Toyota

About: Toyota is a company organization based out in Safenwil, Switzerland. It is known for research contribution in the topics: Internal combustion engine & Battery (electricity). The organization has 40032 authors who have published 55003 publications receiving 735317 citations. The organization is also known as: Toyota Motor Corporation & Toyota Jidosha KK.

Nature of proton dynamics in a polymer electrolyte membrane, nafion: a first-principles molecular dynamics study

Abstract: First-principles molecular dynamics simulations have been carried out to investigate the nature of proton dynamics in Nafion, a representative polymer electrolyte membrane (PEM) widely used in PEM fuel cells. From the trajectories of the simulations, diffusion coefficients for the protonic defects were calculated to be 0.3 × 10−5 cm2 s−1 and 7.1 × 10−5 cm2 s−1 for λ = 4.25 and 12.75, respectively, where λ denotes hydration levels inside Nafion defined as a number of water molecules per sulfonic group. Our simulations show that proton hopping probability does not depend much on the water content inside Nafion. This finding indicates that the classical vehicular (or en masse) diffusion model, which has been employed to account for the slow diffusion process of protons in low water-content Nafion, is an oversimplification and does not correctly describe proton dynamics. Furthermore, it is found that difference in the value of the proton diffusion coefficient with respect to water content inside Nafion is related to the different character of proton hopping occurring in the water hydrogen bond network. When the water content is low, the proton hopping occurs in a manner that does not contribute constructively to proton mobility, while when the water content is high, it occurs in a manner which is beneficial to overall proton mobility. Such a different nature of proton hoppings arises mainly from the difference in the connectivity of water hydrogen bond network. Our results broadly support earlier simulation studies and provide the molecular level origin of properties arising from the proton dynamics in Nafion.

Micro-optical resonator type organic electroluminescent device

Abstract: A micro-optical resonator type organic electroluminescent device utilizing an organic electroluminescent material high in emission efficiency but broad in emission spectrum width, has a narrow half bandwidth in the emission peak and a superior forward directivity and an excellent monochromaticity in light not separate into components, wherein a micro-optical resonator is formed by a multi-layered mirror and a metal mirror. The optical length of the micro-optical resonator, calculated from the total thickness and the refractive index of a transparent conductive layer and a luminous layer placed between the multi-layered mirror and the metal mirror and also from the light penetration depth into the multi-layered mirror, is 1.5 times the wavelength of a desired light emitted from the device, and the desired light is set on the short wavelength side of the emission spectrum of the electroluminescent material.

Synchronizer for transmission

Abstract: Balls to be moved radially outward by a centrifugal force are held in a clutch hub, and projections extending around the outer circumferences of the balls are united with a synchronizer ring. Those portions of the projections, which radially confront the balls, are formed with slopes for establishing an axial force to push the synchronizer ring away from the spline piece on the basis of the centrifugal force of the balls. Thus, the axial force for disengaging the synchronizer ring from a rotating member to be synchronized can be increased to prevent the chatter at a low number of revolution and to effectively eliminate the drag torque at a high number of revolution.

Hood structure for vehicle

Abstract: A level difference portion is formed on a food outer panel of a hood along a longitudinal direction of a vehicle body. A flange that connects a bone portion and a bone portion of a food inner panel is formed at a portion below the level difference portion of the hood outer panel. The flange of the hood inner panel extends so as to be curved along the level difference portion of the hood outer panel. The flange of the hood inner panel is connected to the level difference portion of the hood outer panel using an adhesive agent.