Temperature dependence of birefringence for strained natural rubber vulcanizates

The birefringence for uniaxially extended DCP-cured natural rubber was measured in the temperature range of 213K–353K. The variation of birefringence reflected the changes of the network structure, i.e. the development and disappearence of strain-induced crystals, and the degree of the orientation of amorphous network chains. It became clear from the variation of birefringence that the nucleation condition which is required to allow growth of an extended chain crystal occurred at extension ratio of 2.5–3.5.     

A design of generalized minimum-state-change FSSP algorithms and their implementations

The firing squad synchronization problem (FSSP) on cellular automata has been studied extensively for more than 50 years, and a rich variety of FSSP algorithms has been proposed. Here we consider the FSSP from a view point of state-change complexity that models the energy consumption of SRAM-type storage with which cellular automata might be built. In the present paper, we propose minimum-state-change generalized FSSP (GFSSP) algorithms for synchronizing any one-dimensional (1D) cellular automaton, where the initial synchronization operation is started by any cell in the array. First, we construct two minimum-time, minimum-state-change GFSSP implementations on finite state automata: one is based on Goto’s algorithm, known as the first minimum-time FSSP algorithm that was reconstructed again recently in Umeo et al. (A new reconstruction and the first implementation of Goto’s FSSP algorithm, 2017), and the other is based on Gerken’s (Diplomarbeit, Institut für Theoretische Informatik, Technische Universität Braunschweig, pp 1–50, 1987) one. These implementations are optimal not only in time but also in the state-change complexity. The implementations of the minimum-time GFSSP algorithms are the first ones having the minimum-state-change complexity. In addition, we also present a six-state 145-rule non-minimum-time, minimum-state-change GFSSP implementation. The implemented GFSSP algorithm is the smallest one, known at present, in number of states of the finite state automaton.     

Mechanical properties and microstructure of high toughness Fe-base filaments produced by glass-coated melt spinning

High toughness Fe_57.5Co₅Cr₁₅Mn₁₀Cu₂B₁₀Ti_0.5 filaments having a high tensile strength of 1740 M Pa and high elongation of 11.0% were produced by the method of glass-coated melt spinning. A noticeable feature of the stress-strain curves of the filament was that rapid hardening to a high stress-level of more than 1500 M Pa was reached in the first few per cent of tensile elongation. The filament was 14.5m diameter and micropolycrystalline with a grain size of 27 nm. The crystal structure of the filament was a mixture of bcc and fcc phases and the two phases were distributed homogeneously in the filament. The high toughness of the filament related to its micropolycrystalline structure and the uniformly mixed structure of bcc and fcc phases. After heat treatment at 573 K for 600 sec, the filament developed a higher toughness with a tensile strength of 2150 M Pa and an elongation of 12.0%.     

Learning from graph data by putting graphs on the lattice

Graph data have been of common practice in many application domains. However, it is very difficult to deal with graphs due to their intrinsic complex structure. In this paper, we propose to apply Formal Concept Analysis (FCA) to learning from graph data. We use subgraphs appearing in each of graph data as its attributes and construct a lattice based on FCA to organize subgraph attributes which are too numerous. For statistical learning purpose, we propose a similarity measure based on the concept lattice, taking into account the lattice structure explicitly. We prove that, the upper part of the lattice can provide a reliable and feasible way to compute the similarity between graphs. We also show that the similarity measure is rich enough to include some other measures as subparts. We apply the measure to a transductive learning algorithm for graph classification to prove its efficiency and effectiveness in practice. The high accuracy and low running time results confirm empirically the merit of the similarity measure based on the lattice.     

High temperature and pressure preparation and properties of iron carbides Fe7C3 and Fe3C

The formation regions of Fe₇C₃ and Fe₃C were determined at high temperature and high pressure in the iron-graphite system. Fe₇C₃ formed at relatively higher pressures and Fe₃C at lower pressures. Both Fe₇C₃ and Fe₃C were isolated from coexisting excess carbon powders by a magnetic method. Fe₇C₃ had a Curie point of 250° C and a saturation magnetization of 120 emu g^–1 at room temperature and Fe₃C had those of 210° C and 125 emu g^–1. Fe₇C₃ decomposed to Fe₃C and carbon at 600° C, but to -Fe and carbon at 700° C at atmospheric pressure, and Fe₃C to -Fe and carbon at 700° C. The substitution of other metals (Cr, Mo and W) for iron in these carbides leads to changes in the thermal stabilities and the magnetic properties.     

