A5051600914- Cold Atom Physics and Bose-Einstein Condensates
- UAV Applications and Optimization
- Air Traffic Management and Optimization
- Geotechnical Engineering and Underground Structures
- Advanced Frequency and Time Standards
- Geotechnical Engineering and Analysis
- Atomic and Subatomic Physics Research
- Vehicular Ad Hoc Networks (VANETs)
- Geotechnical and construction materials studies
- Millimeter-Wave Propagation and Modeling
- Geotechnical Engineering and Soil Stabilization
- Radio Wave Propagation Studies
- Geotechnical Engineering and Soil Mechanics
- Power Line Communications and Noise
- Aviation Industry Analysis and Trends
- Scientific Measurement and Uncertainty Evaluation
- Advanced MEMS and NEMS Technologies
- Dark Matter and Cosmic Phenomena
- Landslides and related hazards
- Climate change and permafrost
- Quantum Mechanics and Applications
- Fusion materials and technologies
- Wildlife Ecology and Conservation
- Construction Engineering and Safety
- Drilling and Well Engineering
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2019-2024
Fraunhofer Institute for Structural Durability and System Reliability
2024
Hahn-Schickard-Gesellschaft für angewandte Forschung
2024
Institute of Navigation
2023
Leibniz University Hannover
2013-2021
Golder Associates (Canada)
1986-2017
Shell (Canada)
2017
Queen's University
2010
Western University
2010
Stockholm University
2002
Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation the wave nature matter. Because their unique coherence properties, Bose-Einstein condensates ideal sources for an atom interferometer in extended free fall. In this Letter we report on realization asymmetric Mach-Zehnder operated with condensate microgravity. The resulting interference pattern is similar to one far field double slit and shows linear scaling time packets expand. We employ...
A method of interpreting conventional oedometer test data using work per unit volume as a criterion for determining both in situ effective and yield stresses clay is presented. This technique was applied to the results tests carried out on samples natural deposits specimens consolidated anisotropically from slurry known stress state. The – relationship, arithmetic scales, can be approximated or fitted linear relationships. intersections these lines are demonstrated provide accurate values...
The state parameter is a quantitative measure of the sand that combines effects void ratio and effective stress in unique way for each sand. Application concept practice requires ability to situ. This Paper examines interpretation cone penetration test terms concept. Existing data obtained from calibration chamber tests are reinterpreted provide relationship tip resistance parameter. To compare different programmes, must be adjusted boundary effects. It concluded provides good A companion...
We study a space-based gravity gradiometer based on cold atom interferometry and its potential for the Earth's gravitational field mapping. The instrument architecture has been proposed in [Carraz et al., Microgravity Science Technology 26, 139 (2014)] enables high-sensitivity measurements of gradients by using interferometers differential accelerometer configuration. present design including subsystems analyze mission scenario, which we derive expected performances, requirements sensor key...
The geotechnical engineering profession in Canada is the process of evaluating limit states design (LSD) for its incorporation into codes practice foundation to provide a consistent approach between and structural engineers. This paper describes work carried out initial development LSD foundations National Building Code Canada. A load resistance factor approach, based on factored overall resistance, used. factors ultimate bearing capacity sliding shallow deep are derived from direct...
This paper examines the foundation design process in terms of level safety associated with current state-of-practice, sources uncertainty and how they are handled, importance engineering judgement experience, role codes practice. Working stress, limit states, reliability-based approcahes described discussed their historical development, fundamental bases differences, advantages, limitations. Limit states conditions under which a structure no longer performs its intended function. considers...
Quantum sensors based on coherent matter-waves are precise measurement devices whose ultimate accuracy is achieved with Bose–Einstein condensates (BECs) in extended free fall. This ideally realized microgravity environments such as drop towers, ballistic rockets and space platforms. However, the transition from lab-based BEC machines to robust mobile sources comparable performance a challenging endeavor. Here we report realization of miniaturized setup, generating flux quantum degenerate...
Microgravity eases several constraints limiting experiments with ultracold and condensed atoms on ground. It enables extended times of flight without suspension eliminates the gravitational sag for trapped atoms. These advantages motivated numerous initiatives to adapt operate experimental setups microgravity platforms. We describe design payload, motivations choices, capabilities Bose-Einstein Condensate Cold Atom Laboratory (BECCAL), a NASA-DLR collaboration. BECCAL builds heritage...
Abstract Urban Air Mobility (UAM) is a new air transportation system for passengers and cargo in urban environments, enabled by technologies integrated into multimodal systems. The vision of UAM comprises the mass use suburban complementing existing systems contributing to decarbonization transport sector. Initial attempts create market last century failed due lack profitability community acceptance. Technological advances numerous fields over past few decades have led renewed interest...
Arctic fox (Alopex lagopus) populations in Scandinavia are small and restricted to alpine regions, while red foxes (Vulpes vulpes) common throughout both Norway Sweden. The two species similar behaviour diet, thus competition between them is likely. This study provides seven observations of aggressive interactions the species. One adult arctic one cub were killed by foxes, male was chased away from his den, female a fled into den as approached, four cubs walked upon it once when no could be...
