Log in

Relevant bibliographies by topics / Flow afterglow / Journal articles

To see the other types of publications on this topic, follow the link: Flow afterglow.

Journal articles on the topic 'Flow afterglow'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 43 journal articles for your research on the topic 'Flow afterglow.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

MIMICA, PETAR, DIMITRIOS GIANNIOS, and MIGUEL ANGEL ALOY. "SIMULATIONS OF DYNAMICS AND EMISSION FROM MAGNETIZED GRB AFTERGLOWS." International Journal of Modern Physics D 19, no. 06 (June 2010): 985–90. http://dx.doi.org/10.1142/s0218271810017007.

Full text

Abstract:

The role of magnetic fields in the GRB flow is still controversial. The afterglow emission, particularly the early phases, may provide a probe into the magnetization of the outflow. Using ultrahigh resolution relativistic MHD simulations, the interaction between radially expanding magnetized ejecta with the interstellar medium is studied. We explore the effect of the magnetic field strength of the ejecta on the afterglow structure, particularly regarding the presence and strength of a reverse shock. We compute synthetic afterglow light curves to quantify the effect of the magnetization of the flow on observed radiation.

APA, Harvard, Vancouver, ISO, and other styles

2

Mazánková, V., D. Trunec, K. Petrová, and F. Krčma. "Study of Argon Afterglow with the Air Addition." PLASMA PHYSICS AND TECHNOLOGY 3, no. 3 (February 14, 2016): 136–39. http://dx.doi.org/10.14311/ppt.2016.3.136.

Full text

Abstract:

The reaction kinetics in argon flowing afterglow (post-discharge) with the air addition was studied by optical emission spectroscopy. The optical emission spectra were measured along the~post-discharge flow tube. A zero-dimensional kinetic model for the reactions in the afterglow was developed. This model allows to calculate the time dependencies of particle concentrations.

APA, Harvard, Vancouver, ISO, and other styles

3

KIMURA, Takeyoshi, Hajime ITOH, and Kazuhiko OGAWA. "Visualization of Hypersonic Separated Flow by Afterglow Technique." Transactions of the Japan Society of Mechanical Engineers Series B 63, no. 610 (1997): 2017–22. http://dx.doi.org/10.1299/kikaib.63.2017.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Mehta, Riddhi, Maxim Barkov, and Maxim Lyutikov. "Radio afterglow of magnetars’ giant flares." Monthly Notices of the Royal Astronomical Society 506, no. 4 (July 26, 2021): 6093–110. http://dx.doi.org/10.1093/mnras/stab2151.

Full text

Abstract:

ABSTRACT We develop a model for the radio afterglow of the giant flare of SGR 1806-20 arising due to the interaction of magnetically dominated cloud, an analogue of Solar Coronal Mass Ejections (CMEs), with the interstellar medium (ISM). The CME is modelled as a spheromak-like configuration. The CME is first advected with the magnetar’s wind and later interacts with the ISM, creating a strong forward shock and complicated backwards exhaust flow. Using 3D magnetohydrodynamic simulations, we study various relative configurations of the magnetic field of the CME with respect to the ISM’s magnetic field. We show that the dynamics of the forward shock mostly follows the Sedov–Taylor blastwave, while the internal structure of the shocked medium is considerably modified by the back flow, creating a multiple shock configuration. We calculate synthetic synchrotron emissivity maps and light curves using two assumptions: (i) magnetic field compression; (ii) amplification of the magnetic field at the shock. We find that models with magnetic field amplification account better for the observed radio emission.

APA, Harvard, Vancouver, ISO, and other styles

5

Squires, Robert R. "Advances in flowing afterglow and selected-ion flow tube techniques." International Journal of Mass Spectrometry and Ion Processes 118-119 (September 1992): 503–18. http://dx.doi.org/10.1016/0168-1176(92)85074-a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Chou, ChinHao, and Jonathan Phillips. "Plasma production of metallic nanoparticles." Journal of Materials Research 7, no. 8 (August 1992): 2107–13. http://dx.doi.org/10.1557/jmr.1992.2107.

Full text

Abstract:

Metallic iron and iron oxide particles were produced by injecting ferrocene into the afterglow region of a low pressure, low power, plasma generated using a microwave power source. This was done as part of an effort to explore the feasibility of using flow type microwave plasmas for the production of metal nanoparticles. It was found that two parameters had the largest impact on the particles: injection point and plasma composition. Analysis done using Mössbauer effect spectroscopy, transmission electron microscopy, and x-ray diffraction indicated that low yields of small particles (ca. 10 nm) resulted from injection into the afterglow region. Much higher yields of large particles (ca. 50 nm) formed if the ferrocene was injected through the coupler. In hydrogen plasmas the particles that were produced were metallic iron, whereas in oxygen and argon plasmas the particles were iron oxide. In all cases significant amounts of graphitic carbon formed around the metal particles.

