Solvent Extraction of Picric Acid from Acid Aqueous Solutions into Cyclohexane with Trioctylphosphine Oxide and Trioctylamine

The solvent extraction of picric acid(Hpic) from acid aqueous chloride solutions into cyclohexane with trioctylphosphine oxide(TOPO) and trioctylamine(TOA) was examined and the UV-visible spectrum of the organic phase was studied. In the organic phase, the acid associates with one or two TOPO molecules but it associates with only one TOA molecule. The absorption peak of the 1:1 associate with TOPO appears only in the UV range and thus it is assumed to be a hydrogen-bonded molecular adduct. The 1:2 associate with TOPO and the 1:1 associate with TOA, on the other hand, has a marked absorption peak in the visible range which is quite similar to that of picrate ions and thus the extracts are assumed to be ion pairs in which an electron transfers from the hydrogen atom to the oxygen atom in the OH-group. For this reason, the spectrum of TOPO extract is dependent on the amount of free extractant but that of TOA extract is not.     

Dynamically-Stable Motion Planning for Humanoid Robots

We present an approach to path planning for humanoid robots that computes dynamically-stable, collision-free trajectories from full-body posture goals. Given a geometric model of the environment and a statically-stable desired posture, we search the configuration space of the robot for a collision-free path that simultaneously satisfies dynamic balance constraints. We adapt existing randomized path planning techniques by imposing balance constraints on incremental search motions in order to maintain the overall dynamic stability of the final path. A dynamics filtering function that constrains the ZMP (zero moment point) trajectory is used as a post-processing step to transform statically-stable, collision-free paths into dynamically-stable, collision-free trajectories for the entire body. Although we have focused our experiments on biped robots with a humanoid shape, the method generally applies to any robot subject to balance constraints (legged or not). The algorithm is presented along with computed examples using both simulated and real humanoid robots.     

Multilayer structure of tantalum anodic oxide films formed in dilute phosphoric acid

An investigation has been made of the multilayer structure of anodic oxide films on pure tantalum, formed up to various voltages with a constant current density of 1.0 mA cm^-2 in 1.0 × 10^-2 N H₃PO₄ at 20°C. For the study, infrared reflectance spectra (IRRS) were recorded and the optical thickness measuring method was successfully applied using the wavelengths of optical interference maxima and a chemical film stripper (concentrated ammonium hydrogen difluoride aqueous solution).The conclusions are that: (1) tantalum anodic oxide films anodized in dilute phosphoric acid consist of three layers, irrespective of the formation voltage; (2) the innermost layer is uniform whatever the anodization voltage; (3) phosphate anions are incorporated in both the outermost and middle layers but not in the innermost layer; (4) all three layers grow from the initial formation stage and the growth rates are nearly equal; (5) for formation voltages below 100 V the middle layer has an unchanging chemical structure, but above 100 V its chemical structure changes with the voltage; (6) the outermost layer appears to vary in chemical structure over all anodization voltages.     

Transcriptional activation of the tobacco retrotransposon Tto1 by wounding and methyl jasmonate

Health visitors and Clinical Medical Officers (CMOs) were trained in parent counselling and worked at home in a highly deprived area with parents of pre-school children with multiple psychosocial problems. Their basic aims were to establish a mutually respectful partnership and to support parents in managing their diverse problems. Detailed evaluation indicated that the Service was highly valued by both parents and referrers, and suggested significant changes, including: improvements in the severity of problems; increased parental self-esteem; decreased levels of parental stress and emotional difficulties; more positive constructions of their children; improvements in the home environment; and decreased child behavioural problems.     

The experimental humanoid robot H7: a research platform for autonomous behaviour

This paper gives an overview of the humanoid robot 'H7', which was developed over several years as an experimental platform for walking, autonomous behaviour and human interaction research at the University of Tokyo. H7 was designed to be a human-sized robot capable of operating autonomously in indoor environments designed for humans. The hardware is relatively simple to operate and conduct research on, particularly with respect to the hierarchical design of its control architecture. We describe the overall design goals and methodology, along with a summary of its online walking capabilities, autonomous vision-based behaviours and automatic motion planning. We show experimental results obtained by implementations running within a simulation environment as well as on the actual robot hardware.     

