Thematische Bibliographien / Observation des jets

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Auswahl der wissenschaftlichen Literatur zum Thema „Observation des jets“

Autor: Grafiati

Veröffentlicht am 25. Mai 2024

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Zeitschriftenartikel zum Thema "Observation des jets"

Okita, Yuji, Katsutaka Nakamura, Yuuta Shiizaki und Daisuke Nobuta. „LASER OBSERVATION ON THE INNER FLOW STRUCTURE OF WATER JETS(Water Jet)“. Proceedings of the International Conference on Jets, Wakes and Separated Flows (ICJWSF) 2005 (2005): 337–42. http://dx.doi.org/10.1299/jsmeicjwsf.2005.337.

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Chen, Hao, und Gang Tao. „Research on Temperature Change and Microstructure Evolution of Bore in Steel Target Penetrated by Copper Jets“. Materials Science Forum 667-669 (Dezember 2010): 641–46. http://dx.doi.org/10.4028/www.scientific.net/msf.667-669.641.

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Copper fragments are found to adhere on penetration channel wall after copper jets penetrate steel target, and the research on it is helpful to know microstructure evolution of jets in the process of penetration and cooling time. This paper is based on the observation of bore in steel target penetrated by copper jets, and uses numerical simulation to study the process of copper jets penetration, then the change of temperature and grain size of jets adhered on penetration channel wall can be gotten, and the results agree with the observation of penetration channel wall taken by SEM. From the observations of copper and steel, we can get the conclusion that copper jets are not melted but have dynamic recrystallization in the process of penetration, then copper grain size increases obviously in cooling time, and twins are formed at the same time.

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Shen, Yuandeng. „Observation and modelling of solar jets“. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 477, Nr. 2246 (Februar 2021): 20200217. http://dx.doi.org/10.1098/rspa.2020.0217.

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The solar atmosphere is full of complicated transients manifesting the reconfiguration of the solar magnetic field and plasma. Solar jets represent collimated, beam-like plasma ejections; they are ubiquitous in the solar atmosphere and important for our understanding of solar activities at different scales, the magnetic reconnection process, particle acceleration, coronal heating, solar wind acceleration, as well as other related phenomena. Recent high-spatio-temporal-resolution, wide-temperature coverage and spectroscopic and stereoscopic observations taken by ground-based and space-borne solar telescopes have revealed many valuable new clues to restrict the development of theoretical models. This review aims at providing the reader with the main observational characteristics of solar jets, physical interpretations and models, as well as unsolved outstanding questions in future studies.

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Guetta, Dafne, Roi Rahin, Imre Bartos und Massimo Della Valle. „Constraining the fraction of core-collapse supernovae harbouring choked jets with high-energy neutrinos“. Monthly Notices of the Royal Astronomical Society 492, Nr. 1 (06.01.2020): 843–47. http://dx.doi.org/10.1093/mnras/stz3245.

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ABSTRACT The joint observation of core-collapse supernovae with gamma-ray bursts shows that jets can be launched in the aftermath of stellar core collapse, likely by a newly formed black hole that accretes matter from the star. Such gamma-ray bursts have only been observed accompanying Type Ibc supernovae, indicating a stellar progenitor that lost its hydrogen envelope before collapse. According to recent hypothesis, it is possible that jets are launched in core-collapse events even when the progenitors still retain their hydrogen envelopes; however, such jets are not able to burrow through the star and will be stalled into the interior of the progenitor star before escaping. These jets are called choked jets. High-energy neutrinos produced by such choked jets could escape the stellar envelope and could be observed. Here, we examine how multimessenger searches for high-energy neutrinos and core-collapse supernovae can detect or limit the fraction of stellar collapses that produce jets. We find that a high fraction of jet production is already limited by previous observational campaigns. We explore possibilities with future observations using Large Synoptic Survey Telescope, IceCube, and Km3NET.

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Kayshap, P., K. Murawski, A. K. Srivastava und B. N. Dwivedi. „Rotating network jets in the quiet Sun as observed by IRIS“. Astronomy & Astrophysics 616 (August 2018): A99. http://dx.doi.org/10.1051/0004-6361/201730990.

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Aims. We perform a detailed observational analysis of network jets to understand their kinematics, rotational motion, and underlying triggering mechanism(s). We analyzed the quiet-Sun (QS) data. Methods. IRIS high-resolution imaging and spectral observations (slit-jaw images: Si IV 1400.0 Å; raster: Si IV 1393.75 Å) were used to analyze the omnipresent rotating network jets in the transition region (TR). In addition, we also used observations from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observation (SDO). Results. The statistical analysis of 51 network jets is performed to understand their various mean properties, e.g., apparent speed (140.16 ± 39.41 km s−1), length (3.16 ± 1.18 Mm), and lifetimes (105.49 ± 51.75 s). The Si IV 1393.75 Å line has a secondary component along with its main Gaussian, which is formed due to the high-speed plasma flows (i.e., network jets). The variation in Doppler velocity across these jets (i.e., blueshift on one edge and redshift on the other) signify the presence of inherited rotational motion. The statistical analysis predicts that the mean rotational velocity (i.e., ΔV) is 49.56 km s−1. The network jets have high-angular velocity in comparison to the other class of solar jets. Conclusions. The signature of network jets is inherited in TR spectral lines in terms of the secondary component of the Si IV 1393.75 Å line. The rotational motion of network jets is omnipresent, which is reported first for this class of jet-like features. The magnetic reconnection seems to be the most favorable mechanism for the formation of these network jets.

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Nagai, Hiroshi. „Inflow and Outflow (Jets) in NGC 1275“. Proceedings of the International Astronomical Union 14, S342 (Mai 2018): 69–72. http://dx.doi.org/10.1017/s1743921318005744.

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AbstractNGC 1275 is one of the best targets to study the high energy emission mechanism in radio galaxies and the accretion flow properties using a young re-started jet 3C 84 as a prober of subpc-to-pc scale environment. In this proceeding, we review the observation results from a series of our VLBI observations and discuss on the origin of gamma-ray emission and accretion flow properties. We also briefly present the preliminary results from our recent ALMA observations.

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Chen, Jiaxuan. „Formation mechanism of blazar jets“. Theoretical and Natural Science 19, Nr. 1 (08.12.2023): 169–75. http://dx.doi.org/10.54254/2753-8818/19/20230529.