APA, Harvard, Vancouver, ISO, and other styles

7

Wu, Shuqun, Xueyuan Liu, Wenhao Mao, Wen Chen, Chang Liu, and Chaohai Zhang. "Non-thermal air plasma jets at atmospheric pressure: The flow-dependent propagation in the afterglow." Journal of Applied Physics 124, no. 24 (December 28, 2018): 243302. http://dx.doi.org/10.1063/1.5052187.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Bierbaum, Veronica M. "Go with the flow: Fifty years of innovation and ion chemistry using the flowing afterglow." International Journal of Mass Spectrometry 377 (February 2015): 456–66. http://dx.doi.org/10.1016/j.ijms.2014.07.021.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Cousty, S., S. Villeger, J. P. Sarette, A. Ricard, and M. Sixou. "Inactivation of Escherichia coli in the flowing afterglow of an N2discharge at reduce pressure: study of the destruction mechanisms of bacteria and hydrodynamics of the afterglow flow." European Physical Journal Applied Physics 34, no. 2 (May 2006): 143–46. http://dx.doi.org/10.1051/epjap:2006036.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Lerner, N. R., and T. Wydeven. "Decrease in the etch rate of polymers in the oxygen afterglow with increasing gas flow rate." Journal of Applied Polymer Science 35, no. 7 (May 20, 1988): 1903–8. http://dx.doi.org/10.1002/app.1988.070350715.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Дубровин, К. А., А. Е. Зарвин, В. В. Каляда, and А. С. Яскин. "Причины свечения аномального вторичного потока в сверхзвуковых кластированных струях, возбужденных высоковольтным электронным пучком." Письма в журнал технической физики 46, no. 7 (2020): 32. http://dx.doi.org/10.21883/pjtf.2020.07.49217.18011.

Full text

Abstract:

The role of clustered particles in the formation of a secondary flow (“wake”) occuring at the gas expiring into a rarefied medium in condensation modes is established. The “wake” boundaries were found by comparing the spectral and photometric measurements. Possible mechanisms for initiating luminescence in "wake" are considered. The role of energy exchange of clusters with background gas in the afterglow of the "wake" has been found out. The wavelengths and corresponding transitions in the neutral (Ar-I) and once ionized (Ar-II) argon atoms, which determine the anomalous glow, were discovered. The lifetimes in the excited state of particles in the central part and on the periphery of the clustered flow are detected. The effect of condensation on the background gas penetration into the primary traditional supersonic jet and into the “wake” zone is found.

APA, Harvard, Vancouver, ISO, and other styles

12

Apostol, Simona, Gabriella Szalai, László Sujbert, Losanka P. Popova, and Tibor Janda. "Non-Invasive Monitoring of the Light-Induced Cyclic Photosynthetic Electron Flow during Cold Hardening in Wheat Leaves." Zeitschrift für Naturforschung C 61, no. 9-10 (October 1, 2006): 734–40. http://dx.doi.org/10.1515/znc-2006-9-1021.

Full text

Abstract:

AbstractThe effect of irradiance during low temperature hardening was studied in a winter wheat variety. Ten-day-old winter wheat plants were cold-hardened at 5 °C for 11 days under light (250 μmol m-2 s-1) or dark (20 μmol m-2 s-1) conditions. The effectiveness of hardening was significantly lower in the dark, in spite of a slight decrease in the Fv/Fm chlorophyll fluorescence induction parameter, indicating the occurrence of photoinhibition during the hardening period in the light. Hardening in the light caused a downshift in the far-red induced AG (afterglow) thermoluminescence band. The faster dark re-reduction of P700+, monitored by 820-nm absorbance, could also be observed in these plants. These results suggest that the induction of cyclic photosynthetic electron flow may also contribute to the advantage of frost hardening under light conditions in wheat plants.

APA, Harvard, Vancouver, ISO, and other styles

13

Storey, Andrew P., Offer M. Zeiri, Steven J. Ray, and Gary M. Hieftje. "Helium conservation by discontinuous introduction in the flowing atmospheric-pressure afterglow source for ambient desorption-ionization mass spectrometry." Journal of Analytical Atomic Spectrometry 30, no. 9 (2015): 2017–23. http://dx.doi.org/10.1039/c5ja00228a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Van Doren, Jane M., Stephan E. Barlow, Charles H. DePuy, and Veronica M. Bierbaum. "Tandem flowing afterglow-selected ion flow tube and its application to the thermal energy reactions of 18O-." Journal of the American Chemical Society 109, no. 14 (July 1987): 4412–14. http://dx.doi.org/10.1021/ja00248a057.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Cohen, Michael H., Cynthia Barckholtz, Brian T. Frink, Joshua J. Bond, C. Michael Geise, Jerry Hoff, John Herlinger, Tom Hickey, and Christopher M. Hadad. "Reactions of Ar+with Selected Volatile Organic Compounds. A Flowing Afterglow and Selected Ion Flow Tube Study." Journal of Physical Chemistry A 104, no. 48 (December 2000): 11318–27. http://dx.doi.org/10.1021/jp002489o.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Bierbaum, Veronica M. "Anions in Space and in the Laboratory." Proceedings of the International Astronomical Union 7, S280 (June 2011): 383–89. http://dx.doi.org/10.1017/s1743921311025130.

