Application of a novel photopolymer to a holographic head‐up display

A novel photopolymer for fabrication of high‐resolution volume holograms, which primarily are used on holographic optical elements such as head‐up display (HUD), is reported. This photopolymer consists of bisphenol‐type epoxy resin and radically polymerizable aliphatic monomer with diaryliodonium salt and 3‐ketocoumarin (KCD) as a complex initiator. The chemistry of imaging formation is based on the radical polymerization of the monomer initiated by a holographic exposure, following by the cationic polymerization of epoxy resin by UV‐exposure after post‐exposure baking. The yellowish color of hologram derived from KCD, the shape of peak of reconstructed light and the blue shift of wavelength of reconstructed light, were improved in order to satisfy the specifications for the combiner of HUD. A stand type holographic HUD system as an example of automotive display attached on the dashboard of an automobile is demonstrated. The display gives a high contrast image, and the combiner has good durability. Copyright © 1999 John Wiley & Sons, Ltd.     

Oxidative coupling polymerization of 4‐methyltriphenylamine

4‐Methyltriphenylamine was oxidatively polymerized in chloroform (CL) or propylene carbonate (PC) in the presence of ferric chloride (FeCl₃) at 50°C. Polymerization proceeded more rapidly and the molecular weight of the resulting polymer was higher in CL than in PC due to the higher oxidation potential of the solution. The linear structure was confirmed by ¹³C NMR, and the resulting polymer exhibited high thermal stability and electrochemical activity.     

Synthesis and Magnetic Properties of (Pyrrolidin‐1‐oxyl)–(Nitronyl Nitroxide)/(Iminonitroxide)‐Dyads

Unlike extensively studied diradicals linked by π‐conjugated systems, only a few studies have investigated weakly coupled diradicals linked by an sp³ carbon atom. Herein, we prepared pyrrolidin‐1‐oxyl–(nitronyl nitroxide)‐dyad 5 and pyrrolidin‐1‐oxyl–iminonitroxide‐dyad 6 . From the observed temperature dependence of the magnetic susceptibility, 5 and 6 were determined to be in singlet ground states with 2J_intra/k_B=?35.2 K and ?13.6 K, respectively. From these results and theoretical calculations of related diradicals, the spin‐polarization model counting the small spin density of the sp³ carbon atom could be used as a spin‐prediction model.     

Influence of contamination layer on thickness evaluation by X-ray reflectometry

In this study, the effect of allowing for a contamination layer on a SiO₂ film/Si substrate system on thickness determination by X-ray reflectometry (XRR) was investigated. The calculated XRR profiles obtained using a calculation model that utilizes a contamination layer for analysis showed good agreement with measured profiles. Further, the obtained physical structures were promising and within acceptable limits. Where the existence of a contamination layer was ignored in the calculation process, a part of the thickness of the contamination layer was incorporated into the determined thickness of the SiO₂ layer. In that case, the evaluated thickness was proportional to the density ratio between the contaminated and SiO₂ layers. The results of investigation of the effect of X-ray energy on layer thickness determination indicated that the effects of contamination also depend on the X-ray energy used for XRR measurements. These effects increase in the case of experiments that employ X-ray energy with a high contrast for the contamination.     

Multielemental analyses of Lonomia obliqua (Lepidoptera,Saturniidae) caterpillar using EDXRF and INAA techniques

In this study, multielemental analysis of Lonomia obliqua (Lepidoptera, Saturniidae) caterpillar was performed using energy dispersive X-ray fluorescence and instrumental neutron activation analysis techniques. This caterpillar is poisonous and has the ability to cause fatal hemorrhagic effects in humans after contact. The need of this study is related to morphological changes (mainly size and color) observed in some caterpillars used for preparation of antilonomic serum (antivenom). The samples were classified as healthy (caterpillars of control) and unhealthy (caterpillars visibly modified). The XRF measurements were performed in an energy dispersive X-ray fluorescence spectrometer and the instrumental neutron activation analysis using the IEA-R1 nuclear reactor at IPEN. The results show significant differences for several elements (mainly, P, Cl, Ca, Ti, Mn, Fe, Ni, and Zn) in unhealthy caterpillars that can affect the development of this species as well as the quality and yield of the antivenom. Furthermore, its elemental characterization contributes for the understanding the potential pharmacological (procoagulant and antithrombotic) in the prevention of life-threatening blood clots.     

Continuous measurements of stable isotopes of carbon dioxide and water vapour in an urban atmosphere: isotopic variations associated with meteorological conditions

Isotope ratios of carbon dioxide and water vapour in the near-surface air were continuously measured for one month in an urban area of the city of Nagoya in central Japan in September 2010 using laser spectroscopic techniques. During the passages of a typhoon and a stationary front in the observation period, remarkable changes in the isotope ratios of CO₂ and water vapour were observed. The isotope ratios of both CO₂ and water vapour decreased during the typhoon passage. The decreases can be attributed to the air coming from an industrial area and the rainout effects of the typhoon, respectively. During the passage of the stationary front, δ¹³C–CO₂ and δ¹⁸O–CO₂ increased, while δ²H–H₂Ov and δ¹⁸O–H₂Ov decreased. These changes can be attributed to the air coming from rural areas and the air surrounding the observational site changing from a subtropical air mass to a subpolar air mass during the passage of the stationary front. A clear relationship was observed between the isotopic CO₂ and water vapour and the meteorological phenomena. Therefore, isotopic information of CO₂ and H₂Ov could be used as a tracer of meteorological information.