Two-pion exchange NN potential from Lorentz-invariant χ\chiEFT

We outline the progress made in the past five years by the S\~ao Paulo group in the development of a two-pion exchange nucleon-nucleon potential within a Lorentz-invariant framework of (baryon) chiral perturbation theory.Comment: 5 pages, Talk given at the 18th International IUPAP Conference on Few-Body Problems in Physics, August 21-26 2006, Santos, Sao Paulo, Brazi

Electromagnetic interactions in Halo Effective Field Theory

After a brief discussion of effective field theory applied to nuclear clusters, I concentrate on the inclusion of two particular aspects, namely, narrow resonances and electromagnetic interactions. As examples of applications, I present the details of our studies on alpha-alpha and proton-alpha scattering.Comment: 11 pages, 5 figures, lead parallel talk given at the 19th Intl. IUPAP Conf. on Few-Body Problems in Physics, Bonn, Germany, Aug.31-Sep.5 200

Nuclear clusters with Halo Effective Field Theory

After a brief discussion of effective field theory applied to nuclear clusters, I present the aspect of Coulomb interactions, with applications to low-energy alpha-alpha and nucleon-alpha scattering.Comment: 6 pages, 3 figures, plenary talk given at the Fourth Asia-Pacific Conference on Few-Body Problems in Physics 2008, Depok, Indonesia, August 19 - 23, 200

Simplified heat engine

In Sterling-cycle heat engine, pneumatic system is used to drive displacer/regenerator, eliminating mechanical linkages and valves

Highly stable microwave delay line

TWM /Traveling Wave Master/ comb structure serves as a highly stable microwave delay line for determining the short-term stability of the hydrogen maser frequency standards used in the deep space network. Cryogenic cooling is used to minimize signal attenuation and thermal noise

Improved cryogenic refrigeration system

Two-position shuttle valve simplifies valving arrangement and crank-shaft configuration in gas-balancing and Stirling-cycle refrigeration systems used to produce temperatures below 173 degrees K. It connects the displacer and regenerator alternately to the supply line or the return line of the compressor, and establishes constant pressure on the drive piston

Refrigeration apparatus Patent

Method and apparatus for producing very low temperature refrigeration based on gas pressure balanc

Centrifugal-reciprocating compressor

A centrifugal compressor is described which includes at least one pair of cylinders arranged in coaxial alignment and supported for angular displacement about a common axis of rotation normally disecting a common longitudinal axis of symmetry for the cylinders. The cylinders are characterized by ported closures located at the mutually remote ends thereof through which the cylinders are charged and discharged, and a pair of piston heads seated within the cylinders and supported for floating displacement in compressive strokes in response to unidirectional angular displacement imparted to the cylinders

The superconducting cavity-stabilized maser oscillator

The possibility of integrating a superconducting cavity with a traveling wave maser is explored to obtain a frequency standard with very high spectral purity