Conceptual servo technique for controlling tape drivers

Electronic speed control design maintains magnetic tape in close synchronism at the airborne and ground stationed devices. Use of the servo system during the record and reproduce modes results in the minimum amount of frequency distortion and flutter

Hierarchical clustering and the baryon distribution in galaxy clusters

The baryon fraction of galaxy clusters in numerical simulations is found to be dependant on the cluster formation method. In all cases, the gas is anti-biased compared with the dark matter. However, clusters formed hierarchically are found to be more depleted in baryons than clusters formed non-hierarchically. There is a depletion of 10 to 15% for hierarchically formed clusters while the depletion is less than 10% for those clusters formed non-hierarchically. This difference is dependent on the mass of the clusters. The mean baryon enrichment profile for the hierarchically formed clusters shows an appreciable baryon enhancement around the virial radius not seen in the clusters formed without substructure. If this phenomenon applies to real clusters, it implies that determinations of the baryon fractions in clusters of galaxies require data extending beyond the virial radius of the clusters in order to achieve an unbiased value.Comment: 13 pages including 2 tables and 2 figures. Submitted to MNRA

Design study of tradeoffs in spacecraft tape recorder development Final engineering report

Tradeoff design study in spacecraft tape recorder developmen

Transforming growth factor-β activation in cell-free extracellular matrix preparations. Commentary

Transforming growth factor-β (TGF-β) is an important regulator of many cellular and immunological functions. It is often deposited in extracellular matrices in a latent form. This commentary is to draw attention to the likelihood that preparing cell-free matrices from tissue cultures by high pH buffers, such as ammonium hydroxide, can activate the TGF-β. Therefore, cells subsequently seeded onto such matrices may respond to the presence of active TGF-β in addition to interactions with macromolecular extracellular matrix components