Showing papers by "California Institute of Technology published in 1972"
TL;DR: In this paper, Arrow has demonstrated that when externalities are present in a general equilibrium system, a suitable expansion of the commodity space would lead to Pareto optimality by bringing externalities under the control of the price system.
1,721 citations
TL;DR: In this paper, the isotopic composition of Pb and the elemental concentration of U, Th and Pb were measured on total rock samples 14053, 14073 and 14310.
927 citations
TL;DR: In this paper, separate wave equations with source terms are presented for electromagnetic and gravitational perturbations of an uncharged, rotating black hole, which describe the radiative field completely, and also part of the non-radiative field.
Abstract: Separable wave equations with source terms are presented for electromagnetic and gravitational perturbations of an uncharged, rotating black hole. These equations describe the radiative field completely, and also part of the nonradiative field. Nontrivial, source-free, stationary perturbations are shown not to exist. The barrier integral governing synchrotron radiation from particles in circular orbits is shown to be the same as for scalar radiation. Future applications (stability of rotating black holes, "spin-down," superradiant scattering, floating orbits) are outlined.
857 citations
Proceedings Article•
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TL;DR: In this paper, the main theoretical and experimental developments to date in Integrated Optics are reviewed, including material considerations, guiding mechanisms, modulation, coupling and mode losses, as well as the fabrication and applications of periodic thin film structures.
Abstract: In order to enable optical systems to operate with a high degree of compactness and reliability it is necessary to combine large number of optical functions in small monolithic structures. A development, somewhat reminiscent of that that took place in Integrated Electronics, is now beginning to take place in optics. The initial challenge in this emerging field, known appropriately as "Integrated Optics", is to demonstrate the possibility of performing basic optical functions such as light generation, coupling, modulation, and guiding in Integrated Optical configurations. The talk will review the main theoretical and experimental developments to date in Integrated Optics. Specific topics to be discussed include: Material considerations, guiding mechanisms, modulation, coupling and mode losses. The fabrication and applications of periodic thin film structures will be discussed.
786 citations
769 citations
TL;DR: In this article, it was shown that super-radiant scattering can also be used to extract rotational energy from a rotating hole, and that a particle radiatively extracts energy from the hole at the same rate as it radiates energy to infinity; thereby it experiences zero net radiation reaction.
Abstract: Penrose1 and Christodoulou2 have shown how, in principle, rotational energy can be extracted from a black hole by orbiting and fissioning particles. Recently, Misner3 has pointed out that waves can also extract rotational energy (“superradiant scattering” in which an impinging wave is amplified as it scatters off a rotating hole). As one application of super-radiant scattering, Misner has suggested the possible existence of “floating orbits”, that is, orbits in which a particle radiatively extracts energy from the hole at the same rate as it radiates energy to infinity; thereby it experiences zero net radiation reaction.
595 citations
TL;DR: In this article, ESHELBY deduced a surface-integral representation for the force on an elastic singularity or inhomogeneity, which gives rise to a conservation law for regular elastostatic fields appropriate to homogeneous but not necessarily isotropic solids in the presence of infinitesimal deformations.
Abstract: Several years ago ESHELBY [1] (1956), in a paper devoted to the continuum theory of lattice defects, deduced a surface-integral representation for the "force on an elastic singularity or inhomogeneity", which-in the absence of such
defects-gives rise to a conservation law for regular elastostatic fields appropriate to homogeneous but not necessarily isotropic solids in the presence of infinitesimal deformations. Morevoer, ESHIELBY noted that his result, when suitably interpreted, remains strictly valid for finite deformations of elastic solids.
583 citations
554 citations
TL;DR: In this article, the effect of rotary Brownian motion on the rheology of a dilute suspension of rigid spheroids in shear flow is considered for various limiting cases of the particle aspect ratio r and dimensionless shear rate γ/D.
