Relevant bibliographies by topics / Compressible MHD

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Academic literature on the topic 'Compressible MHD'

Author: Grafiati
Published: 6 September 2023

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Journal articles on the topic "Compressible MHD"

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Valdettaro, Lorenzo, and Maurice Meneguzzi. "Compressible MHD in Spherical Geometry." International Astronomical Union Colloquium 130 (1991): 80–85. http://dx.doi.org/10.1017/s0252921100079434.

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AbstractThe generation of magnetic field by a conducting, compressible fluid inside a spherical shell is studied by direct numerical simulations. A pseudo-spectral method is used in order to resolve accurately all the scales present in the problem. The range of parameters considered is the following: a unit Prandtl number, Rayleigh numbers up to 100 times critical, Taylor number 625, an aspect ratio of 2, a Mach number slightly less than 1, and pressure and temperature scale heights of the order of the thickness of the shell. A dynamo effect is observed for magnetic Prandtl numbers larger than 1. We present the properties of the turbulent flow, the role of the helicity and of the differential rotation in the enhancement of the magnetic field, and the spectral properties of the flow fields.
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Kowal, Grzegorz, and A. Lazarian. "Scaling Relations of Compressible MHD Turbulence." Astrophysical Journal 666, no. 2 (August 30, 2007): L69—L72. http://dx.doi.org/10.1086/521788.

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Zank, G. P., and W. H. Matthaeus. "The equations of reduced magnetohydrodynamics." Journal of Plasma Physics 48, no. 1 (August 1992): 85–100. http://dx.doi.org/10.1017/s002237780001638x.

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The equations of high- and low-beta reduced magnetohydrodynamics (RMHD) are considered anew in order to elucidate the relationship between compressible MHD and RMHD and also to distinguish RMHD from recently developed models of nearly incompressible MHD. Our results, summarized in two theorems, provide the conditions under which RMHD represents a valid reduction of compressible MHD. The equations for low-beta RMHD and high-beta RMHD are shown to be identical. Furthermore, as a direct consequence of our analysis, the conditions under which both two-dimensional incompressible MHD (in terms of the spatial co-ordinates as well as the fluid variables) and 2½ dimensional incompressible MHD (i.e. only two-dimensional in the spatial co-ordinates) represent a valid reduction of three-dimensional compressible MHD are also formulated. It is found that the elimination of all high-frequency and long-wavelength modes from the magneto-fluid reduces the fully compressible MHD equations to either two-dimensional incompressible MHD in the plasma beta (β) limit β ≪ 1, or 2½-dimensional incompressible MHD for β ≈ 1. Our approach clarifies several inconsistencies to be found in previous investigations in that the reduction is exact. Our results and analysis are expected to be of interest for plasma fusion and space and solar physics.
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Chanteur, G. "Localized Alfvénic solutions of nondissipative and compressible MHD." Nonlinear Processes in Geophysics 6, no. 3/4 (December 31, 1999): 145–48. http://dx.doi.org/10.5194/npg-6-145-1999.

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Abstract. Alfvénic solutions of nondissipative MHD are entirely determined by their magnetic configuration. With the supplementary assumption of incompressibility any solenoidal field can be used to construct an Alfvénic solution. It is demonstrated that for nondissipative and compressible MHD the energy equation constrains the magnetic field of Alfvénic solutions to have a constant strength along field lines. Some topological solitons known in nondissipative and incompressible MHD do not have this property. New localized axisymmetric Alfvénic solutions of nondissipative and compressible MHD are explicitly constructed.
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WISNIEWSKI, MARTINA, RALF KISSMANN, and FELIX SPANIER. "Turbulence evolution in MHD plasmas." Journal of Plasma Physics 79, no. 5 (February 21, 2013): 597–612. http://dx.doi.org/10.1017/s0022377813000147.

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AbstractTurbulence in the interstellar medium has been an active field of research in the last decade. Numerical simulations are the tool of choice in most cases. However, while there are a number of simulations on the market, some questions have not been answered finally. In this paper, we examine the influence of compressible and incompressible driving on the evolution of turbulent spectra in a number of possible interstellar medium scenarios. We conclude that the driving has an influence not only on the ratio of compressible to incompressible component but also on the anisotropy of turbulence.
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王, 帅. "The Important Estimates for Compressible MHD Equations." Pure Mathematics 12, no. 08 (2022): 1305–11. http://dx.doi.org/10.12677/pm.2022.128143.

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Hesse, Michael, Joachim Birn, and Seiji Zenitani. "Magnetic reconnection in a compressible MHD plasma." Physics of Plasmas 18, no. 4 (April 2011): 042104. http://dx.doi.org/10.1063/1.3581077.

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Lu, Ming, Yi Du, and Zheng-an Yao. "Blow-up criterion for compressible MHD equations." Journal of Mathematical Analysis and Applications 379, no. 1 (July 2011): 425–38. http://dx.doi.org/10.1016/j.jmaa.2011.01.043.

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Cho, Jungyeon, and A. Lazarian. "Generation of compressible modes in MHD turbulence." Theoretical and Computational Fluid Dynamics 19, no. 2 (March 11, 2005): 127–57. http://dx.doi.org/10.1007/s00162-004-0157-x.

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Oughton, S., W. H. Matthaeus, Minping Wan, and Tulasi Parashar. "Variance anisotropy in compressible 3-D MHD." Journal of Geophysical Research: Space Physics 121, no. 6 (June 2016): 5041–54. http://dx.doi.org/10.1002/2016ja022496.

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Dissertations / Theses on the topic "Compressible MHD"

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Yalim, Mehmet S. "An artificial compressibility analogy approach for compressible ideal MHD: application to space weather simulation." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210427.

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Ideal magnetohydrodynamics (MHD) simulations are known to have problems in satisfying the solenoidal constraint (i.e. the divergence of magnetic field should be equal to zero, $

ablacdotvec{B} = 0$). The simulations become unstable unless specific measures have been taken.

In this thesis, a solenoidal constraint satisfying technique that allows discrete satisfaction of the solenoidal constraint up to the machine accuracy is presented and validated with a variety of test cases. Due to its inspiration from Chorin's artificial compressibility method developed for incompressible CFD applications, the technique was named as \
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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Flutet, Vincent. "Etude numérique de la dynamique d'une couche limite turbulente avec effet MHD." Paris 6, 2007. http://www.theses.fr/2007PA066605.

