Formation of a high polymer of acrylamide by utilizing Kolbe's electrolysis

During the electro-initiated polymerization of acrylamide by utilizing Kolbe's electrolysis as a source of free radicals in an aqueous solution of acetic acid and potassium acetate, only an oligomer with a molecular weight of 4000–6000 was obtained. However, by the addition of ferric ion, a high-polymer with a molecular weight of a few millions was obtained. The effective action of ferric ions was retarded by the presence of ferrous ion and a large amount of chloride ion. The optimum amount of ferric ion for the formation of high-polymer and the effects and roles of various ions on the process of polymerization are discussed.     

A 3.5 V, 1.3 W GaAs power multi-chip IC for cellular phones

A GaAs power multi-chip IC (MCIC) operable at a voltage of 3.5 V designed for cellular phones has been developed. The MCIC is able to deliver an output power of 1.3 W with a power-added efficiency of 60% in a frequency range from 890 to 950 MHz. This consists of two GaAs MESFET's, three GaAs passive matching chips, and a printed circuit board on which biasing networks are disposed. These are mounted on an aluminum nitride (AlN) package, occupying a half volume of conventional power hybrid IC's, i.e., only 0.4 cc. In order to improve the low voltage operation characteristics, a GaAs power MESFET operable at a low voltage of 3.5 V with an output power of 32 dBm and a power-added efficiency of 65% is developed, and microstrip lines having high impedance characteristics are incorporated also in order to minimize the conductor loss of matching network. The MCIC would be highly useful to develop compact cellular phones with advanced characteristics     

The recovery of chlorine from by-product hydrogen chloride Part 2: Molten metal cathode method

A new method of recovering chlorine from by-product hydrogen chloride is proposed and developed. According to the reaction Me+2HC1 = MeCl₂+H_o (Me = Metal) hydrogen chloride is reduced to give hydrogen and metal chloride. Gaseous hydrogen was drawn out from the reaction system and the metal chloride dissolved in the electrolyte, where it was electrolysed to give chlorine and metal using molten metal as a cathode. The metal was recovered on the cathode in a molten state and reused for the former reaction. Bench scale tests were also carried out, where zinc was used as a molten metal cathode and the cell capacity was about 50 A. The cell voltage was 6.5 V at 50 A (working temperature 560°C, distance between anode and cathode 5 mm) and in this case, the ohmic loss was about 70%. The current efficiency was about 90% (anodic current density 200 A/dm²) when the working temperature was 500°C and electrode distance between anode and cathode was 18 mm.This method seems very promising on the basis of the above-mentioned data.     

Evaluation of the performance of an aluminium alloy friction welded joint by image analysis

Summary

In making a friction welded joint, it is necessary to produce a flash at the weld during the welding process. In this research, the flash was measured by the image processing method and the joint performance was evaluated by the data from such measurements. The monochrome image of the flash was transformed to binary image data in order to remove noise in the image processing process.

Then, the characteristics of the flash were extracted as numerical information on the outline of the welds. The measured features were the height, width, curvature radius of the toe and sectional area of the flash. In this way, an evaluation of friction welded joint performance can be made by recognition of the flash shape.     

Nonaqueous lithium/titanium dioxide cell

The cell performance and the reaction mechanism of the Li/1 M LiClO₄ propylene carbonate/TiO₂ cell, which has an open circuit voltage of 2.85–2.90 V and 950 Wh/kg of theoretical energy density, are presented. The open circuit voltage and the working voltage exceeded the theoretical open circuit voltage (1.1 V) predicted from thermodynamic data assuming 1 electron transfer per molecule of TiO₂ and the products to be Ti₂O₃ and Li₂O. The working voltage of Li/anatase TiO₂ cell is higher than that of Li/rutile TiO₂ cell.The reaction mechanism has been shown by the electrochemical and X-ray diffractional examination to be

The self-discharge test was also done and proved the capacity loss to be negligible during a month of storage. storage.     

Application of a circulating suspended particle-electrode to electrochemical hydrodimerization of acrylonitrile

A circulating suspended particle-electrode was applied to the electrochemical hydrodimerization of acrylonitrile in order to examine the possibility of scaling up the cell capacity. Total current on a feeder electrode was increased remarkably by an addition of lead particles and the current was proportional to the quantity of lead particles added. Total current was also increased with the increase of circulating speed. The current increased with electrolysis time because the surface oxide was gradually reduced with continuing electrolysis. Contact resistance between a suspended particle and a feeder electrode was not as large as in the Kolbe synthesis on a particulated electrode, and electron transfer between the particle and the feeder electrode at their collision was fast compared with charge transfer on the particle electrode. Current efficiency for adiponitrile formation was less on the suspended electrode than on a plane electrode. However, the rate of adiponitrile formation was markedly increased by the use of the suspended electrode.     

Image transmission through a turbulent medium using a point reflector and four-wave mixing. 2: Characteristics of the system

The characteristics of the one-way image transmission system presented in Part 1 are investigated in detail [Appl. Opt. 22, 2192 (1983)]. First, a general expression of the expectation of the transmitted image is derived for turbulence that may be typical in image transmission in the horizontal direction. Then, with the help of numerical examples, the image quality is discussed in terms of the point spread function for both thin layer and uniformly distributed turbulence. It is shown that the image transmission system is effective especially where turbulence exists relatively close to the transmission plane.