"Da Waren Deutsche Auch Dabei!" The Story of a Texas-German Family

Paper by Waltraud Bartsch

The Romanesque

Paper by Alexandra Wilhelmsen and Heri Bert Bartsch

A Look at an Era: Heri Bert Bartscht and His Students Show Card

Show card for A Look at an Era: Heri Bert Bartscht and His Students. April 20 - May 15, 1990.https://digitalcommons.udallas.edu/era_bartscht/1000/thumbnail.jp

Structural Analysis of Bonaire, Netherlands Leeward Antilles-A Seismic Investigation

We show that the island of Bonaire, Netherlands Antilles exhibits strain indicative of local deformational processes and regional tectonics. We acquired ~172 km of 2D multichannel seismic reflection profiles in the nearshore environment on the west side of Bonaire to evaluate the geology for structural deformation. By integration of previous geological and geophysical studies with our data, we ascertained what tectonic stress and local processes affect the island of Bonaire. Our analysis reveals: 1) a large anticline that extends from onshore the north of Bonaire to at least ~17 km offshore, and is the result of regional Pliocene-Quaternary compression; 2) a feature in the seafloor off the SW coast of Bonaire that is either the result of antecedent topography or late Paleogene NW-SE-directed compression; 3) a rotational slump of the seafloor due to either uplift of the entire island or subsidence of the south of the island; 4) NW-SE-striking faults related to a present regional NE-SW-directed extension, which indicates that footwall uplift of reactivated normal faults is the mechanism for recent uplift of the ABCs. This study highlights the utility of a localized inexpensive high-resolution seismic study to fill in knowledge gaps and further constrain the tectonics of the Caribbean-South American plate interaction. Additionally, this study shows what factors potentially influence material failure on unsedimented hard rock marine slopes. Finally, understanding what deformation is present on Bonaire and what stresses are imparting the observed strain, can serve as an aid to the inhabitants of the island to mitigate risk

Kansas farm operators -- 1955 and 1965: a longitudinal study

Call number: LD2668 .T4 1969 B37Master of Scienc

Battery-Electric Powertrain System Design for the HorizonUAM Multirotor Air Taxi Concept

The work presented herein has been conducted within the DLR internal research project HorizonUAM, which encompasses research within numerous areas related to urban air mobility. One of the project goals was to develop a safe and certifiable onboard system concept. This paper aims to present the conceptual propulsion system architecture design for an all-electric battery-powered multirotor electric Vertical Takeoff and Landing (eVTOL) vehicle. Therefore, a conceptual design method was developed that provides a structured approach for designing the safe multirotor propulsion architecture. Based on the concept of operation the powertrain system was initially predefined, iteratively refined based on the safety assessment and validated through component sizing and simulations. The analysis was conducted within three system groups that were developed in parallel: the drivetrain, the energy supply and the thermal management system. The design process indicated that a pure quadcopter propulsion system can merely be designed reasonably for meeting the European Union Aviation Safety Agency (EASA) reliability specifications. By adding two push propellers and implementing numerous safety as well as passivation measures the reliability specifications defined by EASA could finally be fulfilled. The subsequent system simulations also verified that the system architecture is capable of meeting the requirements of the vehicle concept of operations. However, further work is required to extend the safety analysis to additional system components as the thermal management system or the battery management system and to reduce propulsion system weight.Comment: 38 pages, 27 figures, CEAS Aeronautical Journal Special Issue "HorizonUAM - Opportunities and Challenges of Urban Air Mobility