Immobilization of aromatic aldehyde molecules on indium tin oxide surface using acetalization reaction

We demonstrated an acetalization reaction as a versatile method to immobilize aromatic aldehyde molecules on surfaces of metal oxides, silicon dioxide, and indium tin oxide. First, a trimethylsily (TMS) terminated surface was formed using a silylation reaction between a chloride group of trimethylsilychloride and a hydroxyl group of the substrate surfaces. Second, terephthalaldehyde (TPA) was immobilized on the surfaces using an acetalization reaction between the TMS-terminated surface and an aldehyde group of TPA. Results of contact angle, X-ray photoelectron, and ultraviolet absorption spectra revealed that the TPA molecules on the surfaces were well-packed with a high surface density.     

Influence of Acoustic Perturbation and Acoustically Induced Thermal Convection on Premixed Flame Propagation

Interference between an acoustic field and premixed flame is investigated. Two kinds of transport processes are considered to cause combustion promotion in the acoustic field. One is diffusive transport. It has long been considered that the acoustic oscillation promotes diffusion, like turbulence does. The other is convective transport. Acoustically induced thermal convection that is driven by a kind of acoustic radiation force in a standing acoustic field has been previously found (Tanabe et al., Proc Combust Inst 28:1007–1013, 2000). The burning rate of an isolated single droplet is promoted by this thermal convection. In this report, the influence of the acoustic oscillation on the premixed flame propagation was examined through experiment and numerical simulation. The gravitational force was not taken into account since it complicates the combustion phenomena. The experiment and numerical simulation were done in microgravity condition. Each influence of turbulent diffusion and thermal convection were evaluated from the burning velocity, flame shape and flame speed, since the diffusive effect has been considered to have an influence on the burning velocity, while the convective effect has an influence on the flame speed and flame shape. As a result, it was clarified that the diffusive effect has a minor influence on the burning enhancement of the premixed flame in the standing acoustic field. On the contrary, the acoustically induced thermal convection has a significant influence on it. Premixed flame behavior in the standing acoustic field can be explained through the characteristics of the acoustically induced thermal convection.     

Preconcentration of trace elements by adsorption onto a niobium wire for electrothermal atomization atomic absorption spectrometry with a tungsten tube atomizer

In the present work, a new preconcentration method of trace elements by adsorption onto a niobium wire has been developed for electrothermal atomization atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer. Detection limits (pg·mL^–1) by this method combined with ETAAS were 45 for bismuth, 7.0 for cadmium, 20 for copper, 1.3 for gold, 36 for lead, 65 for manganese, 9.5 for rhodium and 19 for silver.     

An analytical system for determining delta17O in CO2 using continuous flow-isotope ratio MS

We developed a simple measurement system for delta17O in nanomole quantities of CO2 using continuous flow isotope ratio mass spectrometry (CF-IRMS). The analytical system consisted of a sample injection system, a helium-purged CO2 purification line, a capillary GC, a combustion unit, and CF-IRMS. A unique feature of the system is that we use molecular CO2 to determine the isotopic compositions including delta17O. The delta17O of CO2 in a sample is calculated from the mass ratios of both 45/44 and 46/44 of two different kinds of CO2, which have been purified quantitatively from different aliquots of a sample. While one aliquot (rCO2) flows into IRMS directly, the other (eCO2) flows through a CuO unit (900 degrees C) prior to injection into IRMS, to exchange oxygen atoms in the sample CO2 molecules with those in CuO for which we can assume Delta17O = 0. In our system, we introduce both rCO2 and eCO2 alternately to IRMS repeatedly by using an automatic multianalytical system to improve analytical precision statistically. The standard deviation of 0.35 per thousand for Delta17O can be realized using as little as 8.7 nmol CO2 in a approximately 3-h analysis. Based on this system, we have quantified delta17O in the stratospheric CO2 over Japan.     

High-speed 1-frame/ms scanning confocal microscope with a microlens and Nipkow disks

We have developed a high-speed confocal laser microscope. A microlens-array disk set in front of a pinhole-array disk improved optical efficiency more than ten times compared with that of conventional Nipkow confocal microscopy. This new microscope achieves a high-speed measurement of 1 frame/ms. We expect that it will be used for measuring biological and industrial active samples.     

Phased Aligned Passive Bus (PAB) Scheme for ISDN User-Network Interface

This paper proposes an alternative to the passive bus realization of the current CCITT ISDN user-network interface. Our new approach is termed phase aligned passive bus (PAB) scheme. An automatic phase adjusting mechanism using a monitor bit is employed in the terminal equipment. This scheme enables the terminals to operate in complete phase synchronization on a passive bus. The advantages that result from this technique are: 1) Eliminates, in principle, the bus length limitation due to round-trip delay time. If line bit rate of 192 kbit/s is kept, then a practical bus length is about 700 m with no limitation on terminal distribution. 2) Allows various extended bus configurations, such as simple repeatered extention, connection of optical link, and multibranched passive bus. 3) Provides spare bit transmission capability to facilitate intrabus communication and maintenance. As an alternative it keeps the general framework of the current CCITT I-series standard such asB + B + Dchannel structure and LAP-Dprotocol. Experiments realizing long passive buses are shown to confirm the feasibility of the proposed scheme. This concept is also shown to be applicable to a 2-wire full duplex user-network interface, advantageous in the existing office environment, employing time compression transmission.     

Optimised bandwidth of optical filter in optical preamplifier

An optimisation scheme is proposed for the optical-filter bandwidth in an optical preamplifier for a given tolerance in the signal-wavelength and a given filter profile. The optimised bandwidth is 3.46 times the conceivable detuning for a Lorentzian-shaped filter profile. Preamplifiers with optimised bandwidth can operate with the lowest noise figure at maximum detuning.<>