Synthesis of 3′-allylindoline spirobenzopyrans derived from 3-allyl-3H-indoles

In this study, 8 new spirobenzopyrans were synthesized. A novel, three-step, facile route for the synthesis of 3′-allylindoline spirobenzopyrans via 3-allyl-3H-indoles was developed. The newly synthesized spirobenzopyrans were evaluated for their photochromic properties. The presence of an allyl moiety at the 3′ position did not disturb the photochromic response. The steric effects of the diallyl groups at the 3′ position affected the interconversion between colored and colorless forms. Therefore, the allyl chain in 3′-allylindoline spirobenzopyrans can be utilized to attach these compounds to a molecular matrix. Consequently, this synthetic methodology could be readily applied to the creation of new photo-switchable materials.     

Flow characteristics of pressure reducing valve with radial slit structure for low noise

Pressure reducing valves are widely used to maintain the pressure of gas reservoirs to specific values. In a normal valve, supply pressure is decompressed with an orifice structure. When compressed air passes through the orifice structure, considerable noise occurs at the downstream side. In this paper, we have developed a radial slit structure that can reduce pressure without noise. The noise is reduced by changing the orifice structure into the radial slit structure. The radial slit structure valve reduces pressure without noise by suppressing the generation of turbulence and shock wave at the downstream. The analysis of the flow in radial slit structure was achieved by CFD2000 software. The flow rate and pressure distribution were simulated and compared with the experimental result. To confirm the generation of shock wave, the flow of orifice and radial slit structure at the downstream was visualized by Schlieren photography method. A shock wave was generated in the orifice structure, but no shock wave was generated in the radial slit structure. Noise reduction efficiency was investigated by the experiment. The experiment apparatus was set up to JIS standards. The experimental results indicated that the noise level decreased by approximately 40 dB in the slit structure. It is confirmed that the radial slit structure has effectiveness for low noise in the pressure reducing flow. And, it is expected that it can be applied to various kinds of industrial fields.     

On the transition rate for the two-electron one-phonon transition

By using different gauges, the relativistic rates for the $\text{K}{}_{\mathrm{\alpha \alpha 2}}\text{(1}\text{s}{}^{\mathrm{?2}}\text{→2}\text{s}{}^{\mathrm{?1}}\text{2}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}\text{) and the}\text{K}{}_{\mathrm{\alpha 2}}{}^{\mathrm{<mtext>h</mtext>}}\text{(1}\text{s}{}^{\mathrm{?2}}\text{→1}\text{s}{}^{\mathrm{?1}}\text{2}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}\text{)}$ transitions are calculated for Ne, Ar, Ca, Fe and Cu. The problem in the use of the single configuration HF model is discussed.     

A microsensor for adenosine-5′-triphosphate pH-sensitive field effect transistors

The sensor for adenosine-5′-triphosphate (ATP) is based on H⁺-ATPase immobilized via a polyvinylbutyral resin on a pH-sensitive field effect transistor. A linear relationship was obtained between the initial rate of change of the differential gate output voltage and the logarithm of the ATP concentration over the range 0.2–1.0 mM ATP. The optimum pH was 9.0 at 40°C but pH 7.0 was preferred for routine measurements. Only slight responses were obtained for 1 mM glucose, creatinine or urea. The ATP-sensing system exhibited a response to 1 mM ATP for at least 18 days.     

Coarse Metal Powder-Assisted pulsed CO2 Laser-induced Breakdown Spectroscopy for the Direct Determination of Heavy Metals in Soil

A novel method of laser-induced plasma spectroscopy utilizing a pulsed transversely excited atmospheric CO₂ laser has been developed for the high-sensitivity determination of heavy metals in soil. A coarse metal powder was used to trap the soil and to assist with plasma generation. When the CO₂ laser (10.6?µm, 1.5?J, 200?ns) was irradiated on the metal and soil powder, a high-temperature and long-lifetime luminous plasma was induced. Fine particles of soil were dissociated and were excited in the plasma region. The method was used for the rapid determination of Cr, Pb, and Hg in loam. The limits of detection for Cr, Pb, and Hg were approximately 0.8, 15, and 0.7?mg/kg, respectively.     

Highly stereoselective, uniformly sized molecularly imprinted polymers for cinchona alkaloids in hydro-organic mobile phases.

Highly stereoselective, uniformly sized molecularly imprinted polymers (MIPs) for cinchona alkaloids, cinchonine (CN) and cinchonidine (CD), were prepared using methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EDMA) as a cross-linker. The MIPs were evaluated using a mixture of phosphate buffer and acetonitrile as the mobile phase. The CN- and CD-imprinted MAA-co-EDMA polymers can recognize the respective template molecule more than the other diastereomer, and afford an excellent diastereomer separation of CN and CD. In addition, the MIPs gave diastereomer separations of structurally related compounds, quinidine and quinine. The retentive and stereoselective properties of those compounds on the MIPs suggest that electrostatic and hydrophobic interactions can work to recognize these compounds. Furthermore, thermodynamic studies reveal that the entropy-driven effect is significant at mobile-phase pH 5.4, while the enthalpy-driven interactions seem to be dominant at mobile-phase pH 9.6.     

PSDF of log-amplitude scintillation for 7 μm band laser beam with absorption by water vapour

The power spectral density function (PSDF) of the log-amplitude scintillation for an infrared laser beam was measured experimentally. To investigate the contribution of the absorption and the dispersion that cause the scintillation, we chose 16 wavelengths of infrared light and one wavelength of visible light. It is found that the spectral density of scintillation for the infrared beam does not agree with that for the visible beam, as predicted by Tatarskii's theory in the low-frequency region below 1 Hz. This disagreement between the experiment and the theory in the low-frequency region should be attributed to water vapour absorption.