Installation of McComb-Romberg tilt-compensation horizontal-component seismometers at the International Latitude Observatory, Ukiah, California*

1934 ◽  
Vol 24 (1) ◽  
pp. 69-71
Author(s):  
H. G. Wrocklage
Keyword(s):  
Horizontal Component

Galilean Relativity

2018 ◽  
Author(s):  
David M. Wittman
Keyword(s):  
Inertial Frame ◽  
Vertical Component ◽  
Horizontal Component ◽  
The Other ◽  
One Dimension ◽  
Everyday Experience ◽  
Low Speed ◽  
Principle Of Relativity ◽  
Galilean Relativity ◽  
Laws Of Motion

Galilean relativity is a useful description of nature at low speed. Galileo found that the vertical component of a projectile’s velocity evolves independently of its horizontal component. In a frame that moves horizontally along with the projectile, for example, the projectile appears to go straight up and down exactly as if it had been launched vertically. The laws of motion in one dimension are independent of any motion in the other dimensions. This leads to the idea that the laws of motion (and all other laws of physics) are equally valid in any inertial frame: the principle of relativity. This principle implies that no inertial frame can be considered “really stationary” or “really moving.” There is no absolute standard of velocity (contrast this with acceleration where Newton’s first law provides an absolute standard). We discuss some apparent counterexamples in everyday experience, and show how everyday experience can be misleading.

scholarly journals Harmonic Morphisms Projecting Harmonic Functions to Harmonic Functions

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
M. T. Mustafa
Keyword(s):  
Harmonic Function ◽  
Riemannian Manifolds ◽  
Harmonic Functions ◽  
Horizontal Component ◽  
Harmonic Morphisms

For Riemannian manifoldsMandN, admitting a submersionϕwith compact fibres, we introduce the projection of a function via its decomposition into horizontal and vertical components. By comparing the Laplacians onMandN, we determine conditions under which a harmonic function onU=ϕ−1(V)⊂Mprojects down, via its horizontal component, to a harmonic function onV⊂N.

An NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra

2008 ◽  
Vol 24 (1) ◽  
pp. 173-215 ◽  
Author(s):  
BrianS-J. Chiou ◽  
Robert R. Youngs
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Hanging Wall ◽  
Response Spectra ◽  
Horizontal Component ◽  
Smooth Functions ◽  
Soil Response ◽  
New Model ◽  
Crustal Earthquakes ◽  
Aleatory Variability

We present a model for estimating horizontal ground motion amplitudes caused by shallow crustal earthquakes occurring in active tectonic environments. The model provides predictive relationships for the orientation-independent average horizontal component of ground motions. Relationships are provided for peak acceleration, peak velocity, and 5-percent damped pseudo-spectral acceleration for spectral periods of 0.01 to 10 seconds. The model represents an update of the relationships developed by Sadigh et. al. (1997) and incorporates improved magnitude and distance scaling forms as well as hanging-wall effects. Site effects are represented by smooth functions of average shear wave velocity of the upper 30 m ( VS30) and sediment depth. The new model predicts median ground motion that is similar to Sadigh et. al. (1997) at short spectral period, but lower ground motions at longer periods. The new model produces slightly lower ground motions in the distance range of 10 to 50 km and larger ground motions at larger distances. The aleatory variability in ground motion amplitude was found to depend upon earthquake magnitude and on the degree of nonlinear soil response, For large magnitude earthquakes, the aleatory variability is larger than found by Sadigh et. al. (1997).

Peripheral representation of antennal orientation by the scapal hair plate of the cockroach Periplaneta americana

2001 ◽  
Vol 204 (24) ◽  
pp. 4301-4309 ◽  
Author(s):  
J. Okada ◽  
Y. Toh
Keyword(s):  
Single Unit ◽  
Periplaneta Americana ◽  
Vertical Component ◽  
Horizontal Component ◽  
Vertical Position ◽  
Horizontal Position ◽  
Joint Movement ◽  
Basal Segment ◽  
Dynamic Phase ◽  
Hair Sensilla

SUMMARY Arthropods have hair plates that are clusters of mechanosensitive hairs, usually positioned close to joints, which function as proprioceptors for joint movement. We investigated how angular movements of the antenna of the cockroach (Periplaneta americana) are coded by antennal hair plates. A particular hair plate on the basal segment of the antenna, the scapal hair plate, can be divided into three subgroups: dorsal, lateral and medial. The dorsal group is adapted to encode the vertical component of antennal direction, while the lateral and medial groups are specialized for encoding the horizontal component. Of the three subgroups of hair sensilla, those of the lateral scapal hair plate may provide the most reliable information about the horizontal position of the antenna, irrespective of its vertical position. Extracellular recordings from representative sensilla of each scapal hair plate subgroup revealed the form of the single-unit impulses in response to hair deflection. The mechanoreceptors were characterized as typically phasic-tonic. The tonic discharge was sustained indefinitely (>20 min) as long as the hair was kept deflected. The spike frequency in the transient (dynamic) phase was both velocity- and displacement-dependent, while that in the sustained (steady) phase was displacement-dependent.

A Discussion on recent research in air pollution - The influence of the turning of wind with height on crosswind diffusion

1969 ◽  
Vol 265 (1161) ◽  
pp. 173-181 ◽  
Keyword(s):  
Wind Profile ◽  
Field Experiments ◽  
Horizontal Component ◽  
Vertical Diffusion ◽  
Fluorescent Tracer ◽  
Ground Source ◽  
Stable Conditions ◽  
Realistic Form ◽  
Horizontal Spread ◽  
Elevated Source

Theoretical indications of the magnitude of horizontal spread resulting from the interaction between vertical diffusion and the wind profile are briefly reviewed. Assuming a fairly realistic form for the spectrum of turbulence the effect of this interaction is evaluated from a treatment by F. B. Smith, and this is combined with the theoretical growth arising directly from the horizontal component of turbulence to give a total crosswind growth curve. Two series of field experiments on dispersion in stable conditions are examined, one in Sweden using an elevated source of smoke puffs, the other in the U.S.A. using a continuous ground release of a fluorescent tracer. Both indicate that distortion of the plume by the turning of the wind became significant beyond 2-3 km downwind, but that the immediate transference of the effect to enhance the spread at a given level was not important within about 5 km for the elevated source or about 12 km for the ground source.

scholarly journals PHYSICAL REQUIREMENTS FOR A TAKEOFF IN SURFING

2017 ◽  
pp. 30
Author(s):  
Akihiko Kimura ◽  
Taro Kakinuma
Keyword(s):  
Wave Front ◽  
Time Variation ◽  
Wave Breaking ◽  
Horizontal Component ◽  
Breaking Point ◽  
Front Face ◽  
The Waves

The conditions required for a takeoff in surfing, are discussed, with the waves simulated numerically, considering two types of wave breaking, i.e., a plunging type, and a spilling type. First, a surfer is required to obtain a sufficient value for the horizontal component of paddling speed, not to be overtaken by a wave peak. Second, when the surfer stops paddling, he needs to be floating at a location where the force on him is downward, along the wave front face. On the basis of both conditions, the time variation of the required value for the horizontal component of paddling speed, is evaluated for both the plunging-type, and spilling-type, cases. When the paddling speed is sufficient, the surfable area is larger in the former case, than in the latter, on the offshore side of the wave-breaking point.

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