air Pollution.

    EPA Science Inventory

    Air quality is affected by many types of pollutants that are emitted from various sources, including stationary and mobile. These sources release both criteria and hazardous air pollutants, which cause health effects, ecological harm, and material damage. They are generally categ...

  5. 75 FR 18061 - Approval and Promulgation of Air Quality Implementation Plans; Texas; Control of Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-09

    ... Air Pollution From Motor Vehicles AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final... amend 30 TAC Chapter 114, Control of Air Pollution from Motor Vehicles. These revisions consist of the... to develop air pollution regulations and control strategies to ensure that air quality meets...

  6. Impact assessment of PM10 cement plants emissions on urban air quality using the SCIPUFF dispersion model.

    PubMed

    Leone, Vincenzo; Cervone, Guido; Iovino, Pasquale

    2016-09-01

    The Second-order Closure Integrated Puff (SCIPUFF) model was used to study the impact on urban air quality caused by two cement plants emissions located near the city of Caserta, Italy, during the entire year of 2015. The simulated and observed PM10 concentrations were compared using three monitoring stations located in urban and sub-urban area of Caserta city. Both simulated and observed concentrations are shown to be highest in winter, lower in autumn and spring and lowest in summer. Model results generally follow the pattern of the observed concentrations but have a systematic under-prediction of the concentration values. Measures of the bias, NMSE and RMSE indicate a good correlation between observed and estimated values. The SCIPUFF model data analysis suggest that the cement plants are major sources for the measured PM10 values and are responsible for the deterioration of the urban air quality in the city of Caserta. PMID:27485615

  7. Fuel cell stack with passive air supply

    DOEpatents

    Ren, Xiaoming; Gottesfeld, Shimshon

    2006-01-17

    A fuel cell stack has a plurality of polymer electrolyte fuel cells (PEFCs) where each PEFC includes a rectangular membrane electrode assembly (MEA) having a fuel flow field along a first axis and an air flow field along a second axis perpendicular to the first axis, where the fuel flow field is long relative to the air flow field. A cathode air flow field in each PEFC has air flow channels for air flow parallel to the second axis and that directly open to atmospheric air for air diffusion within the channels into contact with the MEA.

  8. The Effect of Smoke-Free Air Law in Bars on Smoking Initiation and Relapse among Teenagers and Young Adults

    PubMed Central

    Shang, Ce

    2015-01-01

    Background: Existing evidence has shown that most smoking uptake and escalation occurs while smokers are teenagers or young adults. Effective policies that reduce smoking uptake and escalation will play an important role in curbing cigarette smoking. This study aims to investigate the effect of smoke-free air (SFA) laws in bars on smoking initiation/relapse while controlling for other confounders. Methods: The national longitudinal Survey of Youth 1997 (NLSY97) from 1997–2009 was linked to state-level scores for the strength of SFA laws in order to carry out the analysis. Results and Conclusion: We find that SFA laws in bars with exemptions significantly reduce (p ≤ 0.01) the probability of smoking initiation (one-puff, daily, and heavy smoking initiation). The 100% SFA law in bars without exemption significantly deters smoking relapse from abstinence into daily smoking (p ≤ 0.05) or relapse from abstinence into heavy smoking (p ≤ 0.01) among people age 21 or older. The reduction of one-puff and daily smoking initiation is larger among ages 20 or younger than ages 21 or older, while the reduction in relapse does not differ by whether respondents reach the drinking age. Results also indicate that higher cigarette taxes significantly reduce daily smoking initiation and relapse into nondaily and light smoking. PMID:25584419

  9. Space Derived Air Monitor

    NASA Technical Reports Server (NTRS)

    1983-01-01

    COPAMS, Commonwealth of Pennsylvania Air Monitoring System, derives from technology involved in building unmanned spacecraft. The Nimbus spacecraft carried experimental sensors to measure temperature, pressure, ozone, and water vapor, and instruments for studying solar radiation and telemetry. The process which relayed these findings to Earth formed the basis for COPAMS. The COPAMS system consists of data acquisition units which measure and record pollution level, and sense wind speed and direction, etc. The findings are relayed to a central station where the information is computerized. The system is automatic and supplemented by PAQSS, PA Air Quality Surveillance System.

  10. Air Pollution

    MedlinePlus

    ... tobacco smoke. How is air pollution linked to climate change? While climate change is a global process, it ... ozone levels are also a concern. Impacts of Climate Change on Human Health in the United States: A ...