The L-band digital aeronautical communications system (LDACS) is a key enabler of the new air traffic services and operational concepts necessary for modernization management (ATM). After its initial design, compatibility tests with legacy systems, functional demonstrations in laboratory, currently undergoing standardization process International Civil Aviation Organization (ICAO). However, LDACS has not been demonstrated flight yet. In this article, we present first in-flight demonstration...
Abstract The temperature dependence of the defect production has been investigated by irradiating high purity copper samples with 3 MeV electrons in range 50 to 207 K. From initial damage rate capture radius vacancy for migrating interstitials is derived. observed can be accounted a drift diffusion elastic strain field their native vacancy.
View Video Presentation: https://doi.org/10.2514/6.2021-3197.vid Efficiency, safety, feasibility, sustainability and affordability are among the key characteristics of future urban mobility. The project "HorizonUAM – Urban Air Mobility Research at German Aerospace Center (DLR)" provides first answers to this vision by pooling existing competencies individual institutes within DLR. HorizonUAM combines research about air mobility (UAM) vehicles, corresponding infrastructure, operation UAM...
Abstract For the realization of future urban air mobility, reliable information exchange based on robust and efficient communication between all airspace participants will be one key factors to ensure safe operations. Especially in dense scenarios, direct fast drones drone-to-drone communications is a promising technology for enabling collision avoidance systems. However, mitigate collisions increase overall reliability, unmanned aircraft still lack redundant, higher-level safety net...
Abstract Damage rate measurements have been performed by irradiating copper samples of different purity with electrons at 93 K up to defect concentrations about 10 −4 . The results are interpreted in terms interstitial cluster formation. clusters nucleated impurities.
In order to prevent collisions between unmanned aerial vehicles (UAVs), Drone-to-Drone (D2D) communication is a promising technology for enabling reliable collision avoidance systems. For high system accurate channel models, specifically designed UAVs in typical environments, are needed. Especially, the urban environment small sized very low level (VLL) airspace challenging due rich multipath propagation and non line-ofsight (NLOS) conditions. model real world behavior, measurements with...
View Video Presentation: https://doi.org/10.2514/6.2021-3198.vid The term Urban Air Mobility covers many several applications to meet different transport needs. cross-institutional and interdisciplinary research project "HorizonUAM – Research at the German Aerospace Center (DLR)" brings together a wide variety of departments from DLR fields on vision Mobility. This paper describes five use cases Intra-City, Mega-City, Airport-Shuttle, Sub-Urban Inter-City, which were defined in order create...
The current VHF communications infrastructure for air traffic management is struggling to keep up with growing volume. To address this issue, a new digital aeronautical data link called L-band Digital Aeronautical Communications system (LDACS) has been introduced. be considered implementation the maturity of LDACS advanced. achieve required technology readiness level TRL6, SESAR project PJ33 developed technological validation platform conduct flight trials and verify in realistic setting....
Recent publications on acoustic MEMS transducers present a new three-dimensional folded diaphragm that utilizes buried in-plane vibrating structures to increase the active area from small chip volume. Characterization of mechanical properties plays key role in development transducers, whereby established measurement methods are usually tailored close sample surface. In order access lateral vibrations, extensive and destructive preparation is required. This work presents passive technique...
The ground-based augmentation system (GBAS) is the cornerstone for enabling automated landings without instrument landing (ILS). Currently, GBAS evolving to approach service type-D (GAST-D) category III landings. This development toward GAST-D extends via use of multiple frequencies (L1/L2 and L5) global navigation satellite constellations. requires correction data be broadcast aircraft, which currently handled VHF (VDB) datalink. However, VDB has several known shortcomings: 1) low...
View Video Presentation: https://doi.org/10.2514/6.2021-3199.vid HorizonUAM is a DLR project to research the vision of urban air mobility. One important topic safety and security aspect. This paper discusses considerations in areas of: safe autonomy, reliable multisensor navigation, robust efficient communication, U-space traffic, finally cyber-physical security. As basis for future discussion, challenges gaps are identified, furthermore context briefly outlined. From perspective, missing...
Since 1982, extensive use has been made of the self-bored pressuremeter in Arctic offshore site investigations. One finding this work is that situ geostatic stress ratio K 0 Beaufort Sea clays apparently unrelated to overconsolidation (OCR). The procedures and data support are documented discussed light present geological understanding for area. It concluded independence from OCR may be quite widespread, a contradicts widely held tenet regarding existence single-valued function relating ,...
In this article we describe 77 arctic fox Alopex lagopus dens in Vindelfjällen, northern Sweden, with regard to distribution, morphology and use. The density of the area was 1/21 km 2 were more spaced than random. situated at a mean altitude (± SD) 915 m a.s.l. ± 74, on average 3.5 1.88 from nearest tree line, had number 44 den openings 32 277 237. During 21‐year study period, 31 used by foxes 10 red Vulpes vulpes. Number openings, area, distance line explained 36% use (P < 0.001) 21 %...
Bose-Einstein condensates (BECs) in free fall constitute a promising source for space-borne matter-wave interferometry. Indeed, BECs enjoy slowly expanding wave function, display large spatial coherence and can be engineered probed by optical techniques. On sounding rocket, we explore fringes of multiple spinor components BEC released employing light-pulses to drive Bragg processes induce phase imprinting. The prevailing microgravity played crucial role the observation these interferences...