Walking: technology and biology

If all the signs are to be believed, then the twenty-first century will technologically be characterized by machine walking and its relevant products, which possess all chances to become real bulk goods in the course of the next decades. With several university institutes and with Honda and Sony from the industrial side, Japan is today and without any doubt the leading nation in research and development of walking machines. The US and Europe follow at some distance. Walking machines will influence all areas of daily and industrial life and, with the fast evolution of artificial intelligence, will become a real partner of human beings. All relevant technologies are highly interdisciplinary, they will push the future technologies of all technical fields. The special issue on this topic gives a selection of walking machine research and development including some aspects from biology.     

In-vitro reconstitution of hepatic tissue architectures with neonatal mouse liver cells using three-dimensional culture

Stem cells have the potential to differentiate into multiple lineages, and the capabilities to self-renew, and reconstitute tissues following transplantation. Thus, stem cells are expected to be useful for regenerative medicine; however, the mechanisms that regulate the reconstitution of three-dimensional (3-D) tissues remain to be elucidated. To study such mechanisms, we have established a novel procedure of 3-D culture that supports the formation of tissues from isolated cells, including hepatic stem/progenitor cells in vitro. We cultured neonatal mouse liver cell populations, including hepatic stem/progenitor cells, in a simulated microgravity environment produced by a Rotating Wall Vessel bioreactor. After 8 days in culture, we obtained a 3-D tissue architecture. Histological analysis showed that bile duct structures secreting mucin formed complicated tubular branches in the peripheral region. In the non-bile duct structure region, we observed mature hepatocytes that were capable of producing albumin and storing glycogen. Thus, we were able to establish a novel 3-D culture system that is able to reconstitute functional hepatic tissue architecture from isolated neonatal mouse liver cells.     

A Fast Dynamically Equilibrated Walking Trajectory Generation Method of Humanoid Robot

This paper describes a fast dynamically equilibrated trajectory generation method for a humanoid robot. From a given input motion and the desired ZMP trajectory, the algorithm generates a dynamically equilibrated trajectory using the relationship between the robot's center of gravity and the ZMP. Three key issues are denoted: 1) an enhanced ZMP constraint which enables the calculation of robot stability even if several limbs are contacting the environment, 2) a simplified robot model is introduced that represents the relationship between its center of gravity and ZMP, 3) a convergence method is adopted to eliminate approximation errors arising from the simplified model. Combining these three key issues together with online ZMP compensation method, humanoid robot H5 have succeeded to walk, step down and so on. Experimental results using humanoid robot H5 are described.     

Industrial application of position sensorless active magnetic bearings

Active magnetic bearings (AMBs) are applied to turbomolecular pumps (TMPs) and milling spindles. However, their application areas are limited because they are costlier and require larger space than conventional mechanical bearings. Omitting position sensors from AMBs is one of the promising methods to solve such problems. An additional merit is that rotors can be shortened to have a higher critical speed by removing sensor targets from the rotor. The sensorless operation of AMBs has already been achieved in several instruments developed for experimental study. In this research, the sensorless magnetic suspension method is applied to a TMP manufactured as an industrial product, and it is demonstrated that sensorless AMBs can suspend a high-speed rotor.     

View-based navigation using an omniview sequence in a corridor environment

View- and appearance-based approaches have recently been attracting the interest of those involved in computer vision research. We have already proposed a visual view-based navigation method using a model of the route called the ”view sequence,” which contains a sequence of front views along a route memorized in the recording run. In this paper, we firstly apply the omnidirectional vision sensor to our view-based navigation method and propose an extended model of a route called the ”omniview sequence.” Secondly we propose a map named the ”view-sequenced map” which represents an entire corridor environment in a building. A method for the automatic acquisition of a view-sequenced map based on the exploration in a corridor using both stereo and omnidirectional vision is also described. Finally experimental results of the autonomous navigation and the map acquisition are presented to show the feasibility of the proposed methods. Correspondence to: Y. Matsumoto (e-mail: yoshio@is.aist-nara.ac.jp)