45 results match your criteria: "German Aerospace Center (DLR e.V.)[Affiliation]"

Synthesis and Characterisation of Core-Shell Microparticles Formed by Ni-Mn-Co Oxides.

Molecules

June 2024

Departamento de Física de Materiales, Facultad de CC. Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.

In this work, core and core-shell microparticles formed by Ni-Mn-Co oxides with controlled composition were fabricated by an oxalate-assisted co-precipitation route, and their properties were analysed by diverse microscopy and spectroscopy techniques. The microparticles exhibit dimensions within the 2-6 μm range and mainly consist of NiO and NiMnO, the latter being promoted as the temperature of the treatment increases, especially in the shell region of the microparticles. Aspects such as the shell dimensions, the vibrational modes of the spinel compounds primarily observed in the shell region, the oxidation states of the cations at the surface of the microparticles, and the achievement of a Ni-rich 811 core and a Mn-rich 631 shell were thoroughly evaluated and discussed in this work.

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Characterization of Interfacial Corrosion Behavior of Hybrid Laminate EN AW-6082 ∪ CFRP.

Materials (Basel)

April 2024

Chair of Materials Test Engineering (WPT), TU Dortmund University, Baroper Str. 303, D-44227 Dortmund, Germany.

The corrosion behavior of a hybrid laminate consisting of laser-structured aluminum EN AW-6082 ∪ carbon fiber-reinforced polymer was investigated. Specimens were corroded in aqueous NaCl electrolyte (0.1 mol/L) over a period of up to 31 days and characterized continuously by means of scanning electron and light microscopy, supplemented by energy dispersive X-ray spectroscopy.

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Multifactorial resistance of spores to low-pressure plasma sterilization.

Appl Environ Microbiol

January 2024

Radiation Biology Department, Aerospace Microbiology, Institute of Aerospace Medicine, German Aerospace Center (DLR e.V.), Cologne, Germany.

Common sterilization techniques for labile and sensitive materials have far-reaching applications in medical, pharmaceutical, and industrial fields. Heat inactivation, chemical treatment, and radiation are established methods to inactivate microorganisms, but pose a threat to humans and the environment and can damage susceptible materials or products. Recent studies have demonstrated that cold low-pressure plasma (LPP) treatment is an efficient alternative to common sterilization methods, as LPP's levels of radicals, ions, (V)UV-radiation, and exposure to an electromagnetic field can be modulated using different process gases, such as oxygen, nitrogen, argon, or synthetic (ambient) air.

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Choice of the Miniature Inertial Optomechanical Sensor Geometric Parameters with the Help of Their Mechanical Characteristics Modelling.

Micromachines (Basel)

September 2023

Department of Quantum Metrology, Institute for Quantum Technologies, German Aerospace Center (DLR e.V.), 2022 Wilhem-Runge-Straße 10, 89081 Ulm, Germany.

In this paper, the mechanical characteristics of a miniature optomechanical accelerometer, similar to those proposed for a wide range of applications, have been investigated. With the help of numerical modelling, characteristics such as eigenfrequencies, quality factor, displacement magnitude, normalized translations, normalized rotations versus eigenfrequencies, as well as spatial distributions of the azimuthal and axial displacements and stored energy density in a wide frequency range starting from the stationary case have been obtained. Dependencies of the main mechanical characteristics versus the minimal and maximal system dimensions have been plotted.

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The French-Italian Concordia Research Station, situated on the Antarctic Polar Plateau at an elevation of 3233 m above sea level, offers a unique opportunity to study the presence and variation of microbes introduced by abiotic or biotic vectors and, consequently, appraise the amplitude of human impact in such a pristine environment. This research built upon a previous work, which explored microbial diversity in the surface snow surrounding the Concordia Research Station. While that study successfully characterized the bacterial assemblage, detecting fungal diversity was hampered by the low DNA content.

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The Artificial Gravity Bed Rest - European Space Agency (AGBRESA) study was the first joint bed rest study by ESA, DLR, and NASA that examined the effect of simulated weightlessness on the human body and assessed the potential benefits of artificial gravity as a countermeasure in an analog of long-duration spaceflight. In this study, we investigated the impact of simulated microgravity on the gut microbiome of 12 participants during a 60-day head-down tilt bed rest at the :envihab facilities. Over 60 days of simulated microgravity resulted in a mild change in the gut microbiome, with distinct microbial patterns and pathway expression in the feces of the countermeasure group compared to the microgravity simulation-only group.

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Multifunctional Hybrid Fiber Composites for Energy Transfer in Future Electric Vehicles.

Materials (Basel)

September 2022

Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.

