A synthetic fiber rope is potentially capable of replacing a stainless steel wire rope because it is light weight, and has high tensile strength and flexibility. In order to exploit the maximum tensile strength of the rope, a terminal fixation method with a sufficient fixing force is essential. However, this is extremely difficult in the case of synthetic fiber ropes due to their small friction coefficients. This letter proposes a new terminal fixation method combined with a grooved pulley and pin. The grooved pulley is utilized in order to increase the friction between the synthetic fiber rope and the pulley, and the rope is wound around the grooved pulley. The extremity of the rope is fixed at a pin by hanging a loop with a figure-eight knot. The appropriate groove shape is found experimentally and it is confirmed that our method achieves maximum fixation force of 91.3% against the rope breaking force. We provide implementations examples for a long-reach tendon-driven manipulator.
Currently, synthetic fiber ropes which have high strength while being lightweight, are applied to tendon-driven robots. In our previous works, it is clarified that a rope using UHMWPE has higher strength and repetitive bending durability than not only stainless steel wire rope but also other synthetic fiber ropes. However, there are also some types of UHMWPE fiber, and some rope are heat-set and others are not. In this paper, we focus on repetitive bending durability of heat-set ropes. As a result, a heat-set or densely rope of UHMWPE has high strength. Moreover, the higher strength a rope has, the lower bending durability the rope has.
Magnetisation measurements and electron spin resonance (ESR) spectra of a doped quasi two dimensional (2D) antiferromagnet on a triangular lattice Rb1−xKxFe(MoO4)2 reveal a crucial change of the ground state spin configuration and a disappearance of a characteristic 1/3-magnetisation plateau at x = 0.15. According to theory for triangular antiferromagnets with a weak random modulation of the exchange bonds, this is a result of the competition between the structural and dynamic disorders. The dynamic zero-point or thermal fluctuations are known to lift the degeneracy of the mean field ground state of a triangular antiferromagnet and cause the spin configuration to be the most collinear, while the static disorder provides another selection of the ground state, with the least collinear structure. Low-level doping (x ≤ 0.15) was found to decrease the Néel temperature and saturation field by only few percent, while the magnetisation plateau disappears completely and the spin configuration is drastically changed. ESR spectra confirm an impurity-induced change of the so-called Y-type structure to an inverted Y-structure for x = 0.15. For x = 0.075 the intermediate regime with the decrease of width and weakening of flattening of 1/3-plateau was found.
We observe a disappearance of the $1/3$ magnetization plateau and a striking change of the magnetic configuration under a moderate doping of the model triangular antiferromagnet $\mathrm{RbFe}({\mathrm{MoO}}_{4}{)}_{2}$. The reason is an effective lifting of degeneracy of mean-field ground states by a random potential of impurities, which compensates, in the low-temperature limit, the fluctuation contribution to free energy. These results provide a direct experimental confirmation of the fluctuation origin of the ground state in a real frustrated system. The change of the ground state to a least collinear configuration reveals an effective positive biquadratic exchange provided by the structural disorder. On heating, doped samples regain the structure of a pure compound, thus allowing for an investigation of the remarkable competition between thermal and structural disorder.
We experimentally measure a continuous strain distribution using low-coherence Brillouin optical correlation-domain reflectometry, which suppresses the noise caused by the sidelobes of a beat spectrum of conventional sinusoidal modulation.
ABSTRACT Photochromic ring-closure reaction of a network polymer film ( Poly BPOH-C ) obtained by oxidation polymerization of the closed-ring isomer ( BPOH-C ) of 1,2-bis[2-methyl-6-(o-hydroxyphenyl)-1-benzothiophen-3-yl]hexafluorocyclopentene ( BPOH-O ). In the film, diarylethene molecules are densely packed and they are fixed in photoreactive anti-parallel conformation by cross-linking of the polymer networks. The rate of the film was estimated to be less than 30 ps. These values are similar to those of diarylethene monomers obtained in the solutions, in polymer dispersed system, and in crystalline states, indicating that the oxidation polymer film system keeps high response.
Recently, many very large scale integrations (VLSIs) or processors are integrated onto one place in data centers, artificial intelligence (AI) centers, supercomputers, and so on. In such cases, communication latency and throughput between processors invariably become main concerns. The latency, throughput, and power consumption of a network on a chip are superior to those of external communication between VLSI chips. Therefore, we propose a wafer-scale VLSI to improve the various communication shortcomings. However, wafers have many defects during the production phase. In current fabrications, even if each die size is sufficiently small, the yield ratio of the chips is limited to less than 90 %. Therefore, a wafer-scale VLSI must have many defects. However, if a programmable architecture could be introduced to wafer-scale VLSIs, then defect regions could be avoided. Non-defect regions could be used for operations. This paper therefore presents a wafer-scale VLSI realization using programmable architecture.
Utilizing wasted heat is a important issue to reduce primary fuel consumption. Because wasted heat sources are located far from heat demand, it is required to transport thermal energy efficiently. The objective of this study is to investigate the performance of heat transportation and conversion based on absorption heat pump mechanism with ammonia-water as the working fluid experimentally. The test rig incorporates an external heat exchanger to cool high temperature weak solution from the generator in order to emulate transporting working fluid without thermal insulation. The experiment indicates the proposed system can transport thermal energy at ambient temperature and the function of heat transportation does not affect the efficiency of the cycle.
