scholarly journals On the generalized Schuster density law

1998 ◽  
pp. 15-21 ◽  
Author(s):  
S. Ninkovic
Keyword(s):  
Positive Integer ◽  
Mass Distribution ◽  
Axial Symmetry ◽  
Total Mass ◽  
Spiral Galaxies ◽  
Stellar Systems ◽  
Finite Radius ◽  
Mass Distributions ◽  
Almost All ◽  
Special Case

A special case of the generalized Schuster density law for stellar systems with spherical symmetry is discussed; here the exponent in the denominator is equal to i/2 where i is a positive integer. Special attention is paid to the situation 2 ? i ? 5 since then the mass distributions in almost all approximately spherical stellar systems and subsystems known to exist - e. g. dark coronae of galaxies, bulges and halos of spiral galaxies, as well as the systems with the classical Schuster density law - are included. With certain improvements one can also obtain more ample variants including the density continuously attaining zero at a finite radius, somewhat different descriptions of the mass distribution, as well as generalizations towards axial symmetry. It is shown among others, that a spheroid with this mass distribution (i=4) yields the same total mass as the exponential disc and that the mass distribution proposed by King belongs asymptotically to the generalized Schuster density law (i=3).

scholarly journals Differences in Mass Distribution for Field and Cluster Spiral Galaxies

1987 ◽  
Vol 117 ◽  
pp. 66-66 ◽  
Author(s):  
David Burstein ◽  
Vera C. Rubin
Keyword(s):  
Mass Distribution ◽  
Classification Scheme ◽  
Spiral Galaxies ◽  
Three Dimensional ◽  
Rotation Curves ◽  
Mass Distributions ◽  
Distribution Form ◽  
Simple Classification ◽  
Observational Fact

Our group has now obtained rotation curves for 80 spiral galaxies, Hubble types Sa through Sd. As described in Rubin et al. (Ap. J. 289, 81; 1985), the forms of these rotation curves are similar for all Hubble types. Given this observational fact, we have chosen to analyze the mass distributions for these galaxies under the assumption that the mass distributions for all spirals can be described by the same three-dimensional form, here taken to be spherical for simplicity. The mass distribution forms for 71 of these galaxies can be placed into a simple classification scheme based on the curvature of mass distribution form in a log(radius) - log (integral mass) diagram. The three most common mass forms among this continuum are termed Types I, II and III, the forms of which are displayed below (see also the discussion by Rubin elsewhere in this Symposium).

scholarly journals Hα kinematics of nearby galaxies using Fabry-Perot and IFU data

2016 ◽  
Vol 11 (S321) ◽  
pp. 275-275
Author(s):  
Santiago Erroz-Ferrer ◽  
Keyword(s):  
Spectral Resolution ◽  
Total Mass ◽  
Rotation Curve ◽  
Spiral Galaxies ◽  
Rotation Curves ◽  
Large Sample ◽  
Mass Distributions ◽  
Fabry Perot ◽  
Nearby Galaxies

AbstractI present here analysis of the shapes of the rotation curves of a large sample of nearby spiral galaxies with high angular and spectral resolution Hα (Fabry-Perot GHαFaS) kinematics, and the resulting constraints on their total mass distributions. In particular I discuss how their rotation curve shapes relate to key galaxy properties. Finally I present related results from the MUSE Atlas of Disks (MAD) program, which is dissecting the nearby disk population with IFU spectroscopy at ~100pc resolution.

scholarly journals Effect of Bow Camber and Mass Distribution on Violinists' Preferences and Performance

2021 ◽  
Vol 12 ◽  
Author(s):  
Aurélie Tomezzoli ◽  
Benjamin Michaud ◽  
Eric Gagné ◽  
Mickaël Begon ◽  
Sonia Duprey
Keyword(s):  
Statistical Analysis ◽  
Mass Distribution ◽  
Mechanical Characteristics ◽  
Positive Impact ◽  
Random Order ◽  
Mass Distributions ◽  
Maximum Curvature ◽  
And Performance ◽  
Almost All ◽  
Recorded Performances