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In research of astronomy, cosmology and the basic theoretical physics, the black hole is one of the most concerned celestial bodies. AGN is a kind of observation source with supermassive black hole as the central core, among which Blazar is the key observation subclass of the observer whose jet is facing the Earth. Therefore, the study of the jet has become an crucial subject of black hole research. In this paper, I start with the basic structure model of AGN, briefly describe the characteristics and mechanisms of each structure, especially the jet, and afterward introduce the observed spectral bimodal characteristics, focusing on the analysis of the existing jet formation mechanism from the radio band. Through the existing observations and data fitting, that is, the logarithmic linear fitting of the jet power to the luminosity of the accretion disc and the jet power to the mass and spin parameters of the black hole, corresponding to the Blandford&Payne and the Blandford&Znajek mechanism respectively. Finally, we analyze the conclusion of the two methods and draw the possibility of the two processes and the complementary relationship in theory. Incidentally, the model theory of mixed interpretation of the two mechanisms and processes is obtained.

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Hillier, A., und V. Polito. „Observation of bi-directional jets in a prominence“. Astronomy & Astrophysics 651 (Juli 2021): A60. http://dx.doi.org/10.1051/0004-6361/201935774.

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Quiescent prominences host a large range of flows, many driven by buoyancy, which lead to velocity shear. The presence of these shear flows could bend and stretch the magnetic field resulting in the formation of current sheets which can lead to magnetic reconnection. Though this has been hypothesised to occur in prominences, with some observations that are suggestive of this process, clear evidence has been lacking. In this paper we present observations performed on June 30, 2015 using the Interface Region Imaging Spectrograph Si IV and Mg II slit-jaw imagers of two bi-directional jets that occur inside the body of the prominence. Such jets are highly consistent with what would be expected from magnetic reconnection theory. Using this observation, we estimate that the prominence under study has an ambient field strength in the range of 4.5−9.2 G with ‘turbulent’ field strengths of 1 G. Our results highlight the ability of gravity-driven flows to stretch and fold the magnetic field of the prominence, implying that locally, the quiescent prominence field can be far from a static, force-free magnetic field.

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SHIMIZU, Seiji, Yukio HIRAOKA und Takanori NISHIYAMA. „Instantaneous Photographic Observation of Abrasive Water Suspension Jets“. JSME International Journal Series B 45, Nr. 4 (2002): 830–35. http://dx.doi.org/10.1299/jsmeb.45.830.

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Ishikawa, Tatsurou, und Seiji Shimizu. „208 High Speed Observation of Abrasive Water Jets“. Proceedings of Conference of Tohoku Branch 2008.43 (2008): 217–18. http://dx.doi.org/10.1299/jsmeth.2008.43.217.

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Dissertationen zum Thema "Observation des jets"

Despringre, Vincent. „Observation et modélisation des jets extragalactiques observés en VLBI“. Toulouse 3, 1996. http://www.theses.fr/1996TOU30212.

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Les jets extragalactiques sont une des manifestations de l'activite intense de certains noyaux actifs de galaxies. Ce sont de gigantesques ejections de plasma du cur de la galaxie, a des distances atteignant parfois plusieurs centaines de kiloparsecs. La physique qui les entoure reste encore relativement mysterieuse. Le developpement de la vlbi (very large base interferometry) ou interferometrie continentale, a permis d'atteindre une resolution de l'ordre du milliarcseconde. Son utilisation pour l'observation des jets extragalactiques, a abouti a la decouverte de l'existence de jets proche du cur et a l'echelle du parsec. On les appelle des jets vlbi. Le but de cette these est l'etude de ces objets. A l'aide du reseau d'interferometrie continentale europeen, l'evn (europeen vlbi network), et du reseau connecte merlin, j'ai cartographie la radiosource 3c66b a la frequence de 5 ghz. J'ai alors decouvert, au cur de cette source, un jet vlbi jusque la inconnu. Les premieres cartes de ce jet ainsi qu'une etude detaillee de sa structure et des flux emis sont presentees dans cette these. La structure des jets vlbi, a l'echelle du parsec, montre une architecture relativement complexe: ils presentent un certain nombre de nodosites qui se deplacent le long du jet sur des trajectoires non rectilignes avec, parfois, des vitesses superluminiques. J'ai developpe un modele permettant d'expliquer les observations vlbi: les nodosites seraient des nuages relativistes, formes de paires electron-positron, se deplacant sur une trajectoire helicoidale enroulee autour d'un jet, non ou faiblement relativiste. Les premiers resultats de cette simulation ainsi qu'une comparaison aux observations font l'objet de la seconde partie de cette these

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Garcia, Paulo J. V. „Modélisation et observation de jets optiques issus d'objets stellaires jeunes“. Lyon 1, 1999. http://www.theses.fr/1999LYO10328.

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L'existence de disques autour d'objets stellaires jeunes est une prevision theorique tres ancienne confirmee recemment. La decouverte dans les annees 80 de vents tres collimates (les jets) dans ces objets a ete une surprise. Depuis, un effort theorique et observationnel a conduit a deux classes de modeles magneto-hydrodynamiques pour ces jets : la premiere basee sur un vent resultant de l'interaction du disque avec l'etoile, la seconde, plus robuste, basee sur un vent originaire du disque. C'est dans le cadre de cette derniere que s'inscrit mon travail de these. Le principal objectif suivi est le calcul auto-consistant de la structure thermique d'un jet provenant d'un disque. Dans ce calcul, j'utilise un modele de vent stationnaire et je prends en compte des processus de chauffage magneto-hydrodynamiques, notamment la dissipation par collisions ions - neutres (diffusion ambipolaire), ainsi que le refroidissement du a l'expansion et a l'emission radiative du gaz. Je resouds explicitement l'evolution de l'ionisation le long du jet et je trouve qu'elle est fortement affectee par des effets hors equilibre d'ionisation. Je montre que la temperature du jet est compatible avec les observations, mais que la fraction d'ionisation est trop faible. Je discute les consequences de ce dernier resultat pour d'autres mecanismes de chauffage dans le jet. Parallelement, j'explore les effets d'une couronne du disque dans l'evolution thermique du jet. Je presente les previsions observationnelles du modele sous forme de cartes d'emission, spectres longue fente et profils de raies et les compare aux observations. L'etude observationnelle de jets optiques necessite une tres haute resolution a la fois spectrale et spatiale. Je presente des observations du jet du systeme z cma avec l'optique adaptative de pueo couplee au spectrographe integral de champ oasis. Je discute egalement dans le contexte theorique developpe prece-demment, la detection par interferometrie avec le tavelographe oca + cp40 d'une composante etendue d'emission h autour de t tauri, interpretee comme une couronne de disque.

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Henderson, James T. „An observation of the electroweak production of a W-boson with two associated jets in a vector-boson fusion topology“. Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:8093f8d9-05ab-4448-9c1d-5b31949c9a3b.

