Toroidal plasma configuration with anisotropic pressure

The relation between various surface quantities required in hydrodynamic calculations, and the relation between the parallel and perpendicular currents in an arbitrary magnetic toroidal plasma configuration with scalar pressure, are generalized to the case of anisotropic pressure. Magnetic co-ordinates for hydrodynamic equilibria in this configuration are defined. A general expression for the mean velocity of diffusion through a magnetic surface, on the basis of the one-fluid magnetohydrodynamic equation with anisotropic pressure, is derived.

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Anisotropic pressure correlation spectra in turbulent shear flow

Journal of Fluid Mechanics ◽

10.1017/jfm.2011.502 ◽

2012 ◽

Vol 694 ◽

pp. 50-77 ◽

Cited By ~ 9

Author(s):

Yoshiyuki Tsuji ◽

Yukio Kaneda

Keyword(s):

Mixing Layer ◽

Inertial Subrange ◽

Turbulent Shear ◽

Pressure Probe ◽

Anisotropic Pressure ◽

Turbulent Shear Flow ◽

Velocity Correlation ◽

Mean Velocity ◽

Correlation Spectrum ◽

The Mean

AbstractWe measured the correlation spectrum ${\hat {Q} }_{p} (\mathbi{k})$ of pressure fluctuations in a driving mixing layer with a Taylor-scale Reynolds number ${R}_{\lambda } $ up to ${\simeq }700$ by a newly developed pressure probe with spatial and temporal resolutions that are sufficient to analyse inertial-subrange statistics. The influence of the mean velocity gradient tensor ${S}_{ij} $ in the mixing layer, which is almost constant near its centreline, is studied using an idea similar to that underlying the linear response theory developed in statistical mechanics for systems at or near thermal equilibrium. If we write the spectrum ${\hat {Q} }_{p} (\mathbi{k})$ as ${\hat {Q} }_{p} (\mathbi{k})= { \hat {Q} }_{p}^{(0)} (\mathbi{k})+ \mrm{\Delta} {\hat {Q} }_{p} (\mathbi{k})$, where ${ \hat {Q} }_{p}^{(0)} (\mathbi{k})$ is the isotropic Kolmogorov spectrum in the absence of mean shear, then for small ${S}_{ij} $ the deviation $ \mrm{\Delta} {\hat {Q} }_{p} (\mathbi{k})$ due to the shear is approximately linear and is determined by a few non-dimensional universal constants in addition to ${S}_{ij} $, $k$ and the mean energy dissipation rate. We also measured the pressure–velocity and velocity–velocity correlation spectra. Deviations from isotropy due to shear are shown to be approximately proportional to ${S}_{ij} $ at large ${R}_{\lambda } $.

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Relación entre la potencia y velocidad en press de banca y la velocidad de lanzamiento de balón en jugadores profesionales de balonmano (Relationship between barbell power and velocity in bench press exercise and ball throwing velocity in professional ha

Retos ◽

10.47197/retos.v1i40.82710 ◽

2020 ◽

pp. 53-59

Author(s):

Iker Javier Bautista ◽

Juan Vicente-Mampel ◽

Luis Baraja-Vegas ◽

Isidoro Martínez

Keyword(s):

