scholarly journals On the Relationship between the Pure Delay and the Natural Period of Oscillation

2016 ◽  
Vol 07 (06) ◽  
pp. 504-507
Author(s):  
Daniel Chuk ◽  
Gustavo Rodriguez Medina
Keyword(s):  
Natural Period ◽  
Pure Delay ◽  
The Relationship ◽  
Period Of Oscillation

The Effect of Magnetic Field Strength on the Oscillatory Characteristics of Multimode Magnetoconvection

1993 ◽  
Vol 10 (4) ◽  
pp. 275-277
Author(s):  
J.O. Murphy ◽  
J.M. Lopez ◽  
C.P. Dyt
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
The Relationship ◽  
The Magnetic Field ◽  
Period Of Oscillation

AbstractThe effect of varying magnetic field strength on the frequency of oscillatory motions for cellular multimode magnetoconvection has been investigated. In addition the influence of the thermal, viscous and magnetic diffusivities have been taken into account and the range of preferred horizontal scales established. The relationship between the period of oscillation and the magnetic field strength is determined.

scholarly journals FENDER SELECTION CRITERIA

1988 ◽  
Vol 1 (21) ◽  
pp. 220
Author(s):  
F. Vasco Costa
Keyword(s):  
Selection Criteria ◽  
Natural Period ◽  
Loading And Unloading ◽  
Period Of Oscillation

Fenders are to be selected taking into account two quite distinct functions they have to fulfill: - During berthing manoeuvres fenders have to avoid damage to the ship and to the berthing structure; - After ships are already berthed and moored, fenders have to keep them quiet during loading and unloading operations. To fulfill the first function fenders have to be able, while deflecing, to absorb a very large amount of energy. To fulfill the second function fenders need to be able, while recovering their form, to dissipate a large amount of energy. Besides, they have to contribute to reduce or to increase the natural period of oscillation of already moored ships, depending on their tendency to oscillate in phase or out of phase with waves reaching the berths.

Cellular atmospheric waves in the ionosphere and troposphere

1950 ◽  
Vol 201 (1065) ◽  
pp. 216-234 ◽  
Keyword(s):  
Magnetic Field ◽  
Vertical Component ◽  
Temperature Gradients ◽  
Vertical Shear ◽  
Small Element ◽  
Natural Period ◽  
Specific Heats ◽  
A Value ◽  
Electron Clouds ◽  
Period Of Oscillation

Consideration of horizontally travelling disturbances of electron densities in the F 2 region of the ionosphere suggests that they are identical with the supposed vertically travelling disturbances discovered by Wells, Watts & George (1946). They appear to be due to horizontally travelling atmospheric cellular waves of the type first investigated by Lamb. The theory of such waves is developed to include wind with linear vertical shear, special attention being paid to the conditions of bounding by temperature gradients. It is found that such waves appear to be the cause of the microbarometric oscillations long known in the troposphere. The theory of these is worked out in some detail, and an explanation found for Johnson’s discovery that these oscillations have periods agreeing closely with B runt’s natural period of oscillation of a small element of atmosphere. In the ionosphere, the earth’s magnetic field profoundly affects the observed motions of ionization in the F 2 region, leading to a height gradient in the phase of these oscillatory motions. This gradient makes horizontally travelling disturbances appear to have a vertical component of motion, thus simulating vertically moving electron clouds. The bounding conditions for these cells in the F 2 region appear to necessitate a value for γ, the ratio of specific heats of air, considerably less than 1.4.

scholarly journals Bioelectric Oscillations of Bean Roots: Further Evidence For a Feedback Oscillator I. Extracellular Response to Oscillations in Osmotic Pressure and Auxin

1961 ◽  
Vol 14 (2) ◽  
pp. 231 ◽  
Author(s):  
IS Jenkinson ◽  
BIH Scott
Keyword(s):  
Theoretical Model ◽  
Osmotic Pressure ◽  
Feedback Loop ◽  
Physiological Model ◽  
Natural Period ◽  
Bathing Medium ◽  
Auxin Concentration ◽  
Weakly Conducting ◽  
Period Of Oscillation ◽  
Bioelectric Fields

Bean roots subjected to oscillations in osmotic pressure or in the auxin concentration of their weakly conducting bathing medium exhibit corresponding oscillations in their bioelectric fields with a resonance at the natural period of oscillation (approx. 5 min). The amplitude and phase responses, expressed as a function of the periods of the applied oscillations, are in agreement with those predicted from a theoretical model of a feedback loop. A physiological model compatible with the theoretical one is suggested.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Tinkering with cognitive gadgets: Cultural evolutionary psychology meets active inference

2019 ◽  
Vol 42 ◽  
Author(s):  
Paul Benjamin Badcock ◽  
Axel Constant ◽  
Maxwell James Désormeau Ramstead
Keyword(s):  
Evolutionary Psychology ◽  
Research Program ◽  
Active Inference ◽  
Innovative Research ◽  
Cognitive Faculties ◽  
Cultural Evolutionary ◽  
The Relationship

Abstract Cognitive Gadgets offers a new, convincing perspective on the origins of our distinctive cognitive faculties, coupled with a clear, innovative research program. Although we broadly endorse Heyes’ ideas, we raise some concerns about her characterisation of evolutionary psychology and the relationship between biology and culture, before discussing the potential fruits of examining cognitive gadgets through the lens of active inference.

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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