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La turbulence est un phénomène présent dans la plupart des écoulements. A proximité d'une paroi, un de ses principaux effets est d'augmenter la traînée de l'écoulement. Il peut donc être intéressant d'affaiblir la turbulence afin de réduire la traînée. Différentes études ont montré que l'utilisation d'un champ magnétique pouvait affaiblir la turbulence. Dans un fluide conducteur en mouvement soumis à un champ magnétique se créent des forces qui s'opposent au mouvement. L'objectif de ce travail est d'étudier, dans des conditions subsoniques et supersoniques, l'effet du champ magnétique sur un canal plan turbulent, en particulier sur les structures cohérentes de la couche limite et sur la traînée de l'écoulement. Les résultats ont montré une augmentation de la sensibilité au champ magnétique avec la compressibilité. On observe aussi une réorganisation des structures cohérentes de la couche limite turbulente. Enfin, la présence du champ magnétique entraîne une participation à la traînée qui peut être compensée par une diminution de la traînée turbulente
Turbulence is a phenomenon present in most streams. Near a boundary, its main effect is to increase the stream drag. Thus it can be interesting to weaken turbulence in order to decrease drag. Several studies have shown that the use of a magnetic field could weaken turbulence. Indeed, in a conducting fluid moving under a magnetic fluid counter-movement forces appear. This study aims at determining, under both subsonic and supersonic conditions, the effect of a magnetic field on a turbulent channel flow, especially on coherent structures of the boundary layer and on drag. Results have shown an increase of the sensibility to the magnetic field with compressibility. Reorganisation of coherent structures of boundary layer is also shown. A last, magnetic field causes a participation to drag but causes to a decrease in turbulent drag that is more important
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KHANFIR, RABIA. "Approximation volumes finis de type cinetique du systeme hyperbolique de la mhd ideale compressible a pression isotrope." Paris 11, 1995. http://www.theses.fr/1995PA112163.

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L'objectif de ce travail est l'approximation numerique par une methode de volumes finis de type cinetique du systeme hyperbolique de la magnetohydrodynamique (mhd) ideale des gaz compressibles et non visqueux. Les equations de la mhd ideale decrivent l'ecoulement d'un fluide conducteur, globalement neutre, en presence d'un champ magnetique. Elles admettent une forme conservative traduisant la conservation de la masse, de la quantite de mouvement, de l'energie totale et du champ magnetique (cette derniere equation est aussi appelee equation de faraday). Nous proposons un schema numerique qui s'inspire en partie du point de vue des schemas de boltzmann et debouche sur une decomposition cinetique des flux. L'originalite de cette methode tient d'une part a l'introduction d'une equation cinetique formelle pour l'equation de faraday agissant sur une distribution vectorielle des vitesses et d'autre part a l'utilisation d'une temperature equivalente obtenue a partir de la pression totale (somme de la pression thermique et de la pression magnetique). Pour les autres equations de conservation nous effectuons une extension formelle des formules de flux plus obtenues pour les equations d'euler. La stabilite (lineaire) est assuree par une condition de type cfl utilisant la vitesse du mode rapide. Le schema decentre ainsi obtenu est etendu a l'ordre deux en espace (selon une approche muscl), et en temps (schema de runge-kutta). Nous validons le schema sur differents problemes en dimension un (tubes-a-choc, onde simple transverse, ondes lineaires progressives) et en dimension deux (vortex alfvenique stationnaire, solution autosimilaire, solution de type choc fort de sedov etendue a la mhd). Nous estimons egalement les coefficients de dissipation numerique du schema ainsi que l'ordre effectif (en dimension un et deux)
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Kessler, Philippe. "Simulation des grandes échelles d’écoulements compressibles en géométrie complexe." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0201.

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La transition a la turbulence d'ecoulements en geometrie complexe est etudiee par simulation numerique compressible bidimensionnelle et tridimensionnelle. On presente une simulation des grandes echelles d'un jet rond d'air, comparee a une experience en laboratoire et a une autre simulation numerique incompressible. Cette comparaison nous a permis de valider notre outil numerique. Nous montrons un bon accord entre les resultats experimentaux et notre simulation numerique en zone transitionnelle. On applique notre outil numerique a une geometrie complexe et industrielle: l'entree d'air en incidence. Cette etude est effectuee avec un code a gestion multi-domaine des transferts d'informations par methode aux caracteristiques. Les resultats sont compares a ceux d'une experience faite au ceat de poitiers. Nous avons mis en evidence les tourbillons de kelvin-helmholtz, ainsi que les tourbillons longitudinaux, responsables des fluctuations de pression au niveau du premier etage du compresseur. Enfin, on a reproduit une experience magnetohydrodynamique faite au laboratoire madylam, en geometrie bidimensionnelle ronde. L'influence du champ magnetique sur un ecoulement de mercure soumis aux forces de laplace cree un cisaillement au niveau de l'electrode. On presente une evolution temporelle de la vorticite et de la pression, ainsi que les statistiques obtenues en regime permanent. Nous montrons des resultats qualitatifs satisfaisants, mais par contre sur les statistiques, nous surestimons les valeurs moyennes et fluctuantes. Nous montrons que les caracteristiques de l'ecoulement ne sont pas bidimensionnelles, mais doivent etre tridimensionnelles
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Gomez, Thomas. "Dynamique des structures a petites echelles en ecoulements turbulents compressibles ou mhd : modelisation et intermittence." Paris 6, 1999. http://www.theses.fr/1999PA066566.

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Nous abordons dans cette these l'etude de la turbulence par le biais de l'etude des petites echelles qui se developpent dans les ecoulements turbulents. Deux points de vue, differents mais complementaires, sont utilises pour ce faire. D'une part, nous realisons une etude de la structure geometrique et de la dynamique de ces structures, dans le contexte du tourbillon de lundgren qui est le seul modele liant objet et statistique et conduisant a un spectre d'energie en k 5 / 3 ; cette etude sera etendue au cas d'une turbulence compressible montrant la persistance de ces structures meme en presence de chocs. D'autre part, l'etude est purement de type statistique ; nous generalisons la loi exacte dite en 4/5 de kolmogorov pour un fluide neutre en prenant en compte la presence de correlations vitesse-vorticite. Nous obtenons ainsi une nouvelle loi, liee a l'invariance de l'helicite, pour une fonction de structure ecrite a l'aide de toutes les composantes des champs de vitesse et de vorticite. Enfin, nous etudions numeriquement les lois d'echelle des fonctions de structure pour un fluide conducteur. Nous montrons ainsi que le comportement de ces fonctions indique qu'en presence d'un champ magnetique, les grandeurs physiques de base -vitesse et champ magnetique- sont plus intermittentes. De plus, nous montrons qu'il existe une certaine grandeur, assimilable a un flux a travers les echelles de longueur, qui a un comportement intermittent analogue a celui de la vitesse dans le cas des fluides neutres. Il semble donc que nous ayons confirme dans le cas magnetohydrodynamique un certain caractere universel de l'intermittence.
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TESSARI, Mirko. "Misurazione di marcatori solubili circolanti di danno endoteliale in soggetti ipomobili e stasi veno-linfatica agli arti inferiori sottoposti a un trattamento di compressione pneumatica intermittente." Doctoral thesis, Università degli studi di Ferrara, 2016. http://hdl.handle.net/11392/2403217.