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An observation of Electroweak production of a W-boson in association with two jets at high dijet mass is performed, using √s = 8 TeV pp collision data from the Atlas detector, corresponding to 20.2 fb⁻¹ of data.

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Piron, Anne. „Observation de la convection profonde en mer d'Irminger sur la période 2002-2015 par les flotteurs Argo“. Thesis, Brest, 2015. http://www.theses.fr/2015BRES0059/document.

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Les évènements de convection profonde sont importants car ils forment les masses d'eau intermédiaires et profondes qui nourrissent la circulation globale. La mer du Labrador, qui forme la Labrador Sea Water (LSW), est le site le plus documenté de l'océan Atlantique Nord. La mer d'lrminger a également été citée mais n'est pas entièrement reconnue à cause du manque d'observations directes. Cette thèse fournit la première description de la convection profonde en mer d'lrminger à l'échelle du bassin grâce aux données Argo. Trois évènements de convection se sont produits en mer d'lrminger depuis 2010. Au cours de l'hiver 2O11-2O12, la convection atteint 1000 m et est expliquée par la séquence d'apparition des tip jets groenlandais.La convection de l'hiver 2O13-2O14, qui atteint 1300 m, est caractérisée par un préconditionnement particulièrement important et un forçage par les tip jets faible. La convection de l'hiver 2O14-2O15, qui atteint 1700 m, montre des tip jets très nombreux et persistants. L'advection de LSW provenant de la mer du Labrador explique les profondeurs exceptionnelles observées au cours de ces deux derniers hivers. Les résultats montrent que la convection n'est pas rare en mer d'lrminger et qu'elle joue un rôle non négligeable sur l'équilibre climatique
The deep convection events are important because they form the intermediate and deep water masses feeding the global circulation. The Labrador Sea is the main site of deep convection in the North Atlantic Ocean and produces the intermediate Labrador Sea Water (LSW). The lrminger Sea was also cited but was forgotten during decades because of the lack of direct observations. This thesis provides the first description of the lrminger Sea deep convection at basin scale, thanks to the Argo data. Three convective events occurred in the lrminger Sea since 2010. During the 2011-2012 winter, the convection reached 1000 m and is explained by the sequence of the Greenland tip jets. The event of the 2O13-2O14 winter, reaching 130O m, is characterized by a strong preconditioning and a weak forcings by the Greenland tip jets.The convection event of the 2O14-2015 winter, reaching 1700 m, shows many of persistant tip jets. The advection of LSW from the Labrador Sea explains the deepest mixed layers observed during the last two winters. The results show that deep convection in the lrminger Sea is not a rare isolated event and plays a significant role on the climate balance

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CETORELLI, FLAVIA. „First observation of the electroweak production of a W+W- pair in association with two jets in the fully leptonic channel with the CMS detector at the LHC“. Doctoral thesis, Università degli Studi di Milano-Bicocca, 2022. http://hdl.handle.net/10281/369032.

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Questa tesi riporta la prima osservazione della produzione elettrodebole di una coppia di bosoni W+W- in associazione con due jet nello stato finale leptonico. L’analisi è stata svolta sui dati raccolti dal rivelatore CMS durante le collisioni p-p ad un’energia del centro di massa di 13 TeV, che si sono svolte al Large Hadron Collider (LHC) nel periodo 2016-2018. La produzione elettrodebole di due bosoni W+W- appartiene alla classe dei processi rari di vector boson scattering (VBS). Lo studio di processi VBS è uno degli obiettivi centrali di LHC, poiché sono direttamente connessi al bosone di Higgs e al processo di rottura spontanea della simmetria elettrodebole. Gli eventi sono stati selezionati chiedendo la presenza di due leptoni (e/μ) con carica di segno opposto, due jet con grande massa invariante e grande separazione in pseudorapidità, e una quantità di momento trasverso mancante. Gli eventi sono divisi in categorie rispetto al sapore dei leptoni carichi nello stato finale: ee, μμ, and eμ. La produzione di ttbar-tW costituisce il maggior fondo dell’analisi. Un’altra fonte importante di fondo è data dai diagrammi con due vertici QCD, che producono lo stesso stato finale del segnale (produzione QCD di W+W-). La produzione Drell-Yan (DY) contamina principalmente gli stati finali con due elettroni o due muoni, mentre è fortemente soppressa nello stato finale eμ. Una deep neural network (DNN) è stata allenata per separare il segnale dai fondi ttbar e QCD W+W- nello stato finale eμ. L’uso dell’output della DNN come variabile discriminante in questa categoria ha migliorato le performance dell’analisi. L’analisi riporta l’osservazione del processo elettrodebole di produzione di bosoni W+W- con una significatività statistica di 5.6 deviazioni standard. Inoltre, si riporta la prima misura di sezione d’urto del processo in due spazi fiduciali differenti. Il primo è uno spazio fiduciale inclusivo, definito con tagli su variabili a parton level sui partoni uscenti: si richiede che abbiano pT > 10 GeV e massa invariante mqq > 100 GeV. La sezione d’urto misurata nello spazio fiduciale inclusivo è 99 ± 20 fb, da confrontare con l’attesa teorica LO di 89 ± 5 fb. Il secondo è un volume esclusivo, definito con selezioni sugli osservabili a livello generatore che copiano quelle della regione di segnale dell’analisi. In questo volume fiduciale, la sezione d’urto osservata è 10.2 ± 2.0 fb, mentre quella attesa è 9.1 ± 0.6 fb. I risultati osservati sono in accordo con le previsioni dello standard model. Questa tesi riporta inoltre il lavoro per la calibrazione del calorimetro elettromagnetico (ECAL). Il metodo EFlow, sviluppato durante questo lavoro, produce intercalibrazioni con una granularità spaziale del singolo cristallo e temporale di 1-2 giorni, che correggono la perdita residua di risposta in luce dei cristalli. Il metodo si basa sull’uso di eventi minimum bias provenienti dalle collisioni soft di LHC, come il metodo φ-symmetry. Questi eventi hanno una distribuzione uniforme in φ che può essere sfruttata per calibrare il detector. Il metodo EFlow sviluppa ed estende l’idea del metodo φ-symmetry, normalizzando l’energia di ogni cristallo a quella media del barrel. In questo modo, la risposta di ogni cristallo è adattata alla perdita media del barrel. Gli eventi con elettroni dal decadimento di bosoni W/Z sono utilizzati per correggere la perdita residua globale del barrel. Le correzioni sono competitive con quelle ottenute dal metodo utilizzato durante il Run II, che usava la distribuzione E/p degli elettroni dai decadimenti dei bosoni W/Z. Il metodo EFlow sarà implementato durante Run III per effettuare la calibrazione “prompt” dei dati, poiché garantisce la necessaria finezza spaziale e temporale delle intercalibrazioni.
This thesis reports the first observation of the electroweak production of a W+W- pair of bosons in association with two jets in the fully leptonic final state. The analysis has been performed using the data sample collected by the CMS detector during the 2016-2018 p-p collisions at center-of-mass energy of 13 TeV, provided by the Large Hadron Collider (LHC). The electroweak W+W- production belongs to the very rare class of vector boson scattering (VBS) processes, which are purely electroweak at tree level. The investigation of VBS processes is a central objective of the LHC since they are connected directly to the Higgs boson and the spontaneous symmetry breaking mechanism of the electroweak interaction. The events were selected requiring the presence of two leptons (eμ) with opposite sign charges, two jets with large invariant mass and large pseudorapidity separation, and a certain amount of missing transverse momentum. Events are then separated into different categories considering the flavor of the charged leptons: ee, μμ, and eμ. The ttbar-tW productions constitute the main background of the analysis. Another important source of background is due to diagrams containing two QCD vertices, which produce the same final state as the signal (QCD-induced W+W- production). The Drell-Yan (DY) production contaminates the ee and μμ final states, while this background is highly suppressed in the eμ one. A deep neural network (DNN) was trained to separate the signal from the ttbar and the QCD-induced W+W- production in the eμ final state. The use of the DNN output as a discriminator in this category has boosted the performance of the analysis. Finally, the analysis reaches the observation of the electroweak W+W- signal with a statistical significance of 5.6 standard deviations, whereas 5.2 standard deviations were expected. Moreover, two cross sections are measured into two different fiducial phase spaces. The first one is an inclusive phase space, defined with cuts at parton level on the two outgoing partons: they are required to have a pT > 10 GeV and an invariant mass mqq > 100 GeV. The measured cross section in the inclusive phase space is 99 ± 20 fb to be compared with the theoretical expectation at the lowest order of 89 ± 5 fb. The second one is an exclusive volume, defined with requirements on observables at generator level that mimic the ones of the analysis signal region. In this fiducial volume, the cross section observed is 10.2 ± 2.0 fb, while the expected one is 9.1 ± 0.6 fb. These are the first measurements of the purely electroweak W+W- cross section; the results show good agreement with standard model expectations. The thesis also reports the work for the electromagnetic calorimeter (ECAL) calibration. The EFlow method, developed during this work, provides per-crystal intercalibration with a time granularity of about 1-2 days to correct the time drift in light response that is still visible after laser corrections. The method relies on the use of minimum bias events from soft collisions, as the φ-symmetry method, which are expected to have a uniform distribution in φ. The EFlow extends the idea of the φ-symmetry method, normalizing the energy of each crystal to the mean of the barrel. In this way, the response in time of each crystal is adjusted to the average drift of the barrel. The events with electrons from W and Z decays are used to correct the residual global drift. The corrections derived in this way are competitive with ones obtained by the method employed during Run II, which used the E/p distribution of electrons from W and Z decays. Thanks to the fine space-time granularity of these corrections and the rapidity of deriving them, the method may be implemented in Run III to provide the so-called “prompt” calibrations for the ECAL.