Reducing the weight of electric conductors is an important task in the design of future electric air and ground vehicles. Fully electric aircraft, where high electric energies have to be distributed over significant distances, are a prime example. Multifunctional composite materials with both adequate structural and electrical properties are a promising approach to substituting conventional monofunctional components and achieving considerable mass reductions.

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Ultraviolet disinfection efficacy test method using bacteria monolayers.

J Microbiol Methods

September 2022

Biodeterioration Control Associates, Inc., Princeton, NJ, USA.

Monolayers of bacterial cells of Staphylococcus aureus and Pseudomonas aeruginosa were inoculated on glass slide carriers using an automated inoculum spray deposition system. The use of bacterial monolayers allows for control of critical variables for testing and verification of light-based disinfection technologies. This approach avoids the variability associated with manual inoculation and high inoculum titers, which can engender clustering of cells and the associated photoprotection that clustering incurs.

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A main factor hampering life in space is represented by high atomic number nuclei and energy (HZE) ions that constitute about 1% of the galactic cosmic rays. In the frame of the "STARLIFE" project, we accessed the Heavy Ion Medical Accelerator (HIMAC) facility of the National Institute of Radiological Sciences (NIRS) in Chiba, Japan. By means of this facility, the extremophilic species and were irradiated with high LET ions (i.

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Taurine-Modified Boehmite Nanoparticles for GFRP Wind Turbine Rotor Blade Fatigue Life Enhancement.

Materials (Basel)

November 2021

Department of Multifunctional Materials, Institute of Composite Structures and Adaptive Systems, German Aerospace Center (DLR e. V.), Lilienthalplatz 7, 38108 Braunschweig, Germany.

Advanced nanoparticle-reinforced glass fibre composites represent a promising approach to improving the service life of fatigue-loaded structures such as wind turbine rotor blades. However, processing particle-reinforced resins using advanced infusion techniques is problematic due to, for example, higher viscosity as well as filtering effects. In this work, the effects of boehmite nanoparticles on viscosity, static properties and fatigue life are investigated experimentally.

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The modern concept of the evolution of Mars assumes that life could potentially have originated on the planet Mars, possibly during the end of the late heavy bombardment, and could then be transferred to other planets. Since then, physical and chemical conditions on Mars changed and now strongly limit the presence of terrestrial-like life forms. These adverse conditions include scarcity of liquid water (although brine solutions may exist), low temperature and atmospheric pressure, and cosmic radiation.

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A mixed-methods analysis of mobility behavior changes in the COVID-19 era in a rural case study.

Eur Transp Res Rev

February 2021

Institute of Transportation Systems, German Aerospace Center (DLR e.V.), Rutherfordstraße 2, 12489 Berlin, Germany.

Background: As a reaction to the novel coronavirus disease (COVID-19), countries around the globe have implemented various measures to reduce the spread of the virus. The transportation sector is particularly affected by the pandemic situation. The current study aims to contribute to the empirical knowledge regarding the effects of the coronavirus situation on the mobility of people by (1) broadening the perspective to the mobility rural area's residents and (2) providing subjective data concerning the perceived changes of affected persons' mobility practices, as these two aspects have scarcely been considered in research so far.

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Radiation of ionizing or non-ionizing nature has harmful effects on cellular components like DNA as radiation can compromise its proper integrity. To cope with damages caused by external stimuli including radiation, within living cells, several fast and efficient repair mechanisms have evolved. Previous studies addressing organismic radiation tolerance have shown that radiotolerance is a predominant property among extremophilic microorganisms including (hyper-) thermophilic archaea.

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The potential of in situ melt pool monitoring (MPM) for parameter development and furthering the process understanding in Laser Powder Bed Fusion (LPBF) of CuCr1Zr was investigated. Commercial MPM systems are currently being developed as a quality monitoring tool with the aim of detecting faulty parts already in the build process and, thus, reducing costs in LPBF. A detailed analysis of coupon specimens allowed two processing windows to be established for a suitably dense material at layer thicknesses of 30 µm and 50 µm, which were subsequently evaluated with two complex thermomechanical-fatigue (TMF) panels.

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The cluster model of ultraviolet disinfection explains tailing kinetics.

J Appl Microbiol

April 2020

Space Microbiology Research Group, Radiation Biology Department, German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Cologne, Germany.

Aims: To develop a new mathematical model derived from first principles to define the kinetics of ultraviolet disinfection and to explain the phenomenon known as tailing. The theory presented interprets tailing as the result of photoprotection due to cumulative Mie scattering effects in clustered populations of micro-organisms.