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Introduzione: Molti pazienti affetti per cause diverse da sindrome da ipomobilità maturano edemi ingravescenti degli arti inferiori, ed in fondo una forma di infiammazione cronica dei tegumenti che va ad aggiungersi alla flogosi cronica e degenerazione che in genere contraddistingue il quadro clinico principale. Proprio poiché questa forma di disabilità si discosta da quadro principale, molto spesso c’è disattenzione ed oggettiva difficoltà di trattarlo. Non esistono infatti farmaci in grado di opporsi all’aumento della pressione transmurale a livello del microcircolo poiché essa è strettamente legata al carico idrostatico gravitazionale. L’incremento di pressione esterna indicherebbe l’uso di una calza elastica, essa è difficile da posizionare per individui disabili anche se assistiti. Una ulteriore possibilità terapeutica sarebbe la compressione pneumatica intermittente (CPI), di cui è nota in termini anedottici ma non scientifici una possibile efficacia. Scopo: Studiare secondo i criteri della medicina basata sull’evidenza l’efficacia e la tollerabilità della CPI negli individui ipomobili esposti al gradiente gravitazionale con conseguente edema flebo-linfatico cronico (EFLC) da stasi negli arti inferiori. Le misure di outcome utilizzate saranno cliniche e laboratoristiche, cercando in modo traslazionale di correlare le une con le altre in modo da identificare possibili meccanismi d’azione molecolari della CPI, in questo momento sconosciuti. Metodi: Sono stati selezionati 50 soggetti (36 donne e 14 uomini con un età media di 58.4±9 anni) con sindrome da ipomobilità per due concomitanti cause diffuse di disabilità motorie, rispettivamente una paresi spastica da malattia neurodegenerativa in assenza di patologie flebolinfatiche e artrosi deformanti e/o limitanti le escursioni articolari in pazienti con contemporanea insufficienza venosa e linfatica. I pazienti sono stati randomizzati 1:1 al trattamento CPI o al braccio di controllo. Le misure di outcome clinico sono state: 1) spessore cute-fascia in 8 punti di repere di entrambi gli arti inferiori con ecografia ad altissima risoluzione (USHR); 2) circonferenza degli arti inferiori in 6 punti di repere bilateralmente; 3) range of motion (ROM) dell’articolazione tibio-tarsica in 2 rispettivamente nella flessione plantare e flessione dorsale bilateralmente; 4) pletismografia ad acqua negli arti inferiori bilateralmente; 5) questionario qualità della vita (QoL) SF-36 in 8 scale specifiche. Le misure di outcome laboratoristico sono consistite nella misurazione nel plasma di 29 citochine circolanti secondo un pannello di significatività nei confronti del fenotipo infiammatorio della cellula endoteliale Risultati: Lo studio è stato qualitativamente soddisfacente poiché non abbiamo avuto alcun paziente uscito dal trial per disinteresse o intolleranza al trattamento. 1) misure di outcome clinico: le misure di spessore cute-fascia e di circonferenza sono migliorate in misura altamente significativa nel gruppo pazienti CPI rispetto al braccio di controllo (p<0.0001 e p<0.001 rispettivamente per le misure di spessore cute-fascia e circonferenza). La misura pletismografica non ha potuto essere utilizzata in tutto il campione a causa della elefantiasi di molti soggetti che presentavano un volume della gamba più elevato di quello misurabile dallo strumento. La perdita di potenza non ha pertanto permesso di misurare differenze statisticamente significative nei due bracci circa il volume nelle due gambe, tuttavia è stato dimostrato un miglioramento significativo (p<0.0001) del volume degli arti nel gruppo CPI rispetto alla baseline che non si è verificato nel gruppo controllo, ove si verificato un significativo incremento nel corso del follow-up (p<0.0001). Infine, nonostante non fosse atteso un miglioramento della ROM articolare, in realtà la riduzione dell’edema ha migliorato significativamente l’ampiezza del movimento del piede nel gruppo CPI, confrontando i gradi di escursione alla baseline con quelli in uscita dello studio (p<0.0001). Per quello che riguarda la qualità della vita, solamente il gruppo CPI ha mostrato un miglioramento significativo per quanto attiene attività fisica (p<0.05), salute generale (p<0.004), vitalità (p<0.02) e salute mentale (p<0.01). 2) per quanto attiene le misure laboratoristiche un difetto dell’array di analisi ci impedisce in questo momento di darvi i risultati, che verranno presentati al momento della presentazione formale della tesi di dottorato. Conclusioni: Questo studio randomizzato dimostra l’efficacia e la tollerabilità della CPI nel trattamento degli edemi cronici degli arti inferiori nei soggetti ipomobili, attualmente orfani di trattamenti terapeutici efficaci di questa concomitante disabilità vascolare. Essa infatti incide significativamente nella qualità della vita come dimostrato dal miglioramento nel braccio trattato di ben la metà degli item QoL.
Background: Many patients affected by low motility develop progressively worsening lower limb edema, together with a chronic inflammatory process, affecting their general condition. This indirect condition is often underestimated and undertreated. No drugs counteracting microcirculatory transmural pressure are available, since this last one is strictly related to the hydrostatic gravitational load. The increased internal pressure gives indication to elastic stocking compression. Nevertheless, the easy of use is significantly reduced in patients with physical handicaps, even if assisted. Intermittent pneumatic compression (IPC) is another option, of which there is anecdotal evidence, but not a scientific one. Aims: To investigate effectiveness and safety of IPC in hypomobile patient affected by chronic lower limb phlebo-lymphedema (CPL), related to gravitational gradient, according to evidencebased medicine. Outcome measures are clinical and laboratoristic, looking for a translational correlation, aimed for the identification of potential mechanisms of actions of the IPC that are still unknown up to now. Methods: Fifty subjects were selected (36 females, 14 males, 58.4±9 yo) affected by hypomobility syndrome associated with two concomitant causes of motor disability, neurodegenerative spastic palsy without phlebo-lymphatic disease and deforming arthritis and/or limiting the joint mobility in patients with chronic venous and lymphatic insufficiency. Patients were randomized 1/1 for IPC treatment and control. Clinical outcome measures were: 1) skin-fascia thickness at 8 assessment points in both legs, by high resolution ultrasonography (USHR); 2) lower limb circumference in 6 assessment points bilaterally; 3) Range of motion (ROM) of tibio-tarsal joint during plantar flexion and dorsal flexion bilaterally; 4) water plethysmography for bilateral lower limbs; 5) SF-36 quality of life questionnaire in 8 specific scales Lab outcome measures were represented by the assessment of 29 circulating cytokines, belonging to a significant array related to endothelial cell inflammatory phenotype. Results: No drop out were reported, so making the investigation significant. 1) Clinical outcome measures: skin-fascia thickness and circumference significantly improved in IPC group compared to controls (p<0.0001 and p<0.001, for skin-fascia thickness and circumference respectively). A plethysmographic assessment wasn’t feasible in all patients because of elephantiasis affecting many patients. The loss in significance led to the missing detection of significant variation among the two groups concerning the leg volume. Nevertheless, a significant improvement was reported in IPC group volume, compared to their baseline (p<0.0001), differently from the control group, where a significant increase was reported during the follow up (p<0.0001). Even if a ROM improvement wasn’t expected, following the edema decrease, a significant improvement in ROM was detected in IPC group, compared to the baseline (p<0.0001). As for the quality of life, only the IPC group showed a significant improvement with regard to physical activity (p<0.05), general health (p<0.004), vitality (p<0.02) and mental health (p<0.01). 2) Concerning the lab outcome, a defect in the array analysis doesn’t allow the data release up to now. These data will be presented during the PhD thesis discussion. Conclusion: This randomized investigation demonstrated the IPC efficacy and the tolerability for the lower limb chronic edema in hypomobile patients, up to know lacking in effective treatments for this important vascular disability. In fact, this condition significantly impacts the quality of life, as demonstrated by the improvement of more than the half items in the treated group.
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Wu, Wen-Chou. "In vitro compressive fracture resistance of the human maxillary first premolar with different mod cavity design and restorative materials." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2007m/wu.pdf.

