MHD Modeling for Formation Process of Coronal Mass Ejections: Interaction between Ejecting Flux Rope and Ambient Field

We performed magnetohydrodynamic simulation of a formation process of coronal mass ejections (CMEs), focusing on interaction (reconnection) between an ejecting flux rope and its ambient field. We examined three cases with different ambient fields: no ambient field, and cases with dipole field of two opposite directions which are parallel and anti-parallel to that of the flux rope surface. As a result, while the flux rope disappears in the anti-parallel case, in other cases the flux ropes can evolve to CMEs and show different amounts of rotation of the flux rope. The results imply that the interaction between an ejecting flux rope and its ambient field is an important process for determining CME formation and CME orientation, and also show that the amount and direction of magnetic flux within the flux rope and the ambient field are key parameters for CME formation. Especially, the interaction (reconnection) plays a significant role to the rotation of the flux rope, with a process similar to "tilting instability" in a spheromak-type experiment of laboratory plasma.Comment: 24 pages, 5 figures. Accepted for publication in Ap

CKP Hierarchy, Bosonic Tau Function and Bosonization Formulae

We develop the theory of CKP hierarchy introduced in the papers of Kyoto school [Date E., Jimbo M., Kashiwara M., Miwa T., J. Phys. Soc. Japan 50 (1981), 3806-3812] (see also [Kac V.G., van de Leur J.W., Adv. Ser. Math. Phys., Vol. 7, World Sci. Publ., Teaneck, NJ, 1989, 369-406]). We present appropriate bosonization formulae. We show that in the context of the CKP theory certain orthogonal polynomials appear. These polynomials are polynomial both in even and odd (in Grassmannian sense) variables

747-4 Evaluation of Regurgitant Jets by Sound Intensity Using a Pulsatile Flow Model: Potential Contribution of Regurgitant Volume and Reynolds Number

Our goal in this study was to determine whether a new type of digital heart sound analysis method could give quantitative information about flow velocity and volume so as to allow a potentially lower-cost approach to followup studies of patients with stenotic or regurgitant valve lesions. To elucidate the relationships between hydrodynamic factors such as Reynolds number, flow velocity and flow volume and the sound characteristics of cardiac murmurs, we developed an in vitro pulsatile flow model with variable orifice size and shape (circular 0.11 cm2, 0.24 cm2, 1.77 cm2and 3.80 cm2; oval 0.24 cm2, with a ratio of major to minor axis=2; rectangular 0.24 cm2, ratio=4). Heart sounds were recorded with a new digital system (MCG) with real time spectral analysis and display and averaged over 15 “cardiac” cycles. Mean flow rate ranged from 0.6 l/min to 6 l/min. Actual instantaneous flow rate was measured using an ultrasonic flow meter for peak flow rates 1.6 l/min to 16.8 l/min. Reynolds number ranged from 6820 to 40050. For each orifice, there was an excellent relationship between total integrated sound energy (See figure: integration of intensity (I) and frequency (F) over time (T).) obtained by digital processing and Reynolds number, peak flow velocity and peak flow rate (r=0.89–0.97, 0.89–0.97, 0.93–D.99, P<0.001, respectively). The best relationship was obtained for the smallest orifice. Higher sound energies were detected for any given flow volume in asymmetrical orifices, probably due to higher turbulence. For all orifices combined, a correlation was found between peak frequency and peak velocity, but only total sound energywas correlated with peak flow rate (r=0.84, P<0.0t). Total integrated sound energy determined digitally is related to peak flow rate; peak velocity and Reynolds number parallel peak sound frequency

Validation of the accuracy of both right and left ventricular outflow volume determinations and semiautomated calculation of shunt volumes through atrial septal defects by digital color Doppler flow mapping in a chronic animal model

AbstractOBJECTIVESThe aim of the present study was to quantitate shunt flow volumes through atrial septal defects (ASDs) in a chronic animal model with surgically created ASDs using a new semiautomated color Doppler flow calculation method (ACM).BACKGROUNDBecause pulsed Doppler is cumbersome and often inappropriate for color flow computation, new methods such as ACM are of interest.METHODSIn this study, 13 to 25 weeks after ASDs were surgically created in eight sheep, a total of 24 hemodynamic states were studied at a separate open chest experimental session. Electromagnetic (EM) flow probes and meters were used to provide reference flow volumes as the pulmonary and aortic flow volumes (Qpand Qs) and shunt flow volumes (Qpminus Qs). Epicardial echocardiographic studies were performed to image the left and right ventricular outflow tract (LVOT and RVOT) forward flow signals. The ACM method digitally integrated spatial and temporal color flow velocity data to provide stroke volumes.RESULTSLeft ventricular outflow tract and RVOT flow volumes obtained by the ACM method agreed well with those obtained by the EM method (r = 0.96, mean difference = 0.78 ± 1.7 ml for LVOT and r = 0.97, mean difference = −0.35 ± 3.6 ml for RVOT). As a result, shunt flow volumes and Qp/Qsby the ACM method agreed well with those obtained by the EM method (r = 0.96, mean difference = −1.1 ± 3.6 ml/beat for shunt volumes and r = 0.95, mean difference = −0.11 ± 0.22 for Qp/Qs).CONCLUSIONSThis animal study, using strictly quantified shunt flow volumes, demonstrated that the ACM method can provide Qp/Qsand shunt measurements semiautomatically and noninvasively