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MIT researchers have shown that one fuel can power both chemical and electric spacecraft thrusters, potentially transforming what small satellites can do。 The approach combines quick bursts of speed with highly efficient long-range propulsion in a single compact system。 A NASA-supported CubeSat mission will soon test the technology in orbit
"That would be an awesome capability
The paper addresses the issue of the send-on-delta data collecting strategy tocapture information from the environment. Send-on-delta concept is the signal-dependenttemporal sampling scheme, where the sampling is triggered if the signal deviates by deltadefined as the significant change of its value. It is an attractive scheme for wireless sensornetworking due to effective energy consumption. The quantitative evaluations of send-on-delta scheme for a general type continuous-time bandlimited signal are presented in thepaper. The bounds on the mean traffic of reports for a given signal, and assumed samplingresolution, are evaluated. Furthermore, the send-on-delta effectiveness, defined as thereduction of the mean rate of reports in comparison to the periodic sampling for a givenresolution, is derived. It is shown that the lower bound of the send-on-delta effectiveness(i.e. the guaranteed reduction) is independent of the sampling resolution, and constitutes thebuilt-in feature of the input signal. The calculation of the effectiveness for standard signals,that model the state evolution of dynamic environment in time, is exemplified. Finally, theexample of send-on-delta programming is shown.
A consequence of the dramatic rise in international student mobility is the trend for international students to remain in the country in which they study after graduation. Countries such as Australia, the UK and Canada stand to benefit from international student migration, as they are able to fill skill shortages with locally trained foreign students who also expand the demand for goods and services and add to gross national production. The effects on the sending country, however, are potentially less favourable and the emigration of highly educated people can have a detrimental effect, depleting an already scarce resource. However, more recently it has been suggested that an increasing proportion of migratory movement is temporary and that sending countries may benefit from circular or temporary migration via financial remittances, technology transfer, entrepreneurial partnering, and the development of personal networks and diplomatic ties. This paper will consider the impacts of international student migration on sending countries and discuss the policy responses that various sending countries have employed in attempt to regulate student migration.
A new study suggests Earth may have been sending tiny hitchhikers to Venus for billions of years。 Researchers found that asteroid impacts could launch microbes into space, where some might survive the journey and end up suspended in Venus' clouds。 If future missions detect life there, there's a surprising chance it didn't originate on Venus at all—
A colossal ancient collision may have left some of the Moon’s deepest secrets surprisingly close to future Artemis landing sites。 By recreating the impact that formed the giant South Pole-Aitken basin—the Moon’s largest and oldest crater—scientists found that a low-angle strike from a large, iron-cored object blasted material from deep inside the M
NASA’s Lucy spacecraft discovered that asteroid Donaldjohanson is a wobbling, peanut-shaped relic born from a violent collision and slowly reshaped by the subtle force of sunlight。 It also carries traces of ancient water, making it an important clue to the solar system’s mysterious past
A new catalyst design could significantly improve the conversion of CO2 into methanol, an important fuel and chemical feedstock。 Researchers separated key reaction steps across different catalyst sites, avoiding a long-standing trade-off between speed and efficiency。 The result was about three times more methanol production than standard commercial
Scientists have uncovered a surprising connection between quantum gravity and an exotic quantum state of matter that could explain why the universe isn’t expanding wildly fast。 The study suggests that the very shape of space-time may protect the cosmological constant from disruptive quantum effects
Researchers developed a Wordle-solving strategy that succeeds 99% of the time by focusing on information gain rather than likely answers。 The method uses Shannon entropy to identify guesses that reveal the most about the hidden word。 Each guess is designed to slash uncertainty and narrow the possibilities faster
Scientists have found that staple-shaped particles can tangle together to create a material that is both strong and flexible。 Unlike conventional materials, these particles can be locked into a sturdy structure or rapidly unraveled using vibrations。 The unusual behavior could open the door to recyclable buildings, reconfigurable structures, and eve
A new SETI study suggests we may be overlooking alien signals not because they aren't there, but because their own stars are scrambling them before they escape into space。 Turbulent plasma and powerful stellar storms can spread an ultra-narrow radio transmission across a wider range of frequencies, making it much harder for traditional searches to
Physicists have solved a long-standing problem involving systems that appear to violate Newton’s third law, such as bird flocks and bacterial swarms。 By adding carefully designed “imaginary partners” to their models, they can now simulate these complex systems with unprecedented accuracy