Simulation of a Dripping Faucet

We present a simulation of a dripping faucet system. A new algorithm based on Lagrangian description is introduced. The shape of drop falling from a faucet obtained by the present algorithm agrees quite well with experimental observations. Long-term behavior of the simulation can reproduce period-one, period-two, intermittent and chaotic oscillations widely observed in experiments. Possible routes to chaos are discussed.Comment: 20 pages, 15 figures, J. Phys. Soc. Jpn. (in press

The Two Fluid Drop Snap-off Problem: Experiments and Theory

We address the dynamics of a drop with viscosity $\lambda \eta$ breaking up inside another fluid of viscosity $\eta$. For $\lambda=1$, a scaling theory predicts the time evolution of the drop shape near the point of snap-off which is in excellent agreement with experiment and previous simulations of Lister and Stone. We also investigate the $\lambda$ dependence of the shape and breaking rate.Comment: 4 pages, 3 figure

Shuttle S-band communications technical concepts

Using the S-band communications system, shuttle orbiter can communicate directly with the Earth via the Ground Spaceflight Tracking and Data Network (GSTDN) or via the Tracking and Data Relay Satellite System (TDRSS). The S-band frequencies provide the primary links for direct Earth and TDRSS communications during all launch and entry/landing phases of shuttle missions. On orbit, S-band links are used when TDRSS Ku-band is not available, when conditions require orbiter attitudes unfavorable to Ku-band communications, or when the payload bay doors are closed. the S-band communications functional requirements, the orbiter hardware configuration, and the NASA S-band communications network are described. The requirements and implementation concepts which resulted in techniques for shuttle S-band hardware development discussed include: (1) digital voice delta modulation; (2) convolutional coding/Viterbi decoding; (3) critical modulation index for phase modulation using a Costas loop (phase-shift keying) receiver; (4) optimum digital data modulation parameters for continuous-wave frequency modulation; (5) intermodulation effects of subcarrier ranging and time-division multiplexing data channels; (6) radiofrequency coverage; and (7) despreading techniques under poor signal-to-noise conditions. Channel performance is reviewed

Transduction by Phi Bb-1, a Bacteriophage of Borrelia Burgdorferi

We previously described a bacteriophage of the Lyme disease agent Borrelia burgdorferi designated phi BB-1. This phage packages the host complement of the 32-kb circular plasmids (cp32s), a group of homologous molecules found throughout the genus Borrelia. To demonstrate the ability of phi BB-1 to package and transduce DNA, a kanamycin resistance cassette was inserted into a cloned fragment of phage DNA, and the resulting construct was transformed into B. burgdorferi CA-11.2A cells. The kan cassette recombined into a resident cp32 and was stably maintained. The cp32 containing the kan cassette was packaged by phi BB-1 released from this B. burgdorferi strain. phi BB-1 has been used to transduce this antibiotic resistance marker into naive CA-11.2A cells, as well as two other strains of B. burgdorferi. This is the first direct evidence of a mechanism for lateral gene transfer in B. burgdorferi

Poincar\'{e} cycle of a multibox Ehrenfest urn model with directed transport

We propose a generalized Ehrenfest urn model of many urns arranged periodically along a circle. The evolution of the urn model system is governed by a directed stochastic operation. Method for solving an $N$-ball, $M$-urn problem of this model is presented. The evolution of the system is studied in detail. We find that the average number of balls in a certain urn oscillates several times before it reaches a stationary value. This behavior seems to be a peculiar feature of this directed urn model. We also calculate the Poincar\'{e} cycle, i.e., the average time interval required for the system to return to its initial configuration. The result can be easily understood by counting the total number of all possible microstates of the system.Comment: 10 pages revtex file with 7 eps figure

Management of Technology Focused on the Water Analysis Results in Artesians Wells

The water is an universal soluble, fundamental to every living being. The main component to the human body and indispensable for any form of life, however, there is an increasing preocupation within the quality of their providers, which are the rivers, strands and springs, but as the time passes by are threatened by anthropogenic activities, main causer of the contamination and destruction of the local fauna and habitat. The principal objetictive of this research was to generate necessary information to further make use of this water, specifically located in Porto Velho, Rondônia, in Jamari\u27s River\u27s hidrographic basin sided with Green River\u27s, one affluent and one subfluent of Madeira\u27s River, which is one of the most important hidrographic basins of Amazon\u27s River, yet, lots of physical, chemicals and microbiological parameters were effected, like pH, turbidity, overall alkalinity, overall toughness, iron, chloride, color, fecal coliforms, that are capable of identify the contamination by anthropic action, obtaining the characteristics of the containing waters in the studied area, which in turn had favorable results, following the collected results we could confirm that all them were under acceptable and expectable parameters required by legislation in force of bathing, aquatic community preservation and human consumption, being the last one dependable of a simple threatment (chlorination)

Tests of Dynamical Scaling in 3-D Spinodal Decomposition

We simulate late-stage coarsening of a 3-D symmetric binary fluid. With reduced units l,t (with scales set by viscosity, density and surface tension) our data extends two decades in t beyond earlier work. Across at least four decades, our own and others' individual datasets (< 1 decade each) show viscous hydrodynamic scaling (l ~ a + b t), but b is not constant between runs as this scaling demands. This betrays either the unexpected intrusion of a discretization (or molecular) lengthscale, or an exceptionally slow crossover between viscous and inertial regimes.Comment: Submitted to Phys. Rev.

Attracting Manifold for a Viscous Topology Transition

An analytical method is developed describing the approach to a finite-time singularity associated with collapse of a narrow fluid layer in an unstable Hele-Shaw flow. Under the separation of time scales near a bifurcation point, a long-wavelength mode entrains higher-frequency modes, as described by a version of Hill's equation. In the slaved dynamics, the initial-value problem is solved explicitly, yielding the time and analytical structure of a singularity which is associated with the motion of zeroes in the complex plane. This suggests a general mechanism of singularity formation in this system.Comment: 4 pages, RevTeX, 3 ps figs included with text in uuencoded file, accepted in Phys. Rev. Let

Long-Lived Localized Field Configurations in Small Lattices: Application to Oscillons

Long-lived localized field configurations such as breathers, oscillons, or more complex objects naturally arise in the context of a wide range of nonlinear models in different numbers of spatial dimensions. We present a numerical method, which we call the {\it adiabatic damping method}, designed to study such configurations in small lattices. Using 3-dimensional oscillons in $\phi^4$ models as an example, we show that the method accurately (to a part in 10^5 or better) reproduces results obtained with static or dynamically expanding lattices, dramatically cutting down in integration time. We further present new results for 2-dimensional oscillons, whose lifetimes would be prohibitively long to study with conventional methods.Comment: LaTeX, 8 pages using RevTeX. 6 PostScript figures include