Modification of the carbonization properties of coal-tar pitch by supercritical fluid extraction

The carbonization properties of coal-tar pitch were modified by supercritical fluid (SCF) extraction. Pitches extracted with supercritical toluene (SCFE pitch) contained none of the quinoline insoluble (QI) matter responsible for anisotropic structures with small unit sizes. The size of anisotropic structures from SCFE pitches was closely related to the β-resin (toluene insoluble and quinoline soluble fraction) content. Anisotropic structures from blended pitches prepared to have the same β-resin content as SCFE pitches (by blending toluene soluble (TS) and β-resin fractions obtained through a conventional liquid solvent extraction) were smaller. Extraction of the β-resin fraction with supercritical toluene could be interpreted by the co-solvent effects of the TS fraction dissolved in the extract phase. The high concentration of TS fraction in the extract phase enhanced the solubility of the β-resin fraction into this phase. In the raffinate phase, the heavier β-resin components, which are unsuitable for the development of mesophase structures, coagulated and formed unextractable QI matter through reduction in the concentration of the TS fraction. Since the TS concentration in both the phases depends on pressure and the ratio of the amounts of supercritical toluene and pitch, the control of the β-resin content in the SCFE pitches is possible through the adjustment of these two parameters.     

Perfectly alternating ethylene–carbon monoxide copolymer crystallized epitaxially on alkali halides. 2. Energy calculation

As reported in our previous papers, edge-on lamellar crystals of poly(3-oxotrimethylene) (POK) can be epitaxially grown from solution on alkali halides, and the crystal orientation depends on the type of substrate utilized: The chain-stems on the (001) surface of NaCl orient in the 110 directions of the substrate, while those on the (001) surface of KI orient in the 100 directions of the substrate. In order to explain this experimental evidence, calculations of the interaction energy between one rigid POK chain-segment of planar–zigzag conformation and a given substrate (the (001) surface of NaCl or KI) were carried out: in the calculations, the Lennard–Jones 6–12, the Coulomb and the induced-dipolar potentials were utilized. The calculation results were in good agreement with the experimental facts. Particularly in the calculation for POK on KI, the Coulomb energy was found to be the most important of the three to explain the the 100 orientation of the chain-segment. It was concluded that the interaction energy between the oxygen atoms in the POK chain-segment and the positive ions in a given alkali halide is an important factor to determine the orientation of the chain-stem in epitaxial crystallization of POK on these alkali halides.     

Crystallization kinetics of poly(L‐lactide) in contact with pressurized CO2

The effect of CO₂ on the isothermal crystallization kinetics of poly(L‐lactide), PLLA, was investigated using a high‐pressure differential scanning calorimeter (DSC), which can perform calorimetric measurements while keeping the sample polymer in contact with pressurized CO₂. It was found that the crystallization rate followed the Avrami equation. However, the crystallization kinetic constant was changed depending upon the crystallization temperature and concentration of CO₂ dissolved in the PLLA. The crystallization rate was accelerated by CO₂ at the temperature in the crystal‐growth rate controlled region (self‐diffusion controlled region), and depressed in the nucleation‐controlled region. CO₂ has also decreased the glass transition temperature, T_g, and the melting temperature, T_m. As a result, the CO₂‐induced change in the crystallization rate can be predicted from the magnitudes of depression of both T_g and the equilibrium melting temperature. The crystalline structure and crystallinity of polymers crystallized in contact with pressurized CO₂ were also investigated using a wide angle X‐ray diffractometer (WAXD). The resulting crystallinity of the sample was increased with the pressure level of CO₂, although the presence of CO₂ did not change the crystalline structure.     

Adaptive rollover prevention controller for driver–vehicle systems

In the paper, we propose an adaptive rollover prevention controller for heavy vehicles. At first, a design method for an ideal vehicle model is proposed. The designed ideal vehicle model has the property that good rollover prevention performance can be assured even if the driver steering characteristics vary. If the behavior of the actual heavy vehicle tracks that of the designed ideal vehicle model, rollover prevention can be achieved. Therefore, next, to realize good rollover prevention, we propose an adaptive steering controller. In the heavy vehicle system using the controller, the actual heavy vehicle can track the ideal vehicle model. Then, rollover prevention can be achieved. Finally, to demonstrate the usefulness of the proposed controller, numerical simulations are carried out.     

Adaptive steering control without using measurements of lateral velocity of vehicles

In this paper, we propose an adaptive steering controller without using measurements of lateral velocity of vehicles. At first, we show a new dynamic expression suitable for the design of a stable adaptive steering controller without using the lateral velocity. Next, we develop an ideal vehicle model. In the designed ideal vehicle model, a good steering performance can be achieved even if the drivers’ steering characteristics vary. Finally, an adaptive steering controller is developed, so that the actual vehicles can track ideal vehicle model and realize good steering performance.     