Full text

Abstract:

AbstractThe astronomical detection of molecular anions has prompted our study of their chemical reactions with atomic species that are abundant in the interstellar medium. We have recently explored the chemistry of a variety of Cx Ny− anions with hydrogen atoms and determined their reaction rate constants and products using the flowing afterglow-selected ion flow tube technique. Computational studies allow characterization of the structures of reactants and products, as well as the energetics along the reaction pathway. For anions containing one or two nitrogen atoms, reactions with hydrogen atoms are facile, and proceed primarily by associative detachment. In contrast, anions containing three nitrogen atoms are unreactive with hydrogen atoms due to reaction barriers and unfavorable thermodynamics.

APA, Harvard, Vancouver, ISO, and other styles

17

Bierbaum, V. M. "Laboratory Studies of Ion Chemistry in the Interstellar Medium." Proceedings of the International Astronomical Union 9, S297 (May 2013): 258–64. http://dx.doi.org/10.1017/s1743921313015962.

Full text

Abstract:

AbstractStudies of gas phase ion-neutral reactions provide insight into many areas of astrochemistry, including the elusive characterization of the Diffuse Interstellar Bands (DIBs). This presentation gives an overview of our experimental studies of several classes of positive and negative ions, using the flowing afterglow-selected ion flow tube and a newly modified ion trap. Earlier studies of carbon chain anions and polycyclic aromatic hydrocarbon (PAH) cations, both of which have been suggested as carriers of the DIBs, are described. More recent work including isomeric PAHs, nitrogen-containing PAHs, negative ions of PAHs, and negative ions of 5-membered heterocyclic rings are discussed. Finally, the study of quantitative thermochemistry by coupling our results with data from Photoelectron Spectroscopy is described.

APA, Harvard, Vancouver, ISO, and other styles

18

Bernasconi, Claude F., Michael W. Stronach, Charles H. DePuy, and Scott Gronert. "Reaction of anions with activated olefins in the gas phase. A flowing afterglow-selected ion flow tube study." Journal of the American Chemical Society 112, no. 25 (December 1990): 9044–52. http://dx.doi.org/10.1021/ja00181a003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Milligan, Daniel B., David A. Fairley, Colin G. Freeman, and Murray J. McEwan. "A flowing afterglow selected ion flow tube (FA/SIFT) comparison of SIFT injector flanges and H3+ + N revisited." International Journal of Mass Spectrometry 202, no. 1-3 (October 2000): 351–61. http://dx.doi.org/10.1016/s1387-3806(00)00263-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

da Maia, J. V., R. S. Pessoa, A. S. da Silva Sobrinho, M. Massi, and H. S. Maciel. "Optical Characterization of Glow and Afterglow Regions of Ar/O2Microwave Plasma: Effect of Applied Power and Gas Flow." Journal of Physics: Conference Series 511 (May 7, 2014): 012016. http://dx.doi.org/10.1088/1742-6596/511/1/012016.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Storey, Andrew P., Offer M. Zeiri, Steven J. Ray, and Gary M. Hieftje. "Use of Interrupted Helium Flow in the Analysis of Vapor Samples with Flowing Atmospheric-Pressure Afterglow-Mass Spectrometry." Journal of The American Society for Mass Spectrometry 28, no. 2 (October 18, 2016): 263–69. http://dx.doi.org/10.1007/s13361-016-1520-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Schmiedberger, Josef, Werner Fuß, and Libor Juha. "Strong Sensitized Ultraviolet Luminescence from He–C2F4–NO Flowing Plasma Afterglow: A Route to Short-Wavelength Gas-Flow Lasers?" Plasma Chemistry and Plasma Processing 39, no. 4 (March 27, 2019): 1115–26. http://dx.doi.org/10.1007/s11090-019-09978-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Martinez, Oscar, Theodore P. Snow, and Veronica M. Bierbaum. "Ion chemistry in the interstellar medium." Proceedings of the International Astronomical Union 4, S251 (February 2008): 139–40. http://dx.doi.org/10.1017/s1743921308021388.

