Ablation structures Patent

Design, development, and characteristics of ablation structure

Vehicle parachute and equipment jettison system Patent

Parachute system for lowering manned spacecraft from post-reentry to ocean landin

Aerial capsule emergency separation device Patent

Aerial capsule emergency separation device using jettisonable tower

Nondestructive testing of brazed rocket engine components

Report details study made of nondestructive radiographic, ultrasonic, thermographic, and leak test methods used to inspect and evaluate the quality of the various brazed joints in liquid-propellant rocket engine components and assemblies. Descriptions of some of the unique equipment and methods developed are included

Modification and improvements to cooled blades Patent

Modification and improvement of turbine blades for maximum cooling efficienc

Spontaneous Spin Polarization in Quantum Wires

A number of recent experiments report spin polarization in quantum wires in the absence of magnetic fields. These observations are in apparent contradiction with the Lieb-Mattis theorem, which forbids spontaneous spin polarization in one dimension. We show that sufficiently strong interactions between electrons induce deviations from the strictly one-dimensional geometry and indeed give rise to a ferromagnetic ground state in a certain range of electron densities.Comment: 4 pages, 4 figure

From Point Defects in Graphene to Two-Dimensional Amorphous Carbon

While crystalline two-dimensional materials have become an experimental reality during the past few years, an amorphous 2-D material has not been reported before. Here, using electron irradiation we create an sp2-hybridized one-atom-thick flat carbon membrane with a random arrangement of polygons, including four-membered carbon rings. We show how the transformation occurs step-by-step by nucleation and growth of low-energy multi-vacancy structures constructed of rotated hexagons and other polygons. Our observations, along with first-principles calculations, provide new insights to the bonding behavior of carbon and dynamics of defects in graphene. The created domains possess a band gap, which may open new possibilities for engineering graphene-based electronic devices.Comment: 10 pages, 10 figures including supplementary informatio

Linear response in infinite nuclear matter as a tool to reveal finite size instabilities

Nuclear effective interactions are often modelled by simple analytical expressions such as the Skyrme zero-range force. This effective interaction depends on a limited number of parameters that are usually fitted using experimental data obtained from doubly magic nuclei. It was recently shown that many Skyrme functionals lead to the appearance of instabilities, in particular when symmetries are broken, for example unphysical polarization of odd-even or rotating nuclei. In this article, we show how the formalism of the linear response in infinite nuclear matter can be used to predict and avoid the regions of parameters that are responsible for these unphysical instabilities.Comment: Based on talk presented at 18th Nuclear Physics Workshop "Maria and Pierre Curie", 2011, Kazimierz, Polan

Integrability of the critical point of the Kagom\'e three-state Potts mode

The vicinity of the critical point of the three-state Potts model on a Kagom\'e lattice is studied by mean of Random Matrix Theory. Strong evidence that the critical point is integrable is given.Comment: 1 LaTex file + 3 eps files 7 page