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Yao, Yijun. „Exploration d’un équipement d'observation non intrusif pour la compréhension des processus de projection thermique“. Electronic Thesis or Diss., Bourgogne Franche-Comté, 2023. http://www.theses.fr/2023UBFCA025.

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La quatrième révolution industrielle a inauguré une nouvelle ère technologique caractérisée par la numérisation et l'intelligence. Dans ce contexte, on observe une tendance croissante à combiner les technologies traditionnelles avec les technologies plus modernes de l'information. Cette approche forme une nouvelle voie d’interprétation pour la recherche scientifique.Dans le cadre de cette étude propre à la projection thermique, le travail a consisté à utiliser un dispositif de visualisation non invasif pour la collecte en ligne des images d’un jet ensemencé de particules de poudre. Le traitement de ces images par un algorithme spécifiquement développé a abouti à l’extraction de données pertinentes et fiables sur les processus de construction d’un revêtement de projection.En effet, la projection thermique, en tant que technologie traditionnelle dans le domaine des traitements de surface est aussi une technique très prometteuse dans le domaine de la fabrication additive. Les revêtements produits par cette méthode présentent d’excellentes propriétés et sont largement appliqués dans des secteurs variés. Il parait donc important de changer son paradigme en y intégrant les technologies de l'informatique.Les expériences réalisées ont permis d’observer les phénomènes/processus mis en œuvre au cours d’une projection plasma de particules d’alumine et un algorithme a été développé pour extraire les données intéressantes contenues dans les images observées (distribution de la taille des particules en vol, schéma de croissance du revêtement sur le substrat, efficacité du dépôt, etc.). De cette manière, il a été possible d'étudier les distributions de la vitesse des particules et l'angle de vol tout au long du processus de projection plasma.Par la suite, la validation de la technique d'observation et de l’algorithme appliqué à la projection plasma a permis de s’intéresser au processus existant en projection à froid. L'observation in situ de particules de cuivre a donc été conduite pour identifier le processus d'empilement des couches pulvérisées à froid, d’en quantifier la taille et la dispersion des particules formant le dépôt. L'étude a également associé différentes méthodes de caractérisation de façon à comprendre le processus d'empilement des couches lors d’une projection à froid
The fourth industrial revolution ushered in a new technological era characterized by digitalization and intelligence. In this context, there is a growing tendency to combine traditional technologies with more modern information technologies. This approach is opening up a new avenue of interpretation for scientific research.In the context of this study, which is specific to thermal spraying, the work involved using a non-invasive display device to collect on-line images of a jet seeded with powder particles. Processing these images using a specially developed algorithm resulted in the extraction of relevant and reliable data on the construction processes of a spray coating.Indeed, thermal spraying, as a traditional technology in the field of surface treatments, is also a very promising technique in the field of additive manufacturing. The coatings produced by this method have excellent properties and are widely applied in a variety of sectors. It therefore seems important to change the paradigm by incorporating computer technologies.The experiments carried out enabled us to observe the phenomena/processes involved in the plasma spraying of alumina particles, and an algorithm was developed to extract the interesting data contained in the images observed (size distribution of the flying particles, growth pattern of the coating on the substrate, deposition efficiency, etc.). In this way, it was possible to study the particle velocity and flight angle distributions throughout the plasma spraying process.Subsequently, validation of the observation technique and the algorithm applied to plasma spraying made it possible to study the existing cold spraying process. In situ observation of copper particles was therefore carried out to identify the stacking process of cold-sprayed layers and to quantify the size and dispersion of the particles forming the deposit. The study also combined different characterization methods to understand the process of layer stacking during cold spraying

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Stoeffler, Clara. „Spectroscopie à très haute résolution de molécules sublimées en jet supersonique : vers une observation de la non conservation de la parité dans les molécules chirales par spectroscopie laser“. Phd thesis, Université Paris-Nord - Paris XIII, 2011. http://tel.archives-ouvertes.fr/tel-00647517.

