Simulation and experimental study of proton bunch self-modulation in plasma with linear density gradients

This paper describes an experimental study of the drag of two- and three-dimensional bluff obstacles of various cross-stream shapes when towed through a fluid having a stable, linear density gradient with Brunt-Vaisala frequency, N . Drag measurements were made directly using a force balance, and effects of obstacle blockage ( h / D , where h and D are the obstacle height and the fluid depth, respectively) and Reynolds number were effectively eliminated. It is shown that even in cases where the downstream lee waves and propagating columnar waves are of large amplitude, the variation of drag with the parameter K ( = ND /π U ) is qualitatively close to that implied by linear theories, with drag minima existing at integral values of K . Under certain conditions large, steady, periodic variations in drag occur. Simultaneous drag measurements and video recordings of the wakes show that this unsteadiness is linked directly with time-variations in the lee and columnar wave amplitudes. It is argued that there are, therefore, situations where the inviscid flow is always unsteady even for large times; the consequent implications for atmospheric motions are discussed.

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FRACTIONATION OF HUMAN LYMPHOCYTES ON LINEAR DENSITY GRADIENTS

Regulatory Mechanisms in Lymphocyte Activation ◽

10.1016/b978-0-12-458050-3.50090-4 ◽

1977 ◽

pp. 554-556

Author(s):

Karen Zier ◽

Christoph Huber ◽

Herbert Braunsteiner

Keyword(s):

Linear Density ◽

Human Lymphocytes ◽

Density Gradients

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Experimental study of ionospheric electron density gradients and their effect on VLF propagation

Journal of Atmospheric and Terrestrial Physics ◽

10.1016/0021-9169(76)90190-2 ◽

1976 ◽

Vol 38 (1) ◽

pp. 27-36 ◽

Cited By ~ 10

Author(s):

L. Cairó ◽

J.C. Cerisier

Keyword(s):

Experimental Study ◽

Electron Density ◽

Density Gradients ◽

Ionospheric Electron Density ◽

Vlf Propagation

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Apparatus for preparation of linear density gradients

Analytical Biochemistry ◽

10.1016/0003-2697(71)90444-1 ◽

1971 ◽

Vol 39 (2) ◽

pp. 530-532 ◽

Cited By ~ 2

Author(s):

David Freifelder ◽

Atis Folkmanis

Keyword(s):

Linear Density ◽

Density Gradients

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STUDY OF CUTTING AERIAL PMMA WITH MINIATURE DETONATION CORD

International Journal of Modern Physics B ◽

10.1142/s0217979208050826 ◽

2008 ◽

Vol 22 (31n32) ◽

pp. 5566-5571

Author(s):

Z.Q. LI ◽

L.M. ZHAO ◽

Y.G. ZHAO

Keyword(s):

Experimental Study ◽

Dynamic Analysis ◽

Nonlinear Dynamic ◽

Linear Density ◽

Nonlinear Dynamic Analysis ◽

Plate Versus ◽

Cutting Depth ◽

Simulation Results ◽

Relationship Of ◽

The Relationship

In order to shorten the time of through-the-canopy-ejection, and to ensure pilot safely escape and survive. The application of linear cutting technique using miniature detonation cord( MDC) in through-the-canopy-ejection-system is proposed. A series of different kinds of MDC are designed. Firstly experimental study on the cutting process of the PMMA plate wiht MDC is carried out. Material of metal cover explosive types and the range of charge quantities are determined. Consequently the phenomena of spallation is observed, and the relationship between the cutting depth and charge quantities is obtained. For the comparison, the process of explosion cutting PMMA plate is simulated by means of nonlinear dynamic analysis code LS-DYNA. Spallation phenomena which occurs in the experiment, is also observed in the simulation. Simulation results present the relationship of cutting depth of PMMA plate versus charge linear density, which well agree with experimental ones.

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Experimental study of wakefields driven by a self-modulating proton bunch in plasma

Physical Review Accelerators and Beams ◽

10.1103/physrevaccelbeams.23.081302 ◽

2020 ◽

Vol 23 (8) ◽

Cited By ~ 1

Author(s):

M. Turner ◽

P. Muggli ◽

E. Adli ◽

R. Agnello ◽

M. Aladi ◽

...

Keyword(s):

Experimental Study ◽

Proton Bunch

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Effect of flyer speed on yarn breakages in production of jute yarn

Daffodil International University Journal of Science and Technology ◽

10.3329/diujst.v4i2.4364 ◽

1970 ◽

Vol 4 (2) ◽

pp. 23-27

Author(s):

AKM Mahabubuzzaman ◽

Md Osman Ghani Miazi ◽

Ayub Nabi Khan

Keyword(s):

Experimental Study ◽

Key Words ◽

Experimental Observation ◽

Linear Density ◽

Science And Technology ◽

The World ◽

International University ◽

Almost All ◽

Jute Yarn

In Bangladesh, jute mills are producing conventional yarns heavier than 275 tex. These are used as hessian, sacking, carpet backing cloth etc. For diversified uses of jute it is most essential to produce medium count yarn of 241 to 275 tex. In this regard, slip draft spinning machine has been studied. This machine is capable to produce yarn of 241 to 280 tex at flyer speed of 2900 rpm to 4850 rpm. But there is a relation between flyer speed and yarn breakages of the machine. In addition spinning efficiency of the machine also depends on the yarn breakages. Through a series of experiment, a relation has been established between flyer speed and yarn breakages of the experimental machine for production of jute yarn. From the experimental observation, it shows that for production of 241 tex jute yarn 4700 rpm flyer speed is the most suitable speed and 4800 rpm flyer speed is the most suitable speed for production of 275 tex jute yarn. In addition productivity of the machine also maximum at that flyer speed of the machine. In this experimental study, it was found that at 4850 rpm it was very difficult to spin yarn due to its random breakages. That consequently lowered the productivity. Therefore, it is necessary to select proper flyer speed for the production of yarn of particular linear density (tex). It was also observed that the number of breakages increased with the increase of flyer speed. At 2900-rpm flyer speed, the yarn breakage was 0.8/ spindle-hr and at 4850 rpm the yarn breakages is 3.5/spindle-hr. for producing 241 tex jute yarn. Almost all jute mills of Bangladesh have been slip draft spinning machine. Using proper flyer speed, which was found from the experiment, can use the machine in production of medium count jute yarn. The produced yarn can replace the synthetic/manmade fibre in the world textile market. Key Words: Spinning, Tex, Productivity, yarn and Breakages. DOI: 10.3329/diujst.v4i2.4364 Daffodil International University Journal of Science and Technology Vol.4(2) 2009 pp.23-27

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