Full text

Abstract:

AbstractWithout accurate data on reaction rates and branching ratios, models of interstellar chemistry are unreliable. Recent research has identified a number of reactions of unusual importance because the rates and branching ratios are unknown or poorly known. Efforts to expand and improve on current databases are underway using a flowing afterglow-selected ion flow tube (FA-SIFT) coupled to a quadrupole mass spectrometer. Our current focus is on the reactions of C+, a major cation in the interstellar medium, with the neutrals O2, H2O, CH4, NH3 and C2H2. Future planned work includes studies of polycyclic aromatic hydrocarbons (PAHs), developing comprehensive pathways for their formation, and identification of those PAHs important to interstellar chemistry. The recent discovery of ISM anions has highlighted the importance of examining mechanisms of anionic chemistry in the interstellar medium, and we plan to obtain data relevant to the formation and destruction processes of molecular anions in space.

APA, Harvard, Vancouver, ISO, and other styles

24

Blanksby, Stephen J., Shuji Kato, Veronica Bierbaum, and G. Barney Ellison. "Fragmentations of Deprotonated Alkyl Hydroperoxides (ROO− Upon Collisional Activation: A Combined Experimental and Computational Study." Australian Journal of Chemistry 56, no. 5 (2003): 459. http://dx.doi.org/10.1071/ch03039.

Full text

Abstract:

The collision-induced dissociation (CID) mass spectra of the [M − H]– anions of methyl, ethyl, and tert-butyl hydroperoxides have been measured over a range of collision energies in a flowing afterglow–selected ion flow tube (FA-SIFT) mass spectrometer. Activation of the CH3OO– anion is found to give predominantly HO– fragment anions whilst CH3CH2OO− and (CH3)3COO– produce HOO– as the major ionic fragment. These results, and other minor fragmentation pathways, can be rationalized in terms of unimolecular rearrangement of the activated anions with subsequent decomposition. The rearrangement reactions occur via initial abstraction of a proton from the α-carbon in the case of CH3OO– or the β-carbon for CH3CH2OO– and (CH3)3COO–. Electronic structure calculations suggest that for the CH3CH2OO– anion, which can theoretically undergo both α- and β-proton abstraction, the latter pathway, resulting in HOO– + CH2CH2, is energetically preferred.

APA, Harvard, Vancouver, ISO, and other styles

25

DePuy, Charles H., Roustam Gareyev, and Simonetta Fornarini. "Generation and assay of C6HxD(7-x)+ (x = 1–6) benzenium ions: a flowing afterglow-selected ion flow tube study." International Journal of Mass Spectrometry and Ion Processes 161, no. 1-3 (February 1997): 41–45. http://dx.doi.org/10.1016/s0168-1176(96)04393-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

BERNASCONI, C. F., M. W. STRONACH, C. H. DEPUY, and S. GRONERT. "ChemInform Abstract: Reaction of Anions with Activated Olefins in the Gas Phase. A Flowing Afterglow-Selected Ion Flow Tube Study." ChemInform 22, no. 12 (August 23, 2010): no. http://dx.doi.org/10.1002/chin.199112100.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Coxon, J. A., and U. K. Roychowdhury. "A Spectrometric Technique for Monitoring [O2(a1 Δg)] in the Gas Phase." Applied Spectroscopy 40, no. 2 (February 1986): 203–9. http://dx.doi.org/10.1366/0003702864509411.

Full text

Abstract:

The reaction of chlorine with alkaline hydrogen peroxide has been used to produce O2( a1 Δ g) in a fast flow system at partial pressures up to about 0.5 Torr, and total pressures (mostly argon) in the range 0.8–2.5 Torr. Absolute concentrations of O2( a1 Δ g) were determined from the intensity of absorption of hydrogen emission lines in the vacuum-UV at 144.095 and 148.66 nm, for which the cross sections are known. The intensity of the O2 ( a → X) transition at 1270 nm, monitored simultaneously with a simple germanium detector, was found to vary linearly with [O2( a1 Δ g)], as expected. The germanium detector was calibrated at 1270 nm with a readily reproducible standard, the air afterglow continuum due to NO2* at defined concentrations of O(3P) and NO. The ratio of ka for O2( a) ka O 2( X) + hvt to kc for O + NO kc NO2 + hv, is (1.4 ± 0.2) × 10−7 mol L−1 at 1270 nm.