Bench Press ◽

Average Power ◽

Mean Velocity ◽

Specific Performance ◽

Relevant Variables ◽

The Mean ◽

Incremental Protocol ◽

The One ◽

The Relationship ◽

Correlation Range

Los objetivos de este estudio fueron (a) analizar la relación existente entre la una repetición máxima (1-RM) en press de banca y la velocidad de lanzamiento en jugadores de balonmano U18 de nivel internacional y, (b) analizar qué variables del ejercicio del press de banca son más relevantes en el rendimiento específico (velocidad de lanzamiento del balón) durante el test de velocidad de lanzamiento (T3-Step). Dieciséis jugadores de la Selección Española de Balonmano Juvenil participaron en la presente investigación. Todos los sujetos realizaron un protocolo incremental en el ejercicio del press de banca, además del T3-Step de velocidad de lanzamiento del balón. Por un lado, se analizó la relación existente entre la velocidad media (Velmedia), velocidad media de la fase propulsiva (VelMFP), velocidad pico (Velpico), potencia media (Potmedia), potencia media de la fase propulsiva (PotMFP), y potencia pico (Potpico) en todo el espectro de cargas en relación con la velocidad de lanzamiento. También se realizaron los mismos análisis con la carga en donde se obtuvo la máxima potencia media (CargaMP). Los resultados mostraron, por un lado que el rango de correlación de la CargaMP, PotmediaMP, PotMFPMP y PotpicoMP y la velocidad de lanzamiento fueron de .61 (p= .012), .702 (p< .01), .734 (p< .01) y .63 (p< .01), respectivamente. El coeficiente de correlación de Pearson entre la 1-RM y la velocidad de lanzamiento fue de r = .61 (p < .01). En conclusión, las variables relevantes a nivel de rendimiento específico con la velocidad de lanzamiento fueron la 1RM, la CargaMP, la PotMFPMP y la VelMFPMP. Todas estas analizadas en función del 60% de la 1-RM. Abstract. The objectives of this study were (a) to analyze the relationship between one repetition maximum (1-RM) in free bench press exercise and ball throwing velocity in handball players U18 of international level and, (b) to analyze which variables of bench press exercise are more relevant in the specific performance during the ball throwing velocity test (T3-Step). Sixteen (n = 16) players of the Spanish Youth Handball Team participated in the present investigation. All subjects included performed an incremental protocol bench press exercise, in addition to the T3-Step. On the one hand, it analyzed the relationship between the mean velocity (Velmean), the mean velocity of propulsive phase (VelmeanPP), peak velocity (Velpeak), the average power (Powermean), the average power of the propulsive phase (PowermeanPP), and peak power (Powerpeak) over the entire spectrum of charges in relation to the launch speed. The same analyzes were also obtained with the load where the maximum average power (LoadMP). The results obtained, on the one hand that the correlation range of the LoadMP, PowermeanPP, PowerMPPMP and PowerpeakPP and ball throwing velocity were .61 (p = .012), .70 (p < .01), .73 (p < .01) and 0.63 (p < .01), respectively. The correlation coefficient between the 1-RM and ball throwing velocity was r = 0.61 (p< .01). In conclusion, the relevant variables at the specific performance level with the ball throwing velocity were 1-RM, LoadMP, PowerMFPMP and VelMFPMP. All these analyzed according to 60% of the 1-RM.

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Nonlinear waves with a threefold rotational symmetry in pipe flow: influence of a strongly shear-thinning rheology

Journal of Fluid Mechanics ◽

10.1017/jfm.2017.149 ◽

2017 ◽

Vol 818 ◽

pp. 595-622

Author(s):

Emmanuel Plaut ◽

Nicolas Roland ◽

Chérif Nouar

Keyword(s):

Reynolds Number ◽

Laminar Flow ◽

Nonlinear Waves ◽

Pipe Flow ◽

Rotational Symmetry ◽

Shear Thinning ◽

Transition To Turbulence ◽

Mean Velocity ◽

The Mean ◽

The One

In order to model the transition to turbulence in pipe flow of non-Newtonian fluids, the influence of a strongly shear-thinning rheology on the travelling waves with a threefold rotational symmetry of Faisst & Eckhardt (Phys. Rev. Lett., vol. 91, 2003, 224502) and Wedin & Kerswell (J. Fluid Mech., vol. 508, 2004, pp. 333–371) is analysed. The rheological model is Carreau’s law. Besides the shear-thinning index $n_{C}$, the dimensionless characteristic time $\unicode[STIX]{x1D706}$ of the fluid is considered as the main non-Newtonian control parameter. If $\unicode[STIX]{x1D706}=0$, the fluid is Newtonian. In the relevant limit $\unicode[STIX]{x1D706}\rightarrow +\infty$, the fluid approaches a power-law behaviour. The laminar base flows are first characterized. To compute the nonlinear waves, a Petrov–Galerkin code is used, with continuation methods, starting from the Newtonian case. The axial wavenumber is optimized and the critical waves appearing at minimal values of the Reynolds number $\mathit{Re}_{w}$ based on the mean velocity and wall viscosity are characterized. As $\unicode[STIX]{x1D706}$ increases, these correspond to a constant value of the Reynolds number based on the mean velocity and viscosity. This viscosity, close to the one of the laminar flow, can be estimated analytically. Therefore the experimentally relevant critical Reynolds number $\mathit{Re}_{wc}$ can also be estimated analytically. This Reynolds number may be viewed as a lower estimate of the Reynolds number for the transition to developed turbulence. This demonstrates a quantified stabilizing effect of the shear-thinning rheology. Finally, the increase of the pressure gradient in waves, as compared to the one in the laminar flow with the same mass flux, is calculated, and a kind of ‘drag reduction effect’ is found.

