A simple geometrical model for emulsifier free polymer colloid formation

A periodic modulation in the optical flux from Nova Cygni 1975 has been observed since shortly after outburst (Tempesti 1975) and the period is known to have varied by at least a few percent (Semeniuk et al. 1976). We account for the modulation in terms of a simple geometrical model in which the wind emanating from the nova is shadowed by its binary companion (see Fabian and Pringle 1977 for a fuller account). This produces an azimuthal variation in the radius of the surface of last scattering, RS, which an observer sees as a periodic modulation of the. continuum with period roughly equal to the orbital period. Variation of the observed period is accounted for in terms of variation of the size of RS.

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Experimental determination of the instrumental transparency function of texture goniometers

Journal of Applied Crystallography ◽

10.1107/s0021889800007251 ◽

2000 ◽

Vol 33 (4) ◽

pp. 1162-1174 ◽

Cited By ~ 8

Author(s):

K. Moras ◽

A. H. Fischer ◽

H. Klein ◽

H. J. Bunge

Keyword(s):

Pole Figure ◽

Silicon Crystal ◽

Window Size ◽

Geometrical Model ◽

Bragg Angle ◽

Rocking Curve ◽

Order Of Magnitude ◽

Simple Geometrical Model ◽

Position Sensitive Detectors

The instrumental transparency functions of five commercially available texture goniometers were measured experimentally with six monocrystalline samples cut in different orientations from a large highly perfect silicon crystal with a rocking curve of less than 0.01°. Transparency functions were measured in steps of 0.02 to 0.2° in the pole-figure angles α, β. The window size Δα depends on the Bragg angle θ in the form 1/sinθ; the window size Δω is constant for each goniometer. The dominant instrumental parameter determining the long axis Δα of the pole-figure window is the axial width of the detector entrance slit. This parameter is smallest for area detectors (smaller by more than an order of magnitude compared with conventional scintillation detectors as well as one-dimensional position-sensitive detectors). The main features of the pole-figure window and their dependence on the instrumental parameters can be deduced fairly well from a simple geometrical model. The particular shapes of the transparency functions of the studied goniometers are markedly different. Particularly, they are not very well represented by Gauss functions. The two-dimensional transparency function can be fairly well characterized by its α and β profiles. The normalized profiles are virtually independent of the goniometer angles 2θ and α. The increasing size of the pole-figure window with decreasing θ puts a lower limit on the Bragg angle below which pole-figure measurement ceases to be meaningful.

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Numerical Analysis of the Failure Processes of Plates Made of S 960 QC Steel

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.598.184 ◽

2014 ◽

Vol 598 ◽

pp. 184-189 ◽

Cited By ~ 1

Author(s):

Andrzej Neimitz ◽

Adrian Grzegorczyk

Keyword(s):

Numerical Analysis ◽

Maximum Principle ◽

Ductile Failure ◽

Geometrical Model ◽

Thin Plates ◽

Failure Plane ◽

The Maximum Principle ◽

Simple Geometrical Model

In the paper a simple geometrical model is proposed to explain the observation that in the certain thin plates made of steels the ductile failure plane is not inclined by 45 degrees to the plane of the maximum principle stress. This angle is smaller. The hypothesis was supported by results of the numerical observations.

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Spatial Reconstruction of Trajectories of an Array of Recording Microelectrodes

Journal of Neurophysiology ◽

10.1152/jn.00581.2004 ◽

2005 ◽

Vol 93 (4) ◽

pp. 2318-2330 ◽

Cited By ~ 20

Author(s):

Thomas Naselaris ◽

Hugo Merchant ◽

Bagrat Amirikian ◽

Apostolos P. Georgopoulos

Keyword(s):

Motor Cortex ◽

Coordinate Transformation ◽

Three Dimensional ◽

Geometrical Model ◽

Topographic Maps ◽

Dimensional Structure ◽

Recording Site ◽

Macaque Monkeys ◽

Spatial Reconstruction ◽

Simple Geometrical Model

We present a method for estimating the locations of sites visited by an array of microelectrodes. The method relies on visualization of tracks made by electrodes coated in a fluorescent dye. These tracks are used to estimate the parameters of a simple geometrical model that generates coordinates for each recording site. We describe several ways to measure the error of this procedure and present experimental results from recordings in the motor cortex of macaque monkeys that suggest that errors are of the order of 230 μm. We also introduce a coordinate transformation that takes into account the convoluted structure of the cortex near sulci to conveniently visualize recording site locations in a rectilinear representation. This method greatly extends the capabilities of microelectrodes for studying the three-dimensional structure of topographic maps in the cortex.

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Polarized Luminescence of Defects in CuGaSe2

MRS Proceedings ◽

10.1557/proc-1012-y13-01 ◽

2007 ◽

Vol 1012 ◽

Cited By ~ 1

Author(s):

Susanne Siebentritt ◽

Sven Augustin ◽

Niklas Papathanasiou ◽

Damon Hebert ◽

Angus Rockett ◽

...

Keyword(s):

Geometrical Model ◽

Direction Parallel ◽

Cubic Symmetry ◽

Metal Site ◽

Polarized Luminescence ◽

Simple Geometrical Model ◽

Shallow Acceptors ◽

Defects In Semiconductors ◽

Predominant Direction ◽

Linear Polarisation

AbstractThe linear polarisation of luminescence light allows conclusions on the symmetry of defects in semiconductors with non-cubic symmetry, like chalcopyrites, for which three shallow acceptors have been identified by photoluminescence. The polarisation dependent photoluminescence allows to determine the symmetry of the defects relative to the c-axis of the crystal. A simple geometrical model implies that chalcogen sites show a predominant direction perpendicular to the c-axis, while metal sites show a predominant direction parallel to the c-axis. Since all three shallow acceptors show polarization parallel to the c-axis, it can be concluded that they are situated on a metal site

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