摘要:

A new type of respirometer is described. The method involves a ``diver'' which is composed of a rigid respiratory chamber containing a CO2absorbent and an O2‐containing collapsible sack feeding O2into the chamber by way of a capillary tube. As O2is used by the organism in the respiratory chamber, replacement O2arrives from the collapsible sack thereby decreasing the buoyancy of the system. The change in buoyancy is recorded on a kymograph drum by an ink‐recording spring scale. The method has been put in practice using 50 ml Soxhlet distilling flasks with rubber stoppers penetrated by 27‐gauge hypodermic needles as the respiratory chamber and sections of Saran tubing (Visking Corporation of Chicago) with an O2capacity of 40–50 ml attached to the stopper as the collapsible sacks. Recording spring scales with variable ranges from 2 to 20 g which have served satisfactorily for measuring natural variations in rates of O2consumption for certain small animals are described.

ISSN:0034-6748    

DOI:10.1063/1.1771089

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A vortex burner has been developed that permits direct comparison of flame stability of fast‐burning and of slow‐burning gaseous fuels and their mixtures.In this burner, air is introduced tangentially into a chamber to generate a vortex. The vortex is then accelerated by means of a converging nozzle which directs the air into a throat section where fuel is injected radially from ports in the periphery of the throat. The flame is stabilized in space in a divergent, pressure‐recovery section and burns as a whirling inverted cone.Flame stability is independent of tangential velocity at any given air rate. However, changes in other parameters, such as throat diameter and length of the pressure‐recovery section, do have an effect on flame stability.The results of these investigations with the vortex burner suggest that further studies with longer recovery sections are of interest. Likewise, the effect of gas temperature on flame stability will be studied.

ISSN:0034-6748    

DOI:10.1063/1.1771090

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A single crystal x‐ray spectrometer has been constructed in which the change in Bragg angle is effected through a linear rather than angular motion of the crystal. In certain measurement problems this design offers advantages over the conventional type from a standpoint of versatility and ease of alignment.

ISSN:0034-6748    

DOI:10.1063/1.1771091

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

The spectroscopy of burning solid propellants has been generally limited to a photographic integration of the various flame zones as the burning strand is consumed and the flame passes a spectrographic slit. A few instances have been reported in which separation of the spectral emission from the different zones of the flame has been attempted, but the results are deficient either through loss of resolution of the spectrograph system or shortness of exposure time. An automatic constant level device is reported which now permits the isolation and detailed exposure of a definite flame zone throughout the complete time of burning of a 72‐inch length of strand. A discussion of the technique, illustrated with typical data on the degree of control, is presented. Typical absorption and emission spectrograms are given.

ISSN:0034-6748    

DOI:10.1063/1.1771092

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A magnetic deflector for the bevatron is described. Particles initially circulating at some distance from the deflecting field are caused to enter the field during the course of a single turn because of a small energy loss in a suitable placed target. The estimated efficiency is about 1 percent in.−2at a detector located twenty feet from the circulating current.

ISSN:0034-6748    

DOI:10.1063/1.1771093

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

The fundamental principles of electric field measurement by the use of inductors and vacuum tube amplifiers are reviewed. An electric field meter is described that employs a rotating inductor and a synchronous ac generator to provide a sign responsive meter reading proportional to the electric field. The synchronized circuits eliminate moving contact rectifiers and promote calibration stability.A simplified field meter using rectified inductor currents to operate a high‐impedance push‐pull bridge circuit is also described. Design features are incorporated in both instruments that permit them to operate continuously under unusually severe storm conditions.

ISSN:0034-6748    

DOI:10.1063/1.1771094

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

Deuterons can be accelerated in the 184‐in. cyclotron to 190 Mev. To produce higher‐energy deuterons, doubly charged He3ions are accelerated to 493 Mev, and a fraction of them are stripped in an internal target, yielding deuterons with an average energy of 330 Mev. A current of 5×10−13ampere is obtained in the experimental ``cave'' external to the cyclotron shielding. Range measurements indicate that these deuterons have an average energy of about 320 Mev.The high cost of He3necessitates an efficient gas‐recovery system. The exhaust from the cyclotron diffusion pump is passed through activated charcoal traps which are cooled to liquid‐nitrogen temperatures, and the gas that is not adsorbed (presumably helium) is returned to the cyclotron source. The loss from all causes is 0.8 cc/hour.

ISSN:0034-6748    

DOI:10.1063/1.1771095

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

The performance of large, efficient storage containers for liquid helium is indicated, and liquid helium transfer techniques permitting correspondingly efficient use of the stored liquid are described.

ISSN:0034-6748    

DOI:10.1063/1.1771096

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

The results of an experimental study of the temperature dependence of commercial BF3neutron counters are reported. The arrangement used for this investigation is described and the results analyzed. The conclusion is reached that during a given pulse there is an increase in the number of negative ions formed by electron attachment with an increase in temperature of the tube. This effect is an equilibrium process. Upon reduction of the tube temperature the tube characteristics return to their original values. The consequence of this temperature dependence on the resultant counting rate is discussed.

ISSN:0034-6748    

DOI:10.1063/1.1771097

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A method has been developed to obtain an accurate estimate of the mean ionization of energetic, heavy charged particles using a device which has small stopping power. A sample of the frequency distribution of energy losses in each ofnidentical proportional counters is obtained. This information is treated by selecting the smallest of thenpulses and using this smallest pulse to represent the mean ionization of the particle. The experimental results are compared with Landau's theory of the statistical fluctuations in the specific ionization of charged particles.

ISSN:0034-6748    

DOI:10.1063/1.1771098

出版商:AIP    

年代:1954

数据来源: AIP