US Government as Represented by the Secretary of the Army

University of Missouri

Dabir S Viswanath

Tushar K Ghosh

Mark A Prelas

Robert V Tompson, Jr

Veera M Boddu

Kent James Hay

Sudarshan Loyalka

Tushar K Ghos

Various embodiments of the present disclosure provide a method of simultaneously co-doping a wide band gap material with p-type and n-type impurities to create a p-n junction within the resulting wide band gap composite material. The method includes disposing a sample comprising a dopant including both p-type and n-type impurities between a pair of wide band gap material films and disposing the sample between a pair of opposing electrodes; and subjecting the sample to a preselected vacuum; and heating the sample to a preselected temperature; and applying a preselected voltage across the sample; and subjecting the sample to at least one laser beam having a preselected intensity and a preselected wavelength, such that the p-type and n-type impurities of the dopant substantially simultaneously diffuse into the wide band gap material films resulting in a wide band gap compound material comprising a p-n junction.

Systems and methods for co-doping wide band gap materials

Perlite, particularly, perlite in powdered form, is employed to adsorb metals and metal compounds from fluids, in particular gases at elevated temperature. Treatment of perlite by boiling with sulfuric acid or suspending in a suspension of sulfur in carbon disulfide has been shown to significantly expand the surface area of perlite, thus increasing the efficiency of the process. In select embodiments, powdered perlite is treated to expand its surface area and injected into a fluid stream, such as flue gas, held for a specific retention period, and removed for subsequent disposal. In other embodiments powdered perlite is provided in an adsorption bed. Fluids containing metals or metal compounds in vapor form are permitted to pass through the adsorption bed until the expanded perlite powder is saturated (exhausted) with the metal and metal compounds adsorbed thereon. The perlite is then replaced, disposing of the exhausted perlite.

Method of treating fluid containing vapor phase metals, vapor phase metal compounds, or both

A chemical and biological agent sensor includes an electrostatic thin film supported by a substrate. The film includes an electrostatic charged surface to attract predetermined biological and chemical agents of interest. A charge collector associated with said electrostatic thin film collects charge associated with surface defects in the electrostatic film induced by the predetermined biological and chemical agents of interest. A preferred sensing system includes a charge based deep level transient spectroscopy system to read out charges from the film and match responses to data sets regarding the agents of interest. A method for sensing biological and chemical agents includes providing a thin sensing film having a predetermined electrostatic charge. The film is exposed to an environment suspected of containing the biological and chemical agents. Quantum surface effects on the film are measured. Biological and/or chemical agents can be detected, identified and quantified based on the measured quantum surface effects.

Electrostatic thin film chemical and biological sensor

Perlite, particularly, perlite in powdered form, is employed to adsorb metals and metal compounds from a fluid flow. In select embodiments, the perlite is treated to expand its surface area and injected into a fluid stream, such as flue gas, held for a specific retention period, and removed for subsequent disposal. In other embodiments the perlite is provided in a fixed adsorption bed and the fluid flow permitted to pass through the bed until the perlite surface is exhausted. The perlite in the fixed bed is then replaced, with the exhausted perlite disposed of as appropriate. Treatment of perlite by boiling with sulfuric acid or suspending in a suspension of sulfur in carbon disulfide has been shown to significantly expand the surface area of perlite.

Growing community of inventors

Columbia, MO, United States of America

Dabir S Viswanath