Nano-microscale moulding of some metal plates with high strength Ni–W alloy moulds

High strength nanocrystalline and amorphous Ni-14–24 at. % W alloys with their tensile strengths of about 3 GPa have been prepared by electrodeposition. Nano-microscale Ni–W alloy mould inserts, consisting of line and space structures with the line-widths of 700 and 300 nm and the height of 200 nm, were fabricated. High compression stress moulding of some metal plates of pure-Al, SUS-316L stainless steel and Zr₆₉Cu₁₆Ni₅Al₁₀ bulk metallic glass with the Ni–W alloy inserts was carried out at room temperature. In the case of the pure-Al under moulding stress of about 350 MPa, full moulding was achieved with the depths of about 200 nm approximately equal to the height of the inserts. Repeat moulding of 200 cycles did not cause any noticeable change or degradation of the Ni–W alloy inserts. In the case of the SUS-316L stainless steel under the moulding stress of about 1 GPa, however, the nano-microscale moulding was not achieved. This may be due to the high strain hardening ability of the SUS-316L stainless steel during plastic deformation. In the case of the Zr₆₉Cu₁₆Ni₅Al₁₀ bulk metallic glass with a high yielding stress of about 1.5 GPa and no strain hardening ability, full moulding was almost achieved successfully under the high moulding stress of about 2 GPa.     

Characterization of multicomponent crystal formed between indomethacin and lidocaine

Purpose: Crystalline complex was formed between indomethacin (IDM) and lidocaine (LDC) at molar ratio 2:1 from ethanol solution. The purpose of this study was elucidation of an interactive manner between IDM and LDC in ethanol solution and mechanism of the complex formation through solid state as well as liquid state. Methods: The chemical and physical nature of the complex was clearly elucidated by the alliance of powder X-ray diffractometry, differential scanning calorimetry, and infrared spectroscopy. The complex was also formed via solid-state reaction by cogrinding and heating treatment without any solvent. Results: The complexation process was estimated to be as follows: (i) mixing and contact of two components, (ii) disorder of crystalline LDC by grinding or fusion, and then (iii) crystal growth by heating. In addition, 1H-NMR coupled with microchanneled cell for synthesis monitoring revealed that a primary interactive force between IDM and LDC molecule was coulomb energy.     

Activity recognition with hand-worn magnetic sensors

Activity recognition is a key technology for realizing ambient assisted living applications such as care of the elderly and home automation. This paper proposes a new activity recognition method that employs hand-worn magnetic sensors to recognize a broad range of activities ranging from simple activities that involve hand movements such as walking and running to the use of portable electrical devices such as cell phones and cameras. We sense magnetic fields emitted by electrical devices and the earth with hand-worn sensors, and recognize what a user is doing or which electrical device the user is employing. We frequently use a large number of different electrical devices in our daily lives, and so we can estimate high-level daily activities by recognizing their use. Our approach permits us to recognize a range extending from low-level simple activities to high-level activities that relate to the hands without the need to attach any sensors to the electrical devices.     

Multi-physics analysis of nano-structured ferroelectrics by first-principles simulations

Unusual ferroelectricity emerges in nanoscale Perovskite oxides owing to their characteristic structures, and it strongly interacts with mechanical stress/strain, namely, “multi-physics property”. For systematic understanding, the ferroelectricity and multi-physics property in the nano-components are discussed in terms of their “macroscopic” component shape (e.g., films, wires, tubes and dots) and “inner” inhomogeneous structure (e.g., domain walls and grain boundaries), based on the first-principles density-functional theory calculations. Moreover, this paper also presents a remarkable interplayed effect of the macroscopic shape and the inner structure on the property through a theoretical investigation on polydomain PbTiO₃ ultrathin films.     

Reaction Behavior of Stratified SiO2 Granules during Electrochemical Reduction in Molten CaCl2

The electrochemical reduction behavior of stratified SiO₂ granules in molten CaCl₂ at 1123 K (850 °C) was investigated to develop a new process for producing solar-grade silicon. The cross sections of the electrolyzed electrode prepared from a graphite crucible filled with SiO₂ granules were observed and analyzed. The visual and SEM observations indicate that the overall reduction proceeds via two different routes. In one route, the reduction proceeds along the granule surfaces from the SiO₂ near the conductor to the distant SiO₂. In the other route, the reduction proceeds from the granule surface to the core of each granule. The reduction along the granule surfaces is faster than that from the surface to the core. Fine SiO₂ granules are expected to be favorable for a high reduction rate.     

Formation control of multiple nonholonomic mobile robots

Tracking control problem of multiple mobile robots is considered. Our system is composed of a reference and follower robots of unicycle type. The robots are assumed to satisfy pure rolling and nonslipping conditions, which lead to nonholonomic constraints. The purpose is to control the followers so that the reference is tracked with arbitrary desired clearance and also to avoid interrobot collisions. To accomplish this goal, we first introduced a virtual robot (VR) tracking control to establish and maintain the formation when no collision is detected. VR is an ideal robot fixed with each follower and helps in simplifying the control, as the tracking error becomes zero in the final stage. During the process, if the possibility of collision is detected, a collision avoidance technique (l?ψ or l?l control) will be applied to the lower priority robot. The result of this control gives a monotonic convergence in an internal shape of distance variables, which enables us to predict the movement of the robots during this control and leads to collision‐free movement. These processes are repeated until the desired motion is accomplished. Simulation results prove the efficiency of our control techniques. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(3): 81–88, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20192 Copyright © 2006 Wiley Periodicals, Inc.     

Seed specification for displaying a streamline in an irregular volume

Two techniques are presented for specifying seed points, which are the starting points for streamlines, in an irregular volume. One is an interactive seed specification technique, in which efficient data probing is achieved by traversing the adjacency graph of the volume. The other is an automatic seed specification technique. A seed point is placed near a critical point, where the velocity vector is zero. Efficient algorithms are given for finding and classifying the critical point by using a tetrahedral cell. A successful application of these techniques to a problem in a clean room is also described.koyamadaattrl.ibm.co.jp