Novel Catalytic Properties of Rh Sulfide for the Synthesis of Methanol from CO + H2 in the Presence of H2S

Rh sulfide yielded 800 gkg-cat^–1h^–1 of methanol at 593 K and 5.1 MPa from CO + H₂ (syngas) even in the presence of H₂S 100 ppm in concentration. The obtained space-time yield of methanol was comparable with that obtained with a commercial Cu/Zn/Al catalyst at a conventional reaction condition (523 K and 5.1 MPa) from a feed containing both syngas and CO₂.     

New Compound in the System La2O3-Al2O3

A new compound, 5La₂O₃-2Al₂O₃, is formed from an amorphous material prepared by the simultaneous hydrolysis of lanthanum and aluminurn alkoxides. It has an orthorhombic unit cell with a=0.9704 nm, b=0.5967 nm, and c=1.5473 nm. The structure contains tetrahedral AlO₄ groups and octahedral AlO₆ groups.     

Properties of syndiotactic-rich poly(vinyl alcohol) thin films in water. VI. Elastic behavior of undrawn/annealed thin films by repeated elongation/contraction in water

The elastic behavior of undrawn/annealed swollen thin films of syndiotactic-rich poly(vinyl alcohol), derived from vinyl trifluoroacetate, was studied by repeated elongation/contraction in water. For the films annealed at temperatures below 175°C, the characteristic of deformation was divided into low-drawn and high-drawn regions. The elastic deformation was dominant over the plastic deformation in the low-drawn region and vice versa in the high-drawn region. The effect of heat treatment on the elastic behavior of the swollen films in water almost independent of annealing temperatures below 125°C. The elastic deformation in water at 70°C was especially remarkable in the low-drawn region for the films annealed at temperatures below 125°C and at 80°C for the films annealed at 150°C. For the films annealed at 200°C, considerable plastic deformation occurred in addition to elastic deformation from the initial drawing; the films were broken in the low-drawn region.     

Synthesis of Strontium Barium Niobate Thin Films through Metal Alkoxide

Highly oriented Sr_0.5Ba_0.5Nb₂O₆ (SBN50) thin films have been prepared using a sol-gel method. A homogeneous and stable strontium barium niobate (Sr_1-xBa_xNb₂O₆, SBN) precursor solution could be prepared via the reaction control of metal alkoxides. The SBN precursor was stabilized by the coordination of the 2-ethoxyethoxy group to metals. SBN thin films on MgO(100) crystallized to a mixture of orthorhombic and tetragonal phase at 700°C and then transformed completely to the tetragonal phase of tungsten bronze at 1000°C. Two crystal lattice planes of SBN were intergrown at an orientation of 18.5° on MgO(100). SBN50 thin films on Pt(100)/MgO(100) substrates exhibited the P-E hysteresis.     

Preparation of ion exchange membranes by preirradiation induced grafting of styrene/divinylbenzene into crosslinked PTFE films and successive sulfonation

Ion exchange membranes (IEMs) were prepared by preirradiation induced grafting of styrene with or without divinylbenzene (DVB) into crosslinked polytetrafluoroethylene (RX‐PTFE) films and successively sulfonated by chlorosulfonic acid. The effects of the DVB concentration and solvent on the kinetic of the graft polymerization were studied. The ion exchange capacity (IEC) values of the prepared membranes ranging from 1.5 to 2.8 mequiv/g were obtained. The degree of swelling increased with the increase in the degree of grafting, while higher crosslinking density of both the RX‐PTFE matrices and the grafts suppressed the degree of swelling. The chemical stabilities of the IEMs were tested by recording the weight of the membranes being soaked in hot H₂O₂ solutions. The weight‐time curves of the prepared membranes showed one‐step quick decrease due to the decomposition of the poly(styrene‐sulfonic acid) (PSSA) grafts. Higher crosslinking density in both the RX‐PTFE matrices and the grafts improved the chemical stability of the IEMs. The ionic conductivity of the IEMs increases with the increase in the IEC values. The IEMs with IEC values higher than 2.2 mequiv/g hold the higher ionic conductivity than that of Nafion® 112 membrane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3587–3599, 2006