Numerical analysis of a downsized 2-stroke uniflow engine

In order to optimize the 2-stroke uniflow engine performance on vehicle applications, numerical analysis has been introduced, 3D CFD model has been built for the optimization of intake charge organization. The scavenging process was investigated and the intake port design details were improved. Then the output data from 3D CFD calculation were applied to a 1D engine model to process the analysis on engine performance. The boost system optimization of the engine has been carried out also. Furthermore, a vehicle model was also set up to investigate the engine in-vehicle performance

Sex and outcrossing in a sessile freshwater invertebrate

SUMMARY1. The freshwater bryozoan Cristatella mucedo, in common with other sessile, benthic freshwater taxa, has an unusual life history: sex occurs during a relatively brief period near the start of the growing season, and overwintering occurs in the form of asexually produced dormant propagules (statoblasts). Consistent observed heterozygosity (Ho) deficits in C. mucedo populations have previously suggested that inbreeding is common, although a possible contribution of a Wahlund effect to low Ho could not be discounted. 2. We have used microsatellite data in the first study based on codominant markers to genetically characterise maternal colonies and larval offspring of C. mucedo. The 'population' represented by the larvae was in Hardy–Weinberg equilibrium, which has previously been found in only one of 39 populations of C. mucedo. At least 64% of larvae were the products of outcrossing. We suggest that the unusual early timing of sex may be a strategy to maximise rates of outcrossing within populations of sessile freshwater invertebrate

Induced Ge Spin Polarization at the Fe/Ge Interface

We report direct experimental evidence showing induced magnetic moments on Ge at the interface in an Fe/Ge system. Details of the x-ray magnetic circular dichroism and resonant magnetic scattering at the Ge L edge demonstrate the presence of spin-polarized {\it s} states at the Fermi level, as well as {\it d} character moments at higher energy, which are both oriented antiparallel to the moment of the Fe layer. Use of the sum rules enables extraction of the L/S ratio, which is zero for the {\it s} part and $\sim0.5$ for the {\it d} component. These results are consistent with layer-resolved electronic structure calculations, which estimate the {\it s} and {\it d} components of the Ge moment are anti-parallel to the Fe {\it 3d} moment and have a magnitude of $\sim0.01 \mu_B$.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let

Functional Aspects of Primate Grooming

Author Institution: Division of Biological Sciences, University of Michigan, Ann Arbor, and New York Zoological SocietyExperimental walks with a tame primate reveal that free living primates are likely to be subject to frequent infestation by ticks. Observations on the grooming behavior of mangabeys, red colobus and blue monkeys demonstrated that self grooming is primarily directed to parts of the body not subjected to allo-grooming, and that its role is a cursory brushing away of loose particles rather than a detailed cleansing. Allo-grooming is directed towards the detailed cleansing of the skin and fur, and is associated with frequent particle removal. Length of body fur has a considerable influence on the amount of grooming different parts of the body receive. I suggest that sexual dimorphism, age, sex and dominance status are important in determining rates of ectoparasite acquisition, and so the amount of grooming individuals need and receive

Boron enrichment in Martian clay

We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration

Five meter diameter conical furlable antenna

An investigation was made to demonstrate that a 5-meter-diameter, furlable, conical reflector antenna utilizing a line source feed can be fabricated utilizing composite materials and to prove that the antenna can function mechanically and electrically as prototype flight hardware. The design, analysis, and testing of the antenna are described. An RF efficiency of 55% at 8.5 GHz and a surface error of 0.64 mm rms were chosen as basic design requirements. Actual test measurements yielded an efficiency of 53% (49.77 dB gain) and a surface error of 0.61 mm rms. Atmospherically induced corrosion of the reflector mesh resulted in the RF performance degradation. An assessment of the antenna as compared to the current state of the art technology was made. This assessment included cost, surface accuracy and RF performance, structural and mechanical characteristics, and possible applications

From Star Wars to Space Wars - The Next Strategic Frontier: Paradigms to Anchor Space Security

Military blueprints by major space-faring powers now encapsulate concepts of ‘space support’ and ‘force enhancement’ which point to a central role of space assets in facilitating military operations while notions of ‘space control’ and ‘force application’ suggest the weaponization of space, and the putative view that space may in the near future be a theatre of military operations. As defence goals increasingly focus on space as the final frontier evident in development of national missile defence systems, anti-satellite weapons and other space-based systems, international peace and security faces a new challenge. Creators of the current legal regime for space failed to foresee the rapid rate at which technological and engineering breakthroughs would take place. Now the shortcomings in the current regime beg the question of how the law can keep up and address space technology. It is imperative that the international community act now rather than later. In light of the existing lacunae in the international space law regime, this Article seeks to explore avenues/paradigms through which the militarization of space may be regulated and its weaponization addressed

QUASAT: An orbiting very long baseline interferometer program using large space antenna systems

QUASAT, which stands for QUASAR SATELLITE, is the name given to a new mission being studied by NASA. The QUASAT mission concept involves a free flying Earth orbiting large radio telescope, which will observe astronomical radio sources simultaneously with ground radio telescopes. The primary goal of QUASAT is to provide a system capable of collecting radio frequency data which will lead to a better understanding of extremely high energy events taking place in a variety of celestial objects including quasars, galactic nuclei, interstellar masers, radio stars and pulsars. QUASAT's unique scientific contribution will be the increased resolution in the emission brightness profile maps of the celestial objects