Abstract: The effect of rotary Brownian motion on the rheology of a dilute suspension of rigid spheroids in shear flow is considered for various limiting cases of the particle aspect ratio r and dimensionless shear rate γ/D. As a preliminary the probability distribution function is calculated for the orientation of a single, axisymmetric particle in steady shear flow, assuming small particle Reynolds number. The result for the case of weak-shear flows, γ/D [Lt ] 1, has been known for many years. After briefly reviewing this limiting case, we present expressions for the case of strong shear where (r3 + r−3) [Lt ] γ/D, and for an intermediate regime relevant for extreme aspect ratios where 1 [Lt ] γ/D [Lt ] (r3 + r−3). The bulk stress is then calculated for these cases, as well as the case of nearly spherical particles r ∼ 1, which has not hitherto been discussed in detail. Various non-Newtonian features of the suspension rheology are discussed in terms of prior continuum mechanical and experimental results.
476 citations
TL;DR: In this paper, the authors analyzed the surface topography of the Pacoima Dam accelerogram, based on the semi-cylindrical canyon, for the two-dimensional scattering and diffraction of plane SH waves.
Abstract: The two-dimensional scattering and diffraction of plane SH waves by a semi-cylindrical canyon is analysed for a general angle of wave incidence The closed-form solution of the problem shows that the surface topography can have prominent effects on incident waves only when the wavelengths of incident motion are short compared to the radius of a canyon The surface amplification of displacement amplitudes around and in the canyon changes rapidly from one point to another, but the amplification is always less than 2 The over-all trends of amplification pattern are determined by two principal parameters: (1) γ, the angle of incidence of plane SH waves, and (2) η, the ratio of radius of the canyon to one-half wave length of incident waves The higher η leads to greater complexity of the pattern of surface displacement amplitudes characterized by more abrupt changes of amplification from one point to another, while γ mainly determines the over-all trends of displacement amplitudes For grazing and nearly grazing incidences, for example, a strong shadow zone is developed behind the canyon
The qualitative analysis of the topographic effects on the Pacoima Dam accelerogram,1 based on the semi-cylindrical canyon, suggests that this strong-motion record was not seriously affected by surface topography of the recording site
430 citations
TL;DR: In this paper, the physical phenomena which will ultimately limit MOS circuit miniaturization are considered and it is found that the minimum MOS transistor size is determined by gate oxide breakdown and drain-source punch-through.
Abstract: The physical phenomena which will ultimately limit MOS circuit miniaturization are considered. It is found that the minimum MOS transistor size is determined by gate oxide breakdown and drain-source punch-through. Other factors which limit device size are drain-substrate breakdown, drain ‘corner’ breakdown and substrate doping fluctuations. However these limitations are less severe than the oxide breakdown limitation mentioned above. Power dissipation and metal migration limit the frequency and/or packing density of fully dynamic and of complementary MOS circuits. In static non-complementary circuits, power dissipation is the principal limitation of the number of circuit functions per chip. The channel length of a minimum size MOS transistor is a factor of 10 smaller than that of the smallest present day devices. The tolerances required to manufacture such a transistor are compatible with electron beam masking techniques. It is thus possible to envision fully dynamic silicon chips with up to 10^7–10^8 MOS transistors per cm^2.
TL;DR: An in vitro reaction in which rhodopsin is phosphorylated by AT 32 p is found, which is stimulated by prior exposure of ROS membranes to light.
TL;DR: By making genetic mosaics and constructing embryonic “fate maps” it is possible to locate the anatomical site of abnormalities affecting behaviour.
Abstract: By making genetic mosaics and constructing embryonic “fate maps” it is possible to locate the anatomical site of abnormalities affecting behaviour.
TL;DR: In this article, the authors analyzed the evolution of scalar-field and gravitational-field perturbations using the Newman-Penrose tetrad formalism, and provided some technical details missing in the gravitational-perturbation analysis of Paper I.
