Manipulation of deformable linear objects using knot invariants to classify the object condition based on image sensor information

Using a topological model and knot theory, we propose a method for describing the condition of a rope. We also propose a recognition method based on the image information obtained from the charge-coupled device cameras to obtain the structure of the rope when manipulated by a robot. This method will help solve the difficulties of robots manipulating deformable objects by providing a theoretical framework of error recovery for deformable object manipulation. We confirm the effectiveness of the methods through experiments.     

Time-Dependent Analysis of the Multiple-Route Packet Combining Scheme in Wireless Multihop Networks

In this paper, we apply the multiple-route packet combining scheme (In Proceedings of the 1st International Symposium on Wireless Communication Systems, pp. 183–187, Mauritius, 2004) to wireless multihop networks in order to support delay-sensitive applications. The performance of the system is time-dependent and is greatly affected by network-level performance. Therefore, it is necessary to develop an analytical framework to evaluate the performance of the system with taking into account its time-dependency. We use queuing theory to analyze the performance of the system. From numerical results, it is shown that the performance degradation of the system is mainly caused by the increase of packet delay, which is due to the increase of the traffic intensity. To prevent the increase of traffic, we propose a packet discarding scheme. We analyze the average packet error probability of the proposed system with the equilibrium point analysis (EPA). Numerical results show that the packet discarding scheme can improve the average packet error probability under heavy traffic conditions.     

High Ambipolar Mobility in a Neutral Radical Gold Dithiolene Complex

A new anionic gold dithiolene complex NBu₄·[1] is synthesized from the (1‐((1,1‐biphenyl)‐4‐yl‐)‐ethylene‐1,2‐dithiolene ligand 1, and the cis and trans isomers are separated by recrystallization. The trans isomer is oxidized via electrocrystallisation to the neutral gold dithiolene complex 2. Complex 2 crystalizes in 1D chains, held together by short (3.30–3.37 Å) S–S contacts, which are packed in a herringbone arrangement in the ab‐plane. The complex exhibits semiconductor behavior (σ_RT = 1.5 × 10^?4 S cm^?1) at room temperature with a small activation energy (E_a = 0.11 eV), with greater conductivity along the stacking direction. The charge transport behavior of complex 2 is further investigated in single‐crystal field‐effect transistor (FET) measurements, the first such measurements reported for gold dithiolene complexes. Complex 2 shows incredibly balanced ambipolar behavior in the single‐crystal field‐effect transistor (SC‐FET), with high charge‐carrier mobilities of 0.078 cm² V^?1 s^?1, the highest ambipolar mobilities reported for metal dithiolene complexes. This well‐balanced behavior, along with the activated conductivity and band structure calculations, suggests that 2 behaves as a Mott insulator. The magnetic properties are also studied by superconducting quantum interference device (SQUID) magnetometry and solid state ¹H NMR, with evidence of a nonmagnetic ground state at low temperature.     

The photochromism of nitrospiropyran included in γ-cyclodextrin

Summary The inclusion compounds of 1, 3, 3-trimethyl-6-nitrospiro-[2H, 1-benzo-pyran-2, 2-indoline] (NSP) with -cyclodextrin (-CD), 2,3,6,0-permethylated -CD (-MCD), and naphthyl modified -CD (-NCD) showed normal photochromism in the solid state with high light sensitivity comparable with that of NSP dispersed in polymer matrices. This is in sharp contrast with NSP in the crystalline state, which is much less photosensitive. These results suggest that the host cavity offers a sufficient free volume for phototransformation of the guest molecule. The colored form of the inclusion compounds were found to be more stable both chemically upon prolonged UV irradiation and thermally in the dark as compared with that in a PMMA film.     

Separation of the enantiomers of 1-alkyl-2-acyl-rac-glycerol and of 1-alkyl-3-acyl-rac-glycerol by high performance liquid chromatography on a chiral column

High performance liquid chromatographic separations of two enantiomeric pairs of 1-alkyl-2-acyl-rac-glycerol (1-alkyl-2-acyl- and 3-alkyl-2-acyl-sn-glycerols) and 1-alkyl-3-acyl-rac-glycerol (1-alkyl-3-acyl- and 3-alkyl-1-acyl-sn-glycerols) as 3,5-dinitrophenylurethanes (3,5-DNPUs) were carried out on a chiral stationary phase, N-(R)-1-(α-naphthyl)ethylaminocarbonyl-(S)-valine chemically bonded to γ-aminopropyl silanized silica (Sumipax OA-4100). Good separation of the enantiomers of 1-hexadecyl-2-hexadecanoyl-rac-glycerol was easily achieved within 10 min using hexane/ethylene dichloride/ethanol (80∶20∶1, v/v/v) as a mobile phase. Separation of the enantiomers of 1-hexadecyl-3-hexadecanoyl-rac-glycerol was more difficult and required about 80 min to achieve satisfactory peak resolution (0.8) using hexane/ethylene dichloride/ethanol (250∶20∶1, v/v/v) as a mobile phase. Presented at the American Oil Chemists' Society 79th Annual Meeting, Phoenix, AZ, May, 1988.     

