Effects Of Environmental Temperature Changes Research Articles

1104 市販特殊アスファルト・ルーフィングの性能試験(材料・施工)

1104 市販特殊アスファルト・ルーフィングの性能試験(材料・施工)

Precise Calibration of Sea-Going Velocimeters

A method is suggested for separating sound propagation and instrumental delay times. In addition, the effect of environmental temperature changes on the circuit operation is measured.

Long-Term Frequency Stability for a Reflex Klystron without the Use of External Cavities

The reflex klystron is widely used as a tunable low-power oscillator in frequency-modulated microwave radio relay systems, both as the transmitter and as the local oscillator in the receiver. Automatic frequency control is generally used to limit frequency error due to drift of the transmitter klystron when the environmental temperature changes. In the TL Radio System developed at Bell Telephone Laboratories, the transmitting klystron frequency is stabilized by minimizing the effects of environmental temperature changes with completely passive methods. The 457A klystron frequency stability is better than 50 parts per million over an ambient temperature range of 100°C when used at mid-band. In the TL Radio System, the design objective for frequency stability of 500 parts per million is attained at extreme conditions of ambient temperature, atmospheric pressure, and voltage regulation; therefore the need for automatic frequency control has been eliminated. The operating temperature of the 457A klystron in the TL Radio System is controlled by a liquid-vapor heat exchanger, which is described. The design of the klystron mechanical tuner includes compensation to minimize the thermal coefficient of frequency. The compensation feature is described, and typical results of the program to stabilize the klystron frequency are presented.

The effect of environmental temperature changes on the circulation of the mouse spleen.

The effect of environmental temperature changes on the circulation of the mouse spleen.

The effects of environmental temperature changes upon blood concentration.

Experiments upon normal dogs, kept at rest in hot and cold baths up to the neck, have shown regular changes in total blood solids. Blood solids were determined simply by weighing a sample of 15-16 drops shed freely from the ear vein and drying to constant weight.Exposure to hot baths for various intervals is illustrated by Table I, to cold baths by Table II.It will be seen from the tables that normal dogs respond regularly to a moderately high environmental temperature by hemodilution and to a cold environment by hemo-concentration. Roughly, the change usually approximates 2 per cent. of the total blood weight, which means a 10 per cent. change in the fluid content of the blood.The circulatory factor in regulation against overheating and cooling consists not merely in transferring of blood respectively to or from the body surface but also in actual shifting of water into or out of the blood stream. The response to a hot environment is peripheral vasodilation plus hernodilution; a cold environment evokes v...