Abstract We construct infinitely many families of Lorenz knots that are satellites but not cables, giving counterexamples to a conjecture attributed Morton. amend the state satellite have companion knot, and pattern equivalent knot. show this amended holds very broadly: it is true for all obtained by high Dehn filling on parent link, other examples.

The natural satellites of planets in the solar system display a rich variety of orbital configurations and surface characteristics that have intrigued astronomers, physicists, and mathematicians for several centuries. As detailed information about satellite properties have become available from close spacecraft reconnaissance, geologists and geophysicists have also joined the study with conside...

In this paper, we consider a scheduling problem for a set of agile Earth observation satellites for scanning  different parts of the Earth’s surface. We assume that preemption is allowed to prevent repetitive images and develop four different preemption policies. Scheduling is done for the imaging time window and transmission time domain to the Earth stations as well. The value of each picture ...

BACKGROUND It has been reported that the tumor suppressor gene, PTEN, which is inactivated in many malignant tumors, plays an important role in apoptosis, cell cycle arrest, cell migration, and cell spread. For cancer gene therapy, one of the most important problems is low gene transfection efficiency. METHODS In the present study, to take full advantage of adenovirus in gene expression, we p...

Recent technological advances have accelerated a renaissance in usage of non-geostationary (non-GSO) communication satellites in provision of various services domestically and globally. Early ventures into communication satellites have used satellites in low Earth orbits. The main reasons for this mode of operation were that the booster technology was not available to lift satellites into a hig...

Thanks to post-flight analyses of several artificial satellites carried out during last years, the meteoroids hazard for space navigation and in-orbit satellites permanence is now clear. Even if catastrophic impact is a rare event, high meteoroids fluxes can erode and weaken the satellite or space station main structures. However, the main danger seems to be the impact-generated plasma, which c...

Conventional magnetic attitude control methodologies require several orbital periods to accomplish the required attitude maneuvers due to the existence of an uncontrollable axis, namely the local Earth’s magnetic field vector. Since in some attitude maneuver missions the elapsed time is of critical importance, those time-consuming controllers are not satisfactory and we need a much faster contr...