  11. Air Apparent.

    ERIC Educational Resources Information Center

    Harbster, David A.

    1988-01-01

    Explains the principle upon which a barometer operates. Describes how to construct two barometric devices for use in the classroom that show air's changing pressure. Cites some conditions for predicting weather. (RT)

  12. Air supply distributor for fireplaces

    SciTech Connect

    Eberhardt, H.A.

    1984-09-18

    An air supply distributor for fireplaces having an opening in the hearth for the supply of relatively cold air is used in combination with means, such as a log holder or grate, for supporting combustible products and comprises a pair of side walls and a top cover. The distributor is adapted to be positioned under the log holder or grate to overlie the hearth opening so that relatively cold air passing through the hearth opening is directed toward the front opening of the fireplace from which it passes to the fire for supporting combustion thereof thereby minimizing the amount of air drawn from the room.

  13. Air Cleaning Technologies

    PubMed Central

    2005-01-01

    , and personal protection methods. Engineering methods that are usually carried out by the building’s heating, ventilation, and air conditioning (HVAC) system function to prevent the spread of airborne infectious pathogens by diluting (dilution ventilation) and removing (exhaust ventilation) contaminated air from a room, controlling the direction of airflow and the air flow patterns in a building. However, general wear and tear over time may compromise the HVAC system’s effectiveness to maintain adequate indoor air quality. Likewise, economic issues may curtail the completion of necessary renovations to increase its effectiveness. Therefore, when exposure to airborne infectious pathogens is a risk, the use of an in-room air cleaner to reduce the concentration of airborne pathogens and prevent the spread of airborne infectious diseases has been proposed as an alternative to renovating a HVAC system. Airborne transmission is the spread of infectious pathogens over large distances through the air. Infectious pathogens, which may include fungi, bacteria, and viruses, vary in size and can be dispersed into the air in drops of moisture after coughing or sneezing. Small drops of moisture carrying infectious pathogens are called droplet nuclei. Droplet nuclei are about 1 to 5μm in diameter. This small size in part allows them to remain suspended in the air for several hours and be carried by air currents over considerable distances. Large drops of moisture carrying infectious pathogens are called droplets. Droplets being larger than droplet nuclei, travel shorter distances (about 1 metre) before rapidly falling out of the air to the ground. Because droplet nuclei remain airborne for longer periods than do droplets, they are more amenable to engineering infection control methods than are droplets. Droplet nuclei are responsible for the airborne transmission of infectious diseases such as tuberculosis, chicken pox (varicella), measles (rubeola), and dessiminated herpes

  14. 77 FR 72432 - Application of Boutique Air, Inc. for Commuter Air Carrier Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ... Department of Transportation is directing all interested persons to show cause why it should not issue an order finding Boutique Air, Inc., fit, willing, and able, and awarding it commuter air carrier...

  15. Air cleaning system

    SciTech Connect

    Tidwell, J.H.

    1987-06-16

    This patent describes an air cleaning system comprising: a motor housing; a motor mounted within the housing; a fan attached to and rotatably driven by the motor; a fan chamber surrounding the fan and having an air inlet and outlet; a separator housing means mounted adjacent to and in spaced relation with the motor housing, the separator housing means having an inlet disposed in communication with a chamber within separator housing means; an outlet disposed in communication with the fan chamber; an air driven separator means mounted in chamber of the separator housing means to receive airflow from inlet for rotation of the separator means and removal of foreign matter from airflow by centrifugal force responsive to rotation of the separator means; the airflow is further directed through the outlet of separator housing means to the fan chamber to be ejected by the fan.

  16. Chapter 22: Compressed Air Evaluation Protocol

    SciTech Connect

    Benton, N.

    2014-11-01

    Compressed-air systems are used widely throughout industry for many operations, including pneumatic tools, packaging and automation equipment, conveyors, and other industrial process operations. Compressed-air systems are defined as a group of subsystems composed of air compressors, air treatment equipment, controls, piping, pneumatic tools, pneumatically powered machinery, and process applications using compressed air. A compressed-air system has three primary functional subsystems: supply, distribution, and demand. Air compressors are the primary energy consumers in a compressed-air system and are the primary focus of this protocol. The two compressed-air energy efficiency measures specifically addressed in this protocol are: high-efficiency/variable speed drive (VSD) compressor replacing modulating compressor; compressed-air leak survey and repairs. This protocol provides direction on how to reliably verify savings from these two measures using a consistent approach for each.

