Study to establish cost predictions for the production of Redox chemicals

The chromium and iron chloride chemicals are significant first costs for NASA Redox energy storage systems. This study was performed to determine the lowest cost at which chromium and iron chlorides could be obtained for a complex of redox energy storage systems. In addition, since the solutions gradually become intermixed during the course of operation of Redox units, it was an objective to evaluate schemes for regeneration of the operating solutions. Three processes were evaluated for the production of chromium and iron chlorides. As a basis for the preliminary plant design and economic evaluation, it was assumed that the plant would produce about 25,000 tons of contained chromium as CrCl3 and an equivalent molar quantity of FeCl2. Preliminary plant designs, including materials and energy balances and sizing of major equipment, were prepared, and capital and operating costs were estimated

Gluon contributions to the pion mass and light cone momentum fraction

We calculate the matrix elements of the gluonic contributions to the energy-momentum tensor for a pion of mass 600 < Mpi < 1100 MeV in quenched lattice QCD. We find that gluons contribute (37 +/- 8 +/- 12)% of the pion's light cone momentum. The bare matrix elements corresponding to the trace anomaly contribution to the pion mass are also obtained. The discretizations of the energy-momentum tensor we use have other promising applications, ranging from calculating the origin of hadron spin to QCD thermodynamics.Comment: 4 pages, 2 figure

Design of hydraulic output Stirling engine

A hydraulic output system for the RE-1000 free piston stirling engine (FPSE) was designed. The hydraulic output system can be readily integrated with the existing hot section of RE-1000 FPSE. The system has two simply supported diaphragms which separate the engine gas from the hydraulic fluid, a dynamic balance mechanism, and a novel, null center band hydraulic pump. The diaphragms are designed to endure more than 10 billion cycles, and to withstand the differential pressure load as high as 14 MPa. The projected thermodynamic performance of the hydraulic output version of RE-1000 FPSE is 1.87 kW at 29/7 percent brake efficiency

D0-brane tension in string field theory

We compute the D0-brane tension in string field theory by representing it as a tachyon lump of the D1-brane compactified on a circle of radius $R$. To this aim, we calculate the lump solution in level truncation up to level L=8. The normalized D0-brane tension is independent on $R$. The compactification radius is therefore chosen in order to cancel the subleading correction $1/L^2$. We show that an optimal radius $R^*$ indeed exists and that at $R^*$ the theoretical prediction for the tension is reproduced at the level of $10^{-5}$. As a byproduct of our calculation we also discuss the determination of the marginal tachyon field at $R\to 1$.Comment: 13 pages, 3 Eps figure

Comparison of prediction methods and studies of relaxation in hypersonic turbulent nozzle-wall boundary layers

Turbulent boundary layer measurements on axisymmetric hypersonic nozzle wall

A multi-object spectral imaging instrument

We have developed a snapshot spectral imaging system which fits onto the side camera port of a commercial inverted microscope. The system provides spectra, in real time, from multiple points randomly selected on the microscope image. Light from the selected points in the sample is directed from the side port imaging arm using a digital micromirror device to a spectrometer arm based on a dispersing prism and CCD camera. A multi-line laser source is used to calibrate the pixel positions on the CCD for wavelength. A CMOS camera on the front port of the microscope allows the full image of the sample to be displayed and can also be used for particle tracking, providing spectra of multiple particles moving in the sample. We demonstrate the system by recording the spectra of multiple fluorescent beads in aqueous solution and from multiple points along a microscope sample channel containing a mixture of red and blue dye