Studio portrait of expressionist painter Emil Luethy; Basel Portraits Men

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Studio portrait of Ernst Blum; Vienna Portraits Men

Handwritten on verso: Dem Richter des "i" damit es nicht verdorrt. Signed Ernst Blum

Group portrait at the farewell banquet for Dr. William Antopol from the laboratory staff of Mount Sinai Hospital; Ken's Chop House, New York city Portraits Groups

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Portrait of unidentified man Portraits Men

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Portrait of unidentified girl; East Orange, New Jersey Portraits Children

Signed by photographer bottom right

Portrait of William and Charlotte Engel Levison Portraits Couples

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Studio portrait of Charlotte (Lotte) Engel Levison; New Jersey Portraits Women

Signed by photographer

Studio portrait of Charlotte (Lotte) Engel Levison Portraits Women

Signed by photographer bottom right

Portrait of Dr. William Levison Portraits Men

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Portrait of Dr. William Levison in military uniform Portraits Men

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Thermal characterization of microheaters from the dynamic response

Thermal characterization of surface-micromachined microheaters is carried out from their dynamic response to electrothermal excitations. An electrical equivalent circuit model is developed for the thermo-mechanical system. The mechanical parameters are extracted from the frequency response obtained using a laser Doppler vibrometer. The resonant frequencies of the microheaters are measured and compared with FEM simulations. The thermal time constants are obtained from the electrical equivalent model by fitting the model response to the measured frequency response. Microheaters with an active area of 140 µm × 140 µm have been realized on two different layers (poly-1 and poly-2) with two different air gaps (2 µm and 2.75 µm). The effective time constants, combining thermal and mechanical responses, are in the range of 0.13–0.22 ms for heaters on the poly-1 layer and 1.9 µs–0.15 ms for microheaters on the poly-2 layer. The thermal time constants of the microheaters are in the range of a few microseconds, thus making them suitable for sensor applications that need a faster thermal response.

Group US Army military portrait including Dr. William Levison (top row, third from left); Schofield Barracks, Hawaii Portraits Groups Men

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Portrait of Dr. William Levison smoking a corn pipe Portraits Men

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Unterprima (eleventh grade) boys school class portrait Portraits Groups Men

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Portrait of Ruth Landsberger.

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