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Implantable energy harvesting system utilizing contraction of an electrically-stimulated skeletal muscle is proposed for alternative batteries of implantable medical devices. In order to realize high conversion efficiency, we propose a resonance generator utilizing vibration of the skeletal muscle, which is called as incomplete tetanus. Experimental results showed the incomplete tetanus was a suitable form for the energy harvesting and the stimulation at the frequency of 10 Hz was maximized the work of the muscle. Dimensions of the springs of the generator were designed so that its natural frequency was 10 Hz. On the simulation, the maximum generated power was achieved 122.5 μW, which is enough to power the IMDs.Clinical Relevance-The proposed system has a potential to eliminate conventional batteries in the implantable medical devices. It will be beneficial for patients since the periodical surgery for the battery replacement will be avoided.

Biohybrid actuators consisting of skeletal muscle and artificial lattice have unique characteristics such as self-growth and self-repair functions. As a first step for developing model-based design and model-based control methods for the biohybrid actuators, we have developed a muscle contraction model. When the stimulation voltage is applied to the muscle, the electrical charges are stored in the dihydropyridine receptor, and the calcium ions are released. According to the concentration of the ions, the contractile elements generate contraction force. We have modeled this phenomenon with three characteristics in the proposed model-electrical dynamic, physiological, and mechanical dynamic characteristics. Unlike the previous models, the proposed model was verified under the condition of tetanus and incomplete tetanus with the muscle length changed. The simulated contraction force showed good agreement with the experimentally measured contraction force generated by the gastrocnemius muscle of a toad.Clinical Relevance- Biohybrid actuators are expected as a new material for medical and assistive devices having a soft and flexible characteristic. This study provides a basic contraction model for such biohybrid actuators.

We propose an energy harvesting device driven by a contraction of an electrically-stimulated skeletal muscle for an alternative battery of implantable medical devices. In order to realize a durable generator, we proposed a contactless plucking mechanism utilizing parallel leaf springs and magnets, with which the generator can be driven without friction. By utilizing this mechanism, the generator can be driven not only in a contraction phase, but also a relaxant phase. We optimized the stiffness of the parallel leaf springs, air gap between the magnets, and magnetic circuit in order to maximize generated power of the generator. The generated power of the prototype in nonliving environment was evaluated. The result showed the protype could achieve 35.8 μW, the value of which is enough to drive the implantable medical devices. Finally, the generated power was evaluated in the ex-vivo experiment using a gastrocnemius muscle of a toad with a weight of 193.4 g. In this experiment, the generator achieved 18.1 μW from only 3.5 g of the skeletal muscle. Also, we confirmed that the generated power exceeded the power consumption of the electrical stimulation on the skeletal muscle. Hence, we concluded the results showed the feasibility of the energy harvesting system with proposed mechanism.

We propose a contactless energy harvesting system driven by the contraction of an electrically-stimulated skeletal muscle to be used to supply electrical energy to implantable medical devices. In order to realize a durable generator, the one proposed here has a contactless clutch mechanism with parallel leaf springs, with which the generator can be driven without friction. In this system, the muscle connected to the parallel leaf spring is intentionally contracted by electrical stimulation. The generator can be driven not only in the contraction phase of the muscle, but also relaxation phase. The result an evaluation showed that the prototype could generate 26.1 $\mu \mathrm{W}$ with an efficiency of 13.7%. Finally, we conducted an animal experiment using the gastrocnemius muscle of a toad with a weighing of200 g The generator was driven in the contraction phase generating 1.37 $\mu \mathrm{W}$ of power from the energy supplied by the muscle.

In order to investigate the occurrence of the intergranular cracking, the fatigue crack propagatin tests have been carried out on copper bicrystal specimens in which the constituent crystals have several orientation relationships close to Σ3(111) coherent twin boundary. It was found that fatigue crack growth behavior depended significantly on the deviation angle from the Σ3(111) relation. In the specimens having the deviation angles less than 3°, no any intergranular crack growths were observed. When the deviation angle increased up to abount 5°, the fatigue cracks often propagated along the GBs. However at the deviation angles more than 9°, the intragranular cracking became predominant again. Such intragranular cracks propagated along well-developed slip bands. This deviation-angle dependence of the intergranular cracking could be understood in terms of the changes in both the grain boundary character and the development of the slip bands within the constituent grains.

