Herman Sommerfeld (center) with other reserve soldiers in military uniform Portraits Men

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Herman Sommerfeld (center) with other soldiers in military uniform Portraits Men

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Herman Sommerfeld (right) in military uniform with an unidentified soldier Portraits Men

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Studio portrait of Herman Sommerfeld in military uniform Portraits Men

Handwritten on verso: Zur Erinnerung an meiner ? Zeit, Dein Hermann, Flughafen-Doberitz, Zum austuecken bereit

Studio portrait of Dr. Moritz Kroner in military uniform.

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Studio portrait of Dr. Moritz Kroner (center) with two unidentified men in military uniform.

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Portrait of Dr. William Levison in military uniform Portraits Men

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Studio portrait of Leopold Landsberger in military uniform, before the Verdun battle of World War I.

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Studio portrait of unidentified Levy brother (most likely Arthur or Hermann) in military uniform; Nogent-Sur-Seine, France.

Photographer's imprint lower left corner

Prediction of Breakdown Voltages of Binary Gas Mixtures in Uniform Electric Fields

A simple equation to predict the breakdown voltages for binary mixtures (Vmix) of electronegative gases (SF6, CCl2F2) and buffer gases (N2, N2O, CO2, air) under uniform electric field has been proposed. Values of Vmix evaluated using this equation for mixtures of SF6-N2, SF6-air, SF6-N2O, SF6-CO2 and CCl2F2-N2 over a wide range of pd show an excellent agreement with the experimentally measured data available in the literature.

Studio portrait of Benno Strauss in military uniform after being drafted to fight on the front during World War I at the age of thirty-nine.

Father of Herbert Strauss

Portrait of Jacob Picard in military uniform Military; Portraits

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Portrait of Leopold Meyerhof in his World War I officer's uniform Military; World War I; Portraits

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Calculation of Sparking Potentials of SF6 and SF6-GAS Mixtures in Uniform and Non-Uniform Electric Fields

A simple formula is developed to predict the sparking potentials of SF6 and SF6-gas mixture in uniform and non-uniform fields. The formula has been shown to be valid over a very wide range from 1 to 1800 kPa·cm of pressure and electrode gap separation for mixtures containing 5 to 100% SF6. The calculated values are found to be in good agreement with the previously reported measurements in the literature. The formula should aid design engineers in estimating electrode-spacings and clearances in power apparatus and systems.