Thermal behavior and reactivities of prepolymers prepared from aromatic biscyanamides and bismaleimide

Novel polymers obtained by reaction of aromatic biscyanamide and bismaleimide compounds were investigated. By heating 4,4′-methylene bis(o-methylphenylcyanamide) (BMCA) with 4,4′-methylene bis (phenylmaleimide) (BMI) at 120°C in N,N-dimethylformamide (DMF), prepolymers were obtained by the conversion of cyanamide to cyanoguanidine and the addition of an imino group on the double bond of maleimide. The prepolymer showed suitable behavior for thermosetting resin used in molding, i.e., it melted temporarily and then polymerized in an isochronal heating process (5°C/min). On heating above 170°C, the prepolymer could polymerize with ring formation of melamine and isomelamine. The cured product had good heat-resistant properties.     

Proposed fibrinogen standard material with purified fibrinogen for plasma fibrinogen measurement on coagulation analyser

A commercially available fibrinogen standard calibrated by a World Health Organization (WHO) reference material is widely used in Japan, and most clinical laboratories use the Clauss method for plasma fibrinogen measurement. However, a current issue in fibrinogen measurement is poor laboratory-to-laboratory variability. To improve the reliability of fibrinogen values and thereby solve the poor precision and accuracy of plasma fibrinogen testing, the present paper develops a simple and large preparation procedure for a suitable fibrinogen standard and quality control material and evaluates their basic performance. With a new procedure getting high purified fibrinogen by glycine precipitation, the calibrator determined by both the Clauss and Jacobson methods produced a fibrinogen concentration of 2.20 g l(-1). The total precision of the calibrator was excellent (coefficient of variation 1.4-2.1%) in comparison with current plasma fibrinogen materials from the WHO (#98/612) and with a commercial standard (CV 1.9-3.9%). The within-run precision of the calibrator on the coagulation analysers was 1.7-2.8%. Within-analyser variability among the five instruments had good consistency (mean 2.20 +/- 0.022 g l(-1); CV 1.0%). The degradation study of the calibrator suggested that storage at 9( degrees )C for two years was as predicted. In conclusion, the results show that the calibrator prepared herein can be useful as a candidate Japanese fibrinogen standard and is applicable to automated and semi-automated coagulation analysers. Additionally, it is expected that it will be widely used in Japan by diagnostic manufacturers and clinical laboratories as a recommended secondary standard to estimate a fibrinogen value according to the WHO primary standard.     

New formation process of plating thin films on several substrates by means of self-assembled monolayer (SAM) process

This review describes our recent works on the preparation of Ni-alloy films deposited by electroless deposition as a diffusion barrier layer for ultra large-scale integration (ULSI) interconnects by using an all-wet process.In this process, we create a novel wet fabrication process including a self-assembled monolayer (SAM) as an attachment technique between diffusion barrier layer and a substrate. Our proposal process was applied to the substrates of SiO₂/Si and both organic (methyl silsesquioxane) and inorganic (hydrogen silsesquioxane) low-k dielectrics. The key technique of this proposed process is using SAM as a catalyst trapping layer. The Ni-alloy films such as NiB were deposited on catalyzed SiO₂ or low-k substrates. The electrolessly deposited NiB films were found to exhibit sufficient thermal stability and an acceptable barrier property for preventing Cu diffusion into the SiO₂ and low-k dielectrics.     

How informed are messaging app users about politics? A linkage of messaging app use and political knowledge and participation

Mobile messaging apps, such as Snapchat, Facebook Messenger, and WhatsApp, were unique campaign and information platforms in the 2016 U.S. presidential election. This study assesses how using such apps for campaign information is related to political knowledge and participation. Data from an online survey conducted prior to the election indicate that using messaging apps for news is positively related to knowledge miscalibration. Knowledge miscalibration is positively related to offline and online political participation. Findings are discussed in terms of the role of messaging apps in the political process.     

Selective oxidation of FeCr alloys in the 295–450 K temperature range

A series of iron-chromium alloys were oxidized for 10² to 6×10⁴ s in air and in the 295–500 K temperature range. Room-temperature oxidation of iron, chromium, antimony, and copper were also conducted at extended times. Oxidation characteristics such as oxide thickness and composition of the oxide and of the underlying alloy were evaluated from measurements by electron spectroscopy for chemical analysis (ESCA). An initial selective oxidation of chromium with a concomitant chromium depletion in the alloy was found. This initial oxidation step is followed by growth of an outer, iron rich oxide which causes the former chromium depletion to vanish. Apparent activation energies extracted from parabolic oxidation kinetics (295–500 K) of the investigated metals were found to be in the 10–20 kcal/mole range.