APA, Harvard, Vancouver, ISO, and other styles

28

Shepelenko, A. A., N. V. Kupryaev, and P. A. Mikheyev. "Singlet delta oxygen concentration and the main process of its decrease in the afterglow of a DC discharge in oxygen flow." High Temperature 50, no. 1 (February 2012): 137–44. http://dx.doi.org/10.1134/s0018151x11060216.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Ducruet, Jean-Marc, Miruna Roman, Michel Havaux, Tibor Janda, and André Gallais. "Cyclic electron flow around PSI monitored by afterglow luminescence in leaves of maize inbred lines (Zea mays L.): correlation with chilling tolerance." Planta 221, no. 4 (February 2, 2005): 567–79. http://dx.doi.org/10.1007/s00425-004-1464-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Rimetz-Planchon, J., F. Dhooghe, N. Schoon, F. Vanhaecke, and C. Amelynck. "MS/MS studies on the selective on-line detection of sesquiterpenes using a flowing afterglow-tandem mass spectrometer." Atmospheric Measurement Techniques Discussions 3, no. 5 (October 5, 2010): 4285–311. http://dx.doi.org/10.5194/amtd-3-4285-2010.

Full text

Abstract:

Abstract. A Flowing Afterglow-Tandem Mass Spectrometer (FA-TMS) was used to investigate the feasibility of selective on-line detection of a series of seven sesquiterpenes (SQTs). These SQTs were chemically ionized by either H3O+ or NO+ reagent ions in the FA, resulting among others in protonated SQT and SQT molecular ions, respectively. These and other Chemical Ionization (CI) product ions were subsequently subjected to dissociation by collisions with Ar atoms in the collision cell of the tandem mass spectrometer. The fragmentation spectra show similarities with mass spectra obtained for these compounds with other instruments such as a Proton Transfer Reaction-Linear Ion Trap (PTR-LIT), a Proton Transfer Reaction-Mass Spectrometer (PTR-MS), a Triple Quadrupole-Mass Spectrometer (QqQ-MS) and a Selected Ion Flow Tube-Mass Spectrometer (SIFT-MS). Fragmentation of protonated SQT is characterized by fragment ions at the same masses but with different intensities for the individual SQT. Distinction of SQTs is based on well-chosen intensity ratios and collision energies. The fragmentation patterns of SQT molecular ions show specific fragment ion tracers at m/z 119, m/z 162, m/z 137 and m/z 131 for α-cedrene, δ-neoclovene, isolongifolene and α-humulene, respectively. Consequently, chemical ionization of SQT by NO+, followed by MS/MS of SQT+ seems to open a way for selective quantification of SQTs in mixtures.

APA, Harvard, Vancouver, ISO, and other styles

31

Rimetz-Planchon, J., F. Dhooghe, N. Schoon, F. Vanhaecke, and C. Amelynck. "MS/MS studies on the selective on-line detection of sesquiterpenes using a Flowing Afterglow–Tandem Mass Spectrometer (FA-TMS)." Atmospheric Measurement Techniques 4, no. 4 (April 7, 2011): 669–81. http://dx.doi.org/10.5194/amt-4-669-2011.

Full text

Abstract:

Abstract. A Flowing Afterglow-Tandem Mass Spectrometer (FA-TMS) was used to investigate the feasibility of selective on-line detection of a series of seven sesquiterpenes (SQTs). These SQTs were chemically ionized by either H3O+ or NO+ reagent ions in the FA, resulting among others in protonated SQT and SQT molecular ions, respectively. These and other Chemical Ionization (CI) product ions were subsequently subjected to dissociation by collisions with Ar atoms in the collision cell of the tandem mass spectrometer. The fragmentation spectra show similarities with mass spectra obtained for these compounds with other instruments such as a Proton Transfer Reaction-Linear Ion Trap (PTR-LIT), a Proton Transfer Reaction-Mass Spectrometer (PTR-MS), a Triple Quadrupole-Mass Spectrometer (QqQ-MS) and a Selected Ion Flow Tube-Mass Spectrometer (SIFT-MS). Fragmentation of protonated SQT is characterized by fragment ions at the same masses but with different intensities for the individual SQT. Distinction of SQTs is based on well-chosen intensity ratios and collision energies. The fragmentation patterns of SQT molecular ions show specific fragment ion tracers at m/z 119, m/z162, m/z 137 and m/z 131 for α-cedrene, δ-neoclovene, isolongifolene and α-humulene, respectively. Consequently, chemical ionization of SQT by NO+, followed by MS/MS of SQT+ seems to open a way for selective quantification of SQTs in mixtures.

APA, Harvard, Vancouver, ISO, and other styles

32

Mimica, Petar, Dimitrios Giannios, and Miguel Ángel Aloy. "Afterglow light curves from magnetized GRB flows." Proceedings of the International Astronomical Union 6, S275 (September 2010): 358–62. http://dx.doi.org/10.1017/s1743921310016406.

Full text

Abstract:

AbstractUsing the RMHD code MRGENESIS and the radiative transfer code SPEV we compute multiwavelength afterglow light curves of magnetized ejecta of gamma-ray bursts interacting with a uniform circumburst medium. We are interested in the emission from the reverse shock when ejecta magnetization varies from σ0 = 0 to σ0 = 1. For typical parameters of the ejecta, the emission from the reverse shock peaks for magnetization σ0 ~ 0.01 − 0.1, and is suppressed for higher σ0. We fit the early afterglow light curves of GRB 990123 and 090102 and discuss the possible magnetization of the outflows of these bursts. Finally we discuss the amount energy left in the magnetic field which is available for dissipation at later afterglow stages.

APA, Harvard, Vancouver, ISO, and other styles

33

Dhooghe, F., C. Amelynck, J. Rimetz-Planchon, N. Schoon, and F. Vanhaecke. "Flowing afterglow selected ion flow tube (FA-SIFT) study of ion/molecule reactions in support of the detection of biogenic alcohols by medium-pressure chemical ionization mass spectrometry techniques." International Journal of Mass Spectrometry 285, no. 1-2 (August 2009): 31–41. http://dx.doi.org/10.1016/j.ijms.2009.04.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Pavlov, A. V. "The role of vibrationally excited oxygen and nitrogen in the ionosphere during the undisturbed and geomagnetic storm period of 6-12 April 1990." Annales Geophysicae 16, no. 5 (May 31, 1998): 589–601. http://dx.doi.org/10.1007/s00585-998-0589-5.

Full text

Abstract:

Abstract. We present a comparison of the observed behavior of the F-region ionosphere over Millstone Hill during the geomagnetically quiet and storm periods of 6–12 April 1990 with numerical model calculations from the IZMIRAN time-dependent mathematical model of the Earth's ionosphere and plasmasphere. The major enhancement to the IZMIRAN model developed in this study is the use of a new loss rate of O+(4S) ions as a result of new high-temperature flowing afterglow measurements of the rate coefficients K1 and K2 for the reactions of O+(4S) with N2 and O2. The deviations from the Boltzmann distribution for the first five vibrational levels of O2(v) were calculated, and the present study suggests that these deviations are not significant. It was found that the difference between the non-Boltzmann and Boltzmann distribution assumptions of O2(v) and the difference between ion and neutral temperature can lead to an increase of up to about 3 or a decrease of up to about 4 of the calculated NmF2 as a result of a respective increase or a decrease in K2. The IZMIRAN model reproduces major features of the data. We found that the inclusion of vibrationally excited N2(v > 0) and O2(v > 0) in the calculations improves the agreement between the calculated NmF2 and the data on 6, 9, and 10 April. However, both the daytime and nighttime densities are reproduced by the IZMIRAN model without the vibrationally excited nitrogen and oxygen on 8 and 11 April better than the IZMIRAN model with N2(v > 0) and O2(v > 0). This could be due to possible uncertainties in model neutral temperature and densities, EUV fluxes, rate coefficients, and the flow of ionization between the ionosphere and plasmasphere, and possible horizontal divergence of the flux of ionization above the station. Our calculations show that the increase in the O+ + N2 rate factor due to N2(v > 0) produces a 5-36 decrease in the calculated daytime peak density. The increase in the O++ O2 loss rate due to vibrational-ly excited O2 produces 8-46 reductions in NmF2. The effects of vibrationally excited O2 and N2 on Ne and Te are most pronounced during the daytime.Key words. Ion chemistry and composition · Ionosphere – atmosphere interactions · Ionospheric disturbances

APA, Harvard, Vancouver, ISO, and other styles

35

Mimica, P., D. Giannios, and M. A. Aloy. "Multiwavelength afterglow light curves from magnetized gamma-ray burst flows." Monthly Notices of the Royal Astronomical Society 407, no. 4 (July 1, 2010): 2501–10. http://dx.doi.org/10.1111/j.1365-2966.2010.17071.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Naumov, V. V., and S. A. Zhdanok. "Afterglows in nonequilibrium reactive plasma flows near atmospheric pressure." Physica Scripta T63 (January 1, 1996): 295–96. http://dx.doi.org/10.1088/0031-8949/1996/t63/056.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Chandra, B. P., V. K. Chandra, and Piyush Jha. "Mechanoluminescence of Coloured Alkali Halide Crystals." Defect and Diffusion Forum 361 (January 2015): 121–76. http://dx.doi.org/10.4028/www.scientific.net/ddf.361.121.

