In this paper, we propose a new method for biped humanoids to compensate for large amounts of angular momentum induced by strong external perturbations applied to the body during gait motion. Such ...angular momentum can easily cause the humanoid to fall down onto the ground. We use an Angular Momentum inducing inverted Pendulum Model (AMPM), which is an enhanced version of the 3D linear inverted pendulum model to model the robot dynamics. Because the AMPM allows us to explicitly calculate the angular momentum generated by the ground reaction force, it is possible to calculate a counteracting motion that compensates for the angular momentum generated by external perturbations in real-time.
An aggregometer technique was used to study urease-induced crystallizations in synthetic urine and human urine from healthy subjects and patients with chronic spinal cord injuries. The two different ...phases of crystallization, calcium phosphate and magnesium ammonium phosphate, were easily evaluated with a single assay using this technique. The crystallization of calcium phosphate and magnesium ammonium phosphate varied markedly among the different urine specimens after incubation with urease. The turbidity curves from human urine were divided into four patterns. We assumed that the variations in the patterns of the turbidity curves appeared to be mainly due to differences in the composition of the urine and in the original pH, and that the calcium and magnesium concentrations were very important in the urinary constituents.
When any muscle in the human musculoskeletal system is damaged, other muscles and ligaments tend to compensate for the role of the damaged muscle by exerting extra effort. It is beneficial to clarify ...how the roles of the damaged muscles are compensated by other parts of the musculoskeletal system from the following points of view: From a clinical point of view, it will be possible to know how the abnormal muscle and joint forces caused by the acute compensations lead to further physical damage to the musculoskeletal system. From the viewpoint of rehabilitation, it will be possible to know how the role of the damaged muscle can be compensated by extra training of the other muscles. A method to evaluate the influence of muscle deactivation on other muscles and joints is proposed in this report. Methodology based on inverse dynamics and static optimization, which is applicable to arbitrary motion was used in this study. The evaluation method was applied to gait motion to obtain matrices representing (1) the dependence of muscle force compensation and (2) the change to bone-on-bone contact forces. These matrices make it possible to evaluate the effects of deactivation of one of the muscles of the musculoskeletal system on the forces exerted by other muscles as well as the change to the bone-on-bone forces when the musculoskeletal system is performing the same motion. Through observation of this matrix, it was found that deactivation of a muscle often results in increment/decrement of force developed by muscles with completely different primary functions and bone-on-bone contact force in different parts of the body. For example, deactivation of the iliopsoas leads to a large reduction in force by the soleus. The results suggest that acute deactivation of a muscle can result in damage to another part of the body. The results also suggest that the whole musculoskeletal system must go through extra retraining in the case of damage to certain muscles.
To prepare organic solar cells with practical level of energy-conversion efficiency, the following strategies were adopted. By using HD as the photosensitizer, which is heterodimer consisting of a ...weak electron-donating 5, 10, 15, 20-tetra(2, 5-dimethoxyphenyl)porphyrinatozinc and a weak electron-accepting 5, 10, 15-triphenyl-20-(3-pyridyl)porphyrin, intramolecular photoinduced electron transfer is promoted resulting in effective charge separation. To create an energetically well-arranged system, the HD was placed between an electron-acceptor layer of PV (perylene-3, 4, 9, 10-tetracarboxyl-bis-benzimidazole) and strong electron-donor layer of MC (3-carboxymethyl-5-(3-ethyl-2(3H)-benzothiazolylidine)ethylidene-2-thioxo-4-thiazolidinone), where photoinduced intermolecular electron transfer from HD to PV and rapid injection of electrons from MC to HD suppress back electron transfer in the charge-separated HD. As a result of this, the three-layer solar cell Al/PV/HD/MC/Au showed fairly good photovoltaic properties, short-circuit photocurrent quantum yield of 49.2%, open-circuit photovoltage of 0.39
V, fill factor of 0.51, and energy conversion yield of 3.51% when irradiated with 445
nm monochromatic light of 12
μW
cm
−2 intensity transmitted through the Al/PV interface. Since the photocurrent hardly decreased with age, the photocurrent observed here is really from energy conversion and not from photocorrosion of Al electrode being occasionally responsible for the photocurrent.
We report an atomistic study on solid phase epitaxy processes of amorphous Si layers on Si(001) using a scanning tunneling microscope. The amorphous layers are prepared by vacuum evaporation, Ar
...+-ion sputtering, or P
+-ion implantation. The surface morphology of the as-prepared surface is strongly damaged by energetic impinging particles. The solid phase epitaxy processes are strongly correlated with the surface damage: crystallization of amorphous layers by annealing at around 250°C is observed on both the vacuum deposited and Ar
+-ion sputtered surfaces, while an annealing temperature higher than 730°C is needed to recover the crystallinity of the P
+-ion implanted surface.
Type 304 stainless steel samples were irradiated with MeV-energy H and He ions and deuterium concentrations were in-situ observed by a nuclear reaction analysis (NRA) under a condition of continuous ...plasma exposure. It was found that one type of trap was produced by the irradiation and its trapping energy was 0.28 eV. The trap production rates to displacement were 6.8x10
-3
for He ion and 5.1x10
-4
for H ion, respectively. The trap was annihilated at 489 K in H-irradiated sample.
Water solubility in all pH region for externally HCl-doped conducting polyaniline (ED-SPAN) enables us to do its detail characterization by UV–VIS spectra, cyclic voltammogram, ESR spectra, and ...electrical conductivity in relation to the doping level. It was found that one free radical was produced in polyaniline backbone by the addition of one proton onto the imino-nitrogen. The electrical conductivity of ED-SPAN solid film remarkably increased with increasing free radical in polyaniline backbone because of remarkable increase of the hole mobility. Undoping of ED-SPAN solid occurred by heating at more than 40
°C.
An enhanced photocurrent was observed for a two-layer cell consisting of a regioregular polythiophene (PTh) blended with metal-free porphyrin (H
2tpp) and a perylene tetracarboxylic derivative (PV), ...compared to a PTh (without H
2tpp)/PV two-layer cell. This is because photoexcited H
2tpp molecules efficiently transfer holes to PTh molecules and then produced electrons in H
2tpp molecules rapidly transfer to PV molecules at the mixed solid/PV interface. In the two-layer photocell with the mixed solid, H
2tpp behaves as a sensitizer, PTh and PV solids as carrier transport layers, and the mixed solid/PV interface as a charge separation site. Power conversion efficiency attained to
η=2.9% for the PTh (with H
2tpp)/PV two-layer cell under monochromatic light with 6
μW
cm
−2 intensity.
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