  17. 14 CFR 212.7 - Direct sales.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights...

  18. 14 CFR 212.7 - Direct sales.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Direct sales. 212.7 Section 212.7 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or...

  19. Direct Multizone System.

    ERIC Educational Resources Information Center

    Lennox Industries, Inc., Marshalltown, IA.

    Describes Lennox indoor direct multizone equipment and controls. The following areas are covered--(1) unit features, (2) controls and operations, (3) approvals, (4) air patterns, (5) typical applications, (6) specifications and ratings, (7) dimensioned drawings of a typical unit, (8) mixing boxes, (9) blower data, (10) water valve selection and…

  20. Air surveillance

    SciTech Connect

    Patton, G.W.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the air surveillance and monitoring programs currently in operation at that Hanford Site. Atmospheric releases of pollutants from Hanford to the surrounding region are a potential source of human exposure. For that reason, both radioactive and nonradioactive materials in air are monitored at a number of locations. The influence of Hanford emissions on local radionuclide concentrations was evaluated by comparing concentrations measured at distant locations within the region to concentrations measured at the Site perimeter. This section discusses sample collection, analytical methods, and the results of the Hanford air surveillance program. A complete listing of all analytical results summarized in this section is reported separately by Bisping (1995).

  1. Air Pollution.

    ERIC Educational Resources Information Center

    Scorer, Richard S.

    The purpose of this book is to describe the basic mechanisms whereby pollution is transported and diffused in the atmosphere. It is designed to give practitioners an understanding of basic mechanics and physics so they may have a correct basis on which to formulate their decisions related to practical air pollution control problems. Since many…

  2. /Air Atmospheres

    NASA Astrophysics Data System (ADS)

    Emami, Samar; Sohn, Hong Yong; Kim, Hang Goo

    2014-08-01

    Molten magnesium oxidizes rapidly when exposed to air causing melt loss and handling difficulties. The use of certain additive gases such as SF6, SO2, and CO2 to form a protective MgO layer over a magnesium melt has been proposed. The oxidation behavior of molten magnesium in air containing various concentrations of SF6 was investigated. Measurements of the kinetics of the oxide layer growth at various SF6 concentrations in air and temperatures were made. Experiments were performed using a thermogravimetric analysis unit in the temperature range of 943 K to 1043 K (670 °C to 770 °C). Results showed that a thin, coherent, and protective MgF2 layer was formed under SF6/Air mixtures, with a thickness ranging from 300 nm to 3 μm depending on SF6 concentration, temperature, and exposure time. Rate parameters were calculated and a model for the process was developed. The morphology and composition of the surface films were studied using scanning electron microscope and energy-dispersive spectroscope.

  3. Air Pollution

    PubMed Central

    Clifton, Marjorie

    1964-01-01

    Dr Marjorie Clifton describes the classification of gaseous and nongaseous constituents of air pollution and then outlines the methods of measuring these. The National Survey embraced 150 towns of all sizes throughout England and Wales and provided data on smoke and sulphur dioxide in relation to climate, topography, industrialization, population density, fuel utilization and urban development. Dr W C Turner discusses the relationship between air pollution and mortality from respiratory conditions, and particularly the incidence of chronic bronchitis. He postulates a theory that such respiratory conditions arise as an allergy to the spores of certain moulds, spore formation being encouraged by the air humidity in Greatv Britain and overcrowded and damp living conditions. He describes the results of a twenty-week study undertaken in 1962-3, showing associations between respiratory disease and levels of air pollution. Dr Stuart Carne undertook a survey in general practice to plot the patterns of respiratory illness in London during the winter of 1962-3. There were two peaks of respiratory illnesses coinciding with the fog at the beginning of December and the freeze-up from the end of December until the beginning of March. PMID:14178955

  4. Air Trafficco

    ERIC Educational Resources Information Center

    Kasunic, Kevin

    1970-01-01

    The work of the 14,000 air traffic controllers can be both challenging and nerve-racking. Concentration, steady nerves, and a clear voice are required to remember the routing and identification of the maze of aircraft and to instruct each of them accurately. Controllers must have a high school diploma and three years work experience or a college…

  5. [Air pollution].

