Abstract: The invention relates to high power, spark induced breakdown spectroscopy (SIBS) detectors with controllable delay time and to spark induced breakdown spectroscopy plasma generators with dual electrodes with specific electrode material, both for use in methods and apparatuses for detecting spectral signatures of atomic emissions, (e.g., from heavy metals such as lead, mercury, chromium, cadmium, arsenic, antimony and beryllium and radioactive materials such as uranium, plutonium, thorium and technetium) for measuring, for example, atomic concentrations of samples such as vapors and airborne particulates.

Abstract: In the disclosed electrochemical cell for the production of an alkaline solution of peroxide, especially on-site production, the electrolyte is divided into an aqueous alkaline catholyte and an aqueous alkaline anolyte, and the cathode is a gas-diffusion electrode. The active material of the electrolyte side of the gas-diffusion cathode comprises a particulate catalyst support material having a surface area of about 50 to about 2000 m.sup.2 /g, and, deposited on the particles of this support material, 0.1 to 50 weight-%, based on the weight of the active layer, of gold or gold alloy particles having an average size >40 but less than about 200 .ANG.. These gold or gold alloy particles are substantially selectively catalytic for the reduction of oxygen to peroxide (e.g. HOO.sup..crclbar.). The electrolyte flow patterns are designed to avoid loss of peroxide resulting from oxidation at the anode. In the operation of the cell, a product with a hydroxyl:perhydroxyl ratio lees than 2:1 can be obtained.

Abstract: In the disclosed electrochemical cell for the production of an alkaline solution of peroxide, especially on-site production, the electrolyte is divided into an aqueous alkaline catholyte and an aqueous alkaline anolyte, and the cathode is a gas-diffusion electrode. The active material of the electrolyte side of the gas-diffusion cathode comprises a particulate catalyst support material having a surface area of about 50 to about 2000 m.sup.2 /g, and, deposited on the particles of this support material, 0.1 to 50 weight-%, based on the weight of the active layer, of gold or gold alloy particles having an average size >40 but less than about 200.ANG.. These gold or gold alloy particles are substantially selectively catalytic for the reduction of oxygen to peroxide (e.g. HOO.sup..crclbar.). The electrolyte flow patterns are designed to avoid loss of peroxide resulting from oxidation at the anode. In the operation of the cell, a product with a hydroxyl:perhydroxyl ratio less than 2:1 can be obtained.

Abstract: In the disclosed electrochemical cell for the production of an alkaline solution of peroxide, especially on-site production, the electrolyte is divided into an aqueous alkaline catholyte and an aqueous alkaline anolyte, and the cathode is a gas-diffusion electrode. The active material of the electrolyte side of the gas-diffusion cathode comprises a particulate catalyst support material having a surface area of about 50 to about 2000 m.sup.2 /g, and, deposited on the particles of this support material, 0.1 to 50 weight-%, based on the weight of the active layer, of gold or gold alloy poly-crystal particles having an average size .gtoreq.5 but less than about 20 nanometers. These poly-crystal gold or gold alloy particles have a structure consisting essentially of combined individual monocrystals and are substantially selectively catalytic for the reduction of oxygen to peroxide ion or hydrogen peroxide (e.g. HOO.sup..theta.).