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FELISATTI, Michele. "Compressione pneumatica intermittente negli stadi avanzati di arteriopatia periferica: studio delle modificazioni emodinamiche e della perfusione distale indotte da un dispositivo originale e confronto con uno strumento disponibile sul mercato." Doctoral thesis, Università degli studi di Ferrara, 2011. http://hdl.handle.net/11392/2389232.

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Introduction: Intermittent pneumatic compression (IPC) is a technique based on the application of pressure at the level of various points of the inferior limb, aimed at provoking haemodynamic modifications starting from the treatment zone. IPC devices, that are mainly used in the area of venous-lymphatic pathologies to reduce edema and for the prevention of venous thromboembolism, have also been applied for treatment of peripheral arterial occlusive disease (PAOD). An IPC device, “Gradient Pump” (GP), based on new haemodynamic concept and technical solutions, has been recently developed by the Vascular Diseases Center of the University of Ferrara-Italy. Aim of the present study in PAOD patients is a) to evaluate the effects of GP on haemodynamic parameters and foot perfusion during a single operative cycle and during a therapeutic cycle and b) to compare efficacy and compliance to the treatment of GP versus a traditional device for PAOD available on the market. Subjects and Methods: In the study were enrolled and evaluated a) 7 patients (12 diseased legs) with PAOD at III-IV Fontaine’s stage and b) 12 patients (21 diseased legs, 12 out of them affected by critical ischemia). The GP device is composed of a single inflatable cuff to be positioned at the thigh, including a rigid element to apply a proper pressure to the femoral vein. The cuff is connected to a compressor which produces periodic sequences of pressure at 1 operative cycle/minute (20 sec of compression, 40 sec of decompression). The therapeutic cycle is composed by a 5min working period followed by a 5min resting period repeated for 3-4 times, modifiable by a manual electromechanical timer. The pressure of cuff inflation is set by a manual pressure regulator to patient’s blood systolic pressure – 20 mmHg with maximal value at 120 mmHg. For the phase A of the study, haemodynamic measurements as Time Average Velocity (TAV) and Blood Flow (BF) were performed by Echo color doppler (ECD) at the femoral vein at different phases of the operative cycle, at rest (basal level), early compression (In1), full compression (In) and full decompression (Out). The haemodynamic measurements during a therapeutic cycle were performed before the start of the first working cycle (basal level), at the end of the second cycle and at the end of the last working period, during the phase Out of both operative cycles. The study of tissue perfusion at the foot was performed using a Near Infrared Spectroscopy (NIRS) device, in order to detect variations in total (tHb), oxygenated (O2Hb) and deoxygenated haemoglobin by means of probes positioned on the dorsum of the foot. The changes of these parameters were recorded and quantified by the calculation of the areas under the curve (AUC). Measurements were performed continuously for a 5min period before the treatment and for the whole treatment. For the phase B of the study, GP was compared to a device available on the market (Art Assist ACI Medical, LLC San Marcos, CA), with cuffs to be positioned at foot and calf sequentially inflating (foot cuff first and calf cuff after 3 seconds, 20 seconds of rest). The device operates for 3 cycles/min at a fixed pressure of inflation of 120 mmHg. Outcome measures: a) Ankle-Brachial Index (ABI) measured according to the standard at rest and after treatment b) Haemodynamic measurements by ECD, including TAV e BF evaluation at femoral vein and at popliteal artery, performed before treatment, after 30 min in the decompression phase of the operative cycle and at the end of the treatment c) Evaluation of Foot perfusion by NIRS device as above described, by measurements performed continuously for a 5 min period before the treatment and for the whole treatment with both devices.4) Compliance, measured by a properly developed questionnaire proposed to the patients before and after the treatment with both devices to evaluate symptoms reduction and satisfaction. The effects of the AA instrument and GP device were measured in the same subjects in supine position in two different days with an interval of 48 ± 2 hours between the two treatments and an alternate order for each device. AA was tested for two consecutive hours of treatment and GP for 35 minutes. Results: A): the treatment with GP was well tolerated, without reported negative symptoms. During a single operative cycle BF and TAV at the femoral vein significantly increased during In e In1 phases (p>0.01). During a therapeutic cycle (25 min) BF and TAV slightly increased during the phase “out” from the beginning to the end of the treatment (p=0,10 n.s.). The foot perfusion was improved, with a significant increase both of tHbAUC and HbO2AUC (p<0.005), correlated to the TAV variations from the basal level recorded at femoral vein during the phase “out” (p<0.05). B): all patients completed the treatment with GP, while three out of them interrupted the treatment for painful symptoms at the foot. ABI increased from the baseline after treatment with GP (n=21, p=0.005), being unmodified after treatment with AA. After 30min of GP treatment the ECD parameters (TAV e BF) increased significantly at the femoral vein (n=21, p<0.05) as well BF at popliteal artery (p=0.011), while no variations were observed after AA treatment. Following compression with GP an improved foot perfusion was observed, with increase of tHbAUC (p<0.0001) and Hb O2AUC (p=0.001) that instead decreased after AA treatment (p=0.03). Compared to the AA treatment, the compression therapy with GP obtained a higher score for compliance, reduction of symptoms, easy use of the device and patients’ satisfaction (p<0.0001). Conclusions: GP, a new device for IPC in PAOD, evokes favourable haemodynamic changes with increased foot perfusion. Haemodynamic changes, distal perfusion and compliance with GP are more relevant than those observed after treatment with a traditional IPC device available on the market.
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Gargouri, Yosra. "Nouveau récepteur radio numérique pour les observations astrophysiques spatiales dans la bande de fréquence 1 kHz à 50 MHz." Thesis, Paris, ENST, 2017. http://www.theses.fr/2017ENST0057/document.