Abstract: A nearly spherical star collapses through its gravitational radius. Nonspherical perturbations exist in its density, pressure, electromagnetic field, and gravitational field, and in other (hypothetical) zero-rest-mass, integer-spin fields coupled to sources in the stars. Paper I analyzed the evolution of scalar-field and gravitational-field perturbations. This paper treats fields of arbitrary integer spin and zero rest mass, using the Newman-Penrose tetrad formalism. The analysis of each multipole ($\mathrm{order}=l$) of each field ($\mathrm{spin}=s$) is reduced to the study of a two-dimensional wave equation, with a "curvature potential" that differs little from one field to another. The analysis of this wave equation for the scalar case ($s=0$) carries over completely to fields of arbitrary spin $s$. In particular, any radiatable multipole ($l\ensuremath{\ge}s$) gets radiated away completely in the late stages of collapse; if the multipole is static prior to the onset of collapse, it will die out as ${t}^{\ensuremath{-}(2l+2)}$ at late times. Nonradiatable multipoles ($lls$) are conserved. This paper also treats gravitational perturbations in the Newman-Penrose framework, and supplies some technical details missing in the gravitational-perturbation analysis of Paper I.
TL;DR: In this article, a method has been developed for calculating on a chemical element-by-element basis the contribution of various sources to the aerosol of a polluted atmosphere, and four major sources have been considered and their relative contributions estimated by employing certain trace elements characteristic of each source; sodium, aluminum, lead and vanadium were utilized for sea salt, soil, automobile emissions, and fuel oil fly ash, respectively.
TL;DR: In this article, the authors analyze various types of gradient composites and consider some of their properties, and review reported and potential applications of gradient composite materials and their potential applications for engineering applications.
TL;DR: In this article, the equatorial region between 30 deg N and 30 deg S latitude is depicted in four geologic sketch maps, and seventeen geologic units are defined on the basis of their textural characteristics.
TL;DR: It is concluded that the Wiener theory of nonlinear system identification was applied to a three-stage neuron chain in the catfish retina and can predict quantitatively, with reasonable accuracy, the nonlinear, dynamic behavior of the neuron chain.
Abstract: The Wiener theory of nonlinear system identification was applied to a three-stage neuron chain in the catfish retina in order to determine the functional relationship between the artificial polarization of the horizontal cell membrane potential and the resulting discharge of the ganglion cell. A mathematical model was obtained that can predict quantitatively, with reasonable accuracy, the nonlinear, dynamic behavior of the neuron chain. The applicability of the method is discussed. We conclude that this is a very powerful method in the analysis of information transfer in the central nervous system.
TL;DR: In this paper, the Kutta-Joukowski lift force, the momentum flux due to the axial motion, and the tension of the vortex lines were used to obtain results for vortices of non-uniform structure and displacements which are not necessarily small compared with the core radius.
Abstract: Infinitesimal waves on a uniform vortex with axial flow are studied The equation for the frequency of helical waves is obtained, and solved for the case of long waves which leave the internal structure almost unaltered A method is developed to obtain results for vortices of non-uniform structure and for displacements which are not necessarily small compared with the core radius The approach consists of balancing the Kutta—Joukowski lift force, the momentum flux due to the axial motion, and the ‘tension’ of the vortex lines A general equation for the motion of a vortex filament is obtained, valid for arbitrary shape and internal structure, and in the presence of an external irrotational velocity field When the axial flow vanishes, the method is equivalent to using the Biot—Savart law for the self-induced velocity, with a suitable cutoff The impulse of a vortex filament is discussed and its rate of change is given
TL;DR: In this article, the authors explored the nature of certain special classes of solutions to the equation of coagulation for the case of Knudsen aerosols and showed that self-preserving solutions may exist.
TL;DR: In this paper, it is suggested that the anomalous properties of the moon, such as its enrichment in Ca, Al, Ti, and other refractories and its depletion in iron and volatiles can be explained if the bulk of the Moon represents a high temperature condensate.
Abstract: Recent studies of the dynamics and thermodynamics of the early solar nebula have provided a basis for a theory of the origin of the moon which is consistent with presently developed views of the origin of the solar system. The hypothesis of inhomogeneous planetary accretion is extended. It is suggested that the anomalous properties of the moon, such as its enrichment in Ca, Al, Ti, and other refractories and its depletion in iron and volatiles can be explained if the bulk of the moon represents a high temperature condensate. It is proposed that the moon is composed chiefly of compounds that condense before iron and that the volatile content of the moon was brought in as a thin veneer after the solar nebula dissipated.
