Nixie tube display unit employs time-shared logic

Cathodes of display tubes wired in parallel achieve input switching simplification of a Nixie tube display system. Use of time- shared logic energizes the appropriate anode and inhibits all unnecessary cathodes

An Exposition of Augustine\u27s Theodicy: From Its Influences to Its Modern Application

This paper delineates the thrust of Augustine\u27s theodicy against the broader background of his Christian Neoplatonic outlook. We examine Augustine\u27s initial Manichean influences and see how these beliefs carry over to his mature thought, which is evident in the seventh book of the Confessions. After Augustine\u27s time with the Manicheans, we look at how he was so influenced by the books of the Platonists (libri platonicorum). Although Augustine\u27s position regarding the problem of evil shifts, his idea of the primacy of the soul is still evident in his thought process. To wit, Augustine posits that evil must be considered a privation of the Good, so much so as to reach the point of complete nonentity. Human beings\u27 ability to be corrupted by evils rests in their position as being created ex-nihilo by God. With this creation also comes an inherent mutability. Due to human mutability, Augustine believes that God is not responsible for such evil actions. This paper also contrasts this belief with modern empiricist David Hume\u27s idea regarding God\u27s responsibility for human actions. Hume argues that the volition of all human actions rests in God as Creator of the world. As creator, Hume claims that God places human beings in a position to act. If humans are predisposed to perform evil actions, they cannot be faulted. Augustine would counter that argument by claiming that evil is not a substance. Not being a substance, evil is there not ascribable to God. Ultimately, Augustine\u27s theodicy is based upon the goodness of God

High-speed digital plotter

Modified typewriter mechanism with standard logic components provides digital plot of output of multichannel analyzer. Unit plots irregular curves at approximately 14 channels per second, and smooth curves at over 25 channels per second, and is not subject to analog error or drift

Beyond the Margins: Identity Fragmentation in Visual Representation in Michel Tournier’s La Goutte d’or

In Tournier’s novel, the goutte d’or also corresponds to a symbolic object: a Berber jewel. It is the jewel that Idriss brings with him, but which he also subsequently loses upon his arrival in Marseille. From the very moment that the French tourist photographs him, a marginalization of Idriss’s identity occurs. Marginality, quite literally, refers to the spatial property of a location in which something is situated. Figuratively speaking, marginality suggests something that is on the edges or at the outer limits of social acceptability. In this essay, I explore the construction of the marginalized postcolonial self (the “Other”) through an examination of the function of visual representation in the development of a postcolonial identity in La Goutte d’or. In the end, I conclude that the construction of a postcolonial identity is based upon fragmentation and marginalization, which ultimately leads its subject to create an identity based upon false constructions

Swarm behavior of self-propelled rods and swimming flagella

Systems of self-propelled particles are known for their tendency to aggregate and to display swarm behavior. We investigate two model systems, self-propelled rods interacting via volume exclusion, and sinusoidally-beating flagella embedded in a fluid with hydrodynamic interactions. In the flagella system, beating frequencies are Gaussian distributed with a non-zero average. These systems are studied by Brownian-dynamics simulations and by mesoscale hydrodynamics simulations, respectively. The clustering behavior is analyzed as the particle density and the environmental or internal noise are varied. By distinguishing three types of cluster-size probability density functions, we obtain a phase diagram of different swarm behaviors. The properties of clusters, such as their configuration, lifetime and average size are analyzed. We find that the swarm behavior of the two systems, characterized by several effective power laws, is very similar. However, a more careful analysis reveals several differences. Clusters of self-propelled rods form due to partially blocked forward motion, and are therefore typically wedge-shaped. At higher rod density and low noise, a giant mobile cluster appears, in which most rods are mostly oriented towards the center. In contrast, flagella become hydrodynamically synchronized and attract each other; their clusters are therefore more elongated. Furthermore, the lifetime of flagella clusters decays more quickly with cluster size than of rod clusters

Gravitational instantons, extra dimensions and form fields

A broad class of higher dimensional instanton solutions are found for a theory which contains gravity, a scalar field and antisymmetric tensor fields of arbitrary rank. The metric used, a warp product of an arbitrary number of any compact Einstein manifolds, includes many of great interest in particle physics and cosmology. For example 4D FRW universes with additional dimensions compactified on a Calabi-Yau three fold, a torus, a compact hyperbolic manifold or a sphere are all included. It is shown that the solution of this form which dominates the Hartle Hawking path integral is always a higher dimensional generalisation of a Hawking Turok instanton when the potential of the scalar field is such that these instantons can exist. On continuation to Lorentzian signature such instantons give rise to a spacetime in which all of the spatial dimensions are of equal size and where the spatial topology is that of a sphere. The extra dimensions are thus not hidden. In the case where the potential for the scalar field is generated solely by a dilatonic coupling to the form fields we find no integrable instantons at all. In particular we find no integrable solutions of the type under consideration for the supergravity theories which are the low energy effective field theories of superstrings.Comment: 11 pages, 4 figure

Fluid-Induced Propulsion of Rigid Particles in Wormlike Micellar Solutions

In the absence of inertia, a reciprocal swimmer achieves no net motion in a viscous Newtonian fluid. Here, we investigate the ability of a reciprocally actuated particle to translate through a complex fluid that possesses a network using tracking methods and birefringence imaging. A geometrically polar particle, a rod with a bead on one end, is reciprocally rotated using magnetic fields. The particle is immersed in a wormlike micellar (WLM) solution that is known to be susceptible to the formation of shear bands and other localized structures due to shear-induced remodeling of its microstructure. Results show that the nonlinearities present in this WLM solution break time-reversal symmetry under certain conditions, and enable propulsion of an artificial "swimmer." We find three regimes dependent on the Deborah number (De): net motion towards the bead-end of the particle at low De, net motion towards the rod-end of the particle at intermediate De, and no appreciable propulsion at high De. At low De, where the particle time-scale is longer then the fluid relaxation time, we believe that propulsion is caused by an imbalance in the fluid first normal stress differences between the two ends of the particle (bead and rod). At De~1, however, we observe the emergence of a region of network anisotropy near the rod using birefringence imaging. This anisotropy suggests alignment of the micellar network, which is "locked in" due to the shorter time-scale of the particle relative to the fluid

Source Reconstruction as an Inverse Problem

Inverse Problem techniques offer powerful tools which deal naturally with marginal data and asymmetric or strongly smoothing kernels, in cases where parameter-fitting methods may be used only with some caution. Although they are typically subject to some bias, they can invert data without requiring one to assume a particular model for the source. The Backus-Gilbert method in particular concentrates on the tradeoff between resolution and stability, and allows one to select an optimal compromise between them. We use these tools to analyse the problem of reconstructing features of the source star in a microlensing event, show that it should be possible to obtain useful information about the star with reasonably obtainable data, and note that the quality of the reconstruction is more sensitive to the number of data points than to the quality of individual ones.Comment: 8 pages, 3 figures. To be published in "Microlensing 2000, A New Era of Microlensing Astrophysics", eds., J.W. Menzies and P.D. Sackett, ASP Conference Serie