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Plusieurs phénomènes astronomiques émettent des ondes radios basses fréquences tels que les éruptions solaires, les magnétosphères, les pulsars . . . Certains de ces ondes sont mal captées par les observatoires terrestres à cause, principalement, de la coupure ionosphérique. Il devient indispensable d’envoyer des récepteurs radio dans l’espace pour les acquérir. Cependant, ces récepteurs sont consommation d’énergie et le taux de transmission. Un paradigme récent pour l’acquisition et la reconstruction des signaux, appelé l’échantillonnage comprimé (Compressive sampling, Compressed Sensing, CS) pourra être une réponse adéquate à ces problématiques en limitant, dès l’acquisition, la quantité de données numérisés : En effet, le CS a permis l’émergence d’un nouveau type de Convertisseur Analogique-Numérique (ADC) appelé Convertisseur Analogique-Information (AIC) qui permet d’échantillonner à une fréquence potentiellement inférieure à celle prescrite par Nyquist-Shannon, en exploitant le caractère parcimonieux des signaux. Nous proposons dans le cadre de cette thèse d’étudier l’application de l’échantillonnage comprimé pour l’acquisition des signaux astrophysiques spatiaux dans la bande de fréquence [1kHz à 50 MHz]. Nous nous focalisons sur des signaux émis par les deux sources radio les plus brillantes dans le ciel telles que vues de la Terre, à savoir le Soleil et Jupiter. En se basant sur les propriétés caractéristiques de nos signaux d’intérêt, nous avons construit progressivement et méthodologiquement notre schéma d’acquisition : En commençant par l’étude de compressibilité des signaux, puis l’identification de l’architecture du Convertisseur Analogique-Information (AIC) appropriée et enfin le choix de l’algorithme de reconstruction du signal. Nous avons également proposé une nouvelle implémentation flexible et programmable de l’AIC retenu, qui permet l’acquisition de différents types de signal ayant le même domaine de compressibilité avec différents facteurs de compression. En utilisant une technologie CMOS 65 nm, nous avons évalué le gain en quantité de données acquise et en consommation de puissance de cette architecture par rapport au convertisseur analogique-numérique traditionnel
Several astronomical phenomena emit low-frequency radio waves such as solar flares, magnetospheres, pulsars ... Some of these emissions are poorly captured by ground-based observatories mainly because of the Earth’s ionospheric cutoff frequency. It becomes necessary to send radio receivers in space to acquire them. However, these receivers are faced with strong restrictions on storage capacity, energy consumption and transmission rate.To overcome these challenges, sampling architectures should be reviewed and improved. A recent paradigm for signal acquisition and reconstruction, known as compressive sampling hat require a limited number of measurements and leads to the development of a new type of converter : the Analog to Information Converter (AIC). Unlike standard Analog to Digital converters (ADC), AIC can sample at a lower rate than that prescribed by Nyquist Shannon, exploiting the sparsity of signals.The main goal of this thesis is to study the application of compressed sampling for the acquisition of spatial astrophysical signals in the frequency band [1 kHz to 50 MHz]. We focus on signals emitted by the two brightest radio sources in the sky as seen from the Earth, namely the Sun and Jupiter. Based on the characteristic properties of our signals of interest, we progressively and methodologically constructed our acquisition scheme : From the study of signals compressibility, to the choice of the AIC architecture and the signal reconstruction algorithm. We also proposed a new, flexible and programmable implementation of the selected AIC which allows the acquisition of different types of signal having the same compressibility domain and with different compression factors. Using a 65-nm CMOS technology, we evaluated the gain in terms of the amount of data acquired and power consumed of this architecture compared to the traditional analog-to-digital converter
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Gasparetto, Nicola. "Arresto cardiaco e cure post arresto cardiaco in ambito cardiologico." Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3422778.