    PubMed

    Bauters, Christophe; Bauters, Gautier

    2016-01-01

    Short-term exposure to particulate matter (PM) air pollution is associated with an increased cardiovascular mortality. Chronic exposure to PM is also associated with cardiovascular risk. Myocardial infarction and heart failure are the most common cardiovascular events associated with PM pollution. The pathophysiological mechanisms related to PM pollution are inflammation, thrombosis, vasomotion abnormalities, progression of atherosclerosis, increased blood pressure, and cardiac remodeling. A decrease in PM exposure may be particularly beneficial in subjects with a high cardiovascular risk. PMID:26547674

  6. Air filtering device

    SciTech Connect

    Backus, A.L.

    1992-07-28

    This patent describes a room air cleaning device. It comprises: a box housing having an air inlet and an air outlet provided therein; a vertical baffle coupled to the box housing opposite the air outlet and spaced form the box housing such that an air egress outlet is formed between the vertical baffle and the box housing; air cleansing means substantially disposed within the box housing and cleansing air passing into the inlet and out of the air egress outlet; a fan disposed within the box housing, the fan providing air movement through the air inlet and the air egress outlet; wherein air exits the room air cleaning device through the air egress outlet as a vertical plane of moving air; and wherein formation of the vertical plane of moving air contributes to the formation of a low pressure area drawing impure air toward the air inlet.

  7. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, K.H.

    1987-12-10

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  8. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, Katharine H.

    1990-01-01

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry.

  9. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, K.H.

    1990-05-22

    An inertial impactor is designed which is to be used in an air sampling device for collection of respirable size particles in ambient air. The device may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  10. Small Break Air Ingress Experiment

    SciTech Connect

    Chang Oh; Eung Soo Kim

    2011-09-01

    The small break air-ingress experiment, described in this report, is designed to investigate air-ingress phenomena postulated to occur in pipes in a very high temperature gas-cooled reactor (VHTRs). During this experiment, air-ingress rates were measured for various flow and break conditions through small holes drilled into a pipe of the experimental apparatus. The holes were drilled at right angles to the pipe wall such that a direction vector drawn from the pipe centerline to the center of each hole was at right angles with respect to the pipe centerline. Thus the orientation of each hole was obtained by measuring the included angle between the direction vector of each hole with respect to a reference line anchored on the pipe centerline and pointing in the direction of the gravitational force. Using this reference system, the influence of several important parameters on the air ingress flow rate were measured including break orientation, break size, and flow velocity . The approach used to study the influence of these parameters on air ingress is based on measuring the changes in oxygen concentrations at various locations in the helium flow circulation system as a function of time using oxygen sensors (or detectors) to estimate the air-ingress rates through the holes. The test-section is constructed of a stainless steel pipe which had small holes drilled at the desired locations.

  11. Connaissances, attitudes et pratiques de la population de l'aire de santé SAMBWA en rapport avec le traitement de l'onchocercose à l'ivermectine sous directives communautaires

    PubMed Central

    Philippe, Cilundika Mulenga; Bienvenu, Yogolelo Asani; Francoise, Malonga Kaj; Eric, Mukomena Sompwe; Abdon, Mukalay wa Mukalay; Luboya, Oscar Numbi

    2014-01-01

    Introduction L'onchocercose constitue un problème majeur de santé publique et l'on a noté environ 13 millions de personnes affectées et 26 millions exposées au cours de l'année 2012 en RDC. L'objectif de notre étude est fournir les données sur le niveau de connaissance, d'attitudes et des pratiques de la communauté huit ans après le lancement de la distribution de l'ivermectine sous directives communautaires. Méthodes Il s'agit d'une étude descriptive transversale dans la communauté de l'aire de santé SAMBWA de la zone de santé de KAFUBU. La population cible de l’étude est toute personne de la communauté âgée de 15 à 65 ans. Les paramètres étudiés sont: âge, niveau d'instruction, connaissance de la maladie en langue locale et des signes, attitudes devant les personnes atteintes, perception de la maladie, utilisation des pratiques traditionnelles, association entre le niveau d'instruction et la connaissance de savoir si l'on peut suivre un traitement. Résultats La moyenne d’âge des répondants était de 38±14 ans et 67,54% des enquêtés étaient de niveau primaire. L’étude a montré que 99,53% des répondants connaissaient le terme onchocercose en langue locale (UBUMFUKU) et un niveau moyen de connaissance en ce qui concerne les lésions de la peau (66,9%) était noté. 1,9% des répondants craignaient les personnes atteintes et 42,2% des répondants percevaient l'onchocercose comme une maladie. Une proportion de 55% qui prenaient les plantes comme médicament. Il y avait association significative entre le niveau d'instruction et la connaissance de suivre un traitement contre l'onchocercose (p: 0,008). Conclusion Ces résultats interpellent en ce qui concerne la sensibilisation de la communauté sur l'onchocercose. Les stratégies de lutte contre l'onchocercose devraient prendre en compte ces différentes insuffisances de la communauté pour améliorer le traitement des masses par l'ivermectine tant au niveau du ménage que des

