Space vehicle electrical power systems study

Developing suitable solid state power controllers for space vehicles electrical power system

Development of advanced digital techniques for data acquisition processing and communication Interim scientific report

Image correlation and computerized simulation applied to data acquisition and imaging technique

PCM telemetry data compression study, phase II Quarterly report, 25 Nov. 1965 - 25 Feb. 1966

Model analyses and computer simulations used in data compression study for improved pulse code modulation telemetry link

The development of advanced digital techniques for data acquisition processing and communication Interim scientific report

Digital techniques for characterization of image sources, second order interpolation, sensitivity of compressed pictures to error, and simulation of mapping technique

PCM telemetry data compression study, phase 1 Final report, 15 Sep. 1964 - 15 Aug. 1965

Pulse Code Modulation /PCM/ telemetry data compression study using S-6 Explorer XVII DAT

Electrical control of inter-dot electron tunneling in a quantum dot molecule

We employ ultrafast pump-probe spectroscopy to directly monitor electron tunneling between discrete orbital states in a pair of spatially separated quantum dots. Immediately after excitation, several peaks are observed in the pump-probe spectrum due to Coulomb interactions between the photo-generated charge carriers. By tuning the relative energy of the orbital states in the two dots and monitoring the temporal evolution of the pump-probe spectra the electron and hole tunneling times are separately measured and resonant tunneling between the two dots is shown to be mediated both by elastic and inelastic processes. Ultrafast (< 5 ps) inter-dot tunneling is shown to occur over a surprisingly wide bandwidth, up to ~8 meV, reflecting the spectrum of exciton-acoustic phonon coupling in the system

Scaling Down Large-Scale Thawing of Monoclonal Antibody Solutions: 3D Temperature Profiles, Changes in Concentration, and Density Gradients

PURPOSE Scale-down devices (SDD) are designed to simulate large-scale thawing of protein drug substance, but require only a fraction of the material. To evaluate the performance of a new SDD that aims to predict thawing in large-scale 2 L bottles, we characterised 3D temperature profiles and changes in concentration and density in comparison to 125~mL and 2 L bottles. Differences in diffusion between a monoclonal antibody (mAb) and histidine buffer after thawing were examined. METHODS Temperature profiles at six distinct positions were recorded with type T thermocouples. Size-exclusion chromatography allowed quantification of mAb and histidine. Polysorbate 80 was quantified using a fluorescent dye assay. In addition, the solution's density at different locations in bottles and the SDD was identified. RESULTS The temperature profiles in the SDD and the large-scale 2 L bottle during thawing were similar. Significant concentration gradients were detected in the 2 L bottle leading to marked density gradients. The SDD slightly overestimated the dilution in the top region and the maximum concentrations at the bottom. Fast diffusion resulted in rapid equilibration of histidine. CONCLUSION The innovative SDD allows a realistic characterisation and helps to understand thawing processes of mAb solutions in large-scale 2 L bottles. Only a fraction of material is needed to gain insights into the thawing behaviour that is associated with several possible detrimental limitations

Chandra Discovery of a 300 kpc X-ray Jet in the GPS Quasar PKS1127-145

We have discovered an X-ray jet with Chandra imaging of the z=1.187 radio-loud quasar PKS1127-145. In this paper we present the Chandra X-ray data, follow-up VLA observations, and optical imaging using the HST WFPC2. The X-ray jet contains 273+/-5 net counts in 27ksec and extends ~30 arcsec, from the quasar core, corresponding to a minimum projected linear size of ~330/h_50 kpc. The evaluation of the X-ray emission processes is complicated by the observed offsets between X-ray and radio brightness peaks. We discuss the problems posed by these observations to jet models. In addition, PKS1127-145 is a Giga-Hertz Peaked Spectrum radio source, a member of the class of radio sources suspected to be young or ``frustrated'' versions of FRI radio galaxies. However the discovery of an X-ray and radio jet extending well outside the host galaxy of PKS1127-145 suggests that activity in this and other GPS sources may be long-lived and complex.Comment: 22 pages, 11 ps figures, 1 figure in a JPG file, 3 tables. AASTEX. Accepted by The Astrophysical Journa