Little is known about how bow mechanical characteristics objectively and quantitatively influence violinists' preferences and performance. Hypothesizing that the bow shape (i.e., camber) and mass distribution modifications would alter both violinists' appreciations of a bow and objective assessments of their performance, we recruited 10 professional violinists to play their own violin using 18 versions of a single bow, modified by combining three cambers and six mass distributions, in random order. A musical phrase, composed for this study, was played legato and spiccato at three octaves and two tempi. Each violinist scored all 18 bows. Then, experts assessed the recorded performances according to criteria inspired by basic musical analysis. Finally, 12 audio-descriptors were calculated on the same note from each trial, to objectivise potential acoustic differences. Statistical analysis (ANOVA) reveals that bow camber impacted the violinists' appreciations (p < 0.05), and that heavier bow tips gave lower scores for spiccato playing (p < 0.05). The expert evaluations reveal that playing with a lighter bow (tip or frog), or with a bow whose camber's maximum curvature is close to the frog, had a positive impact on some violinists' performance (NS to p < 0.001). The “camber-participant” interaction had significant effects on the violinists' appreciations (p < 0.01 to p < 0.001), on the expert's evaluation and on almost all the audio-descriptors (NS to p < 0.001). While trends were identified, multiple camber-participant interactions suggest that bow makers should provide a variety of cambers to satisfy different violinists.

scholarly journals The contribution of the dark matter to the rotation of spiral galaxies and its mass distribution

1999 ◽  
pp. 1-4
Author(s):  
S. Ninkovic
Keyword(s):  
Dark Matter ◽  
Mass Distribution ◽  
Spiral Galaxy ◽  
Axial Symmetry ◽  
Spiral Galaxies ◽  
The Other ◽  
Continuous Increase ◽  
Homogeneous Sphere ◽  
Circular Velocity ◽  
Other Hand

The rotation of a test spiral galaxy with two contributors - the disc and the corona - is considered. The disc is exponential, whereas the corona is the dark subsystem. For the latter several variants of mass distribution are considered. It is found that the homogeneous sphere is almost unavoidable if the circular velocity has a continuous increase, at least in its observable part. On the other hand the rather often applied quasi-isothermal law offers the most satisfactory fit for the case of constant circular velocity though the classical Schuster law may also be used, especially taking into account its simplicity and the consequent possibility of generalising its potential towards the more general case of axial symmetry.

scholarly journals Agricultural tractor traction efficiency by changing the mass distribution between axles and speed

2021 ◽  
Vol 25 (4) ◽  
pp. 277-281
Author(s):  
Lauro Strapasson Neto ◽  
Maíra Laskoski ◽  
Samir P. Jasper ◽  
Gabriéle S. de Campos ◽  
Leonardo L. Kmiecik ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Total Mass ◽  
Rear Axle ◽  
Block Design ◽  
Front Axle ◽  
Mass Distributions ◽  
Tukey Test ◽  
Randomized Block Design ◽  
Displacement Speed ◽  
Agricultural Tractor

ABSTRACT The traction efficiency of the agricultural tractor can be maximized by adjusting the total mass and its distribution between the axles. The experiment’s objective was to determine the configuration of mass distribution between axles and the displacement speed that provides greater traction efficiency in the harrowing operation. A randomized block design in a 2 × 3 factorial scheme with five replications was used. The first factor was two mass distributions between axles, and the second factor was three gears. The collected data were submitted to analysis of variance and the Tukey test. The condition that maximizes the tractor’s performance corresponds to 39% of the total mass on the front axle and 61% on the rear axle, with a gear that provides speed close to 10 km h-1.

scholarly journals The Stellar Cluster

1989 ◽  
Vol 136 ◽  
pp. 477-486 ◽  
Author(s):  
K. Sellgren
Keyword(s):  
Mass Distribution ◽  
Total Mass ◽  
Galactic Center ◽  
Current Debate ◽  
Core Radius ◽  
Stellar Cluster ◽  
Mass Distributions ◽  
The Core ◽  
Gas Kinematics ◽  
The Galaxy

Observations of the stellar cluster in the central 10 pc of the Galaxy are reviewed. The stellar density law derived from the observed light distribution and the effects on this density law of variable extinction, the possibility of a varying mass-to-light ratio, and the current debate as to the core radius of the cluster are all important for establishing the true mass distribution of the stellar cluster. The presence of the supergiant IRS 7 in the Galactic Center establishes that some recent star formation has occurred, but the age and extent of a possible starburst are still being established. The kinematics of the stellar cluster show predominantly velocity dispersion, in contrast to the systematic gas motion observed, yet the total mass distributions derived from stellar and gas kinematics agree reasonably well. The core radius of the cluster is critical to establishing whether or not a central dark mass is required to explain the total mass distribution.