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Forward and Backward Running Waves in the Arteries: Analysis Using the Method of Characteristics

Journal of Biomechanical Engineering ◽

10.1115/1.2891191 ◽

1990 ◽

Vol 112 (3) ◽

pp. 322-326 ◽

Cited By ~ 298

Author(s):

K. H. Parker ◽

C. J. H. Jones

Keyword(s):

Transient Flow ◽

Impedance Analysis ◽

Time Domain Analysis ◽

Mean Velocity ◽

One Dimensional ◽

Acceleration And Deceleration ◽

The Mean ◽

The One ◽

Made In

The one-dimensional equations of flow in the elastic arteries are hyperbolic and admit nonlinear, wavelike solutions for the mean velocity, U, and the pressure, P. Neglecting dissipation, the solutions can be written in terms of wavelets defined as differences of the Riemann invariants across characteristics. This analysis shows that the product, dUdP, is positive definite for forward running wavelets and negative definite for backward running wavelets allowing the determination of the net magnitude and direction of propagating wavelets from pressure and velocity measured at a point in the artery. With the linearizing assumption that intersecting wavelets are additive, the forward and backward running wavelets can be separately calculated. This analysis, applied to measurements made in the ascending aorta of man, shows that forward running wavelets dominate during both the acceleration and deceleration phases of blood flow in the aorta. The forward and backward running waves calculated using the linearized analysis are similar to the results of an impedance analysis of the data. Unlike the impedance analysis, however, this is a time domain analysis which can be applied to nonperiodic or transient flow.

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Validity and Reliability of a Smartphone Accelerometer for Measuring Lift Velocity in Bench-Press Exercises

Sustainability ◽

10.3390/su12062312 ◽

2020 ◽

Vol 12 (6) ◽

pp. 2312

Author(s):

Javier Peláez Barrajón ◽

Alejandro F. San Juan

Keyword(s):

Bench Press ◽

Basic Program ◽

Validity And Reliability ◽

Training Experience ◽

Mean Velocity ◽

Repetition Maximum ◽

Linear Transducer ◽

The Mean ◽

One Year ◽

The One

The aim of this study was to determine the validity and reliability that a smartphone accelerometer (ACC) used by a mobile basic program (MBP) can provide to measure the mean velocity of a bench-press (BP) lift. Ten volunteers participated in the study (age 23.1 ± 2.5 years; mean ± SD). They had more than one year of resistance training experience in BP exercise. All performed three attempts with different loads: 70%, 90%, and 100% of the estimated value of the one-repetition maximum (1RM). In each repetition, the mean velocity was measured by a validated linear transducer and the ACC. The smartphone accelerometer used by the mobile basic program showed no significant differences between the mean velocities at 70% 1RM lifts (ACC = 0.52 ± 0.11 m/s; transducer = 0.54 ± 0.09 m/s, p > 0.05). However, significant differences were found in the mean velocities for 90% 1RM (ACC = 0.46 ± 0.09 m/s; transducer = 0.31 ± 0.03 m/s, p < 0.001), and 100% 1RM (ACC = 0.33 ± 0.21 m/s; transducer = 0.16 ± 0.04 m/s, p < 0.05). The accelerometer is sensitive enough to measure different lift velocities, but the algorithm must be correctly calibrated.

