Elastic waves from a spherical source: Aperiodic solutions for Scholte's model

1964 ◽  
Vol 54 (3) ◽  
pp. 897-908
Author(s):  
Tomowo Hirasawa
Keyword(s):  
Time Variation ◽  
Elastic Waves ◽  
Step Function ◽  
Wave Form ◽  
Type I ◽  
Type Ii ◽  
Spherical Coordinates ◽  
Force System ◽  
Spherical Source ◽  
S Waves

Abstract The radiation patterns of P and S waves from a spherical cavity, in an infinite elastic medium on which the stress similar to a single couple force acts, were obtained by J. G. J. Scholte and A. R. Ritsema (1962). In this paper the solution for their model is presented in the case when a step function is assumed as the time variation of the stress. As a result, it is found that the wave form of S waves depends on θ in spherical coordinates (r, θ, ø). Generally speaking, the orbit of the particle motion of S waves is not linear. Also the radiation pattern of S waves is similar to that for Type II rather than for Type I force system.

Earthquake mechanism determination by S-wave data

1964 ◽  
Vol 54 (2) ◽  
pp. 457-474
Author(s):  
Anne E. Stevens
Keyword(s):  
Focal Mechanisms ◽  
Type I ◽  
Type Ii ◽  
S Wave ◽  
Force System ◽  
The Earth ◽  
The Family ◽  
Force Systems ◽  
Generalized Force ◽  
Earthquake Mechanism

ABSTRACT The nature of force systems at the foci of earthquakes can be studied by analyzing initial longitudinal (P) and transverse (S) displacements produced by them on the surface of the earth. The force system described in this paper results from a superposition of three mutually orthogonal double forces which act at a point focus. A family of equations is derived which depends only on S polarization angles and not on initial P displacements to determine the orientation of this generalized force system. An IBM 1620 computer has been programmed to solve the family of equations for two particular focal mechanisms—the single couple (Honda's Type I) and the double dipole (Honda's Type II). Two possible force systems are thus calculated for each earthquake using only S angles. The appropriate mechanism for each earthquake is selected by comparing the distribution of initial P displacements actually recorded, with that predicted from the solutions of the mechanism equations making use of S data. Computer solutions are presented for 32 earthquakes for which data are available in the literature. The orientation of the force system for each earthquake calculated from S data alone is in general agreement with that determined from P data.

Reflection and refraction of type-II S waves in elastic and anelastic media

1977 ◽  
Vol 67 (1) ◽  
pp. 43-67 ◽  
Author(s):  
Roger D. Borcherdt
Keyword(s):  
General Theory ◽  
Particle Motion ◽  
Plane Boundary ◽  
Type I ◽  
Type Ii ◽  
S Wave ◽  
S Waves ◽  
Reflection And Refraction ◽  
Linear Behavior ◽  
Inhomogeneous Plane

abstract The general theory of viscoelasticity, which accounts for elastic as well as anelastic linear behavior of materials, predicts that two types of S waves propagate in anelastic earth materials. The particle motion for an inhomogeneous plane S wave of type I is elliptical in the plane defined by the directions of propagation and attenuation, while the particle motion for an inhomogeneous plane S wave of type II is linear perpendicular to this plane. The general theory predicts that an S-wave incident upon a plane boundary perpendicular to the plane defined by the directions of propagation and attenuation generates S waves only of the same type. General characteristics of the type-II S waves reflected and refracted at plane anelastic boundaries are: The general theory predicts these characteristics for the waves whenever a plane type-II S wave interacts with a plane anelastic boundary such as a soil-bedrock, crust-mantle, or core-mantle interface. None of these characteristics are predicted for the plane SH waves described by elasticity theory.

Radiation mode of S waves from a deep-focus earthquake as derived from observations

1963 ◽  
Vol 53 (3) ◽  
pp. 643-659
Author(s):  
Keichi Kasahara
Keyword(s):  
Fault Plane ◽  
Analog Computer ◽  
P Wave ◽  
Wave Form ◽  
Type I ◽  
Radiation Mode ◽  
S Waves ◽  
Plane Solution ◽  
Earthquake Mechanism ◽  
Deep Focus

Abstract Two representative hypotheses on earthquake mechanism (so-called force types I and II) have been examined in comparison with seismograms for the earthquake of February 18, 1956 (south off Honshu, Japan; h = 450 km). On the basis of the fault-plane solution derived from P-wave data, one can predict polarity and relative amplitude of shear wave phases for a given station. The prediction by both of the hypotheses is compared with the observations at Kiruna and several other stations, where the principal seismic phases have been recorded clearly. The comparison has proved that the force type I does not fit the present case. The second type, on the other hand, explains the observations more consistently, although there are minor disagreements with respect to later phases. Reduction of the recorded wave form by an analog computer has shown that the original seismic disturbance (S) from the source is very simple in its wave form and harmonizes very well with Honda's theory. If we accept his theory, the radius of the origin sphere is estimated at 30-40 km for the present case.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

1987 ◽  
Vol 45 ◽  
pp. 792-793
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
M.E. Lidstrom ◽  
C.C. Remsen
Keyword(s):  
Cytoplasmic Membrane ◽  
Structural Features ◽  
Methylotrophic Bacteria ◽  
Type I ◽  
Type Ii ◽  
Membrane Complex ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Wall Structures ◽  
Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

OPTICAL STUDIES OF TYPE I AND TYPE II RECOMBINATION IN GaAs-AlAs QUANTUM WELLS

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-525-C5-528 ◽  
Author(s):  
K. J. MOORE ◽  
P. DAWSON ◽  
C. T. FOXON
Keyword(s):  
Quantum Wells ◽  
Type I ◽  
Type Ii ◽  
Optical Studies

An old friend is better than two new ones? Approaches to market research in the context of digital transformation for the antitrust laws enforcement

2020 ◽  
pp. 37-55 ◽  
Author(s):  
A. E. Shastitko ◽  
O. A. Markova
Keyword(s):  
Business Models ◽  
Rapid Development ◽  
Digital Transformation ◽  
Market Definition ◽  
Type I ◽  
Type Ii ◽  
Digital Platforms ◽  
Advantages And Disadvantages ◽  
Pass Through ◽  
Type Ii Errors

Digital transformation has led to changes in business models of traditional players in the existing markets. What is more, new entrants and new markets appeared, in particular platforms and multisided markets. The emergence and rapid development of platforms are caused primarily by the existence of so called indirect network externalities. Regarding to this, a question arises of whether the existing instruments of competition law enforcement and market analysis are still relevant when analyzing markets with digital platforms? This paper aims at discussing advantages and disadvantages of using various tools to define markets with platforms. In particular, we define the features of the SSNIP test when being applyed to markets with platforms. Furthermore, we analyze adjustment in tests for platform market definition in terms of possible type I and type II errors. All in all, it turns out that to reduce the likelihood of type I and type II errors while applying market definition technique to markets with platforms one should consider the type of platform analyzed: transaction platforms without pass-through and non-transaction matching platforms should be tackled as players in a multisided market, whereas non-transaction platforms should be analyzed as players in several interrelated markets. However, if the platform is allowed to adjust prices, there emerges additional challenge that the regulator and companies may manipulate the results of SSNIP test by applying different models of competition.

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