Minnesota Mining and Manufacturing Company

Wolfgang H Strehlow

Garold L Goken

Pui Kum Lee

A method of radiochemical analysis comprises the steps of providing a solid phase extraction sheet material comprising ion-specific sorptive or reactive particles and a porous matrix as carrier for the particles, and providing a fluid including an ion-containing radiochemical analyte comprising the specific ion, contacting the sheet material with the fluid for a time sufficient for the particles to selectively extract the analyte from the fluid, and analyzing the sheet material in a direct mode for quantitative or qualitative data relating to the radiochemical analyte. Solid phase extraction sheet materials and methods for their preparation are also disclosed.

Solid phase extraction using composite sheet for direct measurement of

A method of radiochemical analysis having the steps of providing a solid phase extraction sheet material containing ion-specific sorptive or reactive particles in a porous matrix as carrier for the particles, and providing a fluid including an ion-containing radiochemical analyte, contacting the sheet material with the fluid for a time sufficient for the particles to selectively extract the analyte from the fluid, and analyzing the sheet material in a direct mode for quantitative or qualitative data relating to the radiochemical analyte. Solid phase extraction sheet materials and methods for their preparation are also disclosed.

Retroreflective material including a medium containing a plurality of diffraction elements comprising light interference fringe patterns is formed by pressing a first medium having on a surface thereof a plurality of light interference fringe patterns defining an array of phase modulated fresnel zone plates onto a surface of a copy medium having a thickness equal to a given focal length associated with the fresnel zone plates and a reflective material is coated on the opposite surface of the copy medium. In making other embodiments a plurality of fringe patterns is recorded throughout the volume of a photosensitive medium.

Method of forming a retroreflective material via light interference

Retroreflective material including a medium containing a plurality of diffraction elements comprising light interference fringe patterns for enabling provision of a retroreflective effect upon light incident thereon. In making one embodiment a plurality of light interference fringe patterns defining an array of phase modulated fresnel zone plates is replicated by embossing at one surface of a copy medium having a thickness equal to a given focal length associated with the fresnel zone plates and a reflective material is coated on the opposite surface of the copy medium. In making other embodiments a plurality of fringe patterns is recorded throughout the volume of a photosensitive medium.

Retroreflective material made by recording a plurality of light

Retroreflective material is made by recording an array of photoreduced images of an original geometric fresnel zone plate image in a photosensitive medium; using the developed photosensitive medium to make a stamper for embossing an array of phase modulated fresnel zone plates corresponding to the photoreduced images; using the stamper to emboss such fresnel zone plates in a transparent copy medium having a thickness equal to a given focal length associated with such fresnel zone plates to provide an array of such fresnel zone plates at one surface of the copy medium; and coating a reflective material on the opposite surface of the copy medium.

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Woodbury, MN, United States of America

Wolfgang H Strehlow