C H dissociation is known to be responsible for the formation of radiation damage of hydrocarbon crystals such as color centers or radicals. Recently, Auger electron photoion coincidence (AEPICO) spectroscopy has allowed us to get detailed information on microscopic processes of radiation damage, because AEPICO spectroscopy can pick up only the fundamental processes, excluding effects due to secondary electrons. In this work, in an attempt to study which electronic state is responsible for the C H bond dissociation, AEPICO spectra of benzene solid were measured at 80 K as a function of photon energy. AEPICO measurements were examined at three photon energies, i.e. 285 eV(π*(e2u) ← 1s), 287 eV(σ*(C H) ← 1s), and 430 eV(ionization← 1s). Relative magnitudes of the AEPICO yieldY(hv), which reflects the C H dissociation yield, were estimated by dividing AEPICO signals with intensities of Auger electron yield. Experimental results showed thatY(287eV)/Y(430eV)≈ 1, whereasY(287eV)/Y(430eV)≈ 0.13. A relation between the small value ofY(287eV)/Y(430eV) with the small values of the radiation damage yieldη(hv) near 285 eV is discussed. In that case,η(nearKedge)η(overKedge)≈ 0.1∼0.3 [5] [A. Kimura, K. Nakagawa, K. Tanaka, M. Kotani, R. Katoh, Nucl. Instr. and Meth. in Phys. Res. B91 (1994) 67].

We have studied the effects of Nd 4 Ba 2 Cu 2 O 10 (Nd422) on the pinning characteristics of NdBa 2 Cu 3 O 7− δ (Nd123) crystals. Like Y 2 BaCuO 5 particles in the Y–Ba–Cu–O system, the addition of Nd422 could enhance critical current density J c at lower fields. The peak field ( B pk ) and the J c value at B pk were almost independent of Nd422 contents although a slight decrease in J c at B pk was observed with increasing Nd422 contents. The normalized relaxation rate ( S ) increased for all the samples when the field exceeded B pk . The addition of Nd422 was effective in preventing a rapid increase in S above B pk . The exponent μ , defined in the collective creep model, was deduced by fitting the experimental data and was found to show strong field dependence. We found that μ changes from positive to negative at around B pk , suggesting that the flux creep mechanism is different below and above B pk .

Feasibility of transmutation of long-lived Fps in BWR is studied from the view point of neuron balance. Pointing out the equilibrium mass amount of LLFP such as 129 I, 99 Tc, and 126 Sn in BWR core, the neutron balance analysis shows that the available neutrons produced by the current BWR core modification is satisfactory to the required amount of neutrons for LLFP transmutation. Core performance of the LLFP-recycled BWR is then analyzed and the result shows satisfactory results for the present core design criteria. The results confirm the potential of the transmutation of LLFP in BWR and that the eventual radioactive hazard of the radwaste coming form the LLFP recycled BWR can be reduced well below the hazard level of the burned uranium.

To reduce the cost of a DVD player, we have integrated peripheral functions to the audio and video decoder LSI. The peripheral functions are controlled by the I/O processing tasks on single I/O control processor. I/O processing tasks are switched in constant cycle without overhead, to achieve real-time performance and flexibility of software control. In the case of video output handling, software can control each line parameter. Therefore software with line level support of hardware can perform many kinds of functions; image resizing, copy guard and dynamic blending of the image and graphics.

The energy absorptions of crashworthy structures composed of welded aluminium alloys were evaluated using finite element analysis (FEA). In the FEA, a damage-mechanics model was employed as a material model for the parent aluminium alloys and the welding materials. For the welded regions, several combinations of material parameters included in the damage-mechanics model were examined. Using the numerical results, sensitivity of the energy absorption to the material parameters was assessed. Results of the sensitivity study clarified which parameters had the largest effect on the energy absorption.

The flux pinning behavior of a Nd 1+ x Ba 2− x Cu 3 O 7−δ (Nd123) single crystal, which exhibited a peak effect, has been studied by monitoring the time decay of the magnetic moment. The apparent pinning energy ( U 0 ∗ ) was deduced from flux creep data on the basis of the Anderson-Kim model. The magnetic field dependence of U 0 ∗ showed maxima at peak fields which depended on the temperatures, in a similar manner to those of critical current densities. In addition, the temperature dependence of U 0 ∗ showed several features. To explain the increase in U 0 ∗ with the field as well as its temperature and field dependence, we made a numerical calculation by introducing an additional pinning energy which increased with increasing field. The results are in good agreement with the experimental data, especially at temperatures above 60 K, where the contribution of field induced pinning centers is believed to be dominant.