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Le travail, présenté dans ce manuscrit, a consisté en l'élaboration et l'optimisation d'un dispositif expérimental dédié à la mesure de la violation de la parité (VP) dans les molécules chirales en jet supersonique. Les molécules envisagées qui sont en cours de synthèse, ont la propriété d'être à l'état solide à 300 K. Afin de pouvoir les mettre en jet, nous avons construit un dispositif permettant de réaliser la mise en phase vapeur par chauffage et leur ensemencement dans un gaz porteur. De plus, nous avons utilisé une technique de détection par temps de vol, afin d'estimer la quantité de molécules ensemencées. Nous avons testé notre dispositif avec le méthyltrioxorhénium (MTO) dont des dérivés chiraux sont en cours de synthèse. Nous avons mis au point une procédure expérimentale afin de déterminer les caractéristiques spectrales et les paramètres moléculaires du MTO. Pour cela, nous avons mesuré le spectre d'absorption saturée en cellule à 300 K. Puis, nous avons réalisé la mise en jet du MTO dans de l'hélium par chauffage et obtenu de très bons résultats, puisqu'une fraction molaire de MTO de ~10% a été mesurée. Enfin, nous avons enregistré le spectre d'absorption linéaire du MTO en jet sur le dispositif expérimental dédié à la mesure de la VP, notamment grâce à l'utilisation d'une cellule multi-passages. L'analyse des données nous a permis d'obtenir une simulation du spectre théorique. Ces résultats sont très prometteurs en vue des expériences sur les molécules chirales.

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McCraw, Jennifer Leigh. „Observations on Upstream Flame Propagation in Ignited Hydrocarbon Jets“. NCSU, 2006. http://www.lib.ncsu.edu/theses/available/etd-03312006-002715/.

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Studies are presented that examine the development of combustion in an initially non-reacting methane jet after ignition at a downstream location. Image measurements depicting the axial location of a fixed energy ignition source that permits transient flame propagation back to the nozzle are presented. The results from the experimental investigations are discussed. Nine different cases were investigated in order to determine the major parameters that impact the axial location of the ignition source at which flame propagation back to the burner was permitted. When the ignition source was located at larger axial distances than those indicated, flame propagation upstream to the burner was not possible and, instead, the flame blew out. The Reynolds number of the jet, the scalar field and the air co-flow magnitude were investigated for their contributions. A standard digital video camera was used in order to film the ignition of the jet and to determine the farthest axial location from the burner at which upstream flame propagation was possible. With the aid of computer software, the height for each case was determined. Conclusions to the effect these parameters had on the axial location are discussed as well as the implications for the physics governing the process.

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Johansson, Petra. „Low-level jets – observationer från Näsudden på Gotland“. Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-303861.

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Vid luftens passage från en typ av yta till en annan byggs ett internt gränsskikt upp där luftens egenskaper förändras successivt. Detta är grunden för bl.a. bildandet av advekterade low-level jets orsakade av en tröghetssvängning, vilken har sitt ursprung i att under vissa förhållanden erhålls obalans mellan de krafter som påverkar vinden. Målet med arbetet var att kartlägga inflytandet av low-level jets på vindprofilen på Näsudden, Gotland, ovan 100 m höjd. För detta syfte användes mätningar under perioden maj 2000 till juli 2001 gjorda i tre mätmaster i området. En mätmast var placerad på land 1.5 km från Näsuddens kust-linje, en andra mast precis vid kustlinjen och en tredje mast ute i Östersjön 4.6 km från kusten. Eftersom masten ute i havet var placerad mitt i Bockstigens vindpark, omgiven av fem vindturbiner, påverkades vindmätningarna av turbinvakar i vissa riktningssektorer. Genom jämförelser mellan vindmätningar i masten och på turbinerna i för masten ostörda sektorer, togs en korrektion fram så att vind-mätningarna gjorda på turbinerna kunde användas i de sektorer mastmätningarna stördes av turbinvakar. För att kunna studera påverkan av low-level jets på vindprofilen användes data från Bockstigens vindpark tillsammans med en vindmodell, byggd på rörelseekvationerna, Monin-Obukhovs similaritetsteori och K-teori. Modellen, som ej kan generera low-level jets, användes för att beräkna vindprofilerna över havet och hur dessa vind-profiler modifierades vid passagen av kusten. Resultatet från modellen jämfördes sedan med observationer från den 145 m höga masten på Näsudden, 1.5 km från kusten. Det visade sig att de observerade vindhastigheterna på 145 m höjd i medeltal var ca 0.8 m/s högre än vad som beräknats med modellen vid vindriktningar från havet in över Näsudden, vilket kan antas bero på inflytandet från low-level jets. Under månaderna mars till maj är vattnet i Ösersjön klimatologiskt sett mycket kallare än luften, ett förhållande som är fördelaktigt för bildandet av low-level jets. Det visade sig att under dessa månader var vindhastigheten mätt på 145 m höjd inom vind-riktningssektorn 220°-250° hela 1.7 m/s högre än vad som beräknades med vind-modellen, vilket understryker betydelsen av low-level jets under denna del av året. Under resten av året befanns skillnaden mellan observerad och modellberäknad vindhastighet på 145 m höjd vara ca 0.8 m/s för samma vindriktningar.
When air is flowing from one type of surface to another, an internal boundary layer is built up where the properties of the air gradually change. This is the basic condition for the development of for example advected low-level jets caused by inertial oscillations, whose origin is that under certain conditions an imbalance will occur between the forces driving the wind. The purpose with the present work was to map the influence from low-level jets on the wind profile at Näsudden, Gotland, above 100 m height. For this purpose, measurements taken on three towers in the area during the period May 2000 to July 2001 were used. One tower was located inland 1.5 km from the coastline of Näsudden, a second tower was located just at the coastline, and a third one was located offshore 4.6 km from the coast. Since the offshore tower was located in the middle of the Bockstigen wind farm, surrounded by five wind turbines, the wind measurements were affected by turbine wakes in certain wind direction sectors. By comparing the wind measurements taken on the tower with measurements taken on the turbines for directions where the tower was not in the wake, corrections were determined where by the wind measurements taken on the turbines could be used for sectors where the tower was located in wakes. To investigate the influence from low-level jets on the wind profile, data from Bockstigen were used together with a wind model based on the equations of motion, Monin-Obukhov’s similarity theory, and K-theory. The model, which is unable to generate low-level jets, was used to calculate the wind profiles over the sea and how these profiles were modified after passage of the coastline. The results from the model were compared to observations made on the 145 m high tower at Näsudden, 1.5 km from the coast. The comparison showed that the observed wind speed at 145 m height on the average was ca 0.8 m/s higher than the wind speed calculated with the model for wind directions from the sea at Näsudden, which could be assumed to be the effect of the presence of low-level jets. During the months March to May the water in the Baltic Sea is climatologically colder than the air temperature, which is favorable for the development of low-level jets. The results from these months showed that the measured wind speed at 145 m height in the wind direction sector 220°-250° was as much as 1.7 m/s higher than what was calculated with the model, which points at the importance of low-level jets during this part of the year. During the rest of the year the average difference between observed and modeled wind speed at the 145 m level was about 0.8 m/s for the same wind direction.