Measurement of the activity of electrolytes and the application of activity to hydrometallurgical studies

The activity of HC1 in solutions of HCl-NaCl, and the approximate values of the activities of H⁺ and Cl⁻ in solutions of HC1, HC1O₄, HCl-NaCl, HClO₄-NaClO₄ and HC1O₄-NaCl were determined at 25 ° by measuring the electromotive force of a cell consisting of a Pt-Pt black electrode and an Ag-AgCl electrode. The liquid junction potential, estimated by using Henderson’s equation as a first approximation, was subtracted from the measured electromotive force of the cell. Some hydrometallurgical problems which were difficult to understand with the concept of concentration were re-examined, using the activity values thus determined. These problems were the rate of non-oxidative leaching of galena and sphalerite, the acid dissolution rate of cupric oxide, and the rate of oxidation of Fe(II) with molecular dissolved oxygen. Although the dependence of the dissolution rates of galena, sphalerite and cupric oxide upon acid concentration appeared to be rather complicated, the dissolution rates of these minerals were found to be of first order with respect to a_H+. It was also possible to elucidate the role of Cl⁻ ions by using thea _Cl-values. A rate equation obtained experimentally for the autoxidation of Fe(II) in HC1 solutions was found to generally explain the experimental results of previous researchers, which seemed to be inconsistent with each other. On leave-of-absence to the Department of Metallurgy and Material Science, University of Toronto, Ontario, Canada.     

Analytical model for time to cover cracking in RC structures due to rebar corrosion

The structural degradation of concrete structures due to reinforcement corrosion is a major worldwide problem. Reinforcement corrosion causes a volume increase due to the oxidation of metallic iron, which is mainly responsible for exerting the expansive radial pressure at the steel–concrete interface and development of hoop tensile stresses in the surrounding concrete. Cracking occurs, once the maximum hoop tensile stress exceeds the tensile strength of the concrete. The cracking begins at the steel–concrete interface and propagates outwards and eventually results in the thorough cracking of the cover concrete and this would indicate the loss of service life for the corrosion affected structures. An analytical model is proposed to predict the time required for cover cracking and the weight loss of reinforcing bar in corrosion affected reinforced concrete structures. The modelling aspects of the residual strength of cracked concrete and the stiffness contribution from the combination of reinforcement and expansive corrosion products have also been incorporated in the model. The problem is modeled as a boundary value problem and the governing equations are expressed in terms of the radial displacement. The analytical solutions are presented considering a simple two-zone model for the cover concrete, viz. cracked or uncracked. Reasonable estimation of the various parameters in the model related to the composition and properties of expansive corrosion products based on the available published experimental data has also been discussed. The performance of the proposed corrosion cracking model is then investigated through its ability to reproduce available experimental trends. Reasonably good agreement between experimental results and the analytical predictions has been obtained. It has also been found that tensile strength and initial tangent modulus of cover concrete, annual mean corrosion rate and modulus of elasticity of reinforcement plus corrosion products combined significantly influence predicted time to cover cracking. The analytical predictions of the proposed model have also been found to be in line with those of the other reported published data.     

基于辐射压力控制的微型元件的加工与检测

We have been developing new fabrication tools based on optical radiation pressur e and related phenomena to develop aflexible and accurate microfabrication tec hnology. In this paper, the laser trapping probe for the nano-CMM for assessment, in addition to micromachining technique using a small particle controlled by optical radiation pressure and laser aggregation technique are discussed. As the positional detection probe for the nano-CMM, an optically trapped silica particle with 8 mm diameter in forced oscillation state is used. A probe sphere retains a stable position when applied with trapping force by Nd:YAG laser light formed an nu lar and is forced to oscillate by the driving force changed by modulating the in tensity of LD emission. Experintal results show that this vibrational microprobe h as the possibility to achieve positional sensing accuracy of less than 25 nm. As a new micromachining technique, nano-removal process using an optically trapped micro-grain is proposed. The laser trapping force enables not only to stably trap the diamond grain with asymmetrical shape but also to freely control the positi on with spinning. Using this micro machining tool, the machining experiments of h ydrocarbon film are performed. AFM observation confirmed that the fine groove wi th depths of about 3～4 nm can be fabricated. As an additive process based on ra diation pressure, a laser microstructure fabrication using laser agglomeration p h enomena of colloidal particles aided by radiation pressure is investigated. By c ontrolling laser beam scanning in slurry containing KOH solution and SiO₂ par ticles with a diameter of 140 nm, colloidal particles are aggregated and adhered firmly to a silicon wafer substrate. Using this laser agglomerating process, two-dimensional grid microstructures at the pitch of 5 mm can be fabricated.     

Enantioselective Reaction of Imines and Benzyl Nitriles Using Palladium Pincer Complexes with C2‐Symmetric Chiral Bis(imidazoline)s

Enantioselective reactions of a wide variety of benzyl nitriles with N‐tosylimines catalyzed by novel chiral 1,3‐bis(imidazolin‐2‐yl)benzene‐palladium(II) [Phebim‐Pd(II)] complexes have afforded the respective products in high yield with good enantioselectivity. A reaction mechanism is proposed based on X‐ray crystal structures of palladium complexes.     

Effects of alginate oligosaccharide mixtures on the growth and fatty acid composition of the green alga Chlamydomonas reinhardtii

Alginate is a natural acidic linear polysaccharide that is produced by brown seaweeds. It is currently used in a broad range of commercial enterprises, such as the food and medical products industries. Recent evidence has demonstrated that alginate oligosaccharides may function as growth promoting agents for certain plant cells, including those of some green algae. Chlamydomonas reinhardtii is a green alga that is used as a model organism in fundamental molecular biology studies; it is also a producer of biohydrogen. In the present study, we examined effects of two types of alginate oligosaccharide mixtures (AOMs), which were prepared by either enzymatic degradation (ED) or acid hydrolysis (AH), on the growth of C. reinhardtii. Growth was significantly promoted by AOM (ED) in a concentration-dependent manner. The maximum effect was observed on day 4 of treatment. The fatty acid composition of C. reinhardtii was also influenced by AOM (ED); the levels of C16:0, C18:2 cis and C18:3 n-3 increased in treated cells. AOM (AH) and the other saccharides that we tested did not affect the growth of C. reinhardtii. The effects that we identified could promote efficient biomass production by reducing culture times and by changing cellular fatty acid levels.