The thin-layer Navier-Stokes equations are solved for two complete missile configurations on an IBM 3090-200 vectro-facility supercomputer. The conservation form of the three-dimensional equations, written in generalized coordinates, are finite differenced and solved on a body-fitted curvilinear grid system developed in conjunction with the flowfield solver. The numerical procedure is based on ...

The relative stability of the cruciform state at the large inverted repeat of plasmid pVH51 is measured. At physiological superhelical densities, the cruciform state is present in a high percentage of the plasmid molecules. Investigation of the relationship between negative superhelical density and cruciform prevalence reveals a sharp transition from an undetectable level to a relatively stable...

Extrusion of cruciform structures in self-complementary regions of DNA is known to be favored by negative supercoiling of DNA. We show here that, in moderately supercoiled DNA, cruciform extrusion is a very slow process. In plasmid pUC7 DNA, with a 48-base-pair palindrome, the half-time of extrusion at 50 degrees C is typically several hours; rates are even slower at lower temperature. The rate...

The coordination complex tris(4,7-diphenylphenanthroline)rhodium(III), Rh(DIP)3(3+), binds to and, upon photoactivation, cleaves both DNA strands near the base of a DNA cruciform. Sites of photoinduced double-stranded DNA cleavage by the rhodium complex map to regions containing cruciforms on closed circular pBR322, pColE1 and phi X174 (replicative form) DNAs. Neither cleavage nor binding by th...

Protein extracts from Saccharomyces cerevisiae have been fractionated to reveal a nuclease activity that cleaves cruciform structures in DNA. Negatively supercoiled plasmids that contain inverted repeats that are extruded into cruciform structures have been used as DNA substrates. The sites of cleavage of pColIR215 DNA are located within the extruded cruciform stems and are symmetrically oppose...

During cruciform extrusion, a DNA inverted repeat unwinds and forms a four-way junction in which two of the branches consist of hairpin structures obtained by self-pairing of the inverted repeats. Here, we use single-molecule DNA nanomanipulation to monitor in real-time cruciform extrusion and rewinding. This allows us to determine the size of the cruciform to nearly base pair accuracy and its ...

in this paper, a new guidance method for surface to surface ballistic missiles without mandatory engine cut-off will be presented. the complexity of solid fuel engine cut-off demands a comprehensive method for guiding these missiles. in the method presented in this paper, a certain guidance law is applied such that by transmitting appropriate commands to the control system, by changing the miss...

This paper analyzes equilibrium superhelical cruciform formation in a topologial domain of DNA containing inverted repeat sequences. The cruciform conformation is shown to he stable when the molecule is sufficiently negatively supercoiled but not when it is positively supercoiled. For a particular sequence containing a single inverted repeat, onset of stability occurs at a degree of negative su...

A rare Phaeodactylum tricornutum cruciform morphotype was obtained and stabilized with a proportion of more than 31.3% in L1 medium and is reported for the first time. Long-term culture and observation showed that the cruciform morphotype was capable of transforming to the oval form following the degeneration of arms by two processes. After three months of culture, four morphotypes existed in a...

In airframe technology, designs have become progressively more compact, to accommodate internal and external carriage by aircraft, launch tubes on warships or torpedo tubes in submarines. Propulsion has evolved from simple pulse jets, through turbojets and liquid propellant rockets or ramjets to the current mix of: turbojets for subsonic tactical cruise missiles, turbofans for subsonic strategi...