Radiant-interchange configuration factors between various selected plane surfaces

doi:10.1098/rspa.1966.0118

Radiant-interchange configuration factors between various selected plane surfaces

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1966.0118 ◽

1966 ◽

Vol 292 (1428) ◽

pp. 51-60 ◽

Cited By ~ 21

Keyword(s):

Diffuse Radiation ◽

Honeycomb Structure ◽

Regular Polygons ◽

Arbitrary Angle ◽

Convex Polygons ◽

Common Edge ◽

Separate Table

The radiant-interchange configuration factor F1-2 (later referred to simply as ‘factor’) is defined as the fraction of the energy leaving an isothermal area Ax that is incident upon another area A 2. The validity of Lambert’s law of diffuse radiation is assumed. The calculation of such factors in the case of two rectangles having a common edge and forming an arbitrary angle is discussed, and a table of calculated values is presented. It is shown how the factors for two parallel, convex polygons, forming the bases of a right prism , can be derived from the results obtained for the rectangles. Values of such factors for a number of regular polygons are tabulated . A separate table gives factors for the honeycomb structure, much used in aviation and aerospace. The importance of much greater accuracy in the calculations than is generally thought necessary is shown by an example.

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Regular Two-Dimensional Packing of Congruent Objects: Cognitive Analysis of Honeycomb Constructions

Applied Sciences ◽

10.3390/app11115128 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5128

Author(s):

Nikolay N. Klevanskiy ◽

Sergey I. Tkachev ◽

Ludmila A. Voloshchuk ◽

Rouslan B. Nourgaziev ◽

Vladimir S. Mavzovin

Keyword(s):

Cognitive Processes ◽

Honeycomb Structure ◽

Two Dimensional ◽

Coordinate Systems ◽

Convex Polygons ◽

New Approach ◽

Covering Density ◽

Regular Packing ◽

Geometric Objects ◽

Cognitive Visualization

A new approach to investigate the two-dimensional, regular packing of arbitrary geometric objects (GOs),using cognitive visualization, is presented. GOs correspond to congruent non-convex polygons with their associated coordinate system. The origins of these coordinate systems are accepted by object poles. The approach considered is based on cognitive processes that are forms of heuristic judgments. According to the first heuristic judgment, regular packing of congruent GOs on the plane have a honeycomb structure, that is, each GO contacts six neighboring GO, the poles of which are vertices of the pole hexagon in the honeycomb construction of packing. Based on the visualization of the honeycomb constructions a second heuristic judgment is obtained, according to which inside the hexagon of the poles, there are fragments of three GOs. The consequence is a third heuristic judgment on the plane covering density with regular packings of congruent GOs. With the help of cognitive visualization, it is established that inside the hexagon of poles there are fragments of exactly three objects. The fourth heuristic judgment is related to the proposal of a triple lattice packing for regular packing of congruent GOs.

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The Sun as a Magnetic Star

International Astronomical Union Colloquium ◽

10.1017/s0252921100080775 ◽

1976 ◽

Vol 32 ◽

pp. 457-463

Author(s):

John M. Wilcox ◽

Leif Svalgaard

Keyword(s):

Recent Work ◽

Rotation Axis ◽

Polar Field ◽

Magnetic Star ◽

Rotational Axis ◽

Field Variation ◽

The Sun ◽

Arbitrary Angle ◽

Solar Magnetism ◽

Oblique Rotator

SummaryThe sun as a magnetic star is described on the basis of recent work on solar magnetism. Observations at an arbitrary angle to the rotation axis would show a 22-year polar field variation and a 25-day equatorial sector variation. The sector variation would be similar to an oblique rotator with an angle of 90° between the magnetic and rotational axis.

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Morphologic alteration in the muscles of patients with hypokalemic periodic paralysis or myopathy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158650 ◽

1990 ◽

Vol 48 (3) ◽

pp. 222-223

Author(s):

T. Shimizu ◽

Y. Muranaka ◽

I. Ohta ◽

N. Honda

Keyword(s):

Clinical Manifestations ◽

Quadriceps Muscle ◽

Honeycomb Structure ◽

Periodic Paralysis ◽

Ultrastructural Changes ◽

Hypokalemic Periodic Paralysis ◽

Electron Microscopic ◽

Tubular Aggregates ◽

Hypokalemic Myopathy ◽

Transmission Electron

There have been many reports on ultrastructural alterations in muscles of hypokalemic periodic paralysis (hpp) and hypokalemic myopathy(hm). It is stressed in those reports that tubular structures such as tubular aggregates are usually to be found in hpp as a characteristic feature, but not in hm. We analyzed the histological differences between hpp and hm, comparing their clinical manifestations and morphologic changes in muscles. Materials analyzed were biopsied muscles from 18 patients which showed muscular symptoms due to hypokalemia. The muscle specimens were obtained by means of biopsy from quadriceps muscle and fixed with 2% glutaraldehyde (pH 7.4) and analyzed by ordinary method and modified Golgimethod. The ultrathin section were examined in JEOL 200CX transmission electron microscopy.Electron microscopic examinations disclosed dilated t-system and terminal cistern of sarcoplasmic reticulum (SR)(Fig 1), and an unique structure like “sixad” was occasionally observed in some specimens (Fig 2). Tubular aggregates (Fig 3) and honeycomb structure (Fig 4) were also common characteristic structures in all cases. These ultrastructural changes were common in both the hypokalemic periodic paralysis and the hypokalemic myopathy, regardless of the time of biopsy or the duration of hypokalemia suffered.

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