Methods And Results: Mie scattering effects at ultraviolet wavelengths are used to compute a shielding constant for each micro-organism based on the average projected diameter.

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Phobos LIFE (Living Interplanetary Flight Experiment).

Astrobiology

September 2019

German Aerospace Center (DLR e. V.), Institute of Aerospace Medicine, Radiation Biology Department, Cologne (Köln), Germany.

The Planetary Society's Phobos Living Interplanetary Flight Experiment (Phobos LIFE) flew in the sample return capsule of the Russian Federal Space Agency's Phobos Grunt mission and was to have been a test of one aspect of the hypothesis that life can move between nearby planets within ejected rocks. Although the Phobos Grunt mission failed, we present here the scientific and engineering design and motivation of the Phobos LIFE experiment to assist with the scientific and engineering design of similar future experiments. Phobos LIFE flew selected organisms in a simulated meteoroid.

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Poly-extreme terrestrial habitats are often used as analogs to extra-terrestrial environments. Understanding the adaptive strategies allowing bacteria to thrive and survive under these conditions could help in our quest for extra-terrestrial planets suitable for life and understanding how life evolved in the harsh early earth conditions. A prime example of such a survival strategy is the modification of vegetative cells into resistant resting structures.

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Single-cell analysis reveals individual spore responses to simulated space vacuum.

NPJ Microgravity

December 2018

1School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan, Guangdong China.

Outer space is a challenging environment for all forms of life, and dormant spores of bacteria have been frequently used to study the survival of terrestrial life in a space journey. Previous work showed that outer space vacuum alone can kill bacterial spores. However, the responses and mechanisms of resistance of individual spores to space vacuum are unclear.

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Experimental studies addressing the longevity of Bacillus subtilis spores - The first data from a 500-year experiment.

PLoS One

May 2019

Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR e.V.), Cologne (Koeln), Germany.

The ability to form endospores allows certain Gram-positive bacteria (e.g. Bacillus subtilis) to challenge the limits of microbial resistance and survival.

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Application areas of robotic grasping extend to delicate objects like groceries. The intrinsic elasticity offered by variable-stiffness actuators (VSA) appears to be promising in terms of being able to adapt to the object shape, to withstand collisions with the environment during the grasp acquisition, and to resist the weight applied to the fingers by a lifted object during the actual grasp. It is hypothesized that these properties are particularly useful in the absence of high-quality sensory feedback, which would otherwise be able to guide the shape adaptation and collision avoidance, and that in this case, VSA hands perform better than hands with fixed stiffness.

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Numerous studies have demonstrated that the martian surface environment is hostile to life because of its rough radiation climate and the reactive chemistry of the regolith. Physical processes such as erosion and transport of mineral particles by wind-driven saltation have hitherto not been considered as a life hazard. We report a series of experiments where bacterial endospores (spores of Bacillus subtilis) were exposed to a simulated saltating martian environment.

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Submarine hydrothermal vents are inhabited by a variety of microorganisms capable of tolerating environmental extremes, making them ideal candidates to further expand our knowledge of the limitations for terrestrial life, including their ability to survive the exposure of spaceflight-relevant conditions. The spore resistance of two Bacillus spp. strains, APA and SBP3, isolated from two shallow vents off Panarea Island (Aeolian Islands, Italy), to artificial and environmental stressors (i.

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Biofilms have been intensively investigated over the past decades. Bacillus subtilis is able to form highly structured colony biofilms, and as one of the most studied Gram-positive model organisms, has helped to decipher the complex genetic regulation of biofilms. Several methods have been developed to analyze the architecture of biofilms.

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Role of DNA Repair and Protective Components in Bacillus subtilis Spore Resistance to Inactivation by 400-nm-Wavelength Blue Light.

Appl Environ Microbiol

October 2018

German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne, Germany

The high intrinsic decontamination resistance of spores is important medically (disease) and commercially (food spoilage). Effective methods of spore eradication would be of considerable interest in the health care and medical product industries, particularly if the decontamination method effectively killed spores while remaining benign to both humans and sensitive equipment. Intense blue light at a ∼400 nm wavelength is one such treatment that has drawn significant interest.

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Antimicrobial properties of ternary eutectic aluminum alloys.

Biometals

October 2018

Radiation Biology Department, German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Cologne, Germany.

Several Escherichia coli deletion mutants of the Keio collection were selected for analysis to better understand which genes may play a key role in copper or silver homeostasis. Each of the selected E. coli mutants had a deletion of a single gene predicted to encode proteins for homologous recombination or contained functions directly linked to copper or silver transport or transformation.

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