Max and Martha Liebermann with unidentified group at a celebration for Max Liebermann at the Akademie der Kunste, Berlin Portraits; Groups

Verso: "Liebermann Feierlichkeiten in der Akademie der Kuenste. In der Mitte: Max Liebermann und Frau. Becker."

Fire resistance of light gauge steel frame wall systems lined with gypsum plasterboards

Light gauge steel frame (LSF) wall systems are increasingly used in residential and commercial buildings as load bearing and non-load bearing elements. Conventionally, the fire resistance ratings of such building elements are determined using approximate prescriptive methods based on limited standard fire tests. However, recent studies have shown that in some instances real building fire time-temperature curves could be more severe than the standard fire curve, in terms of maximum temperature and rate of temperature rise. This has caused problems for safe evacuation and rescue activities, and in some instances has also lead to the collapse of buildings earlier than the prescribed fire resistance. Therefore a detailed research study into the performance of LSF wall systems under both standard fire and realistic fire conditions was undertaken using full scale fire tests to understand the fire performance of different LSF wall configurations. Both load bearing and non-load bearing full scale fire tests were performed on LSF walls configurations which included single layer, double layer, externally insulated wall panels made up of different steel sections and thicknesses of gypsum plasterboards. The non-load bearing fire test results were utilized to understand the factors affecting the fire resistance of LSF walls, while loading bearing fire test results led to development of simplified methods to predict the fire resistance ratings of load bearing LSF walls exposed to both standard and realistic design fires. This paper presents the results of full scale experimental study and highlights the effects of standard and realistic fire conditions on fire performance of LSF walls.

Building that once served as the J. Krakauer Likoerfabrik Nachfolger; Chausseestrasse, Berlin Business Establishments; Factories

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Peter Molling with his governess Ferna and a dog; Berlin. Portraits Groups

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Wall Shear Fluctuations in a Turbulent Boundary Layer

IN the last two decades, the instantaneous structure of a turbulent boundary layer has been examined by many in an effort to understand the dynamics of the flow. Distinct and well-defined flow patterns that seem to have great relevance to the turbulence production mechanism have been observed in the wall region.1'2 The flow near the wall is intermittent with periodic eruptions of the fluid, a phenomenon generally termed "bursting process." Earlier investigations in this field were limited to liquid flows at low speeds and the entire flowpattern was observed using flow visualization techniques.Study was later extended to boundary-layer flows in windtunnels at higher speeds and Reynolds numbers using hot-wiresignals for the analysis of the bursting phenomenon.

Arno Nadel (2nd from right) with undentified men listening to new recordings; Berlin Portraits; Groups; Men

Verso: "Listening to new recordings. Berlin 1932"

Albert Einstein with violin, Josef Schwarz at piano, and Boris Schwarz in background; Haberlandstrasse 5, Berlin Portraits Groups; Men

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First convention of the World Union for Progressive Judaism; Herrenhaus, Berlin Organizations

Verso: "In the chair: Claude Montefiore others on the platform Lily Montegu, Israel Mattuck, Leo Baeck"

Portrait of Heinrich Stahl standing at his desk; Berlin Portraits; Men

Signed lower right by photographer Casparius

Portrait of Heinrich Stahl seated at his desk; Berlin Portraits; Men

Signed lower right by photographer Casparius