Simulation Study on Acquisition Process of Locomotion by Using an Infant Robot

Locomotion is one of the basic functions of a mobile robot. Using legs is one of the strategies for accomplishing locomotion. The strategy allows a robot to move over rough terrain. Therefore, a considerable amount of research has been conducted on motion control of legged locomotion robots. This chapter treats the motion generation of an infant robot, wit

Endurance training facilitates myoglobin desaturation during muscle contraction in rat skeletal muscle.

At onset of muscle contraction, myoglobin (Mb) immediately releases its bound O2 to the mitochondria. Accordingly, intracellular O2 tension (PmbO2) markedly declines in order to increase muscle O2 uptake (mVO2). However, whether the change in PmbO2 during muscle contraction modulates mVO2 and whether the O2 release rate from Mb increases in endurance-trained muscles remain unclear. The purpose of this study was, therefore, to determine the effect of endurance training on O2 saturation of Mb (SmbO2) and PmbO2 kinetics during muscle contraction. Male Wistar rats were subjected to a 4-week swimming training (Tr group; 6 days per week, 30 min × 4 sets per day) with a weight load of 2% body mass. After the training period, deoxygenated Mb kinetics during muscle contraction were measured using near-infrared spectroscopy under hemoglobin-free medium perfusion. In the Tr group, the VmO2peak significantly increased by 32%. Although the PmbO2 during muscle contraction did not affect the increased mVO2 in endurance-trained muscle, the O2 release rate from Mb increased because of the increased Mb concentration and faster decremental rate in SmbO2 at the maximal twitch tension. These results suggest that the Mb dynamics during muscle contraction are contributing factors to faster VO2 kinetics in endurance-trained muscle

Modular law through GKM theory

The solution of Shareshian-Wachs conjecture by Brosnan-Chow and Guay-Paquet tied the graded chromatic symmetric functions on indifference graphs (or unit interval graphs) and the cohomology of regular semisimple Hessenberg varieties with the dot action. A similar result holds between unicellular LLT polynomials and twins of regular semisimple Hessenberg varieties. A recent result by Abreu-Nigro enabled us to prove these results by showing the modular law for the geometrical objects, and this is indeed done by Precup-Sommers and Kiem-Lee. In this paper, we give elementary and simpler proofs to the modular law through GKM theory.Comment: 17 page, 5 figure

Intracellular oxygen tension limits muscle contraction-induced change in muscle oxygen consumption under hypoxic conditions during Hb-free perfusion.

Under acute hypoxic conditions, the muscle oxygen uptake (mV˙O2) during exercise is reduced by the restriction in oxygen-supplied volume to the mitochondria within the peripheral tissue. This suggests the existence of a factor restricting the mV˙O2 under hypoxic conditions at the peripheral tissue level. Therefore, this study set out to test the hypothesis that the restriction in mV˙O2 is regulated by the net decrease in intracellular oxygen tension equilibrated with myoglobin oxygen saturation (∆PmbO2) during muscle contraction under hypoxic conditions. The hindlimb of male Wistar rats (8 weeks old, n = 5) was perfused with hemoglobin-free Krebs-Henseleit buffer equilibrated with three different fractions of O2 gas: 95.0%O2, 71.3%O2, and 47.5%O2 The deoxygenated myoglobin (Mb) kinetics during muscle contraction were measured under each oxygen condition with a near-infrared spectroscopy. The ∆[deoxy-Mb] kinetics were converted to oxygen saturation of myoglobin (SmbO2), and the PmbO2 was then calculated based on the SmbO2 and the O2 dissociation curve of the Mb. The SmbO2 and PmbO2 at rest decreased with the decrease in O2 supply, and the muscle contraction caused a further decrease in SmbO2 and PmbO2 under all O2 conditions. The net increase in mV˙O2 from the muscle contraction (∆mV˙O2) gradually decreased as the ∆PmbO2 decreased during muscle contraction. The results of this study suggest that ΔPmbO2 is a key determinant of the ΔmV˙O2

Performance evaluation of control panel heat exchanger

Due to miniaturization, weight reduction, and high density of electronic equipment, the control panel has become smaller and the internal heat generation temperature is higher. In addition, the installation place of the control panel is a factory etc., heat, dust, moisture, oil mist adversely affect the electronic control unit. Therefore, a control panel heat exchanger is used for sealing the control panel and releasing the heat generated therein to the outside. We evaluated the performance of the control panel heat exchanger in this research. Experiments shall be conducted in accordance with the capacity evaluation test method of the Japan Thermal Solution Equipment for Cabinet Technical Association. Experiments were conducted by installing a heat exchanger in the measurement reference box of 1700 mm in length, 700 mm in width, and 700 mm in depth made of a steel plate to which a heat insulating material with a thickness of 40 mm was attached. The dimensions of the heat exchanger are 900 mm in length, 438 mm in width and 129 mm in depth, and two fans are mounted on the inside of the heat exchanger and two on the outside air side. Twelve thermocouples were installed in the heat exchanger and twelve thermocouples were installed to check the temperature inside the box and the temperature was measured. An experiment was conducted until the temperature inside the panel reached a steady state by setting the heater unit in the measurement reference box and changing the calorific value. Experiments were also conducted until the temperature inside the board reached a steady state by changing the calorific value of the heater unit without operating the heat exchanger, and the heat release amount P0 to the outside of the reference box for measurement was obtained. The calorific value P at the temperature difference of 20 K between the average value of the intake port temperature and the exhaust port temperature inside the panel of the control panel heat exchanger and the outside air temperature was obtained. The heat release amount P0 is subtracted from the calorific value P and the value divided by the temperature difference 20 K is defined as the rated capacity of the control panel heat exchanger. From the experimental results the rated capacity was 56.0 W/K.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers