Results 101 to 110 of about 36,997 (297)

Comparative analyses of space-to-space central power stations [PDF]

open access: yes
The technological and economical impact of a large central power station in Earth orbit on the performance and cost of future spacecraft and their orbital transfer systems are examined.
Garrett, L. B., Holloway, P. F.
core   +1 more source

Beaming effects in GRBs and orphan afterglows

open access: yes, 2004
The overall dynamical evolution and radiation mechanism of $\gamma$-ray burst jets are briefly introduced. Various interesting topics concerning beaming in $\gamma$-ray bursts are discussed, including jet structures, orphan afterglows and cylindrical ...
Cheng, K. S., Huang, Y. F., Lu, T.
core   +2 more sources

Impact of Pre‐Oxidation Treatments on a Recycled MgO/Steel‐Composite as Carbon Free Anode in Aluminum‐Electrolysis Environments

open access: yesAdvanced Engineering Materials, EarlyView.
Cermets (60 vol.% AISI 316L stainless steel, 40 vol.% recycled MgO), intended for use in aluminum electrolysis, were pre‐oxidized in three furnaces with different heating technologies and subjected to a cryolite corrosion test. The different atmospheres influenced the formation of oxide layers, which in turn affected corrosion resistance and ...
Patricia Kaiser   +4 more
wiley   +1 more source

Additive Manufacturing of Continuous Fibre Reinforced Composites: Process, Characterisation, Modelling, and Sustainability

open access: yesAdvanced Engineering Materials, EarlyView.
Additive manufacturing provides precise control over the placement of continuous fibres within polymer matrices, enabling customised mechanical performance in composite components. This article explores processing strategies, mechanical testing, and modelling approaches for additive manufactured continuous fibre‐reinforced composites.
Cherian Thomas, Amir Hosein Sakhaei
wiley   +1 more source

Affecting the Properties of Copper–Graphene Electroconductive Composite by Severe Plastic Deformation

open access: yesAdvanced Engineering Materials, EarlyView.
Copper‐based composites enhanced with carbon feature convenient mechanical properties and favorable electric conductivity. Processing via deformation and thermomechanical treatments can introduce advantageous microstructures further enhancing their performance. Herein, copper–graphene powder‐based composites are directly consolidated via rotary swaging
Radim Kocich   +3 more
wiley   +1 more source

Adaptive optics for laser power beaming [PDF]

open access: yes
It has been proposed to use a high energy pulsed laser to beam power into space for satellites or a lunar base. The effects of atmospheric transmission are critical to such a system. Thermal blooming in the atmosphere can cause the beam to spread rapidly.
Leland, Robert P.
core   +1 more source

The Halo Beaming Model for Gamma-Ray Bursts

open access: yes, 1997
We consider a model for gamma-ray bursts (GRBs) from high-velocity neutron stars in the galactic halo. In this model, bursters are born in the galactic disk with large recoil velocities V_r, and GRBs are beamed to within emission cones of half-angle \phi
Chugai N. N.   +18 more
core   +2 more sources

Understanding the Stochastic Nature of Process Parameter Development of Blown Powder Laser Beam Directed Energy Deposition Additive Manufacturing of Pure Molybdenum

open access: yesAdvanced Engineering Materials, EarlyView.
Identified through the use of statistical design of experiments and metallographic investigation, this study exposes the stochastic origins of intergranular cracks in blown powder laser beam directed energy deposition additive manufacturing of pure molybdenum. It further demonstrates a successful crack mitigation approach with direct correlation to the
Nathaniel J. Lies   +2 more
wiley   +1 more source

Spectral Shapes of Pair Annihilation Line Emission in Magnetar Giant Flares

open access: yesThe Astrophysical Journal Letters
We investigate the gamma-ray spectrum in the MeV range arising from electron–positron pair annihilation in fireballs associated with magnetar giant flares (MGFs), motivated by the recent observation of a MeV gamma-ray line feature in a bright gamma-ray ...
Tomoki Wada, Shigeo S Kimura
doaj   +1 more source

Robust Spot Melting by 3D Spot Arrangements in Electron Beam Powder Bed Fusion

open access: yesAdvanced Engineering Materials, EarlyView.
This work proposes an approach to replace separately melted contours for spot melting in electron beam powder fusion. Adapting the spot arrangements close to the contour combined with stacking yields a comparable surface quality without the inherent challenges of separate contours, as demonstrated, by electron optical images and roughness measurements.
Tobias Kupfer   +4 more
wiley   +1 more source

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