The Dow Chemical Company

Arthur J Kamp

Charles K Bon

Edward R Sederlund

Theodore J Sobieralski

William E Ryan

Philip G Mischler

Dean F Marino

John W Thompson

Kerry J Kelly

An apparatus and method for determining the morphology or dimensions of a polymeric hollow fiber is disclosed. The light absorption pattern of the hollow fiber can be used to determine the inside and outside diameter of the fiber.

Apparatus for measurement of hollow fiber dimensions

2,3,5,6-Tetrachloropyridine is obtained in high selectivity and yield by the electrocatalytic reduction at a stainless steel cathode of pentachloropyridine in an aqueous acetonitrile solution containing zinc chloride. Chlorine or oxygen may be co-produced at the anode.

Electrocatalytic production of 2,3,5,6-tetrachloropyridine from

A method of determining the concentration of each of two salts in a liquid medium is disclosed. Sound velocity, X-ray absorption and temperature information are used to determine the respective concentrations.

Analysis of salt concentrations

Sodium is determined, virtually without known interferences, based on neutron activation of liquid sample to produce radioactive .sup.23 Ne activation product from .sup.23 Na, sparging of the sample whereby a headspace gas mixture comprising .sup.23 Ne in an inert sparging gas is collected, and remote analysis of the headspace gas mixture to determine total parent sodium based on monitoring radiation emissions of .sup.23 Ne. As an illustration of utility, the analysis is demonstrated as applicable to determinations of sodium in aqueous or organic matrices at concentrations of 1 part per thousand and greater using preferred forms of .sup.241 Am/Be radioactive isotope as the activation source.

Neutron activation analysis method and apparatus for determining sodium

A nuclear pulse counting experiment, such as typified by the art of X-ray fluorescence empolys a multichannel analog to digital converter (ADC) which is interfaced with a microprocessor to yield sample/matrix concentration data, as an illustrative example, with a precision which is given by the theoretical nuclear decay statistical limits. In specific regard to X-ray fluorescence analysis, the ADC characterizes each pulse or count according to magnitude without conventional backscatter peak gain stabilization. The data is transferred through a buffer to the microprocessor, which scans the higher energy characterizations for maximum count, identifies that characterization as the peak, .+-. 1 characterization, and interpolates to develop a refined backscatter peak, stated to at least 1/10 of a characterization, and from which data base all ensuing calculations are predicated.

Nuclear pulse counting apparatus and technique

An apparatus and method based on X-ray transmission is disclosed for determining the thickness, or equivalently, the weight per unit area, of a substance containing atoms of a non-radioactive element of atomic number of 11 or greater applied to a fabric, such as a calcium- and/or aluminum-containing latex coating on a carpet. The apparatus employs a source of radiation which emits a single predominant X-ray within the range of 12-19 Kev, such as zirconium which fluoresces at 16 Kev when bombarded with 60 Kev radiation from americium-241; a detector sensitive to the radiation emitted and having resolution at least as sharp as about 20 percent, such as a Kr/CO.sub.2 proportional counter; and a suitable electronic circuit to convert the charge pulse output of the detector to a readout signal related to the amount of the substance on the fabric.

Growing community of inventors

Oakley, CA, United States of America

Arthur J Kamp