Full text

Abstract:

The present paper reports both the experimental and mathematical aspects of elastico-mechanoluminescence (EML), plastico-mechanoluminescence (PML) and fracto-mechanoluminescence (FML) of coloured alkali halide crystals in detail, and thereby provides a deep understanding of the related phenomena. The additively coloured alkali halide crystals do not show ML during their elastic and plastic deformation. The ML emission during the elastic deformation takes place due to the mechanical interaction between bending dislocation segments and F-centres, and the ML emission during plastic deformation takes place due to the mechanical interaction between the moving dislocations and F-centres. The ML emission during fracture is also caused by the mechanical interaction between the moving dislocations and F-centres; however, in certain hard crystals like LiF, NaCl, NaF, etc., fracto ML also occurs due to the gas discharge caused by the creation of oppositely charged walls of cracks. The EML, PML, and solid state FML spectra of coloured alkali halide crystals are similar to their thermoluminescence spectra and afterglow spectra. However, the fracto ML spectra of certain hard crystals like LiF, NaCl, NaF, etc., also contain gas discharge spectra. The solid state ML spectra of coloured alkali halide crystals can be assigned to deformation-induced excitation of halide ions inV2-centres or in other hole-centres. Whereas, the intensity of EML and FML increases linearly with the applied pressure and the impact velocity, the intensity of PML increases quardratically with the applied pressure and the impact velocity because of the plastic flow of the crystals. Both Imand ITincrease with the density of F-centres in the crystals and strain rate of the crystals; however, they are optimum for a particular temperature of the crystals. The ML of diminished intensity also appears during the release of applied pressure. Expressions are derived for the elastico ML, plastico ML and fracto ML of coloured alkali halide crystals, in which a good agreement is found between the experimental and theoretical results. Many parameters of crystals such as band gap between the dislocation band and interacting F-centre energy level, radius of interaction between dislocations and F-centres, pinning time of dislocations, work hardening exponent, velocity of cracks, rise time of applied pressure, lifetime of electrons in the dislocation band, lifetime of electrons in shallow traps, diffusion time of holes, critical velocity of impact, etc., can be determined from the ML measurements. The ML of coloured alkali halide crystals has potential for self-indicating method of monitoring the microscopic and macroscopic processes; mechanoluminescence dosimetry; understanding dislocation bands in crystals; interaction between the dislocations and F-centres; dynamics of dislocations; deformation bleaching of coloration, etc. The ML of coloured alkali halide crystals has also the potential for photography, ML memory, and it gives information about slip planes, compression of crystals, fragmentation of crystals, etc.Contents of Paper

APA, Harvard, Vancouver, ISO, and other styles

38

Dahlgren, H., N. Ivchenko, B. S. Lanchester, M. Ashrafi, D. Whiter, G. Marklund, and J. Sullivan. "First direct optical observations of plasma flows using afterglow of in discrete aurora." Journal of Atmospheric and Solar-Terrestrial Physics 71, no. 2 (February 2009): 228–38. http://dx.doi.org/10.1016/j.jastp.2008.11.015.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Dahlgren, H., N. Ivchenko, B. S. Lanchester, J. Sullivan, D. Whiter, G. Marklund, and A. Strømme. "Using spectral characteristics to interpret auroral imaging in the 731.9 nm O<sup>+</sup> line." Annales Geophysicae 26, no. 7 (July 15, 2008): 1905–17. http://dx.doi.org/10.5194/angeo-26-1905-2008.

Full text

Abstract:

Abstract. Simultaneous observations were made of dynamic aurora during substorm activity on 26 January 2006 with three high spatial and temporal resolution instruments: the ASK (Auroral Structure and Kinetics) instrument, SIF (Spectrographic Imaging Facility) and ESR (EISCAT Svalbard Radar), all located on Svalbard (78° N, 16.2° E). One of the narrow field of view ASK cameras is designed to detect O+ ion emission at 731.9 nm. From the spectrographic data we have been able to determine the amount of contaminating N2 and OH emission detected in the same filter. This is of great importance to further studies using the ASK instrument, when the O+ ion emission will be used to detect flows and afterglows in active aurora. The ratio of O+ to N2 emission is dependent on the energy spectra of electron precipitation, and was found to be related to changes in the morphology of the small-scale aurora. The ESR measured height profiles of electron densities, which allowed estimates to be made of the energy spectrum of the precipitation during the events studied with optical data from ASK and SIF. It was found that the higher energy precipitation corresponded to discrete and dynamic features, including curls, and low energy precipitation corresponded to auroral signatures that were dominated by rays. The evolution of these changes on time scales of seconds is of importance to theories of auroral acceleration mechanisms.

APA, Harvard, Vancouver, ISO, and other styles

40

Chou, Chin-Hao, Ta-Chin Wei, and Jonathan Phillips. "Detailed Model of the Afterglow Region of a Microwave Generated Oxygen Plasma." MRS Proceedings 268 (1992). http://dx.doi.org/10.1557/proc-268-49.

