Comparative analysis of battery electric, hydrogen fuel cell and hybrid vehicles in a future sustainable road transport system

Accepted versio

The Mathematical Universe

I explore physics implications of the External Reality Hypothesis (ERH) that there exists an external physical reality completely independent of us humans. I argue that with a sufficiently broad definition of mathematics, it implies the Mathematical Universe Hypothesis (MUH) that our physical world is an abstract mathematical structure. I discuss various implications of the ERH and MUH, ranging from standard physics topics like symmetries, irreducible representations, units, free parameters, randomness and initial conditions to broader issues like consciousness, parallel universes and Godel incompleteness. I hypothesize that only computable and decidable (in Godel's sense) structures exist, which alleviates the cosmological measure problem and help explain why our physical laws appear so simple. I also comment on the intimate relation between mathematical structures, computations, simulations and physical systems.Comment: Replaced to match accepted Found. Phys. version, 31 pages, 5 figs; more details at http://space.mit.edu/home/tegmark/toe.htm

Combustion Measurements of Synthetic Fuels at Gas Turbine Conditions

Synthetic fuels are of interest as a replacement for aviation, diesel, and other petroleum-based fuels, and the present paper outlines a joint project to study the combustion behavior of Fischer-Tropsch (FT) synthetic fuels. To this end, shock-tube kinetics, shock-tube spray, and high-recirculation combustion rig experiments are being utilized to study the ignition delay times, chemical kinetics, and the formation of soot and emissions of FT jet fuels. The conditions for the present ignition delay times and CH* profiles ranged from 1391 to 1680 K with an average pressure of 2 atm and equivalence ratio of 1, highly diluted in argon. Undiluted experiments were conducted using a recently developed heterogeneous technique wherein the fuel is sprayed directly into the test region of a shock tube. The high recirculation combustion rig is a complete gas turbine where syntroleum was combusted and soot formation and particulates measured. Reduction of soot and emissions was observed, agreeing with previous investigations

A test-theoretic approach to observed-score equating

observed-score equating, equipercentile method, equating criteria, multidimensionality,