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VII. On the viscosity of gases at high exhaustions

Philosophical Transactions of the Royal Society of London ◽

10.1098/rstl.1881.0007 ◽

1881 ◽

Vol 172 ◽

pp. 387-446 ◽

Cited By ~ 7

Keyword(s):

Internal Friction ◽

Plane Surface ◽

Tangential Force ◽

The Other ◽

British Association ◽

Mean Velocity ◽

Total Action ◽

The Mean ◽

The One

635. By the viscosity or internal friction of a gas, is meant the resistance it offers to the gliding of one portion over another. In a paper read before the British Association in 1859, Maxwell† gives the following explanation of the internal friction of gases:— “Particles having the mean velocity of translation belonging to one layer of the gas, pass out of it into another layer having a different velocity of translation, and by striking against the particles of the second layer exert upon it a tangential force which constitutes the internal friction of the gas. The whole friction between two portions of gas separated by a plane surface, depends upon the total action between all the layers on the one side of that surface upon all the layers on the other side.”

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Evaluation of Road Utilisation as Space For Holding Social Ceremonies in Indigenous Residential Area of Ogbomoso, Nigeria

LAUTECH Journal of Civil and Environmental Studies ◽

10.36108/laujoces/8102/10(0131) ◽

2018 ◽

Vol 1 (March 2018) ◽

Author(s):

S.A Okanlawon ◽

O.O Odunjo ◽

S.A Olaniyan

Keyword(s):

Transport Infrastructure ◽

Noisy Environment ◽

Policy Makers ◽

The Core ◽

Local Roads ◽

Strict Enforcement ◽

The Mean ◽

The One ◽

The City ◽

The Town

This study examined Residents’ evaluation of turning transport infrastructure (road) to spaces for holding social ceremonies in the indigenous residential zone of Ogbomoso, Oyo State, Nigeria. Upon stratifying the city into the three identifiable zones, the core, otherwise known as the indigenous residential zone was isolated for study. Of the twenty (20) political wards in the two local government areas of the town, fifteen (15) wards that were located in the indigenous zone constituted the study area. Respondents were selected along one out of every three (33.3%) of the Trunk — C (local) roads being the one mostly used for the purpose in the study area. The respondents were the residents, commercial motorists, commercial motorcyclists, and celebrants. Six hundred and forty-two (642) copies of questionnaire were administered and harvested on the spot. The Mean Analysis generated from the respondents’ rating of twelve perceived hazards listed in the questionnaire were then used to determine respondents’ most highly rated perceived consequences of the practice. These were noisy environment, Blockage of drainage by waste, and Endangering the life of the sick on the way to hospital; the most highly rated reasons why the practice came into being; and level of acceptability of the practice which was found to be very unacceptable in the study area. Policy makers should therefore focus their attention on strict enforcement of the law prohibiting the practice in order to ensure more cordial relationship among the citizenry, seeing citizens’ unacceptability of the practice in the study area.

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The flow of liquid in a stream from the standard turbine impeller

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19790700 ◽

1979 ◽

Vol 44 (3) ◽

pp. 700-710 ◽

Cited By ~ 10

Author(s):

Ivan Fořt ◽

Hans-Otto Möckel ◽

Jan Drbohlav ◽

Miroslav Hrach

Keyword(s):

Reynolds Number ◽

Kinematic Viscosity ◽

Momentum Flux ◽

Relative Size ◽

Mean Velocity ◽

Axial Profile ◽

The Mean ◽

Hot Film ◽

Turbine Impeller

Profiles of the mean velocity have been analyzed in the stream streaking from the region of rotating standard six-blade disc turbine impeller. The profiles were obtained experimentally using a hot film thermoanemometer probe. The results of the analysis is the determination of the effect of relative size of the impeller and vessel and the kinematic viscosity of the charge on three parameters of the axial profile of the mean velocity in the examined stream. No significant change of the parameter of width of the examined stream and the momentum flux in the stream has been found in the range of parameters d/D ##m <0.25; 0.50> and the Reynolds number for mixing ReM ##m <2.90 . 101; 1 . 105>. However, a significant influence has been found of ReM (at negligible effect of d/D) on the size of the hypothetical source of motion - the radius of the tangential cylindrical jet - a. The proposed phenomenological model of the turbulent stream in region of turbine impeller has been found adequate for values of ReM exceeding 1.0 . 103.

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SAT0267 ROLE OF AGGRESSIVE IMMUNOSUPPRESSION ON SUBGLOTTIC STENOSIS IN GRANULOMATOSIS WITH POLYANGIITIS: RETROSPECTIVE ANALYSIS OF A MONOCENTRIC COHORT

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.2582 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 1076.1-1077

Author(s):

L. Moroni ◽

L. Giudice ◽

G. A. Ramirez ◽

S. Sartorelli ◽

A. Cariddi ◽

...

