Solitary and shock waves in discrete double power-law materials

A novel strongly nonlinear laminar metamaterial supporting new types of solitary and shock waves with impact energy mitigating capabilities is presented. It consists of steel plates with intermittent polymer toroidal rings acting as strongly nonlinear springs with large allowable strain. Their force-displacement relationship is described by the addition of two power-law relationships resulting in a solitary wave speed and width depending on the amplitude. This double nonlinearity allows splitting of an initial impulse into two separate strongly nonlinear solitary wave trains. Solitary and shock waves are observed experimentally and analyzed numerically in an assembly with Teflon o-rings.Comment: 14 pages, 6 figure

The Constitutional Model of Mootness

Article III limits the federal courts to deciding cases and controversies, and this limitation has given rise to the black-letter law of standing, ripeness, and mootness. But the law of mootness presents a puzzle: Over time, the Court has recognized various exceptions to ordinary mootness rules, allowing federal courts to hear arguably moot cases. On one hand, the Court consistently asserts that mootness doctrine, including its exceptions, is compelled by the original understanding of Article III. On the other hand, the scholarly consensus is that these exceptions are logically inconsistent with the Court s claims about Article III and that their existence proves that mootness is fundamentally prudential, not constitutional. This Article seeks to provide a coherent justification for the mootness exceptions within the constitutional model. First, some exceptions are not really exceptions at all. Collateral consequences; voluntary cessation; and capable of repetition to the same plaintiff, yet evading review — these doctrines merely recognize a shift from a present harm to a potential future harm. And that harm might be sufficiently likely to occur when examined in the light of Bayes\u27 Theorem. Second, the other exceptions, for class actions, are justified through a better understanding of the history of representative litigation. And that understanding also justifies the extension of the capable of repetition, yet evading review exception to non parties who are similarly situated to the plaintiff. Modern mootness doctrine is therefore conceptually consistent with the Court s understanding of the original meaning of Article III

Crypto heater:a design fiction

This proposal is to exhibit the work named Crypto Heater which is part of a design fiction [c.f 1,5,8:30] series intended to explore a near future world in which cryptographic currencies such as Bitcoin [6] have become commonplace. This work opens up space for discussion about the activities of the distributed peer-to-peer network of so-called "miners" that ensure the security of the Bitcoin network and regulate the supply of new currency in the Bitcoin economy. The physical part of the work (the heater itself) is set within a fictional near-future reality. In this reality, Bitcoin has become central to our financial service industry, and "mining" in domestic settings is promoted by the government, as a means of heating our homes and to ensure security of the network. A "story world" is constructed using devices such as promotional materials from the UK Government's Ministry of Crypto Currency; technical specifications; customer testimonials; and the heater itself. The main element of the exhibit is a fully working Crypto Heater prototype. This device is (in the fictional world, and the real world) part of the distributed network of Bitcoin miners. Through computation, it converts electrical energy into cryptographic currency. Uniquely Crypto Heater dissipates the heat energy (a by-product of the computational effort required to be a Bitcoin miner) through a standard household radiator. By offsetting the value of the cryptographic currency produced, against the cost of electricity used, the heater provides subsidized domestic heating

Statistical multi-moment bifurcations in random delay coupled swarms

We study the effects of discrete, randomly distributed time delays on the dynamics of a coupled system of self-propelling particles. Bifurcation analysis on a mean field approximation of the system reveals that the system possesses patterns with certain universal characteristics that depend on distinguished moments of the time delay distribution. Specifically, we show both theoretically and numerically that although bifurcations of simple patterns, such as translations, change stability only as a function of the first moment of the time delay distribution, more complex patterns arising from Hopf bifurcations depend on all of the moments

Inducer dynamics full-flow, full-admission hydraulic turbine drive Interim report for tasks 1, 2, and 3

Hydrodynamical and mechanical design layout for two-speed hydraulic turbine inducer, computer simulation of pumping system and test facility performance, and study of demonstration uni

Hydraulic design of the M-1 liquid hydrogen turbopump

Hydraulic design of axial flow hydrogen turbopump for M-1 rocket engin