Results 41 to 50 of about 107,756 (305)

Virtual Stationary Satellites over Any Area of the Earth for a Continuous or Set Amount of Time [PDF]

open access: yes
Various embodiments may provide systems and methods for achieving continuous measurements (e.g., continuous video images) of the same spot on the Earth using Low Earth Orbit (LEO) satellite constellations and/or Middle Earth Orbit (MEO) satellite ...
Horan, Stephen J., Regan, Curtis R.
core   +1 more source

GPS-derived orbits for the GOCE satellite [PDF]

open access: yes, 2018
The first ESA (European Space Agency) Earth explorer core mission GOCE (Gravity field and steady-state Ocean Circulation Explorer) was launched on 17 March 2009 into a sun-synchronous dusk-dawn orbit with an exceptionally low initial altitude of about ...
Bock, Heike   +7 more
core  

Copper Doping Enhances the Activity and Selectivity of Atomically Precise Ag44 Nanoclusters for Photocatalytic CO2 Reduction

open access: yesAdvanced Functional Materials, EarlyView.
By a simple anti‐Galvanic reaction, up to six copper atoms could be preferably doped into the Ag2(SR)5 staple motifs and Ag20 dodecahedral shell of an atomically precise Ag44(SR)30 nanocluster. When anatase TiO2 is used as substrate, the (AgCu)44/TiO2 photocatalyst exhibited much improved activity in photocatalytic CO2 reduction compared to Ag44/TiO2 ...
Ye Liu   +5 more
wiley   +1 more source

Precise Orbit Determination for Low Earth Orbit Satellites

open access: yes, 2006
The precise orbit determination problem is to accurately determine the position and velocity vectors of an orbiting satellite. In this paper we review the general contents of the orbit determination process, with particular emphasis on Low Earth Orbit (LEO) satellites.
Hobbs, David, Bohm, Preben
openaire   +3 more sources

Enhancing CoFe Catalysts with V2CTX MXene‐Derived Materials for Anion Exchange Membrane Electrolyzers

open access: yesAdvanced Functional Materials, EarlyView.
MXene dervied CoFe composites show increased initial Oxygen Evolution Reaction (OER) activity compared to the pure CoFe and MXene in an Anion Exchange Membrane device. Vanadium vacancies in the MXene plays a role in increased OER activity and hinders Fe leaching in the AEM device over using the pure V2C MXene as a support material for the CoFe ...
Can Kaplan   +16 more
wiley   +1 more source

Space-Based Relay Simulations [PDF]

open access: yes
This report displays field-of-view studies through computer simulation using the Analytical Graphics, Inc., Systems Tool Kit (STK). This task analyzes the potential performance for a variety of circular low-Earth-orbit (LEO) satellites and some relative ...
Niederhaus, Charles E.   +2 more
core   +1 more source

Self‐supportive Three‐Way Photoelectrochemical System Achieving Uranium Recycling, Organic Oxidation, and Electricity Generation in Complex Waters

open access: yesAdvanced Functional Materials, EarlyView.
A self‐sustaining solar photoelectrochemical cell (SS‐PEC) is developed to recover uranium from aqueous UO22+ with concurrent organic oxidation and electricity production. The monolithical photoanode directly captures electrons from organic compounds, leading to the oxidation of organic compounds and the decomposition of uranium‐organic complexes ...
Yumei Wang   +7 more
wiley   +1 more source

LANDSAT-4 post launch report 1 [PDF]

open access: yes
LANDSAT-4 (formerly LANDSAT-D) was launched successfully at 1:59 p.m. EDT on July 16, 1982, from Vandenberg Air Force Base. The Delta 3920 launch vehicle performed flawlessly and placed the satellite into the planned three sigma low orbit of 694 km.

core   +1 more source

Low Earth orbit communications satellite

open access: yes, 1992
A current thrust in satellite communication systems considers a low-Earth orbiting constellations of satellites for continuous global coverage. Conceptual design studies have been done at the time of this design project by LORAL Aerospace Corporation under the program name GLOBALSTAR and by Motorola under their IRIDIUM program.
Moroney, D.   +9 more
openaire   +1 more source

Engineering Porous Hollow Metal‐Poly(Heptazine Imide) Spheres: An Optimized Synthetic Strategy for Controlling Surface, Morphology, and Properties

open access: yesAdvanced Functional Materials, EarlyView.
Hollow poly(heptazine imide) spheres are prepared through a novel approach that integrates hard templating with ionothermal synthesis. This method enables precise control over surface area, pore volume, hydrophilicity, light absorption, band position, and metal composition. These tunable properties facilitate the customized design of semiconductors for
Lingli Ni   +10 more
wiley   +1 more source

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