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Papantoniou, Dimitris Antony List E. John. „Observations in turbulent buoyant jets by use of laser-induced fluorescence /“. Diss., Pasadena, Calif. : California Institute of Technology, 1986. http://resolver.caltech.edu/CaltechETD:etd-03142008-142149.

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Bücher zum Thema "Observation des jets"

Young, David De. Extragalactic jets: Theory and observation from radio to gamma ray : proceedings of a workshop held in Girdwood, Alaska, USA, 21-24 May 2007. San Francisco: Astronomical Society of the Pacific, 2008.

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K, Kuo Kenneth, und United States. National Aeronautics and Space Administration., Hrsg. Combustion of lox with H(g) under subcritical, critical and supercritical conditions (task 1) ; and, Experimental observation of dense spray and mixing of impinging jets (task 2): Annual report. University Park, PA: Propulsion Engineering Research Center, Pennsylvania State University, 1992.

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Silvano, Massaglia, Bodo Gianluigi und Rossi P. 1962-, Hrsg. Virtual astrophysical jets: Theory versus observations. Dordrecht: Kluwer Academic Publishers, 2004.

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Jets from young stars IV: From models to observations and experiments. Berlin: Springer, 2010.

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Pierce, Stephen D. Acoustic Doppler current profiler observations during the coastal jet separation project on R/V Wecoma, August 23 to September 2, 1994. Corvallis, Or: College of Oceanic and Atmospheric Sciences, Oregon State University, 1996.

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Dash, Sanford M. Observations on practical turbulence modeling for high-speed jet/plume flowfields. Washington, D. C: American Institute of Aeronautics and Astronautics, 1991.

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Pierce, Stephen D. Acoustic Doppler current profiler observations during the coastal jet separation project on R/V Wecoma, 17-24 May 1995. Corvallis, Or: College of Oceanic and Atmospheric Sciences, Oregon State University, 1997.

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Pierce, Stephen D. Acoustic Doppler current profiler observations during the coastal jet separation project on R/V Wecoma, 17-27 August 1995. Corvallis, Or: College of Oceanic and Atmospheric Sciences, Oregon State University, 1997.

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The Sicarii in Josephus's Judean war: Rhetorical analysis and historical observations. Leiden: Brill, 2009.

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The Sicarii in Josephus's Judean war: Rhetorical analysis and historical observations. Atlanta: Society of Biblical Literature, 2009.

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Buchteile zum Thema "Observation des jets"

Reames, Donald V. „A Turbulent History“. In Solar Energetic Particles, 19–48. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-66402-2_2.

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AbstractLarge solar energetic-particle (SEP) events are clearly associated in time with eruptive phenomena on the Sun, but how? When large SEP events were first observed, flares were the only visible candidate, and diffusion theory was stretched to explain how the particles could spread through space, as widely as observed. The observation of coronal mass ejections (CMEs), and the wide, fast shock waves they can drive, provided better candidates later. Then small events were found with 1000-fold enhancements in 3He/4He that required a different kind of source—should we reconsider flares, or their open-field cousins, solar jets? The 3He-rich events were soon associated with the electron beams that produce type III radio bursts. It seems the radio astronomers knew of both SEP sources all along. Sometimes the distinction between the sources is blurred when shocks reaccelerate residual 3He-rich impulsive suprathermal ions. Eventually, however, we would even begin to measure the source-plasma temperature that helps to better distinguish the SEP sources.

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Zensus, J. A. „VLBI observations of jets“. In Jets in Extragalactic Radio Sources, 55–64. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/3-540-57164-7_80.

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Bachiller, Rafael. „Molecular Outflows: Observations“. In Protostellar Jets in Context, 381–93. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-00576-3_46.

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Stenz, C., F. Blasco, J. Stevefelt, J. C. Pellicer, A. Antonetti, J. P. Chambaret, G. Chériaux et al. „Observation of Relativistic Self-Focusing, Self-Channeling and Filamentation of Multiterawatt Ultra-Short Laser Pulses in Optical-Field Ionized Argon Gas Jets“. In Springer Series in Chemical Physics, 115–16. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-80314-7_48.

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Raga, A. C., T. Beck und A. Riera. „Interpreting the Observations of Herbig-Haro Jets“. In Virtual Astrophysical Jets, 27–36. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-2664-5_3.

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Brugel, Edward W., Reinhard Mundt und Thomas Bührke. „Observations of Jets from Young Stars“. In Circumstellar Matter, 177–78. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3887-8_47.

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Perley, R. A. „Observations of galactic and extragalactic jets“. In Radiation Hydrodynamics in Stars and Compact Objects, 403–24. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/3-540-16764-1_22.

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Macchetto, F. „HST Observations of Jets and AGN“. In Physics of Active Galactic Nuclei, 325–37. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-77566-6_75.

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Dougados, C., F. Bacciotti, S. Cabrit und B. Nisini. „Deriving Physical Diagnostics from Observations“. In Jets from Young Stars IV, 213–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-02289-0_7.

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Bridle, A. H., und M. H. Cohen. „Observational Details: Radio“. In Relativistic Jets from Active Galactic Nuclei, 115–52. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527641741.ch5.

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Konferenzberichte zum Thema "Observation des jets"

Held, Manfred. „Direct observation of shaped-charge jets“. In 20th International Congress on High Speed Photography and Photonics, herausgegeben von John M. Dewey und Roberto G. Racca. SPIE, 1993. http://dx.doi.org/10.1117/12.145725.

