Preparation of an acrylics‐grafted polyester and its aqueous dispersion—mechanical properties of acrylics‐grafted polyesters

Mechanical properties of grafted polyesters were discussed. In the case of grafting of acrylics of more than 25% in the grafting product, mechanical properties of the grafting products decreased greatly compared with the raw polyester. The influence of the molecular structure of the grafted polyester was not observed. The effect of composition of the grafted polymers was discussed. Mechanical properties varied with the composition of the side chain. In the case of grafting onto aromatic polyesters, grafting of an aromatic unsaturated monomer improved the mechanical properties of the grafted polymer. On the other hand, in the case of grafting onto an aliphatic polyester, grafting of an aliphatic unsaturated monomer improved mechanical properties of the grafting polymer. We found that the grafting of the polymer having a high compatibility with the polyester improved the mechanical properties of the grafting products, from the determination of the compatibility of each polymer and the mechanical properties of the grafting products. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1149–1157, 2000     

Photonic transport technologies to create robust backbone networks

This article discusses the role of the new optical layer in terms of transport layer architecture and functional allocations. The envisaged future photonic network is identified, and the technologies needed to realize reliable communication are clarified. Network-node interface technologies, and network protection and restoration strategies are discussed in detail, since these are key to developing a network with high integrity that will be a main pillar of the future information society. Finally, applications of photonic network technologies and a network design example are presented; the IP backbone network based on optical path technologies is highlighted     

The Quiescent Cellular State is Arf/p53-Dependent and Associated with H2AX Downregulation and Genome Stability

Cancer is a disease associated with genomic instability and mutations. Excluding some tumors with specific chromosomal translocations, most cancers that develop at an advanced age are characterized by either chromosomal or microsatellite instability. However, it is still unclear how genomic instability and mutations are generated during the process of cellular transformation and how the development of genomic instability contributes to cellular transformation. Recent studies of cellular regulation and tetraploidy development have provided insights into the factors triggering cellular transformation and the regulatory mechanisms that protect chromosomes from genomic instability.     

Conversion of a monodispersed globular protein into an amyloid-like filament by appending an artificial peptide at the N-terminal

The soluble, globular, alpha-helix-rich peptide SipA(446-684) is a domain of a bacterial protein that binds to mammalian filamentous-actin and re-arranges the host cell's cytoskeleton. We show that adding two copies of NHBP-1, a carbon nanomaterial binding peptide, to its N-terminal can induce SipA(446-684) to polymerize and assume a fibrillar structure under physiological conditions. The fibrils formed showed thioflavine T and Congo red staining profiles that are characteristic of and specific for amyloid-like structures. The alpha-helical structure of the globular protein was retained in the fibrils, suggesting the appended NHBP-1 sequence plays a key role in the formation of cross-beta spines within the fibrils. Consistent with that idea, we observed that a synthetic NHBP-1 peptide can form an amyloid-like structure under appropriate conditions. Thus, our findings add a new subtype of amyloid-like structure formation and suggest this method of assembly could be exploited in nano-biotechnology.     

Novel method for measuring cutoff wavelength of HE21-, TE01-and TM01-modes

A new measurement method for the cutoff wavelength of HE21-, TE01-and TM01 modes using a polariser is described. The experimental results show that higher measurement accuracy and sensitivity are obtained compared with the previous method.     

Surface cracking on Σ3, Σ9 CSL and random grain boundaries in helium implanted 316L austenitic stainless steel

The relationship between surface cracking at grain boundaries and the grain boundary nature in helium implanted 316L austenitic stainless steel was investigated by in situ annealing in a high-voltage electron microscope, and by SEM and TEM observations. The nucleation and growth of helium bubbles at a random grain boundary was observed during annealing up to 973 K. After annealing, surface cracking was observed at the random grain boundaries and some coincidence site lattice (CSL) boundaries because of the formation and rupture of the helium bubbles at these grain boundaries. At the faceted CSL boundaries, surface cracking occurred only on one boundary facet plane. This indicates that the twin boundary and pure tilt Σ9 CSL boundary show the highest resistance to cracking because of their low boundary energies.     

Preparation of an acrylic‐grafted polyester and its aqueous dispersion—Effect of the molecular structures of the grafted polyesters on viscosity and rheology of dispersion

An investigation was undertaken to develop a new class of water‐borne polyesters that have various viscosity and various rheological profiles. We discussed the effect of the grafting condition on the molecular weights of the acrylic segments in the acrylic‐grafted polyester. The molecular weights of the acrylic segments could be changed by an initiator concentration, a chain transfer agent concentration, and a monomer concentration. We discussed the viscosity and the rheology of the dispersions obtained from the above‐grafted polyesters. The viscosity of the dispersion decreased as the molecular weights of the acrylic segments decreased. It was considered that the interaction between the particles of the dispersions decreased with a decrease in the thickness of the shell layer. The viscosity of the dispersions also decreased as the solubility of the acrylic segments in water decreased. It was considered that the interaction between the particle of dispersion decreased with the shrinkage of the shell layer. The rheological profile of dispersion was changed not by the molecular weights but the composition of the acrylic segments. The dispersions having various rheological profiles could be obtained by the control of the molecular weights or the composition of the acrylic segments in the grafted polyesters. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 350–356, 2000     

Megahertz operation of voltage-fed inverter for HID lamps usingdistributed constant line

A novel type of solid-state ballast, which operates in the megahertz-range frequency, is presented in this paper. A circuit composed of a voltage-fed half-bridge inverter, a distributed constant line, and a parallel LC resonant circuit has been developed for this purpose. The high-intensity discharge (HID) lamp is connected to the output terminal of the inverter through the distributed constant line. Here, since the length of the line is adjusted to 1/4 of the propagation wavelength λ, the output voltage of the voltage-fed inverter can be converted to a current source on the load side. Based on the experiment results, the ballast appears to be able to supply not only high voltage, but also constant current for ignition of the HID lamp. The experimental results from a prototype system are used to verify the theoretical procedure