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INTRODUCTION: Cardiac arrest (CA) is a dramatic clinical event due to an absence of mechanical myocardial contraction. Without an emergency intervention it is characterized by high mortality and morbidity. High quality cardiopulmonary resuscitation (CPR) and early defibrillation are the only factors able to reduce neurological damage. The following phases of advanced resuscitation may include different strategies to improve neurological recovery but they are less important than the early phases. AIM OF THE STUDY: the aim of this PhD was to examine, from an epidemiological point of view, the impact of CA, the organization of out-of-hospital care, the implementation of post CA care and, consequently, the survival rate of post CA patients in Italy and in Veneto region. One of the most important aims was to determine early parameters related with good neurological outcome in post CA patients. In addition to this we investigate the utility and feasibility of mechanical chest compression devices. Furthermore, in resuscitated patients, the effect of temperature changes on coronary flow velocity by transthoracic echocardiography was investigated. METHODS: the first part of the research (epidemiological) was based on the revision of scientific studies published in PubMed. The survey of therapeutic hypothermia in Intensive Care Units and in Emergency Services was based on a questionnaire/telephonic interview. The second part (clinical research) was based on database analysis of CA patients admitted in Intensive Cardiac Care Units in University Hospital of Padua (for early neurological predictors and coronary blood flow velocity) and in the regional Hospital of Treviso (for mechanical chest compression devices). RESULTS: epidemiological analysis has shown persistent high mortality rate of CA. Italy, compared with the other European countries, has low rate of CPR before emergency medical service arrival. In Italian ambulances and Intensive Care Units the implementation of post CA care is low compared to the other European countries. Our analyses have shown the possibility to determine neurological outcome only after 24 hours from the index event. NSE values more than 45.1 µg/L or NSE values less than 45.1 µg/L in a patient older than 78 years old are index of unfavourable neurological outcome (respectively p<0.0001 and p=0.009). A good neurological outcome, was associated with NSE value at 24 hours less than 45.1 µg/L in a patient younger than 78 years old with S-100B value at 24 hours <0.31 µg/L (p=0.025). During therapeutic hypothermia at 32°C coronary blood flow velocity showed significant reduction, proportional to rate-pressure product reduction (p=0.0001) with a potential in reducing ischemia-reperfusion damage. Finally the use of mechanical chest compression devices is feasible during cardiac arrest, by allowing the transport of cardiac arrest patients with the possibility to perform emergent coronary angioplasty or ECMO implantation. CONCLUSION: high quality CPR and early defibrillation are able to improve survival in out-of-hospital CA patients. For this reason it is crucial to spread the resuscitation culture from an institutional level. To increase the prognosis of these patients it is also important to integrate high quality CPR with early defibrillation and advance post CA care. Our data demonstrate the possibility to determine neurological outcome after 24 hours only with biochemical values and the beneficial effect of temperature reduction for myocardial ischemic-reperfusion damage.
INTRODUZIONE: l’arresto cardiaco (AC) è una condizione clinica drammatica, caratterizzata dall’improvvisa assenza di attività meccanica del cuore. E’ gravata da un’elevatissima mortalità e morbidità se non si interviene prontamente. Per poter garantire al paziente le maggiori possibilità di superare l’evento senza reliquati neurologici è fondamentale un’immediata rianimazione cardiopolmonare (RCP) di base di alta qualità seguita da una precoce defibrillazione. Le successive fasi di rianimazione avanzata comprendono diverse strategie che anch’esse possano aumentare la probabilità di recupero neurologico del paziente ma di secondaria importanza rispetto alle fasi iniziali. SCOPO DELLO STUDIO: nella prima parte del dottorato di ricerca lo scopo è stato quello di indagare epidemiologicamente l’impatto dell’AC, l’organizzazione delle cure nel territorio, la diffusione delle cure post AC e conseguentemente la sopravvivenza globale in Italia e in Veneto. A seguire si sono voluti ricercare gli elementi precoci correlati ad un esito neurologico favorevole, indagare la fattibilità e l’utilità di utilizzo dei massaggiatori meccanici e infine valutare la risposta del miocardio alla riduzione della temperatura durante l’ipotermia terapeutica post arresto cardiaco. METODI: la prima parte della ricerca (parte epidemiologica) è stata basata su una revisione della letteratura ricercando tutti gli studi epidemiologici con i dati di sopravvivenza italiani e i principali europei. In merito alla survey dell’ipotermia terapeutica nelle Terapie Intensive e nei Sistemi di Emergenza ed Urgenza, invece, la raccolta dati è avvenuta mediante un questionario. La seconda parte della ricerca (parte di ricerca clinica) sono stati analizzati i dati dei pazienti ricoverati in UCIC di Padova (per l’analisi sui predittori di outcome neurologico e la variazione della velocità del flusso coronarico) e di Treviso (per l’analisi sull’utilizzo dei massaggiatori meccanici). RISULTATI: l’analisi epidemiologica ha messo in luce come l’AC sia ancora un evento clinico ad elevato impatto sociale e con percentuali di mortalità ancora molto elevate. A differenza degli altri paesi europei l’Italia si colloca come fanalino di coda in particolare quando si analizza la percentuale di RCP da parte di astanti e la diffusione dei sistemi di accesso pubblico alla defibrillazione. Anche nell’ambito della implementazione delle cure post AC nelle ambulanze e nelle nostre Terapie Intensive il dato italiano è ancora i più bassi a livello europeo. L’analisi dei predittori di outcome neurologico ci ha permesso di descriverne alcuni precoci che già dopo 24 ore dall’evento danno preziose informazioni. All’analisi multivariata è emerso come valori di enolasi neurono-specifica (NSE) >45.1 µg/L o NSE <45.1 µg/L ma con età >78 anni erano indici di outcome neurologico sfavorevole (rispettivamente p<0.001 e p=0.009). Un buon recupero neurologico era invece correlato a valori di NSE <45.1 µg/L in paziente con età <78 anni e valori di S-100B <0.31 µg/L (p=0.025). L’analisi dei dati raccolti ci ha permesso inoltre di capire come durante riduzione della temperatura a 32°C nei pazienti post AC, la velocità del flusso coronarico, determinato con tecnica Doppler, mostrava una significativa riduzione, proporzionalmente alla riduzione del doppio prodotto, evidenza di una riduzione del consumo di ossigeno miocardico, potenziale meccanismo capace di ridurre il danno da ischemia-riperfusione. Infine l’utilizzo dei massaggiatori meccanici per facilitare la RCP può permettere il trasporto del paziente durante AC con la possibilità di poter eseguire l’angioplastica o posizionare un sistema di assistenza tipo ECMO. CONCLUSIONI: la diffusione della cultura della RCP e dei sistemi di accesso pubblico alla defibrillazione permettono di migliorare notevolmente le possibilità di sopravvivenza dei pazienti colpiti da AC nel territorio. Molti sono i progressi possibili in Italia che dovrebbero partire a livello istituzionale. E’ molto importante, inoltre, attuare delle ottime cure post AC che si integrino perfettamente con quanto già attuato nel territorio e con ciò che è possibile attuare a livello ospedaliero (es. posizionamento di massaggiatore meccanico per angioplastica primaria o posizionamento di ECMO). L’integrazione di una buona cultura della defibrillazione, i sistemi di accesso pubblico alla defibrillazione, l’ACLS e le cure post arresto cardiaco rappresenta la catena essenziale per migliorare la prognosi dei pazienti colpiti.
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Books on the topic "Compressible MHD"

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Deane, Anil E. solwnd: A 3D compressible MHD code for solar wind studies : version 1.0: Cartesian coordinates. Washington: Goddard Space Flight Center, 1996.

