Dust from collisions: mid-infrared absorbance spectroscopy of Martian meteorites

Mid-infrared transmission/absorbance spectra of a representative range of martian meteorites are presented. The data is used for mineralogical bulk studies, but also for the comparison with astronomical dust spectra

A digital interface for Gaussian relay networks: lifting codes from the discrete superposition model to Gaussian relay networks

For every Gaussian relay network with a single source-destination pair, it is known that there exists a corresponding deterministic network called the discrete superposition network that approximates its capacity uniformly over all SNR's to within a bounded number of bits. The next step in this program of rigorous approximation is to determine whether coding schemes for discrete superposition models can be lifted to Gaussian relay networks with a bounded rate loss independent of SNR. We establish precisely this property and show that the superposition model can thus serve as a strong surrogate for designing codes for Gaussian relay networks. We show that a code for a Gaussian relay network, with a single source-destination pair and multiple relay nodes, can be designed from any code for the corresponding discrete superposition network simply by pruning it. In comparison to the rate of the discrete superposition network's code, the rate of the Gaussian network's code only reduces at most by a constant that is a function only of the number of nodes in the network and independent of channel gains. This result is also applicable for coding schemes for MIMO Gaussian relay networks, with the reduction depending additionally on the number of antennas. Hence, the discrete superposition model can serve as a digital interface for operating Gaussian relay networks.Comment: 5 pages, 2010 IEEE Information Theory Workshop, Cair

Universal patterns of inequality

Probability distributions of money, income, and energy consumption per capita are studied for ensembles of economic agents. The principle of entropy maximization for partitioning of a limited resource gives exponential distributions for the investigated variables. A non-equilibrium difference of money temperatures between different systems generates net fluxes of money and population. To describe income distribution, a stochastic process with additive and multiplicative components is introduced. The resultant distribution interpolates between exponential at the low end and power law at the high end, in agreement with the empirical data for USA. We show that the increase of income inequality in USA originates primarily from the increase of the income fraction going to the upper tail, which now exceeds 20% of the total income. Analyzing the data from the World Resources Institute, we find that the distribution of energy consumption per capita around the world can be approximately described by the exponential function. Comparing the data for 1990, 2000, and 2005, we discuss the effect of globalization on the inequality of energy consumption.Comment: Accepted to New Journal of Physics. 27 pages (IOP preprint style), 8 figures. V.2: Updated figs. 3 and 8, many references added, all text edited. V.3: Minor changes, last 3 references added. V.4: Minor stylistic changes and reference updates in proof

Estimation of energy and material use of sintering-based construction for a lunar outpost - with the example of SinterHab module design

In this paper, we would revisit the usability of microwave for lunar regolith sintering through an in-depth experiment, and examine the minimum materials and energy required for sintering based on the SinterHab design. This will include the minimum layers to print, estimated printing time, minimum energy required for the sintering process and the potential energy sources

Fe isotopic composition of Martian meteorites and some terrestrial analogues

We report Fe isotopic composition of seven martian meteorites and other terrestrial materials that may be considered Martian analogues

Fe isotopic composition of Martian meteorites

In the present work, we have measured iron isotope compositions of a group of Martian meteorites to establish a baseline Fe-isotope fractionation pattern in the case of high-temperature igneous rocks from Mars