Efficient synthesis and magnetic properties of triphenylamine bearing three nitronylnitroxide radicals

Improved synthesis and reinvestigation of the magnetic properties of triphenylamine bearing three nitronylnitroxide radicals (1) were carried out. Single crystal X-ray crystallographic analysis of 1 established that its molecular shape had a C₃-symmetry. Our newly prepared 1 showed different physical properties from those of reported. SQUID measurements of 1 showed that each of the three spins of 1 behaved independently at room temperature. In contrast, the three spins coupled antiferromagnetically at lower temperature as low as ca. 1.8 K. These spin behaviors can be explained by a regular triangular antiferromagnetic model (J/k_B = ?3.3 K) and interpreted as a spin frustration system.     

Design and VLSI evaluation of a high-speed cellular array divider with a selection function

In recent years, very fast dividers have been required for the real-time application of digital signal processing, robot control, and the like. This paper proposes a high-speed cellular array divider with a selection function that is based on the non-restoring algorithm and can deal with both fixed-point and negative operands in two's complement form. This divider uses new techniques that can generate in parallel both the quotient bit of one row and a partial remainder and CLS bit of the next row. The delay time of the proposed divider is calculated in terms of a delay of one unit such as a NAND gate. Finally, by using PARTHENON, a CAD (computer-aided design) system for VLSI, this divider is designed and evaluated. As a result, elimination of the delay time for even rows becomes possible. Thus, the delay time can be decreased to approximately one half that of the high-speed divider proposed by Cappa and Hamacher, which uses the most general high-speed techniques of carry-save and CLA.     

The effect of beam profile at a focal point on welding deformation. A study of the deformation behaviour by laser welding at micron or submicron level in automobile parts

Due to a growing awareness for the environment, demands for functions which enable cleaner exhaust emissions and lower fuel consumption have increased in the field of automotive components. In order to manufacture automotive components that meet these demands and still remain competitive, it is vital to develop high-precision processing technologies for realising new functions. One technique which has been receiving attention is laser processing.^1,2 Laser welding has a higher energy density and hence induces much less welding deformation than arc welding. However, even this degree of deformation is too significant to ignore in welding at micron and sub-micron levels (which is the subject of this study). Also, since the types of lasers used in laser welding vary greatly, an understanding of the characteristics between laser energy distribution (the beam profile) and welding deformation is necessary to improve precision in processing. For example, by examining the effects of different beam profiles at the focal point on welding deformation, it will be possible to obtain a beam profile and enable the reduction and control of welding deformation at the sub-micron level.     

Humanoid robot arm performance optimization using multi objective evolutionary algorithm

As humanoid robots are expected to operate in human environments they are expected to perform a wide range of tasks. Therefore, the robot arm motion must be generated based on the specific task. In this paper we propose an optimal arm motion generation satisfying multiple criteria. In our method, we evolved neural controllers that generate the humanoid robot arm motion satisfying three different criteria; minimum time, minimum distance and minimum acceleration. The robot hand is required to move from the initial to the final goal position. In order to compare the performance, single objective GA is also considered as an optimization tool. Selected neural controllers from the Pareto solution are implemented and their performance is evaluated. Experimental investigation shows that the evolved neural controllers performed well in the real hardware of the mobile humanoid robot platform.     

Solid-State Electrochemical Thermal Transistors

Thermal transistors that electrically control heat flow have attracted growing attention as thermal management devices and phonon logic circuits. Although several thermal transistors are demonstrated, the use of liquid electrolytes may limit the application from the viewpoint of reliability or liquid leakage. Herein, a solid-state thermal transistor that can electrochemically control the heat flow with an on-to-off ratio of the thermal conductivity (κ) of ≈4 without using any liquid is demonstrated. The thermal transistor is a multilayer film composed of an upper electrode, strontium cobaltite (SrCoO_x), solid electrolyte, and bottom electrode. An electrochemical redox treatment at 280 °C in air repeatedly modulates the crystal structure and κ of the SrCoO_x layer. The fully oxidized perovskite-structured SrCoO₃ layer shows a high κ ≈3 .8 W m⁻¹ K⁻¹, whereas the fully reduced defect perovskite-structured SrCoO₂ layer shows a low κ ≈ 0.95 W m⁻¹ K⁻¹. The present solid-state electrochemical thermal transistor may become next-generation devices toward future thermal management technology.     

Combined Effects of Methylated Cytosine and Molecular Crowding on the Thermodynamic Stability of DNA Duplexes

Methylated cytosine within CpG dinucleotides is a key factor for epigenetic gene regulation. It has been revealed that methylated cytosine decreases DNA backbone flexibility and increases the thermal stability of DNA. Although the molecular environment is an important factor for the structure, thermodynamics, and function of biomolecules, there are few reports on the effects of methylated cytosine under a cell-mimicking molecular environment. Here, we systematically investigated the effects of methylated cytosine on the thermodynamics of DNA duplexes under molecular crowding conditions, which is a critical difference between the molecular environment in cells and test tubes. Thermodynamic parameters quantitatively demonstrated that the methylation effect and molecular crowding effect on DNA duplexes are independent and additive, in which the degree of the stabilization is the sum of the methylation effect and molecular crowding effect. Furthermore, the effects of methylation and molecular crowding correlate with the hydration states of DNA duplexes. The stabilization effect of methylation was due to the favorable enthalpic contribution, suggesting that direct interactions of the methyl group with adjacent bases and adjacent methyl groups play a role in determining the flexibility and thermodynamics of DNA duplexes. These results are useful to predict the properties of DNA duplexes with methylation in cell-mimicking conditions.     

Bayesian Segmentation of Hip and Thigh Muscles in Metal Artifact-Contaminated CT Using Convolutional Neural Network-Enhanced Normalized Metal Artifact Reduction

Journal of Signal Processing Systems - In total hip arthroplasty, analysis of postoperative medical images is important to evaluate surgical outcome. Since Computed Tomography (CT) is most...