Populations and Mass Distributions in Spiral Galaxies

1983 ◽  
Vol 5 (2) ◽  
pp. 136-143 ◽  
Author(s):  
P. C. van der Kruit
Keyword(s):  
Mass Distribution ◽  
Rotation Curve ◽  
Gravitational Force ◽  
Velocity Dispersion ◽  
Spiral Galaxies ◽  
Low Velocity ◽  
Mass Distributions ◽  
Circular Velocity ◽  
Detailed Interpretation ◽  
Disk Component

The distribution of mass in a spiral galaxy is usually inferred from its rotation curve. The curve is most conveniently measured using part of its extreme population I such as HI or HII. This has a low velocity dispersion so that the observed tangential motion is in the absence of non-circular motions (van der Kruit and Allen 1978; Bosma 1981a, b) close to the circular velocity required to balance the gravitational force. The main difficulty is that for a detailed interpretation of the rotation curve one has to make assumptions on some general properties of the mass distribution, even though it is true that one can estimate the total mass within the last measured point to an accuracy of about a factor two. That of axial symmetry is only the simplest of assumptions. On the basis of the light distribution with a usually prominent disk component one often assumes that the mass distribution is also basically highly flattened.

scholarly journals A comparison of two mass distributions applicable to globular clusters and dwarf galaxies

2004 ◽  
pp. 15-18 ◽  
Author(s):  
Slobodan Ninkovic
Keyword(s):  
Satisfactory Agreement ◽  
Mass Distribution ◽  
Globular Clusters ◽  
Dwarf Galaxies ◽  
Stellar Systems ◽  
Mass Distributions

A particular case of mass distribution in stellar systems, already described in the literature, is compared to the King model of mass distribution. For the cases which would correspond to the description of real stellar systems such as the globular clusters and dwarf galaxies, one finds a satisfactory agreement between these two mass distributions.

scholarly journals A comparison of two spherical mass-distribution models

2001 ◽  
pp. 17-19
Author(s):  
S. Ninkovic
Keyword(s):  
Density Dependence ◽  
Mass Distribution ◽  
Spherically Symmetric ◽  
Distribution Models ◽  
Mass Distributions ◽  
Spherical Mass ◽  
Special Case ◽  
Scale Length

Two spherically symmetric mass-distribution models - a special case of the generalized Schuster density law and the generalized isochrone model (both yield the same approximate density dependence on the distance in the outer parts) - are compared. It is shown that in the interval of the relative second scale length for the latter case of 0.5-0.6 the two mass distributions are almost identical. Considering to advantages, i.e. disadvantages, of the formulae describing these mass distributions this result can be of interest.

Nonwovens: Global Trends in World Economy, European Foreign Trade, and Selected Case Studies from Poland and Asian Brics Countries

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Zofia Wysokińska ◽  
Tomasz Czajkowski ◽  
Katarzyna Grabowska
Keyword(s):  
Case Studies ◽  
World Economy ◽  
World Market ◽  
Global Trends ◽  
Textile Materials ◽  
Brics Countries ◽  
Recent Trends ◽  
Almost All ◽  
Special Case

AbstractNonwovens are one of the most versatile textile materials and have become increasingly popular in almost all sectors of the economy due to their low manufacturing costs and unique properties. In the next few years, the world market of nonwovens is predicted to grow by 7%–8% annually (International Nonwovens & Disposables Association [INDA], European Disposables and Nonwovens Association [EDANA], and Markets and Markets). This article aims to analyze the most recent trends in the global export and import of nonwovens, to present two case studies of Polish companies that produce them, and to present one special case study of the market of nonwoven geotextiles in China and India, which are the Asian transition economies among the BRICS countries (Brazil, Russia, India, China, and South Africa).

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