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Yang, Yan. Energy Transfer and Dissipation in Plasma Turbulence: From Compressible MHD to Collisionless Plasma. Springer, 2019.

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Yang, Yan. Energy Transfer and Dissipation in Plasma Turbulence: From Compressible MHD to Collisionless Plasma. Springer, 2019.

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Miller, Aaron E., and Teresa M. DeAngelis. Transverse Myelitis. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199732920.003.0004.

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The differential diagnosis of transverse myelitis is lengthy and can present a daunting challenge to the evaluating physician. Emphasizing the critical importance of an initial exclusion of spinal cord compressive causes, we then present several clinical red flags, which can assist in narrowing the potential etiologies and discuss available therapeutic options.
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Vodopivec, Ivana, and Tracey A. Cho. Neurobiology of Transverse Myelitis and Infectious Myelopathies. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199937837.003.0153.

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Infectious agents cause spinal cord pathology by three different mechanisms: direct invasion/infection of neural tissues (i.e., infective myelitis), secondary inflammation and tissue bystander damage with or without autoimmune pathogenesis (parainfectious myelitis), or involvement of extra-axial structures (including the pia-arachnoid, the dura, the epidural space, or the adjacent spinal bones or intervertebral discs), resulting in compressive or ischemic myelopathy. This chapter describes the pathogenesis and treatment of these disorders.
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Katirji, Bashar. Case 8. Edited by Bashar Katirji. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190603434.003.0012.

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Peroneal (fibular) neuropathy is the most common entrapment/compressive mononeuropathy in the lower extremity, often presenting with foot drop and numbness. The majority of the lesions are across the fibular neck, but more proximal and distal lesions exist. This case presents the clinical and electrodiagnostic findings in peroneal neuropathy and discusses in detail the differential diagnoses of foot drop. It highlights the importance of distinguishing peroneal nerve lesions from L5 radiculopathy, lumbar plexopathy, and sciatic neuropathy. Causes of acute and subacute peroneal mononeuropathies are emphasized.
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Katirji, Bashar. Case 16. Edited by Bashar Katirji. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190603434.003.0020.

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Neuralgic amyotrophy is a relatively uncommon disorder but important to recognize since it may be confused with brachial plexopathy, cervical radiculopathy and entrapment/compressive mononeuropathies of the upper extremity. Neuralgic amyotrophy is also known as acute brachial neuritis, acute brachial plexitis, and Parsonage-Turner syndrome. This case highlights the variable clinical and electrodiagnostic findings encountered in patients with neuralgic amyotrophy, with special attention to the most common mononeuropathies affected in this disorder. This include the long thoracic nerve, axillary nerve, phrenic nerve and anterior interosseous nerve. The peculiar needle electromyography findings associated with neuralgic amyotrophy, including selective motor branch involvement, are also discussed.
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Wilson, Thomas J., and Robert J. Spinner. Peroneal Neuropathy—Fibular Tunnel Syndrome. Edited by Meghan E. Lark, Nasa Fujihara, and Kevin C. Chung. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190617127.003.0009.

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Common peroneal neuropathy is the most common compressive neuropathy of the lower extremity, often presenting with acute, progressive foot drop. The most common site of compression of the peroneal nerve is at the point that it courses around the neck of the fibula beneath the fascia of the peroneus longus. This chapter aims to help the surgeon evaluate for peroneal neuropathy using a combination of clinical history, physical examination, electrodiagnostics, and imaging. The chapter also discusses surgical and nonsurgical management of peroneal neuropathy, including a detailed discussion of the operative technique for decompression of the peroneal nerve at the fibular tunnel.
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Shaibani, Aziz. Numbness. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199898152.003.0023.

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Sensory symptoms are the most common symptoms in neuromuscular clinics, yet it is difficult to capture them in videos unless they have a very specific pattern and/or they are associated with objective loss of sensation. Distal sensory loss is a common neuropathic finding. Sensory neuropathies may also present with ataxia or severe pain. Multifocal sensory loss is usually vascular (vasculitis, diabetic amyotrophy). Intercostal pain and numbness are due to radiculopathy (diabetic, zoster, or compressive radiculopathy). Thoracic and abdominal radiculopathies are often misdiagnoses as acute coronary or abdominal emergencies respectively. The distribution of pain and the associated tingling and skin sensitivity to touch are important clues to their neuropathic nature.
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Shaibani, Aziz. Hyperreflexia. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190661304.003.0018.

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Hyperactive deep tendon reflexes (DTRs) is a sign of upper motor neuron (UMN) lesions. It is also commonly seen in normal but anxious people. The proper technique of deep tendon reflex examination and experience play a major role in eliciting and categorizing DTRs. Sustained clonus is the highest degree of hyperreflexia. The most important neuromuscular disease associated with hyperreflexia is amyotrophic lateral sclerosis (ALS) due to degeneration of the cortical motor neurons. Diagnostic difficulty occurs when hyperreflexia and spasticity are the only findings. In these cases, primary lateral sclerosis (PLS), hereditary spastic paraplegia (HSP), and other causes of myelopathies should be entertained. Compressive myelopathies are easily excludable by neuroimaging.
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Book chapters on the topic "Compressible MHD"

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Yang, Yan. "Hybrid Scheme for Compressible MHD Turbulence." In Energy Transfer and Dissipation in Plasma Turbulence, 35–67. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-8149-2_3.

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Yang, Yan. "Energy Cascade in Compressible MHD Turbulence." In Energy Transfer and Dissipation in Plasma Turbulence, 69–90. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-8149-2_4.

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Tu, C. Y., and E. Marsch. "Nature and Origin of Compressible MHD Fluctuations." In MHD Structures, Waves and Turbulence in the Solar Wind, 114–43. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-015-8541-5_5.

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Pettini, Marco, Luigi Nocera, and Angelo Vulpiani. "Compressible MHD Turbulence: An Efficient Mechanism to Heat Stellar Coronae." In Chaos in Astrophysics, 305–16. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5468-7_14.