Recycling of long-lived nuclides into a nuclear reactor is one of the measures for the reduction of radioactive hazard potential on the high level wastes (HLW) after a long storage period. We have considered such a fuel cycle that Np, Am, I and Tc are recycled to the light water reactors (LWRs) with U and Pu. Since LWR neutron spectrum will provide a large neutron capture cross section for most of nuclides, capture (and successive decay/fission) reaction in LWR is one of possibility to transmute longlived nuclide into a short-lived or stable one. Proper amount of long-lived nuclide recycles in LWR and a removal of short-lived products at reprocessing will avoid the cumulative increase of long-lived nuclides. Taking a BWR for a LWR sample, conditions for equilibrium material balance for long-lived nuclides per reactor, reactivity penalty and reactor core performances are presented.

This paper presents a high-voltage inverter configuration employing series connections of 1.2 kV rated standard IGBTs instead of high-voltage rated IGBTs, which allows the losses of switching devices to considerably decrease. Voltage balancing across all of the IGBTs connected in series, which is one of the most critical issues especially during the transient phases, is realized by magnetically coupling of all the gate wires with a two-winding transformer without any snubber components or active gate controls. Moreover, influence of stray capacitance associated with insulators in IGBT modules on the voltage sharing is investigated, and an optimized configuration including these heat sinks is proposed to achieve a more accurate voltage equalization. To validate the performance on the series connection of the standard IGBTs with respect to the voltage sharing and the device losses in practical uses, a prototype 170 kVA rated inverter based on three series connection of 1.2 kV rated IGBTs are implemented and tested. The experimental results are shown.

Conventional AI (artificial intelligence) technology has been criticized on many drawbacks such as brittleness under dynamically changing environments. To overcome this problem, other approaches called behavior-based AI, new AI, emergent computation, animat approach and so on were proposed and confirmed their usefulness. Since computational ability of mobile robots is limited in general, it is required that robots extract feasible information from their environment for appropriate behavior control by themselves. On the other hand, in living organisms, there are mainly two systems to cope with dynamically changing environment: 1) immune system, and 2) emotional system. Based on this fact, in this paper, we present a new method of behavior arbitration mechanisms for autonomous mobile robots by paying close attention to emotional system in living organisms. We confirm the feasibility of our proposed method by applying to an obstacle avoidance problem of a mobile robot as a practical example.

The thermoelectric properties of Na/sub x/CoO/sub 2-/spl delta// single crystal have been evaluated at high temperatures (300

Resent studies have revealed that OCMG-processed RE-Ba-Cu-O (RE = Nd, Sm, Eu, Gd) superconductors show large J c values at fields around 2 to 3 T at 77 K, accompanied by secondary peak effect as well as high irreversibility lines. However, it is not still clear how the relaxation properties are affected when two different pinning centers (normal-conducting secondary phase and field-induced pinning centers) are active. In this paper, we have studied the effect of the size and the volume fraction of the normal conducting secondary phase on the relaxation properties in Nd-Ba-Cu-O superconductors.

Nd-Ba-Cu-O superconductors are known to form a Nd1+xBa2-xCu3O7-xtype solid solution. The range of the solid solution is temperature dependent, and therefore, the superconducting properties of Nd-Ba-Cu-O crystals are strongly dependent on the growth temperature. We found that grain growth at higher temperatures leads to higher Tc, higher irreversibility fields, and relatively low overall Jc values. And relatively lower growth temperatures shift peak position in lower field region and Jc values are enhanced. Such a behavior can be understood in terms of the growth temperature dependence of the chemical composition of Nd1+xBa2-xCu3 O7-x clusters, which act as field induced pinning centers.

