摘要:

A system has been developed for electrical conductivity measurements of molten glasses in which electrode effects and nonuniform sample temperatures have been minimized. The sample shape is a small thin disk held between flat platinum electrodes to give low thermal inertia and minimum temperature gradients. Controlled heating and cooling are provided by a programmed dc power supply. Conductivity and temperature are measured periodically and punched on a paper tape which serves as the computer input. All calculations are performed in the computer and the output is log&sgr; vs 1/Tand activation energy vs temperature. Conductivities of 10−1to 10−6(&OHgr;·cm)−1have been measured in the temperature range of 1000 to 300°C.

ISSN:0034-6748    

DOI:10.1063/1.1684042

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A technique for calibrating a liquid‐vapor deformation calorimeter has been developed which involves the use of an electrical heater coil to simulate a deforming tensile specimen. The known Joule heat generated in a submerged coil vaporizes a measured amount of calorimetric fluid. The calibration heater thus permits evaluation of the relationship between integrated evaporation rate‐time quantities and dissipated energy.

ISSN:0034-6748    

DOI:10.1063/1.1684043

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An x‐ray specimen chamber suited for single crystal diffraction work (particularly for studies of the state of order in alloys) is described. The evacuated chamber can be used between 77 and 1300 K. Temperatures can be controlled to ±1°. The chamber has its own degrees of freedom and no auxiliary equipment is needed to bring any crystallographic plane into diffracting position. The two degrees of freedom provided (the so called &phgr; and &khgr; rotations) permit investigation of large parts of reciprocal space, using only one face of a large flat crystal. As an example of the versatility of the camera, the lattice parameter of copper was measured between 100 and 1200 K.

ISSN:0034-6748    

DOI:10.1063/1.1684044

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The ultrasonic pulse‐echo‐overlap method described by Papadakis [J. Acoust. Soc. Amer.42, 1045 (1967)] has been modified to permit simultaneous measurement of the time delay and the relative voltage ratio between any pair of returning echoes in the pulse‐echo train. All the components involved in the present modification are commercially available items, and this instrumentation system for the ultrasonic pulse‐echo‐overlap method is compatible with the pulse superposition method.

ISSN:0034-6748    

DOI:10.1063/1.1684045

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A new plasma diagnostic tool, called a plasma scanner, has been developed for use in obtaining current cross sections and current‐voltage characteristics of a hollow cathode magnetically confined arc plasma in argon. The scanner assembly consists of an annular copper arc anode, a boron nitride baffle, a boron nitride scanning wheel, and a plane copper current collector. To obtain current cross sections the wheel was rotated at 1 rpm. To obtain current‐voltage characteristics, the wheel was stopped with the collector exposed to the plasma through a chosen scanner hole. Most of the data were produced in an arc of 20 A and 45 V. A cylindrical Langmuir probe provided data for comparison. The scanner showed a sharp increase in electron current in the center of the arc, whereas the probe did not. Typical temperatures derived from the scanner were 4 eV while temperatures obtained using the probe were 3.2 eV. Electronic equipment gave a direct readout of the inverse of the electron temperature.

ISSN:0034-6748    

DOI:10.1063/1.1684046

出版商:AIP    

年代:1969

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684047

出版商:AIP    

年代:1969

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684048

出版商:AIP    

年代:1969

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684049

出版商:AIP    

年代:1969

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684050

出版商:AIP    

年代:1969

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684051

出版商:AIP    

年代:1969

数据来源: AIP