  12. Changes in air flow patterns using surfactants and thickeners during air sparging: Bench-scale experiments

    NASA Astrophysics Data System (ADS)

    Kim, Juyoung; Kim, Heonki; Annable, Michael D.

    2015-01-01

    Air injected into an aquifer during air sparging normally flows upward according to the pressure gradients and buoyancy, and the direction of air flow depends on the natural hydrogeologic setting. In this study, a new method for controlling air flow paths in the saturated zone during air sparging processes is presented. Two hydrodynamic parameters, viscosity and surface tension of the aqueous phase in the aquifer, were altered using appropriate water-soluble reagents distributed before initiating air sparging. Increased viscosity retarded the travel velocity of the air front during air sparging by modifying the viscosity ratio. Using a one-dimensional column packed with water-saturated sand, the velocity of air intrusion into the saturated region under a constant pressure gradient was inversely proportional to the viscosity of the aqueous solution. The air flow direction, and thus the air flux distribution was measured using gaseous flux meters placed at the sand surface during air sparging experiments using both two-, and three-dimensional physical models. Air flow was found to be influenced by the presence of an aqueous patch of high viscosity or suppressed surface tension in the aquifer. Air flow was selective through the low-surface tension (46.5 dyn/cm) region, whereas an aqueous patch of high viscosity (2.77 cP) was as an effective air flow barrier. Formation of a low-surface tension region in the target contaminated zone in the aquifer, before the air sparging process is inaugurated, may induce air flow through the target zone maximizing the contaminant removal efficiency of the injected air. In contrast, a region with high viscosity in the air sparging influence zone may minimize air flow through the region prohibiting the region from de-saturating.

  13. Reconstructing the atmospheric concentration and emissions of CF4, C2F6 and C3F8 prior to direct atmospheric measurements, using air from polar firn and ice

    NASA Astrophysics Data System (ADS)

    Trudinger, Cathy; Etheridge, David; Sturges, William; Vollmer, Martin; Miller, Benjamin; Worton, David; Rigby, Matt; Krummel, Paul; Martinerie, Patricia; Witrant, Emmanuel; Rayner, Peter; Battle, Mark; Blunier, Thomas; Fraser, Paul; Laube, Johannes; Mani, Frances; Mühle, Jens; O'Doherty, Simon; Schwander, Jakob; Steele, Paul

    2015-04-01

    Perfluorocarbons are very potent and long-lived greenhouse gases in the atmosphere, released predominantly during aluminium production, electronic chip manufacture and refrigeration. Mühle et al. (2010) presented records of the concentration and inferred emissions of CF4 (PFC-14), C2F6 (PFC-116) and C3F8 (PFC-218) from the 1970s up to 2008, using measurements from the Cape Grim Air Archive and a suite of tanks with old Northern Hemisphere air, and the AGAGE in situ network. Mühle et al. (2010) also estimated pre-industrial concentrations of these compounds from a small number of polar firn and ice core samples. Here we present measurements of air from polar firn at four sites (DSSW20K, EDML, NEEM and South Pole) and from air bubbles trapped in ice at two sites (DE08 and DE08-2), along with recent atmospheric measurements to give a continuous record of concentration from preindustrial levels up to the present. We estimate global emissions (with uncertainties) consistent with the concentration records. The uncertainty analysis takes into account uncertainties in characterisation of the age of air in firn and ice by the use of two different (independently-calibrated) firn models (the CSIRO and LGGE-GIPSA firn models). References Mühle, J., A.L. Ganesan, B.R. Miller, P.K. Salameh, C.M. Harth, B.R. Greally, M. Rigby, L.W. Porter, L. P. Steele, C.M. Trudinger, P.B. Krummel, S. O'Doherty, P.J. Fraser, P.G. Simmonds, R.G. Prinn, and R.F. Weiss, Perfluorocarbons in the global atmosphere: tetrafluoromethane, hexafluoroethane, and octafluoropropane, Atmos. Chem. Phys., 10, 5145-5164, doi:10.5194/acp-10-5145-2010, 2010.