TL;DR: This paper establishes the possibility of performing certain transformations of triangulations of finite planar point sets by means of the convolution of ellipsoidal brackets.
TL;DR: In this article, the elastic properties of NaCl have been measured ultrasonically as a function of pressure and temperature, from 0 to 8 kbar and from 300 to 800°K.
TL;DR: In this paper, the authors presented numerical quantum mechanical scattering calculations for the collinear H+H2 reaction on a realistic potential energy surface with an 0.424 eV (9.8 kcal) potential energy barrier.
Abstract: We present numerical quantum mechanical scattering calculations for the collinear H+H2 reaction on a realistic potential energy surface with an 0.424 eV (9.8 kcal) potential energy barrier. The reaction probabilities and rate constants are believed to be accurate to within 2% or better. The calculations are used to test the approximate theories of chemical dynamics. The reaction probabilities for ground vibrational state reagents agree well with the vibrationally adiabatic theory for energies below the lowest threshold for vibrational excitation, except when the reaction probability is less than about 0.1. For these low reaction probabilities no simple one-mathematical dimensional theory gives accurate results. These low reaction probabilities occur at low energy and are important for thermal reactions at low temperatures. Thus, transition state theory is very inaccurate at these low temperatures. However, it is accurate within 40% in the higher temperature range 450–1250°K. The reaction probabilities for hot atom collisions of ground vibrational state reagents with translational energies in the range 0.58 to 0.95 eV agree qualitatively with the predictions of the statistical phase space theory. For vibrationally excited reagents the vibrational adiabatic theory is not accurate as for ground vibrational state reagents. The lowest translational energy of vibrationally excited reagents above which statistical behavior manifests itself is less than 1.0 eV.
TL;DR: Patients with partial commissurotomy showed less improvement after nearly 500 trials of training, and performed at a consistently inferior level in terms of both quality and speed, suggesting a control mechanism involving direct interhemispheric interaction of motor corollary outflow was eliminated.
TL;DR: This article describes a technique for studying the detailed morphology of the central nervous system of a simple animal and its applications in medicine and science.
Abstract: This article describes a technique for studying the detailed morphology of the central nervous system of a simple animal.
TL;DR: In this article, the authors present a structured representation of multiprogramming in a high level language, which explicitly associates a data structure shared by concurrent processes with operations defined on it and permits a large class of time-dependent errors to be caught at compile time.
Abstract: This paper presents a proposal for structured representation of multiprogramming in a high level language. The notation used explicitly associates a data structure shared by concurrent processes with operations defined on it. This clarifies the meaning of programs and permits a large class of time-dependent errors to be caught at compile time. A combination of critical regions and event variables enables the programmer to control scheduling of resources among competing processes to any degree desired. These concepts are sufficiently safe to use not only within operating systems but also within user programs.
TL;DR: The kinds, numbers, and distribution of soil microorganisms in the valleys are investigated in order to gain insight into the practical problems of searching for life in an extreme environment and as they apply to martian exploration.
Abstract: The dry valleys of South Victoria Land, Antarctica, together with a few other ice-free areas on the perimeter
of the Antarctic continent, form what is generally considered to be the most extreme cold-desert region of the earth. During the past S years, we have been interested in the dry valleys as a model environment for investigating questions connected with the biological exploration
o£ Mars. The extraordinary aridity of the region, its low temperature, and its geographical isolation give it a quasimartian character, although it is to be
understood that the actual martian environment is still more hostile than that of the valleys. With our associates, we have investigated the kinds, numbers, and distribution of soil microorganisms in the valleys in order to gain insight into the practical problems of searching for life in an extreme environment. Detailed results of these studies have been published by Cameron and co-workers (1-5). In this-article, we review the major findings of our own and of other groups of investigators in this region,
especially as they apply to martian exploration.