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Inokuchi, Makoto, Takashi Sakugawa und Hidenori Akiyama. „Spectroscopic observation of micro plasma jets generated by pulsed power“. In 2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC). IEEE, 2012. http://dx.doi.org/10.1109/ipmhvc.2012.6518791.

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Kubeš, P., J. Kravárik, J. Hakr, J. Píchal, P. Kulhánek, Malcolm Haines und Andrew Knight. „Observation of the Jets in the Gas Embedded Interrupted z-Pinch“. In DENSE Z-PINCHES: Third International Conference. AIP, 1994. http://dx.doi.org/10.1063/1.2949214.

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D'Archino, R., Francesco Bignami, Emanuele Bohm, Emma D'Acunzo und Ettore Salusti. „Satellite observation of cold filaments and surface jets in the Mediterranean Sea“. In Remote Sensing, herausgegeben von Charles R. Bostater, Jr. und Rosalia Santoleri. SPIE, 2004. http://dx.doi.org/10.1117/12.512516.

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Shibata, Sanshiro, Nozomu Tominaga, Hiroyuki Sagawa, Yoshiya Kawasaki, Takashi Sako, Masahiro Takeda und Yoshiki Tsunesada. „Origin of Ultra-High Energy Cosmic Rays: Nuclear Composition of Gamma-ray Burst Jets“. In INTERNATIONAL SYMPOSIUM ON THE RECENT PROGRESS OF ULTRA-HIGH ENERGY COSMIC RAY OBSERVATION. AIP, 2011. http://dx.doi.org/10.1063/1.3628755.

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D'Archino, R., Francesco Bignami, Emanuele Boehm, E. D"Acunzo und Ettore Salusti. „Satellite observation of sharp frontal shear instabilities and surface jets in the Mediterranean Sea“. In International Symposium on Remote Sensing, herausgegeben von Charles R. Bostater, Jr. und Rosalia Santoleri. SPIE, 2003. http://dx.doi.org/10.1117/12.474407.

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D'Archino, R., und Ettore Salusti. „Satellite observation of sharp frontal shear instabilities and surface jets in the Mediterranean Sea“. In International Symposium on Remote Sensing, herausgegeben von Charles R. Bostater, Jr. und Rosalia Santoleri. SPIE, 2002. http://dx.doi.org/10.1117/12.452755.

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Gharib, Morteza. „Optimal Vortex Ring Formation: A Study of Vortex Ring Formation in Starting and Pulsed Jets (Keynote)“. In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45813.

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Pulsatile jet flows are found in many industrially relevant fluid mechanical problems. A common feature of these flows is that they are fundamentally a series of fluid pulses. This aspect of pulsatile jets implies vortex rings are a basic element of the resulting flow. The significance of this observation is based in part on the tendency of vortex rings to entrain ambient fluid during their formation, but more so on the recent discovery of the phenomenon of vortex ring pinch off. This phenomenon was characterized for starting jets (individual pulses) showing that for pulses sufficiently long with respect to the nozzle diameter (i.e., sufficiently large L/D), the vortex ring stops forming and pinches off from the generating jet. This represents a maximization principle for vortex ring formation and suggests that any effects associated with vortex ring formation in pulsatile jets (e.g., enhanced entrainment), might be able to be optimized by properly selecting the L/D for each pulse.

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Bidan, Guillaume, Pierre-Emmanuel Bouladoux, Jeremiah E. Oertling und Dimitris E. Nikitopoulos. „Experimental and Numerical Study of Steady and Modulated Transverse Jets at Low Blowing Ratios“. In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23013.

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The effects of jet flow pulsation were investigated in the case of a fully modulated vertical jet in crossflow over a flat plate using Mie scattering visualizations, hotwire anemometry and Large Eddy Simulations (LES). A preliminary steady state study was conducted over a wide range of blowing ratios to provide a baseline comparison to pulsed results in terms of vortical structures and performance. Based on observation of the vortical structures and hotwire signatures, two distinct regimes were identified separated by a transitional region. LES using the dynamic Smagorinsky sub-grid model were carried out to provide additional insights on vortical structures formation mechanisms and their effect on heat transfer results, showing good agreement with the experimental observations and measurements. The influence of the pulsing parameters such as mean, high and low blowing ratios, forcing frequency and duty cycle was explored in terms of jet coverage metrics and spanwise adiabatic effectiveness. Average blowing ratios of 0.250, 0.350 and 0.450, duty cycles of 25, 50 and 70% and forcing frequencies of St∞ = 0.008, 0.016, 0.079, and 0.159 were investigated. While in most of the cases, forced jets show a decrease in average performance compared to steady state configurations, some improvement was found in part of the forcing cycle. Vortical structures formed at the jet onset are consistent with the classification given by previous studies in terms of stroke-ratio and high blowing ratio over an overlapping range of conditions. The dynamics of the vortical structures formed at the pulse rise are highly responsible for the decrease in performance observed under forced conditions.

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Raputa, V. F., und A. A. Lezhenin. „Methods for estimate the dynamic and thermal characteristics of smoke plumes“. In Spatial Data Processing for Monitoring of Natural and Anthropogenic Processes 2021. Crossref, 2021. http://dx.doi.org/10.25743/sdm.2021.53.21.065.

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Space observations of the propagation of smoke flares from the chimneys of industrial enterprises provide information on the physical characteristics of the emitted gas-air mixtures. Models for estimating the parameters of the rise of impurities under the influence of dynamic and thermal factors are proposed. The basic relations in the estimation models are the solutions of the equations of hydrothermodynamics of the atmosphere. The case of neutral atmospheric stratification is considered in detail. Using satellite information and meteorological observation data, a numerical study of the stage of ascent of smoke jets from the chimneys of the Gusinoozerskaya State District Power Plant was carried out.

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Berichte der Organisationen zum Thema "Observation des jets"

Zilberman, Mark. “Doppler de-boosting” and the observation of “Standard candles” in cosmology. Intellectual Archive, Juli 2021. http://dx.doi.org/10.32370/iaj.2549.