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Lazarian, A., and J. Cho. "Basic Properties of Compressible MHD Turbulence: Implications for Molecular Clouds." In Magnetic Fields and Star Formation, 29–43. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-94-017-0491-5_3.

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Chernyshov, A. A., K. V. Karelsky, and A. S. Petrosyan. "Large Eddy Simulations of Compressible MHD Turbulence in Heat-Conducting Fluid." In Direct and Large-Eddy Simulation VII, 585–89. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-3652-0_86.

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Zhou, Wei, Zhaoyang Guo, Kangkang Wang, Haibo Zhang, and Xuemao Guan. "Influence of Anti-Mud Agent on the Performance of Gangue Backfilling Paste." In Lecture Notes in Civil Engineering, 351–60. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2532-2_29.

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AbstractAnti-mud agents could improve the efficiency of the action of water reducers in concrete by preferentially. The anti-mud agent was preferentially adsorbed on the clay surface, which reduces the ineffective adsorption of the water reducing agent to the paste, thereby improving the water reduction efficiency. However, its application in high-sediment content coal gangue gypsum backfill materials had not been reported. In this paper, The competitive adsorption mechanism echanism of anti-mud agent was first described. Tested its competitive adsorption with water reducer molecules on the surface of gangue powder. The influences of anti-mud agent on the slump, coagulation time and compressive strength of the paste at different ages were studied. The results showed that: as the dosage of anti-mud agent increased, the amount of desorption of the water reducer from the surface of gangue powder increased. When adding the same extra amount of water reducer, the slump of the backfill paste material increased with prolonged the coagulation time. The strength of the paste decreased at 3 d, and the strengths of 7 d and 28 d were not significantly deteriorated. A small amount of anti-mud agent could greatly improve the fluidity of the paste. This study provides a scientific basis for the pumping of pure solid waste paste.
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Herring, Jackson R., and James C. McWilliams. "COMPRESSIBLE MHD TURBULENT RELAXATION." In Lecture Notes on Turbulence, 148–53. WORLD SCIENTIFIC, 1989. http://dx.doi.org/10.1142/9789814434348_0022.

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Pouquet, Annick G. "An Introduction to Compressible MHD Turbulence." In Interstellar Turbulence, 87–94. Cambridge University Press, 1999. http://dx.doi.org/10.1017/cbo9780511564666.014.

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GHOSH, Sanjoy, William H. MATTHAEUS, and Melvyn L. GOLDSTEIN. "TURBULENT RELAXATION IN COMPRESSIBLE TWO-DIMENSIONAL MAGNETOHYDRODYNAMICS." In Turbulence and Nonlinear Dynamics in MHD Flows, 247–52. Elsevier, 1989. http://dx.doi.org/10.1016/b978-0-444-87396-5.50032-8.

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Conference papers on the topic "Compressible MHD"

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Ladeinde, Foluso. "Direct Simulation of Compressible MHD Turbulence." In 33rd Plasmadynamics and Lasers Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2002. http://dx.doi.org/10.2514/6.2002-2140.

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Vázquez-Semadeni, E., T. Passot, and A. Pouquet. "Highly compressible MHD turbulence and gravitational collapse." In The seventh astrophysical conference: Star formation, near and far. AIP, 1997. http://dx.doi.org/10.1063/1.52735.

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Kowal, Grzegorz, and A. Lazarian. "Aspects of density fluctuations in compressible MHD turbulence." In TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS; 6th Annual International Astrophysics Conference. AIP, 2007. http://dx.doi.org/10.1063/1.2778995.

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Shaikh, Dastgeer, P. K. Shukla, Padma K. Shukla, Bengt Eliasson, and Lennart Stenflo. "Three Dimensional Simulations of Compressible Hall MHD Plasmas." In FRONTIERS IN MODERN PLASMA PHYSICS: 2008 ICTP International Workshop on the Frontiers of Modern Plasma Physics. AIP, 2008. http://dx.doi.org/10.1063/1.3013784.

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Srinivasan, K., R. Agarwal, P. Adhikari, and P. Deb. "Development of an object-oriented compressible viscous MHD code." In 32nd AIAA Plasmadynamics and Lasers Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2001. http://dx.doi.org/10.2514/6.2001-2740.

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Miki, Kenji, and Suresh Menon. "Local Dynamic Subgrid Closure for Compressible MHD Turbulence Simulation." In 37th AIAA Plasmadynamics and Lasers Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2006. http://dx.doi.org/10.2514/6.2006-2891.

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Deb, P., and R. Agarwal. "Numerical solution of compressible viscous MHD equations with chemical kinetics." In 40th AIAA Aerospace Sciences Meeting & Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2002. http://dx.doi.org/10.2514/6.2002-203.

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Ladeinde, Foluso, and Datta Gaitonde. "Anisotropy of Compressible MHD Turbulence in a Mean Magnetic Field." In 42nd AIAA Aerospace Sciences Meeting and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2004. http://dx.doi.org/10.2514/6.2004-314.

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Kawai, Soshi. "High-order divergence-free method for compressible MHD with shock waves." In 44th AIAA Plasmadynamics and Lasers Conference. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2013. http://dx.doi.org/10.2514/6.2013-2756.

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Soulaimani, Azzeddine, Gerardo D, and Nizar Be. "Acceleration of GMRES convergence for three-dimensional compressible, incompressible and MHD flows." In 14th Computational Fluid Dynamics Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1999. http://dx.doi.org/10.2514/6.1999-3381.

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Reports on the topic "Compressible MHD"

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Holden, T., R. Hosbons, and J. Root. CWI1988-Andi-21 Neutron Diffraction of Axial Residual Strains Near a Circumferential Crack. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 1989. http://dx.doi.org/10.55274/r0011391.

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Abstract:
The intent of the experiments reported here was to measure the axial residual strain at the 6:00 position of a girth-weld in the presence of a crack which had propagated a few millimeters from the inside diameter of the llnepipe. The linepipe, 914 mm diameter and average thickness 16.2 mm had been previously examined at Chalk River and the strains at the 1:30, 6:00 and 10:30 positions had been measured prior to the introduction of the crack. Large changes in the level of axial residual strain and introduction of strong through-wall strain gradients are observed on re- welding 16 mm line pipe with wet cellulose electrodes. Ahead of the crack, in the mid-wall the strains correspond to yield stresses. Compressive strains are noted behind the crack and at the outside diameter. The tensile strains at the mid-wall remain very large around the circumference beyond the crack.
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