Accession Number : AD0670827

Title :   NON-ISOTHERMAL STUDIES OF CHEMICAL AND PHYSICAL REACTIONS. PART I. KNUDSEN CELL VAPORIZATION OF SILVER AND BORON NITRIDE.

Descriptive Note : Technical rept. 1 Oct 65-15 Oct 67,

Corporate Author : AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Rutner,Emile ; Haury,Gerard L.

Report Date : APR 1968

Pagination or Media Count : 45

Abstract : A technique was devised for studying non-isothermal changes in properties or compositions. The required data in this technique are the total change in property or composition, the temperature-time behavior, and either some assumptions about the temperature behavior of the system or the expression for the rate of change of a property or the composition. The technique was tested by applying it to two different evaporating systems whose products of evaporation effused through a Knudsen cell orifice. For example, the vapor pressures, P, of silver and boron nitride were determined as a function of temperature, T, both isothermally and non-isothermally. The technique is especially applicable in studying decomposing systems in a mass spectrometer, where the relative concentration of the species being evaporated as a function of time and temperature can be followed. The treatment of data can be adapted to the direct calculation of mass loss, changes in properties of systems, and/or changes in composition of various systems, such as ablating systems.

Descriptors :   (*SILVER, VAPOR PRESSURE), (*BORON COMPOUNDS, VAPOR PRESSURE), (*VAPORIZATION, MEASUREMENT), NITRIDES, EVAPORATION, PRESSURE GAGES, RAREFIED GAS DYNAMICS, THERMODYNAMICS, MASS SPECTROSCOPY, REACTION KINETICS

Subject Categories : Test Facilities, Equipment and Methods
      Atomic and Molecular Physics and Spectroscopy
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE