Improved Synchronization Criteria for Chaotic Neural Networks with Sampled-data Control Subject to Actuator Saturation

International Journal of Control, Automation and Systems - In this paper, the synchronization problem for chaotic neural networks with sampled-data control and actuator saturation is investigated....     

Formation of nanosized martensite particles in stainless steels

Martensitic transformations occur in steels and other metals when the material is quenched or cooled. During the transformation, a metastable phase transforms in an autocatalytic way into a thermodynamically stable phase. Thus, it has been considered to be impossible to control the size of martensite in the order of nanometers. Here, we report the formation and dispersion of nanosized martensite in stainless steels by controlling the dislocation density and temperature. Electron microscopy revealed that martensite particles of approximately 5 nm in diameter were dispersed. Since both work hardening and precipitation hardening are effective in this material, this would be an additional, newly discovered strengthening mechanism for steels.     

Plastic limit loads for cracked large bore branch junction

This paper reports plastic limit loads for a cracked large bore branch junction, based on three-dimensional finite element limit analyses using elastic-perfectly plastic materials. Part-through surface and through-wall cracks are postulated in the intersection. For loading conditions, internal pressure and (in-plane and out-of-plane) bending to the branch pipe and to the run pipe are considered. The effect of the crack on limit loads is found to be significant for internal pressure and bending to the branch pipe, but not for bending to the run pipe. The large geometry change effect for bending to the branch pipe is briefly discussed.     

Fabrication of nickel micromesh sheets and evaluation of their water-repellent and water-proof abilities

Nickel micromesh sheets were designed and fabricated and their water-repellent and water-proof abilities were characterized. The network-type microstructures of the micromesh sheets functioned as micro-protrusions of lotus leaves, which allowed the sheets to superhydrophobic. The micromesh enabled the material waves, including sound and light waves, to pass through the microholes, but repelled water. Because of the effects of the micromesh and plasma polymerized fluorocarbon (PPFC) coating, the contact angle of the micromesh sheets was drastically jumped up from 63° of the non-coated nickel flat film to 140° of the PPFC-coated nickel micromesh, which modified the nickel sheet from hydrophilic to superhydrophobic. The narrower lattice width in the micromesh was more effective at enhancing the water-repellency. On the other hand, the narrow lattice width weakened the water-proof ability. Reducing the hole size and increasing the lattice width of the micromesh are necessary to improve the water-proof ability.     

Preparation of conducting polyacrylonitrile/polypyrrole composite films by electrochemical synthesis and their electrical properties

Electrically conducting polyacrylonitrile (PAN)/polypyrrole (PPy) composite films were prepared by electrochemical polymerization of pyrrole in an insulating PAN matrix under various polymerization conditions and their electrical properties were studied. The conductivities of PAN/PPy composite films peeled off from the platinum electrode he lie in the range of 10^?2–10^?3 s/cm, depending on the preparation conditions: The conductivity increased with the concentrations of the electrolyte and the monomer, but it decreased with the polymerization temperature of pyrrole and the applied potential.     

Pinched inlet split flow thin fractionation for continuous particle fractionation: application to marine sediments for size-dependent analysis of PCDD/Fs and metals

It is demonstrated that split-flow thin (SPLITT) fractionation, a continuous separation technique for sorting particles or macromolecules, can be utilized for the fractionation of environmental particles to study a size-dependent analysis of pollutants. In this study, focuses are made on the use of a pinched inlet gravitational SPLITT fractionation, a modified form of SPLITT channel formed by reducing the sample inlet thickness of the channel to improve separation efficiency, to separate marine sediments into five different sizes (<1.0, approximately 1.0 to 2.5, approximately 2.5 to 5.0, approximately 5.0 to 10, and approximately 10 to 53 microm). The resulting size fractions are examined with high resolution gas chromatography/high resolution mass spectrometry to determine the size-dependent distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans along with a statistical data treatment and are analyzed with inductively coupled plasma-atomic emission spectrometry and graphite furnace atomic absorption spectrometry to ascertain its major and trace metals. It is shown that the combined analytical methods detailed in this study can be powerfully utilized in such a way as to analyze pollutant distribution and its concentration with regard to particle sizes for an environmental assessment.