This paper deals with a water distillation experiment with sieve-plate column operated under atmospheric pressure under the condition of total reflux into concentrated heavy water from 0.048Da/0 water. Measurements were made of the Murphree tray efficiency, liquid hold-up in each section, and froth height, which are the data necessary for analyzing the rate of approach to equilibrium of a distillation column. The experimental results are compared with the values determined by established methods for predicting tray efficiencies.
Equations are derived which describe the transient behavior of the plate column under to total reflux with finite hold-up in the condenser and reboiler. The observed results agree fairly well with values computed from the equations except when the holdup in the condenser is assumed to be negligible. The equation relating to time the degree of approach to equilibrium reveals that the time required to reach 99% equilibrium is 16.5 days.

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An analog test is conducted on the transient thermal stress generated in a slab restrained against bending when abruptly heated on one side and cooled on the other, with a finite heat transfer coefficient.
A value of 11.21 has adopted for the Biot number B₁ (heating side) and 4.75 for B₂ (cooling side).
Comparison of the experimental results with the theoretical values reveals the following:
(1) Analog values of temperature distribution agree fairly well with the calculated results.
(2) The analog values of the thermal stress in a combined system of porous material and hollow rubber balls are in tolerably good agreement with theory: There is some discrepancy in the time scale, but fairly good agreement in the values of maximum stress.
(3) The delays on the time scale found in the analog results may be considered to be due to the internal friction of the rubber balls themselves, and should be improved by finding a more suitable material for the balls.

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A method is described of preparing Cr foils as thick as 20 to 50mg/cmcm², to be used as targets in the production of ⁵²Fe.
The Cr was electroplated from an electrolyte solution (300g/l CrO₃, 2.0g/l H₂SO₄ of s.g., 7.0g/l Na₂SiF₆) on a pure Cu sheet and then the Cu was removed by dissolution in (1:1) HNO₃. Free Cr foil thus obtained was soaked in a 1:1 mixture of 20% NH₄OH and 10% (NH₄)₂S₂O₈ for 30min. After the foil was washed with water, it was heated at 120° to 150°C.
For the electroplating, a cell with Pt anode and Cu sheet cathode was made of Lucite (cell (a)) and of glass (cell (b)), with deposition areas of 2.54cmcm² and 7.07cmcm², respectively. Direct current (6V) was supplied from a storage battery.
For the preparation of enriched ⁵⁰Cr targets, the electrolysis conditions were studied in detail. Using cell (a), the electrolysis could be performed without rotating the anode, at 275mA/cmcm² with an average current efficiency of-20%, after striking at 2A (787mA/cmcm2) for 40 to 60 sec. After 4 hr a foil of 60mg/cmcm² thickness was obtained from 3-5ml of the electrolyte solution with a deposition yield of 32%.
For the preparation of natural Cr target with use of cell (b), the striking was at 3.0 to 2.5A for 40-60 sec, and the electroplating was continued for 90 to 120 min at 250-300mA/cmcm² while rotating the anode, resulting in foils of 20-40mg/cmcm² thickness and 30mm in diameter.

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Questionnaires were sent to 307 authors who had orally presented 308 oral contributions to the 1966 Annual Meeting of the Atomic Energy Society of Japan. The following facts were revealed:
(1) Half of the contributions have be subsequently published in the three years and a half following the Annual Meeting.
(2) Sixty % of such publication were in the J. Nucl. Sci. Technol. and the J. Atomic Energt Soc. Japan, issued by the Society.

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