Carbon nanotubes for interconnects in future integrated circuits: The challenge of the density

A CVD process with a high density of CNTs has been developed on doped silicon material thanks to plasma pre-treatment of the catalyst. With this process small diameter double and triple wall CNTs with an average diameter of 3.8 nm have been grown. The density of the best materials on blanket substrate is larger than 10¹² cm^? 2. These materials have been successfully integrated in via holes with a diameter ranging between 1 µm and 0.3 µm with an equivalent density. In 140 nm hole diameter large 70 nm bundle formations have been observed. In these bundles a density of CNT walls close to 10¹³ cm^? 2 has been estimated.     

Quantitative coherent anti-Stokes Raman scattering microspectroscopy using a nanosecond supercontinuum light source

We describe and characterize a multiplex CARS microspectroscopic system that uses a nanosecond supercontinuum generated from a photonic crystal fiber and a sub-nanosecond pulse laser. This system has a high spectral resolution (<0.1 cm^?1) and an ultrabroadband spectral coverage (>2500 cm^?1). The estimated spatial resolutions are 0.45 μm (lateral) and 4.5 μm (axial), respectively. This system enables us to obtain CARS spectra and corresponding images in the fingerprint region as well in the CH stretch region. Using this system, we have successfully obtained label-free and multi-mode vibrational images of a yeast cell.     

Effects of cold rolling and annealing on the structure of γ″ precipitates in a Ni-18Cr-16Fe-5Nb-3Mo alloy

A Ni-18Cr-16Fe-5Nb-3Mo alloy (a modified alloy 718, referred to herein as 718M), in which the γ″ phase is the only precipitation-strengthening phase, was made by substituting most of the aluminum and titanium in INCONEL 718 with niobium. The specimens of alloy 718M were solid-solution heat treated, aged at 1033 to 1073 K for up to 360 ks, and cold rolled to a reduction of 10 to 15 pct at room temperature. After subsequent annealing heat treatments, at the same temperatures used for aging, the morphological and structural changes of the γ″ precipitates were investigated by transmission electron microscopic observation using carbon extraction replicas. Although stacking faults were not noticed in the γ″ precipitates extracted from the aged 718M alloy, stacking faults introduced in the {112} _γ″ planes by cold rolling of the samples were confirmed. The stripelike contrast due to the stacking faults becomes less clear with increasing annealing time. With longer annealing times, necking occurs between the stripes, which eventually separate into plural particles. The selected-area electron diffraction (SAED) patterns of the cold-rolled and annealed particles show that the metastable γ″ precipitates with stacking faults are transformed gradually into a stable δ phase. In this article, we discuss the basis of morphological and structural changes in detail. INCONEL is a trademark of INCO Alloys International, Inc., Huntington, WV.     

Processing and photocatalytic properties of Cu-grafted TiO2 powder from acid treated BaTiO3

The respective influences of calcination, drying methods, and washing conditions on the morphologies, surface properties, and photocatalytic activities of TiO₂ powders prepared from acid treatments of BaTiO₃ were investigated. Rutile powder was obtained using the treatment under strong acid conditions. It possesses a bundle-like shape and comprises rutile nanorods. After calcination, characteristic voids were observed in the particles. Anatase powder was obtained by adjusting pH values of a BaTiO₃ suspension to 2.5-3. Drying at 110 °C engendered the formation of spheroidal anatase, although freeze-dried anatase particles assembled into a flake-like shape. The freeze-dried samples show lower crystallinity. With grafting Cu ions, rutile exhibited better photocatalytic performance for the decomposition of gaseous 2-propanol (IPA) under visible light, although it did not work effectively for anatase.     

A New Consensus Algorithm for Multi-Agent Systems via Decentralized Dynamic Output Feedback

In this paper, we study a consensus problem for multi-agent systems via dynamic output feedback control. The entire system is decentralized in the sense that each agent can only obtain output information from its neighbor agents. For practical purpose, we assume that actuator limitation exists, and require that the consensus be achieved among the agents at a specified convergence rate. By using an appropriate coordinate transformation, we reduce the consensus problem on hand to solving a strict matrix inequality, and then propose to use the homotopy based method for solving the matrix inequality. It turns out that our algorithm includes the existing graph Laplacian based algorithm as a special case.     

Reduction of Second-Order Temperature Dependence of Athermal AWG With Resin-Filled Groove by Pressure Control

In this letter, we have developed a novel technique for improving the temperature stability of an athermal silica-based arrayed-waveguide grating with a resin-filled groove. We compensated for the residual second-order temperature dependence of the passband wavelength using the pressure-induced refractive index change in a resin inserted into the optical paths. Pressure control under the temperature variation was achieved by using a structure composed of an optical fiber piston and bimetal actuators. We demonstrated that the passband wavelength variation was successfully reduced from 0.080 to 0.025 nm in a -40degC - 85degC temperature range, without any insertion loss increase or spectral change.     

Effects of coal rank and reaction conditions upon coprocessing coal with waste tyre

It is well known that the amount of waste tyre increases every year, and a numerous amount of waste tyre is landfilled or dumped all over the world, which causes environmental problems, such as destruction of natural places and the risk of fires. Coprocessing waste tyre and coal is considered as one of the effective processing methods of both materials. Upon coprocessing lower rank coal (Wyoming, C; 68%) with waste tyre, the synergistic effects to upgrading, such as the increase of oil yield and the decrease of residue yield, were appeared. However, the synergistic effects were not observed on coprocessing two kinds of higher rank coals with waste tyre. The reactions of coal with benzophenone were carried out to discuss the hydrogen donatability of coal. Conversion of benzophenone to diphenylmethane on the reaction with Wyoming coal was higher than those of higher rank coals. Accordingly, it was considered that the synergistic effects to upgrading upon coprocessing Wyoming coal with waste tyre were obtained owing to the enhancement of stabilization of radicals from tyre and Wyoming coal through the hydrogen donation from both tyre and Wyoming coal. The effects of reaction temperature and the amount of solvent upon coprocessing Wyoming coal with waste tyre were also discussed in this study.     

Corrosion of MgO—MgAl2O4 Spinel Refractory Bricks by Calcium Aluminosilicate Slag

Microstructural analysis of MgO—MgAl₂O₄ refractory bricks corroded at 1400–1450°C by calcium aluminosilicate slag reveals secondary spinel, monticellite, merwinite, and MgO as microscopic corrosion products, generally forming in this sequence as the brick is penetrated. The secondary spinel forms an incomplete layer close to (but not at) the MgO grain. Thermodynamic calculations are used to support a detailed model of the corrosion mechanism.