  14. 30 CFR 56.13020 - Use of compressed air.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Use of compressed air. 56.13020 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13020 Use of compressed air. At no time shall compressed air be directed toward a...

  15. 30 CFR 56.13020 - Use of compressed air.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Use of compressed air. 56.13020 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13020 Use of compressed air. At no time shall compressed air be directed toward a...

  16. 30 CFR 57.13020 - Use of compressed air.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Use of compressed air. 57.13020 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13020 Use of compressed air. At no time shall compressed air be directed toward...

  17. 30 CFR 56.13020 - Use of compressed air.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Use of compressed air. 56.13020 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13020 Use of compressed air. At no time shall compressed air be directed toward a...

  18. Directions in civil aviation 1980-2000

    NASA Technical Reports Server (NTRS)

    Roberts, L.

    1977-01-01

    The following future directions in civil aviation are considered: (1) greater economy and efficiency in passenger and cargo air service at subsonic speeds, and improved utility and safety for general aviation, (2) greatly improved short haul air transportation using turbofan or turboprop aircraft, and subsequently, rotorcraft and V/STOL aircraft, and (3) supersonic, and ultimately hypersonic, air transportation for transoceanic long range flight. Attention is also given to new directions in research and technology.

  19. Air-Coupled Vibrometry

    NASA Astrophysics Data System (ADS)

    Döring, D.; Solodov, I.; Busse, G.

    Sound and ultrasound in air are the products of a multitude of different processes and thus can be favorable or undesirable phenomena. Development of experimental tools for non-invasive measurements and imaging of airborne sound fields is of importance for linear and nonlinear nondestructive material testing as well as noise control in industrial or civil engineering applications. One possible solution is based on acousto-optic interaction, like light diffraction imaging. The diffraction approach usually requires a sophisticated setup with fine optical alignment barely applicable in industrial environment. This paper focuses on the application of the robust experimental tool of scanning laser vibrometry, which utilizes commercial off-the-shelf equipment. The imaging technique of air-coupled vibrometry (ACV) is based on the modulation of the optical path length by the acoustic pressure of the sound wave. The theoretical considerations focus on the analysis of acousto-optical phase modulation. The sensitivity of the ACV in detecting vibration velocity was estimated as ~1 mm/s. The ACV applications to imaging of linear airborne fields are demonstrated for leaky wave propagation and measurements of ultrasonic air-coupled transducers. For higher-intensity ultrasound, the classical nonlinear effect of the second harmonic generation was measured in air. Another nonlinear application includes a direct observation of the nonlinear air-coupled emission (NACE) from the damaged areas in solid materials. The source of the NACE is shown to be strongly localized around the damage and proposed as a nonlinear "tag" to discern and image the defects.

  20. Electronic cigarettes and indoor air quality: a simple approach to modeling potential bystander exposures to nicotine.

    PubMed

    Colard, Stéphane; O'Connell, Grant; Verron, Thomas; Cahours, Xavier; Pritchard, John D

    2015-01-01

    There has been rapid growth in the use of electronic cigarettes ("vaping") in Europe, North America and elsewhere. With such increased prevalence, there is currently a debate on whether the aerosol exhaled following the use of e-cigarettes has implications for the quality of air breathed by bystanders. Conducting chemical analysis of the indoor environment can be costly and resource intensive, limiting the number of studies which can be conducted. However, this can be modelled reasonably accurately based on empirical emissions data and using some basic assumptions. Here, we present a simplified model, based on physical principles, which considers aerosol propagation, dilution and extraction to determine the potential contribution of a single puff from an e-cigarette to indoor air. From this, it was then possible to simulate the cumulative effect of vaping over time. The model was applied to a virtual, but plausible, scenario considering an e-cigarette user and a non-user working in the same office space. The model was also used to reproduce published experimental studies and showed good agreement with the published values of indoor air nicotine concentration. With some additional refinements, such an approach may be a cost-effective and rapid way of assessing the potential exposure of bystanders to exhaled e-cigarette aerosol constituents. PMID:25547398