Toyota

About: Toyota is a company organization based out in Safenwil, Switzerland. It is known for research contribution in the topics: Internal combustion engine & Exhaust gas. 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.

Synthesis and properties of polyimide-clay hybrid films

Abstract: Polyimide-clay hybrid films with four different sizes of clay minerals have been synthesized to investigate the effect of the size of clay minerals to the properties of the hybrids. Hectrite, saponite, montmorillonite, and synthetic mica were used as clay minerals. Those clays consist of stacked silicate sheets about 460 A (hectrite), 1650 A (saponite), 2180 A (montmorillonite), and 12300 A (synthetic mica) in length, 10 A in thickness. The longer the length of clay mineral was, the more effectively properties of polyimide were improved. In the case of polyimide-mica hybrid, only 2 wt % addition of synthetic mica brought permeability coefficients of water vapor to value less than one-tenth of that of ordinary unfilled polyimide, and thermal expansion coefficient was lowered at the level of 60% of the original one. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2289–2294, 1997

Optically tunable amino-functionalized graphene quantum dots

Abstract: Amino-functionalized graphene quantum dots (af-GQDs) with discrete molecular weights and specific edges were self-limitedly extracted from oxidized graphene sheet. Their optical properties can be precisely controlled only by the selective and quantitative functionalization at the edge sites. The af-GQDS exhibit bright colorful fluorescence under a single-wavelength excitation.

Minimizing age of information in vehicular networks

Abstract: Emerging applications rely on wireless broadcast to disseminate time-critical information. For example, vehicular networks may exchange vehicle position and velocity information to enable safety applications. The number of nodes in one-hop communication range in such networks can be very large, leading to congestion and undesirable levels of packet collisions. Earlier work has examined such broadcasting protocols primarily from a MAC perspective and focused on selective aspects such as packet error rate. In this work, we propose a more comprehensive metric, the average system information age, which captures the requirement of such applications to maintain current state information from all other nearby nodes. We show that information age is minimized at an optimal operating point that lies between the extremes of maximum throughput and minimum delay. Further, while age can be minimized by saturating the MAC and setting the CW size to its throughput-optimal value, the same cannot be achieved without changes in existing hardware. Also, via simulations we show that simple contention window size adaptations like increasing or decreasing the window size are unsuitable for reducing age. This motivates our design of an application-layer broadcast rate adaptation algorithm. It uses local decisions at nodes in the network to adapt their messaging rate to keep the system age to a minimum. Our simulations and experiments with 300 ORBIT nodes show that the algorithm effectively adapts the messaging rates and minimizes the system age.

Twenty Years of Polymer‐Clay Nanocomposites

Abstract: Summary: More than twenty years have passed since we invented PCN, in which only a few wt.-% of silicate is randomly and homogeneously dispersed in the polymer matrix. When molded, these nanocomposites show superior properties compared to those of pristine polymers. The number of papers on PCN has increased rapidly in recent years, reaching over 500 in 2005 alone. Being pioneers of this new technology, we review its history relative to the following epochal events: In 1985 we invented nylon 6-clay hybrid (NCH), the first PCN. In 1989, cars equipped with a NCH part were launched. In 1997, Gilman found revolutionary fire retardancy in NCH. In 1997, a PP-clay nanocomposite was prepared using a compatibilizer. In 1998, a compounding method for producing PCN was completed. In 2002, Haraguchi invented a revolutionary nanocomposite hydrogel. So far, only nylon-clay nanocomposites have been used in practice, but other PCN will become increasingly useful in the future. SEM of etched NCH film.