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“Doppler boosting” is a well-known relativistic effect that alters the apparent luminosity of approaching radiation sources. “Doppler de-boosting” is the name of relativistic effect observed for receding light sources (e.g. relativistic jets of active galactic nuclei and gamma-ray bursts). “Doppler boosting” changes the apparent luminosity of approaching light sources to appear brighter, while “Doppler de-boosting” causes the apparent luminosity of receding light sources to appear fainter. While “Doppler de-boosting” has been successfully accounted for and observed in relativistic jets of AGN, it was ignored in the establishment of Standard candles for cosmological distances. A Standard candle adjustment of an Z>0.1 is necessary for “Doppler de-boosting”, otherwise we would incorrectly assume that Standard Candles appear dimmer not because of “Doppler de-boosting” but because of the excessive distance, which would affect the entire Standard Candles ladder at cosmological distances. The ratio between apparent (L) and intrinsic (Lo) luminosities as a function of the redshift Z and spectral index α is given by the formula ℳ(Z) = L/Lo=(Z+1)α -3 and for Type Ia supernova appears as ℳ(Z) = L/Lo=(Z+1)-2. “Doppler de-boosting” may also explain the anomalously low luminosity of objects with a high Z without the introduction of an accelerated expansion of the Universe and Dark Energy.

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Zilberman, Mark. "Doppler De-boosting" and the Observation of "Standard Candles" in Cosmology. Intellectual Archive, Juli 2021. http://dx.doi.org/10.32370/iaj.2552.

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“Doppler boosting” is a well-known relativistic effect that alters the apparent luminosity of approaching radiation sources. “Doppler de-boosting” is the same relativistic effect observed but for receding light sources (e.g. relativistic jets of AGN and GRB). “Doppler boosting” alters the apparent luminosity of approaching light sources to appear brighter, while “Doppler de-boosting” alters the apparent luminosity of receding light sources to appear fainter. While “Doppler de-boosting” has been successfully accounted for and observed in relativistic jets of AGN, it was ignored in the establishment of Standard candles for cosmological distances. A Standard Candle adjustment of Z>0.1 is necessary for “Doppler de-boosting”, otherwise we would incorrectly assume that Standard Candles appear dimmer, not because of “Doppler de-boosting” but because of the excessive distance, which would affect the entire Standard Candles ladder at cosmological distances. The ratio between apparent (L) and intrinsic (Lo) luminosities as a function of the redshift Z and spectral index α is given by the formula ℳ(Z) = L/Lo=(Z+1)α -3 and for Type Ia supernova appears as ℳ(Z) = L/Lo=(Z+1)-2. “Doppler de-boosting” may also explain the anomalously low luminosity of objects with a high Z without the introduction of an accelerated expansion of the Universe and Dark Energy.

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Zilberman, Mark. PREPRINT. “Doppler de-boosting” and the observation of “Standard candles” in cosmology. Intellectual Archive, Juni 2021. http://dx.doi.org/10.32370/ia_2021_06_23.

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PREPRINT. “Doppler boosting” is a well-known relativistic effect that alters the apparent luminosity of approaching radiation sources. “Doppler de-boosting” is the term of the same relativistic effect observed for receding light sources (e.g.relativistic jets of active galactic nuclei and gamma-ray bursts). “Doppler boosting” alters the apparent luminosity of approaching light sources to appear brighter, while “Doppler de-boosting” alters the apparent luminosity of receding light sources to appear fainter. While “Doppler de-boosting” has been successfully accounted for and observed in relativistic jets of AGN, it was ignored in the establishment of Standard candles for cosmological distances. A Standard candle adjustment of Z>0.1 is necessary for “Doppler de-boosting”, otherwise we would incorrectly assume that Standard Candles appear dimmer, not because of “Doppler de-boosting” but because of the excessive distance, which would affect the entire Standard Candles ladder at cosmological distances. The ratio between apparent (L) and intrinsic (Lo) luminosities as a function of the redshift Z and spectral index α is given by the formula ℳ(Z) =L/Lo=(Z+1)^(α-3) and for Type Ia supernova appears as ℳ(Z)=L/Lo=(Z+1)^(-2). “Doppler de-boosting” may also explain the anomalously low luminosity of objects with a high Z without the introduction of an accelerated expansion of the Universe and Dark Energy.

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Beasley, William H. Balloon-Borne Electric-Field Observations Relevant to Models for Sprites and Jets. Fort Belvoir, VA: Defense Technical Information Center, September 1999. http://dx.doi.org/10.21236/ada380886.

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Marciniak, Michael James. Experimental observations of the breakup of multiple metal jets in a volatile liquid. Office of Scientific and Technical Information (OSTI), Januar 1995. http://dx.doi.org/10.2172/79040.

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Lincoln, Donald W. Observation of Jet Photoproduction and Comparison to Monte Carlo Simulation. Office of Scientific and Technical Information (OSTI), Januar 1994. http://dx.doi.org/10.2172/1372383.

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Winer, K. A., R. D. Breithaupt, S. A. Muelder und D. W. Baum. High-resolution observations of tungsten liner collapse and early jet formation. Office of Scientific and Technical Information (OSTI), Juli 1996. http://dx.doi.org/10.2172/281679.

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Wilson, D., Michael Shaw, Vladimir Ostashev, Michael Muhlestein, Ross Alter, Michelle Swearingen und Sarah McComas. Numerical modeling of mesoscale infrasound propagation in the Arctic. Engineer Research and Development Center (U.S.), Oktober 2022. http://dx.doi.org/10.21079/11681/45788.

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The impacts of characteristic weather events and seasonal patterns on infrasound propagation in the Arctic region are simulated numerically. The methodology utilizes wide-angle parabolic equation methods for a windy atmosphere with inputs provided by radiosonde observations and a high-resolution reanalysis of Arctic weather. The calculations involve horizontal distances up to 200 km for which interactions with the troposphere and lower stratosphere dominate. Among the events examined are two sudden stratospheric warmings, which are found to weaken upward refraction by temperature gradients while creating strongly asymmetric refraction from disturbances to the circumpolar winds. Also examined are polar low events, which are found to enhance negative temperature gradients in the troposphere and thus lead to strong upward refraction. Smaller-scale and topographically driven phenomena, such as low-level jets, katabatic winds, and surface-based temperature inversions, are found to create frequent surface-based ducting out to 100 km. The simulations suggest that horizontal variations in the atmospheric profiles, in response to changing topography and surface property transitions, such as ice boundaries, play an important role in the propagation.

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N.N. Gorelenkov, et al. Predications and Observations of Global Beta-induced Alfven-acoustic Modes in JET and NSTX. Office of Scientific and Technical Information (OSTI), Oktober 2008. http://dx.doi.org/10.2172/943301.

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Seeman, Jeffrey I., Henry V. Secor, P. J. Breen, V. H. Grassian und E. R. Bernstein. A Study of Non-Rigid Aromatic Molecules by Supersonic Molecular Jet Spectroscopy: Observation and Spectroscopic Analysis of the Stable Conformations of Various Alkylbenzenes. Fort Belvoir, VA: Defense Technical Information Center, Juli 1988. http://dx.doi.org/10.21236/ada199409.

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