Anomalous elastic response of silicon to uniaxial shock compression on nanosecond time scales

We have used x-ray diffraction with subnanosecond temporal resolution to measure the lattice parameters of orthogonal planes in shock compressed single crystals of silicon (Si) and copper (Cu). Despite uniaxial compression along the (400) direction of Si reducing the lattice spacing by nearly 11%, no observable changes occur in planes with normals orthogonal to the shock propagation direction. In contrast, shocked Cu shows prompt hydrostaticlike compression. These results are consistent with simple estimates of plastic strain rates based on dislocation velocity data.     

Bit-error-rate analysis for a 100-Gbit/s nonlinear optical loop mirror demultiplexer employing soliton control and signal pulses

On the basis of a previously derived mathematical model, the power penalty associated with a nonlinear optical loop mirror (NOLM) demultiplexer was calculated, with timing jitter noise, bit-to-bit cross talk, and channel cross talk taken into consideration. Simulation results show that a 3-dBm improvement in the receiver sensitivity at a bit error rate of 10(-9) can be achieved by choice of the appropriate walk-off time between the control and the signal pulses within the NOLM demultiplexer.     

CHAOS AND MULTIPLE PERIODS IN AN UNSYMMETRICAL SPRING AND DAMPING SYSTEM WITH CLEARANCE

Chaos and multiple periods are presented for the harmonically excited unsymmetrical spring and damping system with clearance. This paper demonstrates the non-linear behaviour of the motion through simulation and experiment. Intensive care and caution are taken in the experiments to observe the chaos and the multiple periods properly. The focus in this paper is mainly on the change of the bilinear spring stiffness ratio as a prime factor by which chaotic motions occur from quasi-periodic motion. Other investigations and effects on motion are also discussed for the changing of the extent of clearance. The investigations are based on frequency response curves. To understand the dynamics of the non-linearity of this model, all possible data processing and displaying techniques are taken into account. To observe the overall phenomena of this bilinear system, the resonance curves and the bifurcation diagrams are taken thoroughly for a wide frequency region.     

Vapor—liquid equilibria for the binary system 2-methylbutene-2 and 2-methyl-1,3-butadiene at 310.93, 316.48 and 322.04 K

Total pressure, vapor—liquid equilibrium data for the binary system 2-methyl-1,3-butadiene and 2-methylbutene-2 are reported at 310.93, 316.48 and 322.04 K. The experimental uncertainties in measured variables, expressed as standard deviations, are 0.0005 mole fraction, 0.01 K and 0.2% of measured pressure. The coefficients for a modified Wilson solution model are also reported. These coefficients were determined from the experimental data using a general non-linear least-squares technique which accounts for experimental uncertainties in independent and dependent variables. The standard deviations of prediction for temperature-independent coefficients are 0.17% for pressure, 0.001 K for temperature and 0.00001 for mole fraction.     

Non-destructive radiochemical method for determining carbon concentrations in thin sheet 3% Si-Fe alloy

A non-destructive radiochemical method for determining carbon concentrations in thin sheet 3% Si-Fe has been developed. An ingot of 3% Si-Fe was doped with ¹⁴C during the melting operation, and subsequently processed to give a 0.30-mm thick sheet. Decarburizing annealing conditions were controlled in order to obtain sheets having final carbon concentrations in the range 1.5–110 ppm. The β-radiation emanating from a thin surface layer of these sheets was found to be independent of sheet thickness, and linearly correlated to the bulk carbon content determined by the Leco carbon analyser, in the range 1.5–110 ppm. The radiochemical method is more sensitive for carbon concentrations below 20 ppm than techniques which rely on sample combustion.     

Synthesis, characterization, DNA-binding, photocleavage, cytotoxicity and docking studies of Co(III) mixed ligand complexes

A new ligand, (2-ethoxy-6-(1H imadazo[4,5-f][1,10]phenanthroline-2-yl)phenol) (HEPIP) and its three Co(III) complexes [Co(phen)₂(HEPIP)](ClO₄)₃ (1), [Co(bpy)₂(HEPIP)](ClO₄)₃ (2) and [Co(dmb)₂(HEPIP)](ClO₄)₃ (3) have been synthesized and characterized. All three Co(III) complexes exhibited antitumor activity against four human tumor cell lines. The interaction of these complexes with calf thymus DNA was studied by absorption and emission spectroscopy, viscosity measurements and DNA cleavage assays. The DNA-binding constants of complexes 1, 2 and 3 were determined as 6.13 × 10⁵, 4.46 × 10⁵ and 3.72 × 10⁵ M^?1, respectively. The complexes appear to interact with DNA through intercalation. Studies on the mechanism of photocleavage indicated that both superoxide anion radical and singlet oxygen may play an important role.