Keyword(s):

Medical Treatment ◽

Clinical Characteristics ◽

Granulomatosis With Polyangiitis ◽

Balloon Catheter ◽

Subglottic Stenosis ◽

Damage Accrual ◽

The Mean ◽

The One

Background:Subglottic stenosis (SGS) is defined as airway narrowing below the vocal cords and is a common and potentially life-threatening manifestation of Granulomatosis with Polyangiitis (GPA), with an estimated prevalence of 16-23% (1). Balloon catheter dilation is effective in GPA-related SGS, but relapses are frequent. Little is known about the role of immunosuppression in this setting.Objectives:to analyse the clinical characteristics of a monocentric GPA cohort, describe phenotype differences among patients with and without SGS and investigate the role of surgical and medical treatments on relapse risk and general outcome.Methods:Biopsy-proven patients with SGS were identified by review of medical charts among a cohort of patients with GPA, classified according to the algorithm of the European Medicine Agency (2). The clinical characteristics of patients with SGS were retrospectively collected over a median follow-up time of 15.9 years and compared to those of patients without SGS.Results:Fourteen patients with SGS-GPA were identified, with a female to male ratio of 1:1 and a prevalence of 29.2% among the cohort. The mean ± SD age at GPA onset was 30.8 ± 14.4 years, with a mean time from GPA diagnosis to SGS onset of 4.7 ± 4.2 years. ANCA were positive in 78.6% (54.0% anti-PR3, 18.1% anti-MPO and 27.9% IFI only). The mean Birmingham Vasculitis Activity Score (BVAS) at onset was 10.0 ± 5.6. The main clinical manifestations associated with SGS were crusty rhinitis (100%), sinusitis (78%), pulmonary disease (72.7%), otitis/mastoiditis (50%), glomerulonephritis (42.9%), orbital pseudotumor (28.6%). Six patients (42.9%) received medical treatment only, other six (42.9%) had one to three balloon dilations and two (14.2%) underwent four or more procedures. Eight patients had no SGS relapse (maximum one dilation) and they all received immunosuppression with rituximab (RTX), cyclophosphamide (CYC) or azathioprine (AZA). All patients who received no immunosuppression, methotrexate (MTX) or mycophenolate (MMF) had at least one relapse. Patients treated with MTX or MMF had a mean relapse-free survival of 13.1 months, which was comparable to the one of patients not receiving medical treatment (40.2 months; p=NS) and shorter than the one of patients receiving CYC or RTX (153.2 months; p=0.032). CYC use also inversely correlated with the number of surgical procedures (r=-0.691, p=0.006). Compared to patients without SGS (31 consecutive patients with at least 4 years of follow-up), patients with SGS-GPA had an earlier disease onset (mean age 30.8 vs 50.4 years; p<0.001), but with lower BVAS (mean 10.0 vs 15.3; p=0.013) and showed a higher prevalence of crusty rhinitis (100% vs 67.7%; p=0.019). No difference was observed in damage accrual over time between the two groups.Conclusion:Subglottic stenosis is highly prevalent in patients with GPA and may define a milder disease subset occurring more frequently in younger patients. MTX and MMF might be insufficient to prevent SGS relapses requiring balloon dilation. Aggressive immunosuppression (CYC or RTX) might have a non-redundant role in this setting and reduce the risk of relapses.References:[1]Quinn KA, et al. Subglottic stenosis and endobronchial disease in granulomatosis with polyangiitis. Rheumatology 2019; 58 (12), 2203-2211.[2]Watts R, et al. Development and validation of a consensus methodology for the classification of the ANCA associated vasculitides and polyarteritis nodosa for epidemiological studies. Ann Rheum Dis 2007; 66: 222-7.Disclosure of Interests:Luca Moroni: None declared, Laura Giudice: None declared, Giuseppe Alvise Ramirez: None declared, Silvia Sartorelli: None declared, adriana cariddi: None declared, Angelo Carretta: None declared, Enrica Bozzolo: None declared, Lorenzo Dagna Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Consultant of: Prof Lorenzo Dagna received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI.

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