A high-precision wavelength meter for tunable diode laser: Measurements of CO2 and N2O bands at 10 μm

We construct a high-precision wavelength meter for infrared tunable diode lasers (TDL) which consists of moving corner reflectors forming a Michelson interferometer, with a single-frequency HeNe laser as a standard. The design of the wavelength meter is described in detail, and possible sources of errors are discussed. An absolute accuracy of 10^?7 is demonstrated by measuring CO₂ laser wavelengths and almost the same order of accuracy is achieved by applying the wavelength meter to the ν₁ band of N₂O observed by a TDL.     

Studies on isoindoline derivatives and related compounds. I Synthesis and reduction of 1,3-dicarboethoxymethyleneisoindoline

The reaction of iminoether III with benzyl cyanoacetate gave ethyl 1-(α-cyanocarbobenzyl-oxymethylene)isoindoline-3-acetate (V) in a 26% yield. Decarboxylation of ethyl 1-(α-cyanocarboxymethylene)isoindoline-3-acetate (VI), obtained by hydrogenolysis of V, gave a mixture of 1-carboethoxymethyleneisoindoline-3-acetonitrile (VII) as major component and 1-carboethoxymethylene-3-cyanomethyleneisoindoline (VIII) as minor component, which were reconvertible into each other. On the other hand, decarboxylation of VI was successfully carried out to give VII as a single product under a nitrogen atmosphere. Ethanolysis and autoxidation of VII gave crystalline diethyl 1,3-dicarboethoxymethyleneisoindoline (XIII). Catalytic hydrogenation of of XIII over platinum oxide gave diethyl isoindoline-cis-1,3-diacetate (XIV) in a yield of 92%. The uv spectra of these 1,3-disubstituted isoindoline derivatives are summarized in Table I.     

A Convenient Biphasic System (Alumina-Dichloromethane) for the Efficient Aromatic Monochlorination of Alkyl Phenyl Ethers with Sodium Chlorite in the Catalytic Presence of Manganese(III) Salt

A combination of sodium chlorite, (salen)manganese(III) catalyst, and chromatographic neutral alumina in dichloromethane can be successfully utilized for the aromatic monochlorination of a variety of alkyl phenyl ethers in excellent to quantitative yields under mild and anhydrous conditions.     

Numerical and theoretical evaluations of AC losses for single and infinite numbers of superconductor strips with direct and alternating transport currents in external AC magnetic field

AC losses in a superconductor strip are numerically evaluated by means of a finite element method formulated with a current vector potential. The expressions of AC losses in an infinite slab that corresponds to a simple model of infinitely stacked strips are also derived theoretically. It is assumed that the voltage-current characteristics of the superconductors are represented by Bean’s critical state model. The typical operation pattern of a Superconducting Magnetic Energy Storage (SMES) coil with direct and alternating transport currents in an external AC magnetic field is taken into account as the electromagnetic environment for both the single strip and the infinite slab. By using the obtained results of AC losses, the influences of the transport currents on the total losses are discussed quantitatively.     

Performance of an Ozone Decomposition Catalyst in Hybrid Plasma Reactors for Volatile Organic Compound Removal

In order to enhance the energy efficiency of nonthermal plasma methods for volatile organic compound decomposition in a catalyst-hybrid plasma reactor, we used a Cu–Cr catalyst to dissociate ozone into active atomic oxygen species at low temperatures. We investigated the conditions necessary to obtain the synergetic effect in single-stage and two-stage combinations. The ozone decomposition catalyst was not effective for the reaction under plasma discharge in the single-stage combination. In the two-stage combination, the efficiency increased by increasing the amount of catalyst. Although the propensity of catalysts for active oxygen species formation from ozone decomposition is important for optimizing the reaction efficiency, the surface area is even more important. We conclude that ozone decomposition catalysts are more effective in the two-stage combination compared to the single-stage.