There are many factors influencing the growth of the fetus. Since these factors have complex interrelations, they are difficult to clarify. The authors studied the effects of blood coagulation and fibrinolysis on the growth of the fetus during pregnancy, especially from the 2nd trimester into the 3rd trimester. The subjects were 86 normal pregnant women, and the subjects of study were blood coagulation, fibrinolysis activity of the mother, and estimated fetal birth weight after the 28th (2nd trimester) and 36th weeks of gestation (3rd trimester) in each case. 1. Changes in blood coagulation activity and fibrinolysis varied from the 2nd trimester into the 3rd trimester. The percentage of cases showing lowered platelets was 68.6% of the total, and the percentages of cases with reduced platelet ADP, epinephrine, and collagen aggregation were 60.5%, 55.8%, and 51.2%, respectively. The percentages of cases showing shortened prothrombin time and activated partial thromboplastin time were 58.1% and 51.2% of the total, respectively. The percentage of cases with reduced fibrinogen was 24.4% of the total. The percentages of cases with reduced antithrombin III, plasminogen, and alpha 2-plasmin inhibitor activity were 66.3%, 55.8%, and 75.6% of the total, respectively. 2. The birth weight of babies in a group with shortened prothrombin time was 2,935.1 +/- 395.2g(n = 50, mean +/- SD), while that in a group with prolonged prothrombin time was 3,106.2 +/- 357.9g(n = 36). The estimated fetal birth weight gain from the 2nd trimester to the 3rd trimester was 1,431.6 +/- 296.5g in the former group and 1,644.5 +/- 390.5g in the latter group. The differences were significant (p less than 0.05, p less than 0.01). The birth weight of babies in a group with lowered antithrombin III activity was 2,960.1 +/- 341.3g(n = 57), and that in an acceleration group was 3,157.8 +/- 370.0g(n = 29). The estimated fetal weight gain from the 2nd trimester to the 3rd trimester was 1,477.7 +/- 281.9g in the former group and 1,637.1 +/- 390.6g in the latter group. The differences were significant (p less than 0.02, p less than 0.05). 3. The estimated fetal weight gain from the 2nd trimester to the 3rd trimester in the group showing prolongated prothrombin time and activated partial thromboplastin time in this period was significantly larger than in the group showing shortened prothrombin time and activated partial thromboplastin time (p less than 0.001). These results suggested that the changes in blood coagulation and fibrinolysis activity of mothers from the 2nd trimester to the 3rd trimester affected the growth of the fetus.

During fertilization in mammalian species, a sperm-induced intracellular Ca2+ signal [Ca2+] is well suited to mediate the highly specialized spatiotemporal patterns of [Ca2+]i responses that underlie fertilization. Recently, we demonstrated that the expression pattern of inositol 1,4,5- triphosphate receptor type 1 (IP3R1) did not change during in vitro maturation and parthenogenetic activation in mouse oocytes; however, the phosphorylation status of IP3R1 depended on the cell cycle during meiosis. Moreover, it was shown that IP3R1 phosphorylation played a crucial role in the induction of [Ca2+]i oscillations (Lee et al. 2006 Development 133, 4355–4365). In other species, expression of IP3R1, especially phosphorylation levels of IP3R1 during meiosis, has not been examined. The aim of this study was to examine the kinetics of IP3R1 expression and phosphorylation during in vitro maturation and activation in pig oocytes. Immature oocytes at the germinal vesicle (GV) stage were collected from ovaries and cultured in modified NCSU37 up to 48 h. After culture, cumulus cells were removed and oocytes were parthenogenetically activated by 25 µm Ca2+ ionophore for 3 min and 2 mm 6-DMAP for 6 h. After activation, oocytes were further cultured up to the 2-cell stage. Groups of 30 oocytes were collected at each culture period for detection of IP3R1. According to our previous report in the mouse, IP3R1s were detected by western blotting using MPM-2 and Rbt03 antibody for detecting IP3R1 phosphorylation and total IP3R1 expression, respectively (Lee et al. 2006). In pig oocytes, IP3R1 was abundantly expressed at the GV stage. The total level of IP3R1 expression did not change during in vitro maturation or after activation. However, phosphorylated IP3R1 levels increased by 24 h although they were undetectable at the start of culture. Phosphorylation of IP3R1 reached maximal levels at 36 h. After activation, phosphorylation levels decreased progressively until the pronuclear (PN) stage. Phosphorylation of IP3R1 was observed at mitosis I to some extent. From these results, we detected for the first time IP3R1 expression and phosphorylation in pig oocytes. Moreover, our data suggest that phosphorylation of IP3R1 is dependent on cell cycle at least during meiosis, especially M-phase, as already shown for mouse oocytes. In vitro kinase assays for p34cdc2 kinase and MAPK will be carried out to clarify the relationship between IP3R1 phosphorylation and M-phase kinase(s).

The depths and relative densities of the traps in a series of SrAl2O4:Eu2+, Ln (14 rare-earths) phosphors are measured with a transient luminescence method. The observed hole activation energies (trap depths) are quite different across the series and related to the ionization potential and 4fn-4fn−15d transition energies of the divalent ions of this series, reflecting the 4f-electron interaction energy of each rare earth ion.