Full text

Abstract:

ABSTRACTA one dimensional mass continuity equation was used to model a low pressure, high radical concentration, non-isothermal oxygen afterglow reactor. The mathematics are very similar to those used to model flames. It was shown that the model, with no adjustable parameters, yielded very good agreement with experimental measures of O-atom flux. The model was manipulated to study the influence of temperature profile, pressure, homogeneous and heterogeneous kinetics, O-atom generation and flow rate on the afterglow plasma.

APA, Harvard, Vancouver, ISO, and other styles

41

Levedakis, Dimitri A., and Gregory B. Raupp. "Oxygen Atom Induced Deposition of Silicon Dioxide." MRS Proceedings 282 (1992). http://dx.doi.org/10.1557/proc-282-537.

Full text

Abstract:

ABSTRACTSilicon dioxide was deposited from tetraethylorthosilicate (TEOS) and remote microwave oxygen plasma on a heated silicon substrate in a cold-wall reactor. The deposition rate and film quality were examined as functions of substrate temperature, total pressure, absorbed plasma power and O2:TEOS flow ratio. The deposition reaction exhibited an activation energy of approximately 10 kJ/mol for substrate temperatures in the range of 323–623 K. The deposition rate reached a maximum with increasing total pressure. The rate was found to be a near-linear function of the absorbed microwave power. At fixedabsorbed power the rate reached a maximum with increasing O2:TEOS flow ratio. A one-dimensional mathematical model was developed to predict the oxygen radical concentration at the exit of the afterglow region of the oxygen discharge. Comparisons of the predicted oxygen radical concentrations with the deposition rates at corresponding deposition conditions supports the view that the overall SiO2 deposition reaction is largely controlled by the concentration of oxygen radicals. The average refractive index ofthe deposited films was 1.466 ± 0.011. Fourier transform infra-red (FTIR) transmission spectra showed significant concentrations of hydroxyls in the deposited films.

APA, Harvard, Vancouver, ISO, and other styles

42

Mamtha, V., H. N. Narasimha Murthy, V. Pujith Raj, Prashantha Tejas, C. S. Puneet, Achyutha Venugopal, Sham AanMankunipoyil, and C. Manjunatha. "Electrospun PU/MgO/Ag Nanofibers for Antibacterial Activity and Flame Retardency." Clothing and Textiles Research Journal, April 16, 2021, 0887302X2110094. http://dx.doi.org/10.1177/0887302x211009479.

Full text

Abstract:

Antibacterial activity and fire retardation are equally desired for protective clothing. For achieving this, AgNP and MgO are independently researched as nanofillers in Polyurethane based electrospun nanofibers and their synergistic effect is scarcely addressed. This article reports synthesis and characterization of MgO of 70.01 nm and AgNP of 51 to 76 nm by solution combustion and hydrothermal routes respectively and their incorporation in electrospinning of Polyurethane. Flow rate 1 ml/hr, applied voltage 13 kV, tip to collector distance 15 cm were adopted for the electrospinning. Nanofibers of 65 nm were obtained for PU/MgO (3 wt. %) and 106 nm for PU/MgO (3 wt. %)/Ag (1 wt. %). Addition of MgO increased the melting point, after flame time and afterglow time. Incorporation of AgNP improved antibacterial activity. PU/MgO/Ag (2 wt. %) exhibited zone of inhibition of 2.1 cm and 3 cm against E. Coli and S. Aureus, respectively.

APA, Harvard, Vancouver, ISO, and other styles

43

Sydora, R. D., S. Karbashewski, B. Van Compernolle, M. J. Poulos, and J. Loughran. "Drift-Alfvén fluctuations and transport in multiple interacting magnetized electron temperature filaments." Journal of Plasma Physics 85, no. 6 (December 2019). http://dx.doi.org/10.1017/s0022377819000886.

Full text

Abstract:

The results of a basic electron heat transport experiment using multiple localized heat sources in close proximity and embedded in a large magnetized plasma are presented. The set-up consists of three biased probe-mounted crystal cathodes, arranged in a triangular spatial pattern, that inject low energy electrons along a strong magnetic field into a pre-existing, cold afterglow plasma, forming electron temperature filaments. When the three sources are activated and placed within a few collisionless electron skin depths of each other, a non-azimuthally symmetric wave pattern emerges due to interference of the drift-Alfvén modes that form on each filament’s temperature gradient. Enhanced cross-field transport from chaotic ( $\boldsymbol{E}\times \boldsymbol{B}$ , where $\boldsymbol{E}$ is the electric field and $\boldsymbol{B}$ the magnetic field) mixing rapidly relaxes the gradients in the inner triangular region of the filaments and leads to growth of a global nonlinear drift-Alfvén mode that is driven by the thermal gradient in the outer region of the triangle. Azimuthal flow shear arising from the emissive cathode sources modifies the linear eigenmode stability and convective pattern. A steady-current model with emissive sheath boundary predicts the plasma potential and shear flow contribution from the sources.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!